04–Biochem pp69-228 13/7/10 11:58 AM Page 69 CLINICAL BIOCHEMISTRY CLINICAL BIOCHEMISTRY 69 04–Biochem pp69-228 13/7/10 11:58 AM Page 70 Contents CLINICAL BIOCHEMISTRY INDEX: TEST REPERTOIRE - CLINICAL BIOCHEMISTRY including DYNAMIC FUNCTION TESTS INTRODUCTION ...................................... 71 ................................................................................................................... 79 THE CLINICAL BIOCHEMISTRY TEST CYCLE ........................................................... 79 ....................................................... 82 ..................................................................................................... 83 GENERAL INFORMATION / CONTACT DETAILS QUALITY ASSURANCE REQUESTING CLINICAL BIOCHEMISTRY TESTS .................................................... 84 SUMMARY OF BLOOD SPECIMEN VOLUME REQUIREMENTS ........................... Adult Patients ................................................................................................................... Paediatric Patients .......................................................................................................... 85 85 85 TEST PROFILES .................................................................................................................. Test Turnaround Time ..................................................................................................... Repeat Requests ............................................................................................................. Clinical Details .................................................................................................................. Unexpected Results ........................................................................................................ Reference Values ............................................................................................................ Instructions for completion of 24 hour Urine Collections ......................................... 86 87 87 87 87 87 88 70 04–Biochem pp69-228 13/7/10 11:58 AM Page 71 Index: Test Repertoire - Clinical Biochemistry 71 CLINICAL BIOCHEMISTRY ABG (arterial blood gas analysis) 89 ACE (Angiotensin converting enzyme) 89 Acetaminophen (Paracetamol) 89 Acetylcholine Receptor antibodies (ACR antibodies) 90 Acid base studies 90 Acid phosphatase 91 ACTH (Adenocorticotrophic hormone) 91 Acylcarnitine 91 Adenocorticotrophic hormone (ACTH) 92 ADH (Antidiuretic hormone) 92 Adverse (Anaphylactoid) reactions to intravenous drugs: Plasma Tryptase Assay 92 AFP (Alpha-fetoprotein) 93 ALA (delta aminolevulinic acid) 93 Alanine aminotransferase (ALT) 94 Albumin 94 Alcohol (ethanol) 94 Aldolase 95 Aldosterone 95 Alkaline phosphatase 95 Alkaline phosphatase isoenzymes 96 Allergen-specific IgE 96 Alpha-1-acid glycoprotein (orosomucoid) 97 Alpha-1-antitrypsin 97 Alpha-1-antitrypsin phenotyping 97 Alpha-fetoprotein (AFP) 98 ALT (Alanine aminotransferase) 98 Aluminium 98 Amiodarone 99 Amino acids 99 Ammonia 99 Amphetamines 100 Amylase 100 Amyloid A Protein 100 Androgen profile (female patients) 101 Androstenedione 101 Angiotensin Converting Enzyme (ACE) 101 Antidiuretic hormone (ADH) 102 Apolipoprotein E Phenotype 102 Arterial blood gas analysis (ABG) 102 Aspartate aminotransferase (AST) 103 AST (Asparate aminotransferase) 103 Autoantibodies, autoimmune antibodies (Please refer to Serology Section of this Handbook) 103 Azathioprine (for patients about to commence azathioprine, Imuran®, therapy) 103 B2-microglobulin (beta-2-microglobulin) 104 B12 Vitamin (Please refer to Haematology Section of this Handbook) 104 Barbiturates 104 Bence Jones Protein 105 Benzodiazepine (semi-quantitative, serum) 105 Benzodiazepine (semi-quantitative, urine) 105 Beta-hydroxy butyrate 106 Beta 2-glycoprotein-1 (Please refer to the Serology/Immunology Section of this manual) 106 04–Biochem pp69-228 13/7/10 11:58 AM Page 72 CLINICAL BIOCHEMISTRY Beta-2-microglobulin 106 Beta-2-transferrin 106 Bicarbonate (actual; BGA) 107 Bicarbonate (serum/plasma) 107 Bicarbonate (standard) 108 Bile Acids 108 Bilirubin (total) 108 Bilirubin (direct) 109 Biotinidase 109 Blood Gas Analysis 109 BNP (Brain Natriuretic Peptide; NT-proBNP) 110 Bone profile 110 Brain Natriuretic Peptide (BNP; NT-proBNP) 111 BR-MA (alternative CA15.3) 111 C1 Esterase Inhibitor: concentration 112 C1 Esterase Inhibitor: functional assay 112 C3 Complement 112 C4 Complement 113 CA 15.3 (alternative: BR-MA) 113 CA 19.9 (alternative: GI-MA) 113 CA 125 (alternative: OM-MA) 114 Caeruloplasmin 114 Caffeine 114 Calcitonin 115 Calcium (total) 115 Calcium / creatinine ratio in urine 115 Calcium (ionised) 116 Calculus analysis 116 Calprotectin 116 Cannabinoid (THC) 117 Carbamazepine (Tegretol®) 117 Carboxyhaemoglobin 117 Carcinoembryionic antigen (CEA) 118 Cardiac enzyme profile 118 Carnitine (Total and free) 119 Carotene 119 Catecholamines (total) 119 Catecholamine /creatinine ratio 119 CEA (carcinoembryonic antigen) 120 CellCept® (Mycophenolate) 120 CH-50 (whole complement titre) (Please refer requests to the Serology / Immunology Laboratory) 120 Chloride 121 Cholesterol: Total 121 Cholesterol: HDL fraction 121 Cholesterol: LDL fraction 122 Cholinesterase 122 Cholinesterase Phenotype 123 Cholinesterase Genotype 123 Chromogranin A 123 Ciclosporin (cyclosporin) 124 Citrate (citric acid) 124 CK (creatine kinase) 124 CK-MB (Creatine kinase MB isoenzyme) 125 72 04–Biochem pp69-228 13/7/10 11:58 AM Page 73 CLINICAL BIOCHEMISTRY CO2 (serum/plasma) 125 Cocaine metabolite 125 Compliment 126 Copper 126 Cortisol 126 Cotinine 126 C-peptide 127 C-Reactive Protein (CRP) (Please refer to Serology/Immunology Section of this Handbook) 127 Creatine kinase (CK) 127 Creatine kinase MB isoenzyme (CK-MB) 127 Creatinine 128 Creatinine Clearance 128 Crosslaps (CTx) 129 CRP (C-Reactive Protein) (Please refer to Serology/Immunology Section of this Handbook) 129 Cryoglobulins 129 CSF Glucose 130 CSF Oligoclonal IgG banding 130 CSF Protein 130 CTx (Crosslaps) 131 Cyclosporin 131 Cystine 131 Cystine (white cell concentration) 132 7-Dehydrocholesterol 132 Dehydroepiandrosterone sulphate (DHEAS, DHEA sulphate) 132 Delta Aminolevulinic acid (ALA) 133 Deoxypyridinoline 133 DHEA sulphate (DHEAS) 133 Digoxin 134 Dihydrotestosterone (5-αdihydrotestosterone) 134 1,25 Dihydroxy cholecalciferol (1,25 dihydroxy vitamin D) 134 Dopamine 135 Drink, spiked (suspected case of spiked drink) 135 Drugs of abuse in urine (DAU) Screen 135 eGFR (estimated glomerular filtration rate) 136 Elastase-1 (Pancreatic) 137 Electrolytes 137 Electrophoresis (Serum Protein) 138 Electrophoresis (Urine Protein) 138 Enolase (neurone-specific) 138 Environmental toxicology 138 Epanutin® (Phenytoin) 139 Epilim® (Valproate, valproic acid) 139 Estimated Glomerular Rate (eGFR) 139 Estradiol/Oestradiol 140 Ethanol (alcohol) 141 Ethosuximide (Zarontin®) 141 Ethylene glycol 141 Faecal Fat 142 Fasting Lipid profile 142 Fat globules in urine (Please refer to Histopathology Section of this Handbook) 143 Fatty Acids, very long chain (VLCFA) 143 Ferritin 143 FK 506 (Tacrolimus, Prograf®) 143 73 04–Biochem pp69-228 13/7/10 11:58 AM Page 74 CLINICAL BIOCHEMISTRY Flecainide (Tambocor®) 144 Fluoxetine (Prozac®) 144 Folate (Folic Acid) (Please refer to Haematology Section of this Handbook) 144 Food Toxicology 144 Follicle stimulating hormone (FSH) 145 Free Light Chains (Kappa and Lambda) in serum 145 Free T3 (triidothyronine free hormone) 145 Free T4 (thyroxine free hormone) 146 Fructosamine 146 FSH 146 Gabapentin (Neurontin®) 147 GAD (Glutamic Acid Decarboxylase) Antibodies 147 Galactose: disorders of galactose metabolism 147 Gamma GT (gamma glutamyl transferase, GGT) 147 Gastrin 148 GGT (gamma GT = gamma glutamyl transferase) 148 GI-MA (alternative: CA19.9) 148 GL-3 149 Glucagon 149 Glucose 149 Glucose (CSF) 150 Glucose Tolerance Test 150, 230 Glutamic Acid Decarboxylase (GAD) antibodies 152 Glutamine 152 Gonadotrophins (FSH, LH) 152 Growth Hormone 152 Gut hormone profile 153 Haemosiderin stain, urine (Please refer to Haematology Section of this Handbook) 153 HbA1c 153 hCG (human chorionic gonadotrophin) 154 HDL-Cholesterol 156 5HIAA 156 HMMA (=VMA) 156 Homocysteine 157 Human Chorionic Gonadotrophin (hCG) 157 Hydroxyindole acetic acid (HIAA) 158 Hydroxy methoxymandelic acid (HMMA or VMA) 158 17-Hydroxy progesterone 158 Hydroxproline 159 IgE (total) 159 IgE (allergen specific) 159 IGF-1 (insulin-like growth factor-1 (somatomedin C) 160 IGF Binding Protein-3 160 IgG, IgA, IgM 160 IgG Subclasses 161 Immunofixation (serum protein) 161 Immunofixation (urine protein) 162 Immunoreactive trypsin 162 Industrial toxicology 162 Insulin 163 Insulin antibodies 163 Insulin C-peptide 163 Insulin-like growth factor-1 (IGF-1 or somatomedin C) 163 74 04–Biochem pp69-228 13/7/10 11:58 AM Page 75 CLINICAL BIOCHEMISTRY Insulin-like growth factor-1 binding protein 3 (IGF-1 BP3) 164 Iron 164 Iron studies profile 164 Islet cell antibodies 165 Kappa and Lambda Free Light Chains in Serum 165 Keppra® (Levetiracetam) 166 Ketones 166 Lactate 166 Lactate dehydrogenase (LD or LDH) 166 Lambda and Kappa Free Light Chains in Serum 167 Lamictal® (Lamotrigine) 167 Lamotrigine (Lamictal®) 167 LATS replaced by TBII (TSH-binding inhibiting immunoglobulin) 168 Laxatives Screen 168 LD or LDH (Lactate dehydrogenase) 168 LDL-Cholesterol 168 Lead 169 Levetiracetam (Keppra®) 169 Levodopa 170 LFT profile 170 LH 171 Lipase 171 Lipid profile (fasting specimens only) 172 Lipoprotein(a) 172 Lithium 173 Luteinising hormone (LH) 173 Lysosomal enzyme analysis (White cell enzyme analysis) 173 Macroprolactin 174 Magnesium 174 Manganese 175 Mercury 175 Metanephrines 175 Methadone 176 Methaemoglobin 176 Methanol 176 Methotrexate 177 Microalbumin 177 Microalbumin/creatinine ratio 177 Mucopolysaccharides 178 Mycophenolate (CeIlCept®) 179 Myoglobin 179 Mysoline® (Primidone) 179 Neurontin® (Gabapentin) 180 Nicotine metabolite (Cotinine) 180 N-Telopeptide (NTx) 180 Occult blood 181 Oestradiol/estradiol 181 Oligoclonal IgG banding (CSF) 181 OM-MA (alternative: CA125) 182 Opiate 182 Organic Acids 182 Organophosphate and carbamate poisoning 183 Orosomucoid (alpha-1-acid glycoprotein) 183 75 04–Biochem pp69-228 13/7/10 11:58 AM Page 76 CLINICAL BIOCHEMISTRY Osmolality 183 Osteocalcin 184 Oxalate 184 Oxcarbazepine (Trileptal®) 184 Pancreatic Polypeptide 185 Pancreolaurly test 185 Paracetamol (Acetaminophen) 185 Paraprotein studies 186 Paraquat Screen (dithionite test) 187 Paraquat (quantitative) 187 Parathyroid hormone (PTH) intact 187 Parathyroid hormone related protein (PTHrP) 188 Paroxetine (Seroxat®) 188 PCP (Phencyclidine) 188 pCO2 189 pH (BGA) 189 pH (miscellaneous fluids) 190 Phencyclidine (PCP) 190 Phenobarbital 191 Phenylalanine 191 Phenytoin (Epanutin®) 191 Phosphate 192 Phytanic acid 192 Placental alkaline phosphatase isoenzyme 192 pO2 193 Porphoblinogen 193 Pophyrins 193 Potassium 194 Primidone (Mysoline®) 194 Procollagen peptide Type 3 (PIIINP) 195 Progesterone 195 17-Hydroxy progesterone 195 Prograf® (FK 506, Tacrolimus) 196 Prolactin 196 Prostate Specific Antigen (PSA) 196 Prostate Specific Antigen, Free (fPSA) 197 Protein 197 Protein/Creatine ratio (urine) 197 Protein (CSF) 198 Protein Electrophoresis (Serum) 198 Protein Electrophoresis (Urine) 198 Prozac® (Fluoxetine) 198 PSA (Prostate Specific Antigen) 199 PSA (Prostate Specific Antigen) Free 199 PTH (intact) 199 PTHrP (Parathyroid hormone related protein) 200 Pyruvate 200 Rapamune® (Sirolimus) 201 Reducing substances (semi-quantitative test) 201 Renal profile 201 Renin 202 Rhinorrhoea fluid analysis 202 Sabril® (Vigabatrin) 202 76 04–Biochem pp69-228 13/7/10 11:58 AM Page 77 77 CLINICAL BIOCHEMISTRY Salicylate 203 Seroxat® (Paroxetine) 203 Serum Protein Electrophesis 203 Sex hormone binding globulin (SHBG) 203 SHBG (sex hormone binding globulin) 204 Sirolimus (Rapamune®) 204 Sodium 204 Solvent screen for toluene (glue), trichloroethane (Tipex®) and butane 205 Somatomedin C (IGF-1, insulin-like growth factor-1) 205 Spiked drink (suspected case of spiked drink) 205 Steroid Profile 206 Stone analysis (stone with details of source) 206 Sweat Test 207 T3 (triiodothyronine), free hormone 207 T4 (thyroxine), free hormone 208 Tacrolimus (Prograf®, FK 506) 208 Tambocor® (Flecainide) 208 Tau Protein 208 TBG (thyroxine binding globulin) 209 TBII (TSH-binding inhibiting immunoglobulin) 209 Tegretol® (Carbamazepine) 209 Testosterone: males 210 Testosterone: females 210 Testosterone/sex hormone binding globulin (SHBG) ratio 210 Theophylline 210 Thiopurine S-Methyltransferase (Red Blood Cell Thiopurine S-Methyltransferase; TPMT) 211 Thyroglobulin 211 Thyroid hormone profile 211 Thyroid Stimulating Hormone (TSH) 212 Thyroid stimulating immunoglobulin (TBII, TSH-binding inhibiting immunoglobulin) 212 Thyroxine, free hormone (free T4) 212 Thyroxine binding globulin (TBG) 213 TIBC (calculated) 213 Tocopherol (Vitamin E) 213 Topamax® (Topiramate) 213 Topiramate (Topomax®) 214 Toxicology, Environmental 214 Toxicology: Food 214 Toxicology, Industrial 214 Toxins 215 TPMT (Thiopurine S-Methyltransferase) 215 Trace metal monitoring (in patients on nutrition support, especially parenteral nutrition) 215 Transferrin 216 Transferrin saturation 216 Transglutaminase antibodies (Please refer to Serology/Immunology Section of this Handbook) 216 Tricyclic antidepressants (semi-quantitative, serum) 216 Triglyceride 217 Triiodothyronine, free hormone (Free T3) 217 Trileptal® (oxoarbazepine) 218 Troponin I 218 Troponin T (cTnT) 218 Trypsin, immunoreactive 218 Tryptase Assay (plasma) 219 04–Biochem pp69-228 13/7/10 11:58 AM Page 78 CLINICAL BIOCHEMISTRY TSH (Thyroid Stimulating Hormone) 220 TSH-binding inhibiting immunoglobulin (TBII) 220 Type 3 procollagen peptide (P111NP) 220 U & E Profile (urea and electrolytes) 220 Urea 221 Uric Acid (Urate) 221 Urine Protein Electrophoresis 222 Valproate (valproic acid, Epilim®) 222 Vasoactive Intestinal Polypeptide (VIP) 222 Very long chain fatty acids (VLCFA) 223 Vigabatrin (Sabril®) 223 VIP (vasoactive intestinal polypeptide) 223 Viscosity, plasma 224 Vitamin A 224 Vitamin B6: Pyridoxine 224 Vitamin B12 (Please refer to Haematology Section of this Handbook) 224 Vitamin C 224 Vitamin D (25-Hydroxy vitamin D3; 25-Hydroxycholecalciferol) 225 Vitamin D (1,25 dihydroxy = 1,25 Dihydroxy cholecalciferol) 225 Vitamin E (Tocopherol) 225 VMA 226 Volume 226 Weight 226 White cell cystine 226 White cell enzyme analysis (Lysosomal enzyme analysis) 227 Zarontin@ (Ethosuximide) 227 Zinc 227 DYNAMIC FUNCTION TESTS Glucose Tolerance Test 230 Short Synacthen Test 232 Prolonged (Depot) Synacthen Test 233 Low Dose Overnight Dexamethasone Suppression Test 235 Low Dose 2-Day Dexamethasone Suppression Test 236 Lactose Tolerance Test 237 78 04–Biochem pp69-228 13/7/10 11:58 AM Page 79 Introduction The Clinical Biochemistry Department uses biochemical knowledge and techniques to understand human health and to assist in the detection, diagnosis and treatment of disease. The Department’s work involves the provision of analytical results and observations and the conversion of this data into information for the requesting doctor. The Department provides a comprehensive range of analytical results, observations and interpretation for the requesting doctor as well as clinical liaison and advice. The analytical service encompasses indices of fluid balance, liver function, renal function, carbohydrate and lipid metabolism, and various hormones, proteins, enzymes, therapeutic drugs, tumour-associated substances and many other chemical and biochemical compounds. The provision of a clinical biochemistry service is dependent on highly automated analytical systems, electronic data processing and information technology. The Department has an extensive internal quality assurance system and participates in national and international quality assessment schemes. The Clinical Biochemistry Service is supported by on-going training programmes and by research focused on improving patient care. This section of the handbook is designed to give you an easy to use reference to the broad range of clinical biochemistry tests and investigations. If you are unable to find information on what you require, please contact any of the senior members of staff. The Clinical Biochemistry Test Cycle The clinical biochemistry test cycle (Figure 1) begins and ends with the doctor-patient consultation. The cycle consists of sequential cognitive, organisational, action and analytical processes leading from the initial clinical assessment, through the selection and requesting of a test, to the performance of the test by the laboratory and ultimately the integration of the test result into patient care by the requesting doctor. It consists of a pre-analytical phase (steps 1-6), an analytical phase (steps 7-9) and a post-analytical phase (steps 10-14). The cycle should always commence with a clinical question. This question will vary according to the patient, the clinical setting, the severity of symptoms and the treatment options. Time spent in the framing and the focusing of the clinical question is very important and leads to targeted and appropriate laboratory investigations. The selection of a biochemistry test requires a clear understanding of the question being asked and of the capability of the test to answer that question. The value of a biochemistry test depends on its relevance to the problem or question at hand and the extent to which the test result provides a solution to the problem or an answer to the question. 79 CLINICAL BIOCHEMISTRY The term biochemistry (bio-chimie) was first coined by the French chemist and microbiologist, Louis Pasteur (1822-1895). The application of chemistry to the study of disease has a longer history beginning with the Irish physicist and chemist, Robert Boyle (1627-1697), who was born in Lismore, Co. Waterford. 04–Biochem pp69-228 13/7/10 11:58 AM Page 80 Fig. 1. The Clinical Biochemistry Test Cycle CLINICAL BIOCHEMISTRY [1] Doctor – Patient consultation [14] Effect on patient care [2] Clinical question [13] Management decision or action taken [3] Selection of appropriate test [12] Examination of report [4] Generation of a laboratory request [11] Delivery of report to requesting doctor [5] Collection of labelled appropriate specimen(s) [10] Generation of report [6] Transport of request form(s) and specimen(s) to laboratory [9] Authorisation of results [7] Reception, registration and preparation of sample for analysis [8] Analysis / investigation 80 04–Biochem pp69-228 13/7/10 11:58 AM Page 81 CLINICAL BIOCHEMISTRY “Many health professionals nowadays feel the need to carry out every investigation to make sure that 100% of disease possibilities are ruled out and this leads to a very definite overuse of technology. It is often based on what I would call over-investigation and overtreatment, because of the demand to be absolutely certain to cover all possibilities. Society, and not just medical practitioners, will in the future have to decide where to draw the lines defining what is over-investigation and over-treatment as clearly as the definition of under-investigation and lack of treatment. Defining where that line exists will not be easy and is a challenge for us all. However, if that challenge is ignored, we could find ourselves in a situation where each of us year on year go through major programmes of screening and major programmes of treatments for potential illnesses rather than real illnesses. I am not sure that this is sustainable from the point of view of the costs involved, but also because of the amount of worry that it can cause in people’s lives.” Professor Brendan Drumm, Chief Executive Officer, Health Service Executive. In: Callanan, M., ed. Ireland 2022: Towards One Hundred Years of Self-Government. Dublin: Institute of Public Administration, 2007. 81 04–Biochem pp69-228 13/7/10 11:58 AM Page 82 General Information CLINICAL BIOCHEMISTRY Postal address: Clinical Biochemistry Department, Mid-Western Regional Hospital, Dooradoyle, Limerick. Telephone: (061) 482876 (061) 482877 (061) 482878 (061) 482879 Endocrine laboratory (061) 482245 Out-of-hours service (061) 482257 Fax: (061) 482362 Key personnel: Consultant Clinical Biochemist: Dr. Ned Barrett B.Sc., M.Sc., Ph.D., EurClinChem, FRAMI, Dip Healthcare Mgt., Consultant Head of Department; Adjunct Senior Lecturer of Biochemistry, University of Limerick. Telephone (061) 482264; mobile 087 299 6940 Chief Medical Scientist: Mr. Philip Kennedy FAMLS, FIBMS, Cert Healthcare Mgt., Dip Healthcare Mgt. Telephone (061) 482881 Core Working Hours: The Clinical Biochemistry Laboratory is fully staffed during the core hours of 10:00-17:30 Monday to Friday and staff will be available for any enquiries you may have. Out-of-Hours Service: A restricted range of assays is available as an out-of-hours service outside of the core working hours. This service is also available on public holidays. The telephone number for the out-of-hours service is (061) 482257. 82 04–Biochem pp69-228 13/7/10 11:58 AM Page 83 Quality Assurance The Department is a member of the following external quality assessment schemes: IEQAS (Irish External Quality Assessment Scheme for Laboratory Medicine) Clinical Chemistry Scheme IEQAS for Myocardial Markers (Labquality) IEQAS for Acid-Base Status and Electrolytes (Labquality) IEQAS for Faecal Blood (Labquality) IEQAS for HbA1c IEQAS for PSA (Labquality) IEQAS for NT Pro-BNP (Labquality) IEQAS for Haemoxymeters (Labquality) UKNEQAS for Clinical Chemistry UKNEQAS Lipid Scheme UKNEQAS Monoclonal Proteins UKNEQAS Total Immunoglobulin E UKNEQAS Urine Chemistries UKNEQAS for Paediatric Bilirubin UKNEQAS for Specific Proteins UKNEQAS for Sweat Tests UKNEQAS for HbA1c UKNEQAS for Thyroid Hormones UKNEQAS for Peptide Hormones 1 UKNEQAS for Peptide Hormones 2 UKNEQAS Guildford Peptide Hormones UKNEQAS for Pregnancy Testing (urine HCG) UKNEQAS for Steroid Assays UKNEQAS for Tumour Markers UKNEQAS for Therapeutic Drug Monitoring UKNEQAS for Toxicology UKNEQAS for Salicylate and Paracetamol UKNEQAS for Drugs of Abuse in Urine WEQAS General Clinical Chemistry Bio-Rad Tumour Markers Randox RIQAS Lipid Randox RIQAS Human Urine 83 CLINICAL BIOCHEMISTRY The Clinical Biochemistry Laboratory is committed to providing requesting doctors with a service of the highest quality through adherence to laboratory procedures approved by appropriate regulatory bodies, staff competency, comprehensive internal quality control procedures, regular quality assurance audits and participation in external quality assessment schemes. 04–Biochem pp69-228 13/7/10 11:58 AM Page 84 Requesting Clinical Biochemistry Tests CLINICAL BIOCHEMISTRY TERMS AND CONDITIONS (1) Requests for clinical biochemistry tests must be made by a registered medical practitioner or an appropriately qualified healthcare professional acting on the instructions of a registered medical practitioner. (2) Issues concerning patient consent for laboratory investigations are the responsibility of the requesting doctor. The Clinical Biochemistry Laboratory assumes that specimens submitted to it were obtained with the consent of the patient for the performance of biochemical analysis to facilitate diagnosis and treatment. (3) The clinical biochemistry service provided is intended to assist in the clinical management of patients and is not provided for medico-legal or forensic purposes or criminal investigations. (4) Information provided on the request form and the results of laboratory investigations will be stored by the laboratory in accordance with the policies of the Health Service Executive on data storage and document retention. (5) Requests for tests not performed in this laboratory will be referred to specialist external laboratories and will involve the communication of patient information and clinical details to the external laboratory. (6) The patient identification details given in laboratory reports are drawn from the Patient Administration Systems of the Health Service Executive and are based on the information supplied on the request form(s) by the requesting doctor. (7) Results are reported to the appropriate hospital clinician or general practitioner, who can then explain their significance to the patient within the context of their discussions of the clinical problem as a whole. (8) Laboratory reports are copyright of the Health Service Executive. (9) Unless a specific request is made, a patient is deemed to accept the usual procedures of the Clinical Biochemistry Laboratory relating to the storage and disposal of specimens. Any such specific request made must be practicable, reasonable and given with sufficient notice. 84 04–Biochem pp69-228 13/7/10 11:58 AM Page 85 Summary of Blood specimen volume requirements CLINICAL BIOCHEMISTRY Please refer to the alphabetical test listing commencing on page 71 for specific information on the requirements for individual tests. ADULT PATIENTS General biochemistry tests, for example any selection from the following: Urea, electrolytes, creatinine, liver “function” tests, cardiac enzymes, cholesterol, triglyceride, calcium, phosphate, uric acid, magnesium, total protein, albumin. When requesting tests additional to those listed above, a second specimen tube is required. Endocrine and other specialist tests performed in-house Glucose HbA1c Specialist assays referred to external laboratories One serum gel tube Type: Sarstedt S-Monovette 4.9 mL Colour code: BROWN Catalogue number: 04.1935.001 For emergency biochemistry and dialysis patients use one lithium heparin gel tube. Type: Sarstedt S-Monovette 2.6 mL Colour code: GREEN Catalogue number: 04.1907.100 Note: glucose can only be assayed in these tubes if the specimen is received in the laboratory within one hour of specimen collection. Please refer to the specific requirements for individual tests in the alphabetical listing of tests commencing on page 71 One glucose (sodium fluoride and EDTA) tube Type: Sarstedt S-Monovette 2.6 mL Colour code: GREY Catalogue number: 04.1903.100 One EDTA tube Type: Sarstedt S-Monovette 2.7 mL Colour code: MAUVE Catalogue number: 05.1167.100 Please refer to the specific requirements for individual tests in the alphabetical listing of tests commencing on page 71 PAEDIATRIC PATIENTS The Sarstedt Monovette® enclosed blood collection system used throughout the hospital has tube sizes available for paediatric specimens. Sarstedt Micro Tubes are also available for paediatric and neo-natal specimens. Requesting doctors are advised to liaise with the laboratory in advance of specimen collection when difficulties in obtaining blood specimens are expected. In these situations, tests requested should be ranked in order of priority. 85 04–Biochem pp69-228 13/7/10 11:58 AM Page 86 Test Profiles CLINICAL BIOCHEMISTRY Notes: (1) The test profiles defined in the following table are available to requesting doctors. (2) A small number of additional profiles have been set up for use by individual consultants for specific investigations within their area of specialisation. (3) Only profiles encompassed by (1) and (2) above are recognised by the Clinical Biochemistry Department. Non-specific and vague statements such as “bioprofile” should never be used in requesting tests. Likewise, terms such as “toxicology”, “hormone profile”, “tumour markers” or “routine tests” are vague and unfocussed and should not be used in requesting tests. The few extra moments required to carefully specify the tests needed is an integral part of quality patient care. Profile name Assays included in profile U+E (urea and electrolytes) Sodium, potassium, chloride, CO2, urea, creatinine. LFT (liver “function” tests) Total bilirubin, alkaline phosphatase, gamma GT, ALT. CE (cardiac enzymes) Creatine kinase (CK), lactate dehydrogenase (LD), AST. Renal Sodium, potassium, chloride, CO2, urea, creatinine, calcium, phosphate, albumin. Bone Calcium, phosphate, alkaline phosphatase, total protein, albumin. Medical admission basic profile Sodium, potassium, chloride, CO2, urea, creatinine, glucose, total bilirubin, alkaline phosphatase, gamma GT, ALT, calcium, phosphate, total protein, albumin, uric acid. Fasting lipid profile Total cholesterol, LDL-cholesterol, HDL-cholesterol, triglyceride. Iron studies (fasting specimen) Iron, transferrin, transferrin saturation, TIBC. TFT (thyroid “function” tests) TSH, free T4. DAU (drugs of abuse in urine) Amphetamines, barbiturates, benzodiazepine, cocaine, methadone, opiate, cannabinoid (THC). Androgen profile (female) Testosterone, sex hormone binding globulin and testosterone/SHBG ratio. 86 04–Biochem pp69-228 13/7/10 11:58 AM Page 87 TEST TURNAROUND TIME Specimens referred to external specialist laboratories for analysis are dispatched by courier service as appropriate. The turnaround times for receipt of hardcopy reports of tests referred to external specialist laboratories is generally of the order of two to three weeks. REPEAT REQUESTS Requesting doctors should note that requests for repeat laboratory testing made too soon after the previous test has been reported may not add any significant clinical value. CLINICAL DETAILS The inclusion of brief clinical details including relevant medication assists the Clinical Biochemistry Laboratory in providing the most appropriate service for requesting doctors. UNEXPECTED RESULTS Artefactual results may arise from difficulties or errors in, for example, sample collection, the choice of specimen tube, specimen transport or specimen storage. Artefactual results will also occur when samples are drawn from a site proximal to an infusion, when there has been prolonged venous stasis during collection or as a result of difficult or traumatic sample collection. It is important that the laboratory is informed as soon as possible if results appear to be inconsistent with the patient’s condition or at variance with previous results. REFERENCE VALUES Almost all clinical biochemistry results are reported with reference range values, which in some cases are gender and age related. The reference range defines the values of a biochemical test found in 95% of apparently healthy subjects against which the patient’s value can be compared. The term “reference range” is much more than a replacement for the old term “normal range”. It requires careful consideration of the characteristics of the reference population, of how the reference subjects are selected and how their state of health is assessed. It also requires knowledge of the performance of the analytical technique used, control of specimen collection and storage and a detailed understanding of data handling techniques and statistical tools. Almost all of the biochemistry reference 87 CLINICAL BIOCHEMISTRY The availability of each biochemistry test is given in the alphabetical listing of tests commencing on page 71. The turnaround time is the anticipated time taken under normal operating conditions between receipt of the sample in the laboratory and the generation of the report. The time taken for specimen transport or postal delivery should be added to this. The turnaround times for assays performed inhouse are detailed in a separate document entitled “Turnaround times for clinical biochemistry tests performed at the Mid-Western Regional Hospital” (MP-L-BIO-TAT). It is intended that this latter document will be updated on a regular basis. 04–Biochem pp69-228 13/7/10 11:58 AM Page 88 CLINICAL BIOCHEMISTRY ranges used by this laboratory are those approved by regulatory bodies such as the FDA (USA) for the analytical systems we use. The term reference range is free from connotations of judgment and value and should lead to a more objective interpretation of laboratory data. The International Federation for Clinical Chemistry and Laboratory Medicine has developed the concept of reference values and ranges and published methods for their derivation. The reference range concept encounters difficulties with a test such as serum cholesterol since increasing risk of future cardiovascular events is associated with serum cholesterol values within the reference range, for example, the risk doubles between serum cholesterol values of 5.2 and 6.7 mmol/L. In this situation, national or international bodies set target or recommended limits for use in clinical practice. INSTRUCTIONS FOR COMPLETION OF 24 HOUR URINE COLLECTIONS Approved containers for the collection of 24-hour urine are available from the Clinical Biochemistry Laboratory. Please ensure that the identification label on the container contains details of the patient’s name, date of birth, hospital number/address and the name of the requesting doctor. Depending on the tests requested, the container might require a special preservative in either liquid or powder form. If required, such preservatives will be provided in the container by the laboratory. Specific requirements relating to the measurement of individual urine analytes is given in the alphabetical test listing commencing on page 71 of this handbook. Do not discard any preservative provided or wash out the container. It is important that the following instructions are carried out with care; otherwise the results of the tests will be invalid. Procedure: (1) Immediately before the beginning of the collection period (usually the morning) the bladder must be emptied and the urine discarded. Record the time and date on the container label. (2) All urine passed during the next 24 hours must be collected and added to the container. (3) At the end of the 24-hour period, the bladder must be emptied and the urine collected added to that already in the container. Record the time and date on the container label. After completing the collection, arrange for the delivery of the container to the Clinical Biochemistry Laboratory accompanied by the laboratory request form or referral letter. 88 04–Biochem pp69-228 13/7/10 11:58 AM Page 89 CLINICAL BIOCHEMISTRY TEST DIRECTORY ABG (arterial blood gas analysis) Special requirements or comments: The specimen should be brought to the Laboratory immediately. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: Adult pH pCO2 pO2 Base Excess Actual Bicarbonate Standard Bicarbonate Oxygen Saturation 7.35 - 7.45 4.26 - 5.99 kPa 11.04 - 14.36 kPa -2.0 - +2.0 22.0 - 26.0 mmol/L 22.0 - 26.0 mmol/L 96 - 97 % ACE (Angiotensin Converting Enzyme) Specimen type: Serum Special requirements or comments: ACE inhibitors, e.g. captopril, enalapril inhibit ACE activity. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Acetaminophen (Paracetamol) Specimen type Serum: see special requirements. Special requirements or comments: Specimen should be drawn four hours post-overdose and preferably not later than 16 hours. Serum values taken less than four hours post-ingestion are difficult to interpret due to the possibility of continuing absorption and distribution of the drug and may not represent the peak level. Note that results are reported in ug/mL. 89 CLINICAL BIOCHEMISTRY Specimen type: Arterial blood in air-free heparinised syringe. Blood gas analysis sampling kits are available in each ward. Immediately after collection, expel any air from the sample and seal the syringe with the stopper provided in the sampling kit. Once the sample has been drawn, the blood gas syringe must be labelled with the patient’s full name, chart number, ward, date and time of collection. Labels suitable for affixing to blood gas syringes are made available to each ward. These labels display the URGENT alert message in a prominent manner. 04–Biochem pp69-228 13/7/10 11:58 AM Page 90 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Availability of assay: daily, throughout 24 hours. CLINICAL BIOCHEMISTRY Reference range: 0 – 5 µg/mL (0 – 5 mg/L) Plasma paracetamol (mg/L) TREATMENT LINES Plasma paracetamol (mmol/L) Hours after ingestion Acetylcholine Receptor antibodies (ACR antibodies) Please refer to Serology/Immunology Section of this manual. Acid base studies Specimen type: Arterial blood in air-free heparinised syringe. Blood gas analysis sampling kits are available in each ward. Immediately after collection, expel any air from the sample and seal the syringe with the stopper provided in the sampling kit. Once the sample has been drawn, the blood gas syringe must be labelled with the patient’s full name, chart number, ward, date and time of collection. Labels suitable 90 04–Biochem pp69-228 13/7/10 11:58 AM Page 91 CLINICAL BIOCHEMISTRY TEST DIRECTORY for affixing to blood gas syringes are made available to each ward. These labels display the URGENT alert message in a prominent manner. CLINICAL BIOCHEMISTRY Special requirements or comments: The specimen should be brought to the Laboratory immediately. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: Adult pH pCO2 pO2 Base Excess Actual Bicarbonate Standard Bicarbonate Oxygen Saturation 7.35 - 7.45 4.26 - 5.99 kPa 11.04 - 14.36 kPa -2.0 - +2.0 22.0 - 26.0 mmol/L 22.0 - 26.0 mmol/L 96 - 97% Acid phosphatase Prostate Specific Antigen (PSA) has replaced this test in the investigation of prostate disease. ACTH (Adrenocorticotrophic hormone) Specimen type: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. Special requirements or comments: Collect specimen in ice-cold potassium EDTA tube (=FBC tube) and transport immediately to the Clinical Biochemistry Laboratory. Please note that ACTH has a marked circadian rhythm. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Acylcarnitine Specimen type Four blood spots on a Guthrie Card or whole blood in pediatric lithium heparin specimen tube. Special requirements or comments: Appropriate clinical details required. 91 04–Biochem pp69-228 13/7/10 11:58 AM Page 92 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Requests for this test are referred to an external specialist laboratory. CLINICAL BIOCHEMISTRY Reference range: The referral laboratory report provides appropriate reference values. Adrenocorticotrophic hormone (ACTH) Specimen type: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. Special requirements or comments: Collect specimen in ice-cold potassium EDTA tube (=FBC tube) and transport immediately to the Clinical Biochemistry Laboratory. Please note that ACTH has a marked circadian rhythm. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. ADH (Antidiuretic hormone) Specimen type: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. Special requirements or comments: Collect specimen in ice-cold potassium EDTA tube (=FBC tube) and transport immediately to the Clinical Biochemistry Laboratory. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Adverse (Anaphylactoid) Reactions to Intravenous Drugs: Plasma Tryptase Assay Specimen type: The preferred specimen is EDTA plasma (at least 1 mL). It is possible to measure tryptase in serum if EDTA plasma is not available. Special requirements or comments: The first sample should be taken as soon as possible after commencement of the reaction and ideally within the first 30 minutes. Further samples should be taken 3, and 24 hours after reaction. 92 04–Biochem pp69-228 13/7/10 11:58 AM Page 93 CLINICAL BIOCHEMISTRY TEST DIRECTORY This documentation should accompany the plasma samples. Telephone contact: At any stage of the reaction the user of the service is encouraged to telephone the Protein Reference Unit in Sheffield (00 44 114 271 5552) for advice. This advice is based on the cumulative experiences of NARCOS in the assessment of emergency situations. NARCOS provides a 24 hour advisory service via the Hospital switchboard (00 44 114 243 4343). Store specimens at approximately +4 degrees Celsius prior to preparation for dispatch to referral laboratory. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. AFP (Alpha–fetoprotein) Specimen type: Serum Special requirements or comments: Appropriate clinical details required. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: 0 – 15 ng/mL (non pregnant). ALA (delta aminolevulinic acid; aminolevulinic acid) Specimen type: 24-hour urine collection; no preservative. 93 CLINICAL BIOCHEMISTRY Documentation required This should be comprehensive, but brief, and should include the following (although any other factor which the anaesthetist thinks could be a cause of the reaction should be indicated, eg surgical stimulation, undiagnosed hypovolaemia etc). • Surgical procedure, • Date of reaction, • Drugs administered (including premedication and sequences where possible), • Clinical manifestations, • Management of reaction and outcome (eg residual effects or death), • Previous medical and anaesthetic history if known, • Any particular risk factors? (eg known asthmatic, penicillin allergy, anaesthetic reaction or extremely anxious patient etc), • The haematological data (‘routine haematology’ including full differential white cell count and haematocrit), if available. 04–Biochem pp69-228 13/7/10 11:58 AM Page 94 CLINICAL BIOCHEMISTRY TEST DIRECTORY CLINICAL BIOCHEMISTRY Special requirements or comments: Protect the collection from light and keep refrigerated at 4-8°C. Appropriate clinical details are also required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Alanine aminotransferase (ALT) Specimen type: Serum Special requirements or comments: This assay is available as part of the liver test profile. Please ensure that specimens for the assay of transaminase activity (ALT or AST) are delivered to the Laboratory within 24 hours of sample collection. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: Females 14 – 54 IU/L; Males 17 – 63 IU/L. Albumin Specimen type: Serum. Urine albumin: a 24-hour collection is required (no preservative). Special requirements or comments: For urine albumin the 24-hour collection should be kept cool or refrigerated until complete. On completion, the collection should be delivered to the laboratory without delay. Turnaround time: Availability of assay: Serum albumin: daily, throughout 24 hours. Urine albumin: Monday – Friday during core working hours. Reference range: Serum albumin: 35 – 48 g/L Urine albumin: less than 30 mg/24 hours. Alcohol (ethanol) Specimen type: Serum, plasma, urine 94 04–Biochem pp69-228 13/7/10 11:58 AM Page 95 CLINICAL BIOCHEMISTRY TEST DIRECTORY CLINICAL BIOCHEMISTRY Special requirements or comments: This assay is intended to assist in the clinical management of the patient and is not provided for medico-legal purposes or in relation to the Road Traffic Acts. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Serum or plasma: < 10 mg/dL; 50-100 mg/dL: signs of intoxication; >100 mg/dL: depression of CNS; >400 mg/dL: fatalities reported. Urine: <10 mg/dL Aldolase Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Aldosterone Specimen type: Serum Special requirements or comments: Appropriate clinical details required. Record specimen collection time and whether patient was ambulant or recumbent. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Alkaline phosphatase Specimen type: Serum Special requirements or comments: Assay is also available as part of the liver and bone test profiles. 95 04–Biochem pp69-228 13/7/10 11:58 AM Page 96 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Availability of assay: daily, throughout 24 hours. CLINICAL BIOCHEMISTRY Reference range: Adults: 38 – 126 IU/L Age range Serum alkaline phosphatase (IU/L) Males Females Birth - 4 weeks 75 – 316 48 – 406 1 month – 1 year 82 – 383 124 – 341 1 – 3 years 104 – 345 108 – 317 3 – 6 years 93 – 309 96 – 297 6 – 9 years 86 – 315 69 – 325 9 – 12 years 42 – 362 51 – 332 12 – 15 years 74 – 390 50 – 162 15 – 18 years 52 – 171 47 – 119 18 – 100 years 30 – 120 30 – 120 Alkaline phosphatase isoenzymes Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Allergen-specific IgE Specimen type: Serum Special requirements or comments: Each request must be accompanied by completed allergy questionnaire. Appropriate clinical details are required. Note: These tests should not be considered diagnostic for a given allergen - they are merely assays for specific IgE. The medical history and clinical judgment are essential for assessing the significance and relevance of positive and negative test results. 96 04–Biochem pp69-228 13/7/10 11:58 AM Page 97 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Requests for this test are referred to an external specialist laboratory. CLINICAL BIOCHEMISTRY Reference range: The referral laboratory report provides appropriate reference values. Alpha-1-acid glycoprotein (orosomucoid) Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Alpha-1-antitrypsin Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Availability of assay: allow seven days for receipt of report. Reference range: 0.88 – 1.74 g/L Alpha-1-antitrypsin phenotyping Specimen type: Serum Special requirements Appropriate clinical details required Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 97 04–Biochem pp69-228 13/7/10 11:58 AM Page 98 CLINICAL BIOCHEMISTRY TEST DIRECTORY Alpha-fetoprotein (AFP) CLINICAL BIOCHEMISTRY Specimen type: Serum Special requirements or comments: Appropriate clinical details required. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: 0 – 15 ng/mL (non-pregnant). ALT (Alanine aminotransferase) Specimen type: Serum Special requirements or comments: This assay is available as part of the liver test profile. Please ensure that specimens for the assay of transaminase activity (ALT or AST) are delivered to the Laboratory within 24 hours of sample collection. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: Females 14 – 54 IU/L; Males 17 – 63 IU/L. Aluminium Specimen type: Whole blood in trace metal-free tube. Trace metal-free needle must be used in conjunction with trace metal-free tube. Special requirements or comments: This specimen should be collected first if other tests are requested to avoid contamination. Please contact Clinical Biochemistry Laboratory for trace metal-free specimen collection tube and needle. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 98 04–Biochem pp69-228 13/7/10 11:58 AM Page 99 CLINICAL BIOCHEMISTRY TEST DIRECTORY Amiodarone CLINICAL BIOCHEMISTRY Specimen type: Serum Special requirements or comments: Specimen should be drawn at least eight hours after the last dose. Amiodarone is strongly tissue–bound, leading to a half-life of between 14 and 60 days. There is large inter-patient variability. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Amino acids Specimen type: Serum, plasma, urine. Special requirements or comments: Appropriate clinical details are required. Ensure that specimen is sent to the laboratory without delay. Serum must be deproteinised for the measurement of sulphur containing amino acids contact Clinical Biochemistry Laboratory. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Ammonia Specimen type: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. Take at least 0.5 mL of blood into a lithium heparin specimen tube standing in ice. See special requirements. Specimen must be sent to the laboratory immediately. Special requirements or comments: Plasma must be assayed immediately. Blood for plasma ammonia must be drawn, delivered to the laboratory and entire assay completed within 60 minutes. Delay will result in a falsely raised plasma result. Appropriate clinical details are required. Note: haemolysis will affect the reliability of the result. 99 04–Biochem pp69-228 13/7/10 11:58 AM Page 100 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Availability of assay: daily, throughout 24 hours. CLINICAL BIOCHEMISTRY Reference range: Neonatal Period: Paediatric and adult: 0 – 100 µmol/L 10 – 47 µmol/L Amphetamines Specimen type: Random urine specimen collected without any preservative. Special requirements or comments: The assay is intended to assist in the clinical management of the patient and is not provided for medico-legal purposes. The requesting doctor may need to consider whether a patient might avail of opportunities to alter or interfere with the integrity of the specimen. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: The cut-off threshold for a positive result for amphetamine is 1000 ng/mL. A positive result for amphetamine indicates only the presence of amphetamine and does not necessarily correlate with the extent of physiological and psychological effects. A negative result indicates that amphetamines are either not present or are present at levels below the cut-off threshold for this test. Amylase Specimen type: Serum, urine, fluids. Special requirements or comments: None. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: Serum: 36 – 128 U/L Urine: 0 – 350 U/L Amyloid A protein Specimen type: Serum Special requirements or comments: Ensure that specimen is sent to the laboratory without delay. 100 04–Biochem pp69-228 13/7/10 11:58 AM Page 101 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Requests for this test are referred to an external specialist laboratory. CLINICAL BIOCHEMISTRY Reference range: The referral laboratory report provides appropriate reference values. Androgen profile (female patients) Specimen type: Serum Special requirements or comments: Profile includes testosterone, sex hormone binding globulin and testosterone/SHBG ratio. Appropriate clinical details are required. Turnaround time: Availability of assay: allow seven days for receipt of report. Reference range: Testosterone (adult females): Sex hormone binding globulin (SHBG) Testosterone/SHBG ratio 0.2 – 3.0 nmol/L 18 – 114 nmol/L 1.0 – 5.2 Androstenedione Specimen type: Serum Special requirements or comments: Morning specimen recommended. Appropriate clinical details are required. Turnaround time: Availability of assay: allow seven days for receipt of report. Reference range: Adult males 1.1 – 10.9 nmol/L Adult females 0.7 – 10.8 nmol/L Angiotensin Converting Enzyme (ACE) Specimen type: Serum Special requirements or comments: ACE inhibitors, e.g. captopril, enalapril inhibit ACE activity. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 101 04–Biochem pp69-228 13/7/10 11:58 AM Page 102 CLINICAL BIOCHEMISTRY TEST DIRECTORY Antidiuretic hormone (ADH) CLINICAL BIOCHEMISTRY Specimen type: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. Special requirements or comments: Collect two specimens in ice-cold potassium EDTA tubes (=FBC tube) and transport immediately to the Clinical Biochemistry Laboratory. Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Apolipoprotein E phenotype Specimen type: EDTA plasma Special requirements or comments: Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Store specimen at approximately 4 degrees Celsius prior to preparation for dispatch to referral laboratory. Reference range: The referral laboratory report provides appropriate reference values. Arterial blood gas analysis (ABG) Specimen type: Arterial blood in air-free heparinised syringe. Blood gas analysis sampling kits are available in each ward. Immediately after collection, expel any air from the sample and seal the syringe with the stopper provided in the sampling kit. Once the sample has been drawn, the blood gas syringe must be labelled with the patient’s full name, chart number, ward, date and time of collection. Labels suitable for affixing to blood gas syringes are made available to each ward. These labels display the URGENT alert message in a prominent manner. Special requirements or comments: The specimen should be brought to the Laboratory immediately. Turnaround time: Availability of assay: daily, throughout 24 hours. 102 04–Biochem pp69-228 13/7/10 11:58 AM Page 103 CLINICAL BIOCHEMISTRY TEST DIRECTORY 7.35 - 7.45 4.26 - 5.99 kPa 11.04 - 14.36 kPa -2.0 - +2.0 22.0 - 26.0 mmol/L 22.0 - 26.0 mmol/L 96 - 97 % CLINICAL BIOCHEMISTRY Reference range: Adult pH pCO2 pO2 Base Excess Actual Bicarbonate Standard Bicarbonate Oxygen Saturation Aspartate aminotransferase (AST) Specimen type: Serum Special requirements or comments: This assay is also available as part of the cardiac test profile. Please ensure that specimens for the assay of transaminase activity (ALT or AST) are delivered to the Laboratory within 24 hours of sample collection. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: 15 – 41 U/L AST (Asparate aminotransferase) Specimen type: Serum Special requirements or comments: This assay is also available as part of the cardiac test profile. Please ensure that specimens for the assay of transaminase activity (ALT or AST) are delivered to the Laboratory within 24 hours of sample collection. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: 15 – 41 U/L Autoantibodies, autoimmune antibodies Please refer to Serology Section of this Handbook. Azathioprine (for patients about to commence azathioprine, Imuran®, therapy) Requests for the measurement of Thiopurine S-Methyltransferase activity in patients about to commence azathioprine therapy. 103 04–Biochem pp69-228 13/7/10 11:58 AM Page 104 CLINICAL BIOCHEMISTRY TEST DIRECTORY CLINICAL BIOCHEMISTRY Specimen type: Two specimens of whole blood in potassium EDTA tubes. Specimen should be sent to the Clinical Biochemistry Laboratory. Special requirements or comments: Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. B2-microglobulin (beta-2-microglobulin) Specimen type: Serum, urine. Special requirements or comments: The measurement of urinary concentrations of beta-2-microglobulin is of limited value because urine pH<6 is known to degrade this protein in the bladder. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. B12 (Vitamin B12) Please refer to Haematology Section of this Handbook. Barbiturates Specimen type: Random urine specimen collected without any preservative. Special requirements or comments: The assay is intended to assist in the clinical management of the patient and is not provided for medico-legal purposes. The requesting doctor may need to consider whether a patient might avail of opportunities to alter or interfere with the integrity of the specimen. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: The cut-off threshold for a positive result for barbiturate is 200 ng/mL. A positive result for barbiturate indicates only the presence of barbiturate and does not necessarily correlate with the extent of physiological and psychological effects. 104 04–Biochem pp69-228 13/7/10 11:58 AM Page 105 CLINICAL BIOCHEMISTRY TEST DIRECTORY A negative result indicates that barbiturates are either not present or are present at levels below the cut-off threshold for this test. CLINICAL BIOCHEMISTRY Bence Jones Protein Specimen type: Urine. No preservative required: keep refrigerated. Special requirements or comments: Appropriate clinical details are required. Turnaround time: Availability of assay: allow three working days for receipt of report. Reference range: Bence-Jones protein is normally undetectable. Benzodiazepine (semi-quantitative, serum) Specimen type: Serum Special requirements or comments: The assay is intended to assist in the clinical management of the patient and is not provided for medico-legal purposes. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: The cut-off threshold for a positive result for serum benzodiazepine is 300 ng/mL. A positive result for benzodiazepine indicates only the presence of benzodiazepine and does not necessarily correlate with the extent of physiological and psychological effects. A negative result indicates that benzodiazepines are either not present or are present at levels below the cut-off threshold for this test. Benzodiazepine (semi-quantitative, urine) Specimen type: Random urine specimen collected without any preservative. Special requirements or comments: The assay is intended to assist in the clinical management of the patient and is not provided for medico-legal purposes. The requesting doctor may need to consider whether a patient might avail of opportunities to alter or interfere with the integrity of the specimen. Turnaround time: Availability of assay: Monday – Friday during core working hours. 105 04–Biochem pp69-228 13/7/10 11:58 AM Page 106 CLINICAL BIOCHEMISTRY TEST DIRECTORY CLINICAL BIOCHEMISTRY Reference range: The cut-off threshold for a positive result for benzodiazepine is 200 ng/mL. A positive result for benzodiazepine indicates only the presence of benzodiazepine and does not necessarily correlate with the extent of physiological and psychological effects. A negative result indicates that benzodiazepine s are either not present or are present at levels below the cut-off threshold for this test. Beta-hydroxy butyrate Specimen type: The Clinical Biochemistry Laboratory must be contacted before initiating the request so that all collection requirements can be met. Special requirements or comments: Add 3 mL of 5.1% perchloric acid to the special specimen tube. Weigh tube. Add 0.5 – 1.0 mL of whole blood to the weighed tube. Mix thoroughly by inverting several times. Weigh the tube and its contents and calculate the exact weight of blood added. Centrifuge tube at 4 degrees Celsius. Remove supernatant and store at minus 25 degrees Celsius pending dispatch to Referral Laboratory. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Beta 2-glycoprotein-1 Please refer to the Serology/Immunology Section of this manual. Beta-2-microglobulin Specimen type: Serum, urine. Special requirements or comments: The measurement of urinary concentrations of beta-2-microglobulin is of limited value because urine pH<6 is known to degrade this protein in the bladder. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Beta 2 transferrin (Tau Protein; Rhinorrhoea Fluid Analysis) Specimen type: Nasal fluid accompanied by 1 mL of serum. 106 04–Biochem pp69-228 13/7/10 11:58 AM Page 107 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Bicarbonate (actual; BGA) Specimen type: Arterial blood in air-free heparinised syringe. Blood gas analysis sampling kits are available in each ward. Immediately after collection, expel any air from the sample and seal the syringe with the stopper provided in the sampling kit. Once the sample has been drawn, the blood gas syringe must be labelled with the patient’s full name, chart number, ward, date and time of collection. Labels suitable for affixing to blood gas syringes are made available to each ward. These labels display the URGENT alert message in a prominent manner. Special requirements or comments: The specimen should be brought to the Laboratory immediately. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: Adult pH pCO2 pO2 Base Excess Actual Bicarbonate Standard Bicarbonate Oxygen Saturation 7.35 - 7.45 4.26 - 5.99 kPa 11.04 - 14.36 kPa -2.0 - +2.0 22.0 - 26.0 mmol/L 22.0 - 26.0 mmol/L 96 - 97 % Bicarbonate (serum/plasma) Specimen type: Serum/Plasma Special requirements or comments: This assay is also available as part of the electrolyte profile. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: 22 – 32 mmol/L 107 CLINICAL BIOCHEMISTRY Special requirements or comments: Appropriate clinical details are also required. This assay differentiates CSF from other biological fluids. 04–Biochem pp69-228 13/7/10 11:58 AM Page 108 CLINICAL BIOCHEMISTRY TEST DIRECTORY Bicarbonate (standard) CLINICAL BIOCHEMISTRY Specimen type: Arterial blood in air-free heparinised syringe. Blood gas analysis sampling kits are available in each ward. Immediately after collection, expel any air from the sample and seal the syringe with the stopper provided in the sampling kit. Once the sample has been drawn, the blood gas syringe must be labelled with the patient’s full name, chart number, ward, date and time of collection. Labels suitable for affixing to blood gas syringes are made available to each ward. These labels display the URGENT alert message in a prominent manner. Special requirements or comments: The specimen should be brought to the Laboratory immediately. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: Adult pH pCO2 pO2 Base Excess Actual Bicarbonate Standard Bicarbonate Oxygen Saturation 7.35 - 7.45 4.26 - 5.99 kPa 11.04 - 14.36 kPa -2.0 - +2.0 22.0 - 26.0 mmol/L 22.0 - 26.0 mmol/L 96 - 97 % Bile Acids Specimen type: Serum. Note that plasma is not a suitable specimen type for bile acid determination. Special requirements or comments: Appropriate clinical details required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Bilirubin (total) Specimen type: Serum. Special requirements or comments: Protect sample from sunlight. This assay is also available as part of the liver test profile. Turnaround time: Availability of assay: daily, throughout 24 hours. 108 04–Biochem pp69-228 13/7/10 11:58 AM Page 109 CLINICAL BIOCHEMISTRY TEST DIRECTORY Reference range: Adults: 7 – 34 µmol/L CLINICAL BIOCHEMISTRY Paediatric values: Up to 24 hours: 24 – 48 hours: 3 – 5 days: 1 month to adult: <100 µmol/L <140 µmol/L <200 µmol/L <34 µmol/L Bilirubin (direct) Specimen type: Serum. Special requirements or comments: Protect sample from sunlight. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: 2 – 9 µmol/L Biotinidase Specimen type: 1 mL of whole blood in lithium heparin specimen tube. Special requirements or comments: The specimen should be surrounded with ice and brought to the laboratory immediately. Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Blood Gas Analysis Specimen type: Arterial blood in air-free heparinised syringe. Blood gas analysis sampling kits are available in each ward. Immediately after collection, expel any air from the sample and seal the syringe with the stopper provided in the sampling kit. Once the sample has been drawn, the blood gas syringe must be labelled with the patient’s full name, chart number, ward, date and time of collection. Labels suitable for affixing to blood gas syringes are made available to each ward. These labels display the URGENT alert message in a prominent manner. Special requirements or comments: The specimen should be brought to the Laboratory immediately. 109 04–Biochem pp69-228 13/7/10 11:58 AM Page 110 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Availability of assay: daily, throughout 24 hours. CLINICAL BIOCHEMISTRY Reference range: Adult pH pCO2 pO2 Base Excess Actual Bicarbonate Standard Bicarbonate Oxygen Saturation 7.35 - 7.45 4.26 - 5.99 kPa 11.04 - 14.36 kPa -2.0 - +2.0 22.0 - 26.0 mmol/L 22.0 - 26.0 mmol/L 96 - 97 % BNP (Brain Natriuretic Peptide; NT-proBNP) Specimen type: Serum Special requirements or comments: This assay measures N-terminal pro B-type natriuretic peptide in human serum. This assay is only performed on requests authorised by a consultant. Appropriate clinical details are required. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: NT-proBNP values need to be interpreted in conjunction with the medical history, clinical findings and other information. Based on a number of studies, serum NT-proBNP values below 125pg/mL are considered normal. Because of the high biological variability in NT-proBNP within an individual, caution should be exercised in interpreting changes of less than 100% as being related to medical therapy. Bone profile Specimen type Serum Special requirements or comments: Profile includes calcium, phosphate, alkaline phosphate, total protein, albumin. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference ranges: See individual analytes: Serum Calcium: Serum phosphate: Serum protein: Serum albumin: Serum alkaline phosphatase: 110 2.23 – 2.58 mmol/L 0.78 – 1.53 mmol/L 61 – 79 g/L 35 – 48 g/L 38 – 126 IU/L 04–Biochem pp69-228 13/7/10 11:58 AM Page 111 CLINICAL BIOCHEMISTRY TEST DIRECTORY Age range Serum alkaline phosphatase (U/L) Females Birth - 4 weeks 75 – 316 48 – 406 1 month – 1 year 82 – 383 124 – 341 1 – 3 years 104 – 345 108 – 317 3 – 6 years 93 – 309 96 – 297 6 – 9 years 86 – 315 69 – 325 9 – 12 years 42 – 362 51 – 332 12 – 15 years 74 – 390 50 – 162 15 – 18 years 52 – 171 47 – 119 18 – 100 years 30 – 120 30 – 120 CLINICAL BIOCHEMISTRY Males Brain Natriuretic Peptide (BNP; NT-proBNP) Specimen type: Serum Special requirements or comments: This assay is only performed on requests authorised by a consultant. This assay measures N-terminal pro B-type natriuretic peptide in human serum. Appropriate clinical details are required. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: NT-proBNP values need to be interpreted in conjunction with the medical history, clinical findings and other information. Based on a number of studies, serum NT-proBNP values below 125pg/mL are considered normal. Because of the high biological variability in NT-proBNP within an individual, caution should be exercised in interpreting changes of less than 100% as being related to medical therapy. BR-MA (alternative CA15.3) Specimen type: Serum Special requirements or comments: IMPORTANT WARNING: This assay is not validated for use as a screening test for cancer. It has regulatory body approval for the quantitative measurement of BR-MA (CA15.3) antigen in human serum, as an aid in the detection of recurrence in previously treated stage 2 and stage 3 breast cancer patients, and in the management of metastatic breast cancer patients by monitoring disease progression or response to treatment. 111 04–Biochem pp69-228 13/7/10 11:58 AM Page 112 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Availability of assay: Monday – Friday during core working hours. CLINICAL BIOCHEMISTRY Reference range: 0 – 48 U/mL C1 Esterase inhibitor concentration Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. C1 Esterase inhibitor: functional assay Specimen type: 5 mL of whole blood in sodium citrate tube and 1 mL of serum. Special requirements or comments: Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. C3 Complement Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Availability of assay: allow three working days for receipt of report. Reference range: 0.79 – 1.52 g/L 112 04–Biochem pp69-228 13/7/10 11:58 AM Page 113 CLINICAL BIOCHEMISTRY TEST DIRECTORY C4 Complement CLINICAL BIOCHEMISTRY Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Availability of assay: allow three working days for receipt of report. Reference range: 0.16 – 0.38 g/L CA 15.3 (alternative: BR-MA) Specimen type: Serum Special requirements or comments: IMPORTANT WARNING: This assay is not validated for use as a screening test for cancer. It has regulatory body approval for the quantitative measurement of CA15.3 (BR-MA) antigen in human serum, as an aid in the detection of recurrence in previously treated stage 2 and stage 3 breast cancer patients, and in the management of metastatic breast cancer patients by monitoring disease progression or response to treatment. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: 0 – 48 U/mL CA 19.9 (alternative: GI-MA) Specimen type: Serum Special requirements or comments: IMPORTANT WARNING: This assay is not validated for use as a screening test for cancer. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: 0 – 39 U/mL 113 04–Biochem pp69-228 13/7/10 11:58 AM Page 114 CLINICAL BIOCHEMISTRY TEST DIRECTORY CA 125 (alternative: OM-MA) CLINICAL BIOCHEMISTRY Specimen type: Serum Special requirements or comments: IMPORTANT WARNING: This assay is not validated for use as a screening test for cancer. The regulatory body approval for this assay states that it is intended strictly for in vitro diagnostic use as an aid in monitoring the response to therapy for patients with epithelial ovarian cancer, and in detecting residual ovarian cancer in patients who have undergone first-line therapy and would be considered for diagnostic second-look procedures. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: 0 – 48 U/mL Caeruloplasmin Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Availability of assay: allow five working days for receipt of report. Reference range: 0.15 – 0.60 g/L Caffeine Specimen type: Serum Special requirements or comments: Draw specimen at a consistent interval for the last dose. Please state exact time of specimen collection and relationship to the last dose. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: 41 – 72 µmol/L 114 04–Biochem pp69-228 13/7/10 11:58 AM Page 115 CLINICAL BIOCHEMISTRY TEST DIRECTORY Calcitonin Special requirements or comments: Appropriate clinical details are required. A fasting specimen is required. Collect blood in an ice-cold lithium heparin tube. Mix by gentle inversion. Specimen should be surrounded with ice and brought to the Clinical Biochemistry Laboratory immediately. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Calcium (total) Specimen type: Serum. For urine calcium assay a 24-hour urine collection is required with 20mL of 6N HCI as preservative. Special requirements or comments: Prolonged venous compression during blood collection will increase serum calcium. Turnaround time: Availability of assay: Serum calcium: daily, throughout 24 hours. Urine calcium: Monday – Friday during core working hours. Reference range: Serum: 2.23 – 2.58 mmol/L Urine: 3.0 – 8.0 mmol/24 hours. Important notes: Albumin is the principal binding protein for calcium. A decrease in serum/plasma albumin will lead to a fall in albumin-bound calcium and a decrease in total calcium concentration and vice versa. Therefore serum albumin should always be requested with serum calcium. Total serum calcium can be ‘adjusted’ to ‘correct’ for changes in serum albumin. This adjustment of total calcium is to that expected to be present at an albumin concentration of 40 g/L. The adjustment equation used in this laboratory is as follows: Adjusted calcium (mmol/L) = {(40 – albumin) x 0.02} + measured calcium. Calcium / creatinine ratio in urine Specimen type: The ratio is determined on the second urine passed in the morning. Acid preservative is added upon receipt in the laboratory. 115 CLINICAL BIOCHEMISTRY Specimen type: See special requirements 04–Biochem pp69-228 13/7/10 11:58 AM Page 116 CLINICAL BIOCHEMISTRY TEST DIRECTORY Special requirements or comments: The specimen should be brought to the laboratory immediately. CLINICAL BIOCHEMISTRY Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Ratio decreases from 0.09 – 2.20 mmol/mmol creatinine at age 0.5-1 year, to 0.04 – 0.80 mmol/mmol creatinine at age 5-7 years. Calcium (ionised) Specimen type: Whole blood in air-free heparinised syringe. Balanced heparin must be used in the syringe. Special requirements or comments: The specimen should be surrounded with ice and brought to the laboratory immediately. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: Whole blood: 1.12 – 1.32 mmol/L. Calculus analysis Specimen type: Stone(s). Special requirements or comments: Specimen should be washed free of tissue and blood, and submitted in a clean dry container. Include relevant clinical information. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Calprotectin Specimen type: Approximately 1 gram of stools. Sample should be kept cool during transport to the laboratory. Special requirements or comments: Specimen should be sent to the laboratory immediately. Appropriate clinical details are required. 116 04–Biochem pp69-228 13/7/10 11:58 AM Page 117 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Requests for this test are referred to an external specialist laboratory. Cannabinoid (THC) Specimen type: Random urine specimen collected without any preservative. Special requirements or comments: The assay is intended to assist in the clinical management of the patient and is not provided for medico-legal purposes. The requesting doctor may need to consider whether a patient might avail of opportunities to alter or interfere with the integrity of the specimen. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: The cut-off threshold for a positive result for cannabinoid is 50 ng/mL. A positive result for cannabinoid indicates only the presence of cannabinoid and does not necessarily correlate with the extent of physiological and psychological effects. A negative result indicates that cannabinoids are either not present or are present at levels below the cut-off threshold for this test. Carbamazepine (Tegretol®) Specimen type: Serum Special requirements or comments: Specimen should be drawn before the next oral dose with the patient at steady state. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Therapeutic guide: 17 - 51µmol/L Carboxyhaemoglobin Specimen type: Arterial blood in air-free heparinised syringe. Blood gas analysis sampling kits are available in each ward. Once the sample has been drawn, the blood gas syringe must be labelled with the patient’s full name, chart number, ward, date and time of collection. Immediately after collection, expel any air from the sample and seal the syringe with the stopper provided in the sampling kit. 117 CLINICAL BIOCHEMISTRY Reference range: The referral laboratory report provides appropriate reference values. Store specimen at approximately 4 degrees Celsius prior to preparation for dispatch to referral laboratory. 04–Biochem pp69-228 13/7/10 11:58 AM Page 118 CLINICAL BIOCHEMISTRY TEST DIRECTORY Special requirements or comments: Specimen should be sent to the laboratory immediately. CLINICAL BIOCHEMISTRY Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: 0 – 1.5 % Carcinoembryionic antigen (CEA) Specimen type: Serum Special requirements or comments: IMPORTANT WARNING: This assay is not validated for use as a screening test for cancer. CEA is almost never raised in early malignancy. The regulatory body approval for this assay states that it is intended strictly for in vitro diagnostic use in the management of cancer patients and in the assessment of prognosis. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: 0 – 10 ng/mL Cardiac enzyme profile Specimen type: Serum Special requirements or comments: Includes CK, LD and AST. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: See ranges for individual analytes: CK Males: 49 – 397 IU/L Females 38 – 234 IU/L LD 98 – 192 IU/L AST 15 – 41 IU/L 118 04–Biochem pp69-228 13/7/10 11:58 AM Page 119 CLINICAL BIOCHEMISTRY TEST DIRECTORY Carnitine (Total and free) Special requirements or comments: The specimen should be surrounded with ice and brought to the laboratory immediately. Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Carotene Specimen type: Serum Special requirements or comments: Fasting specimen: protect from light. Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Catecholamines (total) Specimen type: 24-hour urine collection; with 20mL of 6 N HCI as preservative. Special requirements or comments: Relevant clinical details and drug history must be provided with the request. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Catecholamine /creatinine ratio (paediatric request; up to 12 years of age) Specimen type: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. 119 CLINICAL BIOCHEMISTRY Specimen type: 1 mL of whole blood in a lithium heparin specimen tube. 04–Biochem pp69-228 13/7/10 11:58 AM Page 120 CLINICAL BIOCHEMISTRY TEST DIRECTORY CLINICAL BIOCHEMISTRY Special requirements or comments: The ratio is determined on a 20 mL urine specimen. Acid preservative is added upon receipt in the laboratory. Specimen must be brought to the laboratory immediately after collection. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. CEA (carcinoembryonic antigen) Specimen type: Serum Special requirements or comments: IMPORTANT WARNING: This assay is not validated for use as a screening test for cancer. CEA is almost never raised in early malignancy. The regulatory body approval for this assay states that it is intended strictly for in vitro diagnostic use in the management of cancer patients and in the assessment of prognosis. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: 0 – 10 ng/mL CellCept® (Mycophenolate) Specimen type: 2 mL of whole blood in potassium EDTA specimen tube. Send specimen to the laboratory immediately so that plasma can be separated within two hours. Special requirements or comments: Special request form for immunosuppressant drug monitoring should be used. The date and time of specimen collection and the date, time and dosage of the last mycophenolate dose must be recorded on the request form. Appropriate clinical details are also required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. CH-50 (whole complement titre) Please contact the Serology / Immunology Laboratory. 120 04–Biochem pp69-228 13/7/10 11:58 AM Page 121 CLINICAL BIOCHEMISTRY TEST DIRECTORY Chloride CLINICAL BIOCHEMISTRY Specimen type: Serum Special requirements or comments: This assay is also available as part of the electrolyte profile. Turnaround time: Availability of assay: Daily, throughout 24 hours. Reference range: 101 – 111mmol/L Cholesterol: Total Specimen type: Serum Special requirements or comments: Prolonged venous compression during blood collection will increase serum cholesterol. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: General population reference values: 4.0 – 6.7 mmol/L In general, total serum cholesterol should be less than 5.0 mmol/L and LDL-cholesterol should be less than 3.0 mmol/L. For patients with clinically established cardiovascular disease and patients with diabetes the treatment goals should be lower: total cholesterol < 4.5 mmol/L and LDL-cholesterol <2.5 mmol/L. Treatment goals are not defined for HDL-cholesterol and triglycerides, but HDLcholesterol < 1.0 mmol/L in men and < 1.2 mmol/L in women, and fasting triglyceride >1.7 mmol/L are markers of increased cardiovascular risk. In asymptomatic individuals the decision to start treatment depends not only on the serum lipid levels but also on an assessment of total cardiovascular risk. Cholesterol: HDL fraction Specimen type: Serum Special requirements or comments: Fasting specimen Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: General population reference values: 1.0 – 2.2 mmol/L 121 04–Biochem pp69-228 13/7/10 11:58 AM Page 122 CLINICAL BIOCHEMISTRY TEST DIRECTORY CLINICAL BIOCHEMISTRY In general, total serum cholesterol should be less than 5.0 mmol/L and LDL-cholesterol should be less than 3.0 mmol/L. For patients with clinically established cardiovascular disease and patients with diabetes the treatment goals should be lower: total cholesterol < 4.5 mmol/L and LDL-cholesterol <2.5 mmol/L. Treatment goals are not defined for HDL-cholesterol and triglycerides, but HDLcholesterol < 1.0 mmol/L in men and < 1.2 mmol/L in women, and fasting triglyceride >1.7 mmol/L are markers of increased cardiovascular risk. In asymptomatic individuals the decision to start treatment depends not only on the serum lipid levels but also on an assessment of total cardiovascular risk. Cholesterol: LDL fraction Specimen type: Serum Special requirements or comments: Fasting specimen Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: General population reference values: 2.5 – 3.5 mmol/L In general, total serum cholesterol should be less than 5.0 mmol/L and LDL-cholesterol should be less than 3.0 mmol/L. For patients with clinically established cardiovascular disease and patients with diabetes the treatment goals should be lower: total cholesterol < 4.5 mmol/L and LDL-cholesterol <2.5 mmol/L. Treatment goals are not defined for HDL-cholesterol and triglycerides, but HDLcholesterol < 1.0 mmol/L in men and < 1.2 mmol/L in women, and fasting triglyceride >1.7 mmol/L are markers of increased cardiovascular risk. In asymptomatic individuals the decision to start treatment depends not only on the serum lipid levels but also on an assessment of total cardiovascular risk. Cholinesterase Specimen type: Serum Special requirements or comments: Appropriate clinical details required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 122 04–Biochem pp69-228 13/7/10 11:58 AM Page 123 CLINICAL BIOCHEMISTRY TEST DIRECTORY Cholinesterase Phenotype CLINICAL BIOCHEMISTRY Specimen type: Serum Special requirements or comments: Appropriate clinical details required Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Cholinesterase Genotype Cholinesterase genotype, plasma cholinesterase genotype, BChE genotype Specimen type: 5 mL of whole blood in potassium EDTA anticoagulant. Special requirements or comments: Appropriate clinical details required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Chromogranin A Specimen type: Serum Special requirements or comments: Deliver the specimen to the Clinical Biochemistry Laboratory within 2 hours of venepuncture. Upon receipt in the laboratory, centrifuge the specimen without delay. Separate the serum immediately after centrifugation and store at minus 25 degrees pending dispatch to referral laboratory. The separated serum sample must remain frozen during transport to the referral laboratory. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 123 04–Biochem pp69-228 13/7/10 11:58 AM Page 124 CLINICAL BIOCHEMISTRY TEST DIRECTORY Ciclosporin (Cyclosporin) CLINICAL BIOCHEMISTRY Specimen type: Whole blood collected in a specimen tube with potassium EDTA as anticoagulant. Special requirements or comments: Special request form for immunosuppressant drug monitoring should be used. Trough levels should be monitored, i.e. 12-18 hours after oral dose, 12 hours after intravenous dose or immediately prior to the next dose. Do not centrifuge the specimen. Turnaround time: Requests for this test are referred to an external specialist laboratory. Store specimen at approximately 4 degrees Celsius prior to preparation for dispatch to referral laboratory. Reference range: The referral laboratory report provides appropriate reference values. Citrate (citric acid) Specimen type: 24-hour urine collection. No preservative is required. The collection should be kept cool / refrigerated during the collection period. Special requirements or comments: On completion, the collection should be delivered to the laboratory without delay. Do not undertake collection if a urinary tract infection is present. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. CK (creatine kinase) Specimen type: Serum Special requirements or comments: After the onset of myocardial infarction, the diagnostic window is from the 12th to the 24th hour. Note that values may be raised by exercise, intramuscular injections and bruising. Haemolysis interferes with the assay resulting in falsely raised values. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: Males: 49 – 397 IU/L Females: 38 – 234 IU/L 124 04–Biochem pp69-228 13/7/10 11:58 AM Page 125 CLINICAL BIOCHEMISTRY TEST DIRECTORY CK-MB (Creatine kinase MB isoenzyme) CLINICAL BIOCHEMISTRY Note: the preferred biochemical marker for myocardial infarction is the cardiospecific protein Troponin-T Specimen type: Serum Special requirements or comments: After the onset of myocardial infarction, the diagnostic window is from the 12th to the 24th hour. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: 0 – 5.0 ng/mL CO2 (serum/plasma) Specimen type: Serum/Plasma Special requirements or comments: This assay is also available as part of the electrolyte profile. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: 22 – 32 mmol/L Cocaine metabolite Specimen type: Random urine specimen collected without any preservative. Special requirements or comments: The assay is intended to assist in the clinical management of the patient and is not provided for medico-legal purposes. The requesting doctor may need to consider whether a patient might avail of opportunities to alter or interfere with the integrity of the specimen. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: The cut-off threshold for a positive result for cocaine metabolite is 300 ng/mL. A positive result for cocaine metabolite indicates only the presence of cocaine metabolite and does not necessarily correlate with the extent of physiological and psychological effects. A negative result indicates that cocaine metabolites are either not present or are present at levels below the cut-off threshold for this test. 125 04–Biochem pp69-228 13/7/10 11:58 AM Page 126 CLINICAL BIOCHEMISTRY TEST DIRECTORY Complement CLINICAL BIOCHEMISTRY Except for C3, C4 and C1-esterase inhibitor please refer requests for the assay of complement components to the Serology / Immunology Laboratory. Copper Specimen type: Whole blood in trace metal-free tube. Trace metal-free needle must be used in conjunction with trace metal-free tube. This specimen should be collected first if other tests are requested so as to avoid contamination. For urine copper a 24-hour urine collection without preservative in a metal-free container is required. Special requirements or comments: Please contact Clinical Biochemistry Laboratory for trace metal-free specimen collection tube and needle. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Cortisol Specimen type: Serum Special requirements or comments: Record specimen collection time. Appropriate clinical details are required. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: 7-9am serum cortisol Midnight serum cortisol 250 – 800 nmol/L <250 nmol/L Cotinine Specimen type: 10 mL of urine collected without a preservative. Special requirements or comments: Cotinine is the major nicotine metabolite found in urine. Turnaround time: Requests for this test are referred to an external specialist laboratory. 126 04–Biochem pp69-228 13/7/10 11:58 AM Page 127 CLINICAL BIOCHEMISTRY TEST DIRECTORY Reference range: The referral laboratory report provides appropriate reference values. Specimen type: Serum Special requirements or comments: Specimen for glucose assay must be drawn at same time. Record specimen collection time. Specimen should be delivered to the laboratory within four hours of venepuncture. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. C-Reactive Protein (CRP) Please refer to Serology Section of this Handbook. Creatine kinase (CK) Specimen type: Serum Special requirements or comments: After the onset of myocardial infarction, the diagnostic window is from the 12th to the 24th hour. Note that values may be raised by exercise, intramuscular injections and bruising. Haemolysis interferes with the assay resulting in falsely raised values. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: Males: 49 – 397 IU/L Females: 38 – 234 IU/L Creatine kinase MB isoenzyme (CK-MB) Note: the preferred biochemical marker for myocardial infarction is the cardiospecific protein Troponin-T Specimen type: Serum Special requirements or comments: After the onset of myocardial infarction, the diagnostic window is from the 12th to the 24th hour. 127 CLINICAL BIOCHEMISTRY C-peptide 04–Biochem pp69-228 13/7/10 11:58 AM Page 128 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Availability of assay: Monday – Friday during core working hours. CLINICAL BIOCHEMISTRY Reference range: 0 – 5.0 ng/mL Creatinine Specimen type: Serum Urine: 24-hour collection Special requirements or comments: In the case of blood specimens for creatinine assay, the serum should be separated from the red blood cells within five hours of venepuncture; otherwise substances are released from the red blood cells, which cause falsely raised serum creatinine concentrations. Both a serum specimen and a 24-hour urine collection are required for creatinine clearance. Turnaround time: Availability of assay: Serum: daily, throughout 24 hours. Urine: Monday – Friday during core working hours. Reference range: Adults: Serum: 35 – 106 µmol/L Urine: 9.0 – 18.0 mmol/24 hours. Age-related ranges: Age range Serum Creatinine (µmol/L) Males Females Birth - 1 week 53 – 97 53 – 97 1-4 weeks 27 – 62 27 – 62 1-6 months 18 – 35 18 – 35 6 months-1 year 18 – 35 18 – 35 1-18 years 18 – 62 18 – 62 18-100 years 62 – 106 35 – 88 Creatinine Clearance Specimen type: Serum and a 24-hour urine collection Special requirements or comments: Both serum specimen and a 24-hour urine collection are required for creatinine clearance. 128 04–Biochem pp69-228 13/7/10 11:58 AM Page 129 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Adults: Males: 85 – 125 mL/minute/1.73m2 (1.41 – 2.08 mL/s/1.73m2) Females: 75 - 115 mL/minute/1.73m2 (1.25 – 1.92 mL/s/1.73m2) For each age decade after 40 years, creatinine clearance falls by approximately 6 – 7 mL/minute/1.73m2. Crosslaps (CTx) Specimen type: Serum Special requirements or comments: Fasting specimen is strongly recommended. To minimise the influence of day-to-day variability, it is important to maintain the same collection protocol. Serial samples should be collected at the same time of day on each occasion, e.g. before breakfast. Appropriate clinical details required. The specimen must reach the laboratory within two hours of collection from the patient. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. CRP (C-Reactive Protein) Please refer to Serology Section of this Handbook. Cryoglobulins Specimen type: The Clinical Biochemistry Laboratory must be contacted before initiating the request so that all collection requirements can be met. Special requirements or comments: Specimen must be collected in a plain Monovette® syringe prewarmed to 37 degrees Celsius, and maintained at 37 degrees Celsius during clotting, centrifugation and separation of the serum fraction. Arrangements for the collection of a specimen for detection of cryoglobulins must always be discussed with the Clinical Biochemistry Laboratory prior to the commencement of specimen collection. Turnaround time: Availability of assay: allow seven days for receipt of report. 129 CLINICAL BIOCHEMISTRY In the case of blood specimens for creatinine assay, the serum should be separated from the red blood cells within five hours of venepuncture; otherwise substances are released from the red blood cells, which cause falsely raised serum creatinine concentrations. 04–Biochem pp69-228 13/7/10 11:58 AM Page 130 CLINICAL BIOCHEMISTRY TEST DIRECTORY Reference range: The laboratory report provides appropriate reference values. CLINICAL BIOCHEMISTRY CSF Glucose Specimen type: CSF. Special requirements or comments: Note that it is Laboratory Policy that all CSF specimens must be delivered to the Microbiology Department for initial examination and processing. Appropriate clinical details required. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: In fasting patients: 2.2 – 3.9 mmol/L. Result should be interpreted in combination with plasma glucose result. CSF glucose should be 60 – 70% of the plasma glucose. CSF Oligoclonal IgG banding Specimen type: CSF and serum obtained at the same time. Special requirements or comments: Appropriate clinical details required. Note that it is Laboratory Policy that all CSF specimens must be delivered to the Microbiology Department for initial examination and processing. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. CSF Protein Specimen type: CSF. Special requirements or comments Appropriate clinical details required. Note that it is Laboratory Policy that all CSF specimens must be delivered to the Microbiology Department for initial examination and processing. 130 04–Biochem pp69-228 13/7/10 11:58 AM Page 131 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Availability of assay: daily, throughout 24 hours. CTx (Crosslaps) Specimen type: Serum Special requirements or comments: Fasting specimen is strongly recommended. To minimise the influence of day-to-day variability, it is important to maintain the same collection protocol. Serial samples should be collected at the same time of day on each occasion, e.g. before breakfast. Appropriate clinical details required. The specimen must reach the laboratory within two hours of collection from the patient. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Cyclosporin (Ciclosporin) Specimen type: See special requirements. Special requirements or comments: Special request form for immunosuppressant drug monitoring should be used. Whole blood collected in specimen tube with potassium EDTA as anticoagulant. Trough levels should be monitored, i.e. 12-18 hours after oral dose, 12 hours after intravenous dose or immediately prior to the next dose. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Cystine Specimen type: 24-hour urine collection. No preservative is required. Special requirements or comments: The collection should be kept cool or refrigerated until complete. On completion, the collection should be delivered to the laboratory without delay. 131 CLINICAL BIOCHEMISTRY Reference range: 0.150 – 0.450 g/L 04–Biochem pp69-228 13/7/10 11:58 AM Page 132 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Requests for this test are referred to an external specialist laboratory. CLINICAL BIOCHEMISTRY Reference range: The referral laboratory report provides appropriate reference values. Cystine (white cell concentration) Specimen type: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. Special requirements or comments: 1-2 mL blood in lithium heparin tube; do not refrigerate or centrifuge, deliver to laboratory without delay. Monday – Wednesday (only) dispatch to Manchester. Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 7-Dehydrocholesterol (in relation to Smith Lemli Opitz syndrome) Specimen type: 1 mL serum or plasma. Special requirements or comments: Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Dehydroepiandrosterone sulphate (DHEAS, DHEA sulphate) Specimen type: Serum Special requirements or comments: Draw specimen in the morning. Appropriate clinical details are required. Turnaround time: Availability of assay: allow seven days for receipt of report. Reference range: Adults Males: Females: Females (postmenopausal) 132 2.17 – 15.19 µmol/L 0.95 – 11.67 µmol/L 0.27 – 5.16 µmol/L 04–Biochem pp69-228 13/7/10 11:58 AM Page 133 CLINICAL BIOCHEMISTRY TEST DIRECTORY Delta Aminolevulinic acid (ALA) CLINICAL BIOCHEMISTRY Specimen type: 24-hour urine collection; no preservative. Special requirements or comments: Protect the collection from light and keep refrigerated at 4-8°C. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Deoxypyridinoline Specimen type: Urine Special requirements or comments: It is recommended that a carefully monitored second void collection is made; patients should be asked to empty their bladders on waking and discard the urine. Then they should collect the next specimen (the second morning void) in the urine container (plain container, no additives). To minimise the influence of day-to-day variability, it is important to maintain the same collection protocol. Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. DHEA sulphate (DHEAS) Specimen type: Serum Special requirements or comments: Draw specimen in the morning. Appropriate clinical details are required. Turnaround time: Availability of assay: allow seven days for receipt of report. Reference range: Adults Males: Females: Females (postmenopausal) 2.17 – 15.19 µmol/L 0.95 – 11.67 µmol/L 0.27 – 5.16 µmol/L 133 04–Biochem pp69-228 13/7/10 11:58 AM Page 134 CLINICAL BIOCHEMISTRY TEST DIRECTORY Digoxin CLINICAL BIOCHEMISTRY Specimen type: Serum Special requirements or comments: The specimen should be drawn when digoxin is in equilibrium between plasma and the tissues. The time to equilibrium following either oral or intravenous dose is usually 8 to 12 hours. Note: with normal renal function and regular dosage intervals, it takes 5 to 7 days to achieve a steady state of digoxin. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Therapeutic guide: 1.3 – 2.6 nmol/L Dihydrotestosterone (5-αdihydrotestosterone) Specimen type: Serum (1-2 mL); in the case of neonatal and paediatric requests, the sample volume may be discussed with the referral laboratory. Special requirements or comments: Appropriate clinical details are required including a summary of prescribed medication. The referral laboratory will undertake to assay both testosterone and dihydrotestosterone in order to advise on the interpretation of the testosterone/5-αdihydrotestosterone ratio. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 1,25 Dihydroxy cholecalciferol (1,25 dihydroxy vitamin D) Specimen type: Serum: see special requirements. Plasma is not suitable for this assay. Special requirements or comments: A fasting specimen is required. The specimen should be protected from light and brought to the laboratory immediately. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 134 04–Biochem pp69-228 13/7/10 11:58 AM Page 135 CLINICAL BIOCHEMISTRY TEST DIRECTORY Dopamine CLINICAL BIOCHEMISTRY Specimen type: 24-hour urine collection with 20mL of 6N HCI as preservative. Special requirements or comments: Appropriate clinical details and a list of all current medication are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Drink, spiked (suspected case of spiked drink) Important notes: (1) Requests for analyses relating to a case of alleged spiking of drink must be made by a registered medical practitioner. (2) The biochemistry service is provided to assist in the clinical management of the patient and is not provided for forensic purposes or as part of a criminal investigation. (3) Specimens should be collected within 24 hours of the alleged incident. Specimens collected more than 24 hours after the alleged incident are unlikely to yield significant findings. (4) The measurement of the subject’s serum or plasma alcohol should be considered a prerequisite to any biochemistry investigations of alleged spiking of drink. Specimen type: Serum or plasma and urine Special requirements or comments: Specimens must be collected within 24 hours of the alleged incident. Specimen collected more than 24 hours after the event are unlikely to yield significant findings. Appropriate clinical details are required including a summary of prescribed medication. No preservative is required for the urine specimen. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Drugs of abuse in urine (DAU) screen Specimen type: Random urine specimen collected without any preservative. 135 04–Biochem pp69-228 13/7/10 11:58 AM Page 136 CLINICAL BIOCHEMISTRY TEST DIRECTORY CLINICAL BIOCHEMISTRY Special requirements or comments: The assay is intended to assist in the clinical management of the patient and is not provided for medico-legal purposes. The requesting doctor may need to consider whether a patient might avail of opportunities to alter or interfere with the integrity of the specimen. The following drugs are tested for as part of the DAU Profile: amphetamines, barbiturates, benzodiazepine, cocaine metabolite, methadone, opiate, cannabinoid (THC). Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: These analytes are reported as Positive or Negative The cut-off threshold for a positive result for each of the drugs is as follows: Drug Cutoff threshold for a positive result Amphetamines 1000 ng/mL Barbiturate 200 ng/mL Benzodiazepine 200 ng/mL Cocaine metabolite 300 ng/mL Methadone 300 ng/mL Opiate 300 ng/mL Cannabinoid 50 ng/mL A positive result indicates only the presence of the drug and does not necessarily correlate with the extent of physiological and psychological effects. A negative result indicates that the drug either is not present or is present at levels below the cut-off threshold for this test. eGFR (estimated glomerular filtration rate) Specimen type: Serum Note: calculation is based on the 4v-MDRD Formula and is only applicable to adults (i.e. patients >18 years old). Special requirements or comments: The serum should be separated from the red blood cells within six hours of venepuncture; otherwise substances are released from the red blood cells, which cause falsely raised serum creatinine concentrations. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: > 90 mL/min/1.73m2 136 04–Biochem pp69-228 13/7/10 11:58 AM Page 137 CLINICAL BIOCHEMISTRY TEST DIRECTORY Important notes on Estimated GFR in adults using formulae (2) Estimates of GFR are unreliable in acute renal failure due to the kinetics of creatinine accumulation. (3) GFR estimates between 60 and 89 mL/min/1.73m2 do not indicate CKD unless there is other laboratory/clinical evidence of disease. (4) Estimated GFR should be multiplied by 1.212 for African-American patients. IDMS-traceable MDRD Study Equation for serum creatinine reported in SI units eGFR (mL/min/1.73 m2) = 175 x (serum creatinine (µmol/L) x 0.011312)-1.154 x (Age)-0.203 x (0.742 if female) x (1.212 if African American) The IDMS-traceable MDRD Study equation is for laboratories that use creatinine methods that have been calibrated to be traceable to IDMS. Elastase-1 (Pancreatic) Specimen type: Approximately 5 grams of stools. Sample should be kept cool during transport to the laboratory. Special requirements or comments: Specimen should be sent to the laboratory immediately Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Electrolytes Specimen type: Serum, plasma Special requirements or comments: The electrolyte panel includes sodium, potassium, chloride, carbon dioxide. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference ranges: Sodium: 136 – 144 mmol/L Potassium: 3.6 – 5.1 mmol/L Chloride: 101 – 111 mmol/L Carbon dioxide: 22 – 32 mmol/L 137 CLINICAL BIOCHEMISTRY (1) Estimated GFR is calculated using the 4v-MDRD Formula (with creatinine assay calibration traceable to ID-MS). 04–Biochem pp69-228 13/7/10 11:58 AM Page 138 CLINICAL BIOCHEMISTRY TEST DIRECTORY Electrophoresis (Serum Protein) CLINICAL BIOCHEMISTRY Specimen type: Serum Special requirements or comments: Appropriate clinical details required. Turnaround time: Availability of assay: allow three working days for receipt of report. Reference range: The laboratory report provides appropriate information. Electrophoresis (Urine Protein) Specimen type: Untimed urine collection or a 24-hour collection. No preservative is required. Keep specimen refrigerated. Special requirements or comments: Appropriate clinical details are required. Turnaround time: Availability of assay: allow three working days for receipt of report. Reference range: The laboratory report provides appropriate information. Enolase (neurone-specific) Specimen type: Serum Special requirements or comments: Specimen should be sent to the laboratory immediately to allow for freezing of serum to minus 25 degrees Celsius within 4 hours of specimen collection. Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Environment toxicology The Clinical Biochemistry Laboratory does not provide an assay service for environmental, industrial or occupational toxic agents or chemicals. The most appropriate agency to contact regarding these matters is the Environmental Protection Agency.; contact details: 138 04–Biochem pp69-228 13/7/10 11:58 AM Page 139 CLINICAL BIOCHEMISTRY TEST DIRECTORY CLINICAL BIOCHEMISTRY EPA Headquarters, PO Box 3000, Johnstown Castle Estate, Co. Wexford, Tel: 053-9160600; Fax:053-9160699; Email: [email protected]; Lo Call: 1890 335599. Web site: www.epa.ie Epanutin® (Phenytoin) Specimen type: Serum Special requirements or comments: Specimen drawn before the next oral dose with the patient at steady state. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Therapeutic guide: 40 – 79 µmol/L Epilim® (Valproate, valproic acid) Specimen type: Serum Special requirements or comments: Specimen drawn before the next oral dose with the patient at steady state. There is no evidence that monitoring serum valproate levels can be valuable in the management of patients with epilepsy. Studies indicate that concentrations are no better a guide to clinical response than is dose. Measurement of serum levels may be useful in the assessment of compliance. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Therapeutic guide: 347 – 693 µmol/L Estimated glomerular filtration rate (eGFR) Specimen type: Serum Note: calculation is based on the 4v-MDRD Formula and is only applicable to adults (i.e. patients >18 years old). Special requirements or comments: The serum should be separated from the red blood cells within six hours of venepuncture; otherwise substances are released from the red blood cells, which cause falsely raised serum creatinine concentrations. 139 04–Biochem pp69-228 13/7/10 11:58 AM Page 140 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Availability of assay: daily, throughout 24 hours. CLINICAL BIOCHEMISTRY Reference range: > 90 mL/min/1.73m2 Important notes on Estimated GFR in adults using formulae (1) Estimated GFR is calculated using the 4v-MDRD Formula (with creatinine assay calibration traceable to ID-MS). (2) Estimates of GFR are unreliable in acute renal failure due to the kinetics of creatinine accumulation. (3) GFR estimates between 60 and 89 mL/min/1.73m2 do not indicate CKD unless there is other laboratory/clinical evidence of disease. (4) Estimated GFR should be multiplied by 1.212 for African-American patients. IDMS-traceable MDRD Study Equation for serum creatinine reported in SI units eGFR (mL/min/1.73 m2) = 175 x (serum creatinine (µmol/L) x 0.011312)-1.154 x (Age)0.203 x (0.742 if female) x (1.212 if African American) The IDMS-traceable MDRD Study equation is for laboratories that use creatinine methods that have been calibrated to be traceable to IDMS. Estradiol / Oestradiol Specimen type: Serum Special requirements or comments: Appropriate clinical details required. This assay has not been validated for use on neonatal samples. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Serum Oestradiol (pmol/L) Females Follicular phase Mid-cycle Mid-luteal phase Males 550 - 1835 110 - 734 Post-menopausal < 92 Adult males <206 Note: lower limit of detection of assay is approximately 73 pmol/L. 140 110 - 551 04–Biochem pp69-228 13/7/10 11:58 AM Page 141 CLINICAL BIOCHEMISTRY TEST DIRECTORY Ethanol (alcohol) CLINICAL BIOCHEMISTRY Specimen type: Serum, plasma, urine. Special requirements or comments: This assay is intended to assist in the clinical management of the patient and is not provided for medico-legal purposes or in relation to the Road Traffic Acts. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Serum or plasma: 50-100 mg/dL: >100 mg/dL: >400 mg/dL: < 10 mg/dL; signs of intoxication; depression of CNS; fatalities reported. Urine: <10 mg/dL Ethosuximide (Zarontin®) Specimen type: Serum Special requirements or comments: Specimen should be drawn before the next oral dose with the patient at steady state. Due to the long half-life of ethosuximide, fluctuations in serum concentration are relatively minor. However, when making comparative measurements, its is advisable that the sampling time to consistent. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Ethylene glycol Specimen type: Serum, plasma. Special requirements or comments: Assay is of value when ethylene glycol ingestion is suspected or when symptoms indicate that possibility. Turnaround time: Requests for this test are referred to an external specialist laboratory. 141 04–Biochem pp69-228 13/7/10 11:58 AM Page 142 CLINICAL BIOCHEMISTRY TEST DIRECTORY Reference range: The referral laboratory report provides appropriate reference values. CLINICAL BIOCHEMISTRY Note: The out-of-hours toxicology call service at Beaumont Hospital is available to all hospitals in the Republic of Ireland, however “the service is restricted to checking only for drugs, which if taken in overdose require a specific antidote or treatment. It is not an aid to diagnosis nor to allow a patient to be discharged.” If the assay is required outside of normal working hours the Toxicologist on-call at Beaumont Hospital must be contacted at 087 2590749. Faecal Fat Specimen type: Quantitative three-day collection is required. A suitable container is available from the Clinical Biochemistry Laboratory. The specimen should be kept cool. On completion, the collection should be delivered to the laboratory without delay. Special requirements or comments: A diet containing 50 grams of fat in the case of children or 100 grams fat in the case of adults should be consumed daily in the days before and during the collection. Laxatives, enemas and barium meals should not be taken immediately before or during the collection. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Fasting Lipid profile Specimen type: Serum: see special requirements Special requirements or comments: The patient must be fasting for 10 hours and have been on a stable diet for the previous two to three weeks Alcohol should not be consumed in the three days before the test. The profile includes; total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglyceride. Turnaround time: Availability of assay: Monday – Friday during core working hours. General population reference values Total Cholesterol Reference Range: 4.0 – 6.7 mmol/L HDL-Cholesterol Reference Range: 1.0 – 2.2 mmol/L 142 04–Biochem pp69-228 13/7/10 11:58 AM Page 143 CLINICAL BIOCHEMISTRY TEST DIRECTORY LDL-Cholesterol Reference Range: 2.5 – 3.5 mmol/L Note: reference ranges for lipids: In general, total serum cholesterol should be less than 5.0 mmol/L and LDL-cholesterol should be less than 3.0 mmol/L. For patients with clinically established cardiovascular disease and patients with diabetes the treatment goals should be lower: total cholesterol < 4.5 mmol/L and LDL-cholesterol < 2.5 mmol/L. Treatment goals are not defined for HDL-cholesterol and triglycerides, but HDLcholesterol < 1.0 mmol/L in men and < 1.2 mmol/L in women, and fasting triglyceride > 1.7 mmol/L are markers of increased cardiovascular risk. In asymptomatic individuals the decision to start treatment depends not only on the serum lipid levels but also on an assessment of total cardiovascular risk. Fat globules in urine Please contact Histopathology. Fatty Acids, very long chain (VLCFA) Specimen type: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. Special requirements or comments: 1 mL of blood in potassium EDTA tube is required; do not refrigerate, deliver to laboratory without delay. Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Ferritin Please refer to Haematology Section of this Handbook. FK 506 (Tacrolimus, Prograf®) Specimen type: Whole blood in specimen tube with potassium EDTA as anticoagulant. 143 CLINICAL BIOCHEMISTRY Triglyceride Reference Range: 0.5 – 2.1 mmol/L 04–Biochem pp69-228 13/7/10 11:58 AM Page 144 CLINICAL BIOCHEMISTRY TEST DIRECTORY CLINICAL BIOCHEMISTRY Special requirements or comments: Special request form for immunosuppressant drug monitoring should be used. Trough levels should be monitored. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Flecainide (Tambocor®) Specimen type: Serum Special requirements or comments: Appropriate clinical details required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Fluoxetine (Prozac®) Specimen type: Serum Special requirements or comments: Details of dosage regimen required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Folate (Folic Acid) Please refer to Haematology Section of this Handbook. Food Toxicology The Clinical Biochemistry Laboratory does not provide an assay service for toxic agents or chemicals in food or food products. The most appropriate agency to contact regarding these matters is the Food Safety Authority of Ireland; contact details: Food Safety Authority of Ireland, Abbey Court. Lower Abbey Street, Dublin 1 Phone 01 817 1300 ; Fax 01 817 1301; Email [email protected] Web address www.fsai.ie 144 04–Biochem pp69-228 13/7/10 11:58 AM Page 145 CLINICAL BIOCHEMISTRY TEST DIRECTORY Follicle stimulating hormone (FSH) CLINICAL BIOCHEMISTRY Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Females: Follicular phase Mid-Cycle Mid-Luteal Post Menopausal Males: 3 - 12 U/L 6 - 12 U/L 2 - 12 U/L 30 - 120 U/L 0.7 – 11.1 U/L Free Light Chains (Kappa and Lambda) in serum This assay is available to consultant haematologists and their teams. The assay should be regarded as experimental. Important diagnostic and patient management decisions should not be made on the basis of serum free light chain assay results only. Specimen type: Serum only. Assay is not available for urine. Special requirements or comments: Appropriate clinical details are required including reason for request. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Free T3 (triidothyronine free hormone) Specimen type: Serum. Special requirements Appropriate clinical details and a list of all current medication are required. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: 2.7 – 7.0 pmol/L 145 04–Biochem pp69-228 13/7/10 11:58 AM Page 146 CLINICAL BIOCHEMISTRY TEST DIRECTORY Free T4 (thyroxine free hormone) CLINICAL BIOCHEMISTRY Specimen type: Serum Special requirements or comments: Appropriate clinical details and a list of all current medication are required. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: 9.9 – 20.1 pmol/L Fructosamine Specimen type: Serum or plasma Special requirements or comments: Appropriate clinical details are required with reasons why HbA1c result is not adequate for the management of the patient. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. FSH Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Serum FSH (U/L) Females Males 146 Follicular phase 3 – 12 Mid-cycle 6 – 12 Mid-luteal phase 2 – 12 Post-menopausal 30 – 120 Adult male 0.7 – 11.1 04–Biochem pp69-228 13/7/10 11:58 AM Page 147 CLINICAL BIOCHEMISTRY TEST DIRECTORY Gabapentin (Neurontin®) CLINICAL BIOCHEMISTRY Specimen type: Serum Special requirements or comments: Specimen drawn before the next oral dose with the patient at steady state. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. GAD (Glutamic Acid Decarboxylase) antibodies Reference range: Refer to Serology/Immunology Section of this manual. Galactose: disorders of galactose metabolism Specimen type: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. Note that galactosaemia is included in the National Newborn Screening Programme. Special requirements or comments: (A) Blood Galactose: (National Neonatal Screening Programme) 4 Blood spots on a Guthrie card and 2 mL of fresh urine. (B) Beutler Test (galactose 1-phosphate uridyltransferase assayed on a Guthrie card): 4 blood spots on a Guthrie card (C) Quantitative enzyme assays (galactose 1-phosphate uridyltransferase; galactokinase, UDP-galactose epimerase): 3 mL of blood in lithium heparin tube for enzyme of interest (D) Monitoring of treatment (Glactose 1-phosphate; galactitol): 2 mL of blood in lithium heparin tube and 10 mL of urine. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Gamma GT (gamma glutamyl transferase, GGT) Specimen type: Serum 147 04–Biochem pp69-228 13/7/10 11:58 AM Page 148 CLINICAL BIOCHEMISTRY TEST DIRECTORY Special requirements or comments: This assay is also available as part of the liver test profile. CLINICAL BIOCHEMISTRY Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: 7 – 50 IU/L Gastrin Specimen type: Serum Special requirements or comments: Patient should be fasting overnight. The specimen should be surrounded with ice and brought to the laboratory immediately. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. GGT (gamma GT = gamma glutamyl transferase) Specimen type: Serum Special requirements or comments: This assay is also available as part of the liver test profile. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: 7 – 50 IU/L GI-MA (alternative: CA19.9) Specimen type: Serum Special requirements or comments: IMPORTANT WARNING: This assay is not validated for use as a screening test for cancer. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: 0 – 39 U/mL 148 04–Biochem pp69-228 13/7/10 11:58 AM Page 149 CLINICAL BIOCHEMISTRY TEST DIRECTORY GL-3 Specimen type: Urine (note: serum/plasma GL-3 assay is no longer available) Special requirements or comments: Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Store specimen at approximately 4 degrees Celsius prior to preparation for dispatch to referral laboratory. Reference range: The referral laboratory report provides appropriate reference values. Glucagon Specimen type: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. Collect 5 mL of blood into an ice-cold EDTA tube containing 0.1 mL of TRASYLOL (aprotinin; 20,000 klUmL). Special requirements or comments: Patient should be fasting overnight. The specimen should be surrounded with ice and brought to the laboratory immediately. Note: haemolysis invalidates this assay. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Glucose Specimen type: Glucose specimen tube containing fluoride EDTA as anticoagulant. Special requirements or comments: Record specimen collection time and state whether the specimen is fasting, post-prandial or part of a glucose tolerance test. Turnaround time: Availability of assay: daily, throughout 24 hours. 149 CLINICAL BIOCHEMISTRY Explanatory note: this test is used in the management of patients with Fabry Disease 04–Biochem pp69-228 13/7/10 11:58 AM Page 150 CLINICAL BIOCHEMISTRY TEST DIRECTORY Reference range: General population reference range: 4.1 – 6.6 mmol/L CLINICAL BIOCHEMISTRY Fasting venous plasma glucose World Health Organisation (WHO) Criteria Normal Impaired fasting glucose Diabetes American Diabetes Association (ADA) Criteria </= 6.0 mmol/L </= 5.5 mmol/L 6.1 – 6.9 mmol/L 5.6 – 6.9 mmol/L >/= 7.0 mmol/L >/= 7.0 mmol/L Glucose (CSF) Specimen type: CSF. Special requirements or comments: Note that it is Laboratory Policy that all CSF specimens must be delivered to the Microbiology Department for initial examination and processing. Appropriate clinical details required. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: In fasting patients: 2.2 – 3.9 mmol/L. Result should be interpreted in combination with plasma glucose result. CSF glucose should be 60 – 70% of the plasma glucose. Glucose Tolerance Test Specimen type: Specimens collected in glucose specimen tubes as follows: Fasting i.e. immediately prior to 75 gram oral glucose load (adult), and 2 hours post glucose load. Special requirements or comments: The oral glucose load is 1.75 grams per kilogram ideal body weight to a maximum of 75 grams. The glucose should be dissolved in 300-350 mL of drinking water and consumed over 5 minutes. Sugar-free lemon and chilling increase palatability and may reduce nausea. The patient should sit throughout the test. In order to avoid false positives, patients should receive adequate carbohydrate (at least 150 grams daily) for the three days before the oral glucose tolerance test. Bookings for oral glucose tolerance test on outpatients may be made with the Laboratory Phlebotomist at (061) 482270. These tests are preformed on Wednesdays and Fridays. 150 04–Biochem pp69-228 13/7/10 11:58 AM Page 151 CLINICAL BIOCHEMISTRY TEST DIRECTORY Volume of Lucozade to provide the equivalent of 75g anhydrous glucose or 82.5g glucose monohydrate: 410mL. For children the recommended test load is 1.75g glucose per kg body weight up to a total of 75g of glucose, this is equivalent to 9 6mL Lucozade (Energy Original, 70kcal/100mL) per kg body weight up to a total of 410mL of Lucozade. Notes on the Oral Glucose Tolerance Test: • Unrestricted diet for three days prior to the test, with a daily intake of at least 150g of carbohydrate and usual physical activity; a reasonable carbohydrate (30-50g) containing meal should be consumed on the evening before the test. • 8-14 hour overnight fast during which water may be drank. • No smoking, eating, drinking or exercise during the test. • Fasting blood specimen drawn for glucose measurement (t=0). • After collection of the fasting sample, the patient should consume 75g anhydrous glucose dissolved in 250-300mL of water. The test is timed from the commencement of the drink. The drink must be consumed in less than five minutes. • The second blood specimen for glucose measurement is drawn two hours after glucose ingestion (t=120). Turnaround time: The waiting time for a glucose tolerance test is about one week. Reference range: WHO and ADA Diagnostic Criteria: Interpretation of 75 gram oral glucose tolerance test Normal Results WHO Criteria ADA Criteria Time of sample Venous plasma glucose mmol/L Venous plasma glucose mmol/L Fasting ≤ 6.0 ≤ 5.5 2 hours post glucose load < 7.8 < 7.8 ≥ 7.0 ≥ 7.0 Diabetes Mellitus Fasting and/or 2 hours post glucose load ≥ 11.1 ≥ 11.1 < 7.0 < 7.0 Impaired Glucose Tolerance Fasting and 2 hours post glucose load 7.8 – 11.0 7.8 – 11.0 Fasting 6.1 – 6.9 5.6 – 6.9 2 hours post glucose load < 7.8 Impaired Fasting Glucose 151 CLINICAL BIOCHEMISTRY The GlaxoSmithKline Lucozade product may be used as a glucose load according to the following instructions: Product Details: Lucozade: Energy Original 70kcal/100mL formulation (website: www.lucozade.com/energy/facts.html) 04–Biochem pp69-228 13/7/10 11:58 AM Page 152 CLINICAL BIOCHEMISTRY TEST DIRECTORY Glutamic Acid Decarboxylase (GAD) antibodies CLINICAL BIOCHEMISTRY Please refer to Serology/Immunology section of this handbook. Glutamine Specimen type: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. 1-2 mL of blood in a lithium heparin tube. Special requirements or comments: A specimen for glutamine assay must be sent to the laboratory immediately after it is drawn. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Gonadotrophins (FSH, LH) Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Females Males Growth Hormone Specimen type: Serum (fasting). 152 Serum FSH (U/L) Serum LH (U/L) Follicular phase 3 - 12 0.5 - 18 Mid-cycle 6 - 12 15 - 80 Mid-luteal phase 2 - 12 0.5 - 18 Post-menopausal 30 - 120 16 - 64 0.7 – 11.1 0.8 – 7.6 Adult male 04–Biochem pp69-228 13/7/10 11:58 AM Page 153 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Gut hormone profile Please refer to specific requirements for individual gut hormones. Haemosiderin stain, urine Please refer to Haematology Section of this Handbook. HbA1c Specimen type: Whole blood in potassium EDTA tube (as for FBC). Special requirements or comments: Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: HbA1c DCCT/NGSP aligned: 4.0 – 6.0 % HbA1c traceable to the new IFCC Reference Measurement Procedure: 20 – 42 mmol/mol. A consensus paper on the worldwide standardization of measurement and reporting of HbA1c has been published recently by the American Diabetes Association (ADA), European Association for the Study of Diabetes (EASD), International Federation of Clinical Chemistry (IFCC) and Laboratory Medicine and the International Diabetes Federation (IDF). This proposal has accepted that the IFCC Reference Measurement procedure should be the international method for calibrating all assays used for the measurement of HbA1c. The consensus paper proposed six actions, which are reproduced as follows: “[1] We agree that the HbA1c results should be standardised worldwide, including the reference system and results reporting. [2] We agree that the IFCC reference system for HbA1c represents the only valid anchor to implement standardisation of the measurement. [3] We agree that the HbA1c assay results be reported worldwide in IFCC units (mmol/mol) and derived NGSP units (%), using the IFCC-NGSP master equation. 153 CLINICAL BIOCHEMISTRY Special requirements Specimen must be brought to the laboratory as soon as possible (less than three hours). Physiological state (e.g. fasting, sleep, feeding, and activity) should be noted on the request form. 04–Biochem pp69-228 13/7/10 11:58 AM Page 154 CLINICAL BIOCHEMISTRY TEST DIRECTORY [4] CLINICAL BIOCHEMISTRY [5] [6] We agree that if the ongoing “average plasma glucose study” fulfills its a priori specified criteria, an HbA1c -derived average plasma glucose (APG) value should also be reported as an interpretation of the HbA1c result. We recommend that all clinical guidelines be expressed in IFCC units, derived NGSP units, and APG. We agree that these recommendations should be implemented globally as soon as possible.” Note: Relationship Between HbA1c Results From NGSP Network and IFCC Network: Master Equation: NGSP = (0.915 x IFCC/10) + 2.15 The relationship between HbA1c values expressed in IFCC (mmol/mol) and NGSP/DCCT (%) units is given in a table on the next page. References: ADA, EASD, IFCC Consensus Committee. Consensus statement on the worldwide standardisation of the HbA1c measurement. Diabetologia 2007;50:2042–3. Consensus meeting on reporting glycated haemoglobin and estimated average glucose in the UK: report to the National Director for Diabetes, Department of Health Ann Clin Biochem 2008; 45: 343–344. For full information check the web site www.hse.ie/go/diabetes hCG (human chorionic gonadotrophin) Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Nonpregnant females: Males: less than 5.3 U/L less than 5.3 U/L Gestational age (weeks) Weeks since last menstrual period Serum hCG U/L 1.3 – 2 3.3 – 4 16 – 156 2–3 4–5 101 – 4870 3–4 5–6 1110 – 31500 4–5 6–7 2560 – 82300 5–6 7–8 23100 – 151000 6–7 8–9 27300 – 233000 154 7 – 11 9 – 13 20900 – 291000 11 – 16 13 – 18 6140 – 103000 16 – 21 18 – 23 4720 – 80100 21 – 39 23 - 41 2700 - 78100 HbA1c (NGSP) % 9.6 9.7 9.7 9.8 9.9 10.0 10.1 10.2 10.3 10.4 10.5 10.6 10.7 10.8 10.8 10.9 11.0 11.1 11.2 11.3 11.4 11.5 11.6 11.7 11.8 11.8 11.9 12.0 12.1 12.2 HbA1c (IFCC) mmol/mol 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 HbA1c (NGSP) % 12.3 12.4 12.5 12.6 12.7 12.8 12.9 12.9 13.0 13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 13.9 14.0 14.0 14.1 14.2 14.3 14.4 14.5 14.6 14.7 14.8 14.9 15.0 CLINICAL BIOCHEMISTRY HbA1c (IFCC) mmol/mol 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 Page 155 HbA1c (NGSP) % 6.8 6.9 7.0 7.1 7.2 7.3 7.4 7.5 7.5 7.6 7.7 7.8 7.9 8.0 8.1 8.2 8.3 8.4 8.5 8.6 8.6 8.7 8.8 8.9 9.0 9.1 9.2 9.3 9.4 9.5 11:58 AM HbA1c (IFCC) mmol/mol 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 13/7/10 HbA1c (NGSP) % 4.1 4.2 4.3 4.3 4.4 4.5 4.6 4.7 4.8 4.9 5.0 5.1 5.2 5.3 5.4 5.4 5.5 5.6 5.7 5.8 5.9 6.0 6.1 6.2 6.3 6.4 6.5 6.5 6.6 6.7 CLINICAL BIOCHEMISTRY TEST DIRECTORY 155 HbA1c (IFCC) mmol/mol 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 04–Biochem pp69-228 Relationship between HbA1c IFCC and NGSP (DCCT) values 04–Biochem pp69-228 13/7/10 11:58 AM Page 156 CLINICAL BIOCHEMISTRY TEST DIRECTORY HDL-Cholesterol CLINICAL BIOCHEMISTRY Specimen type: Serum Special requirements or comments: Fasting specimen Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: General population reference values: 1.0 – 2.2 mmol/L In general, total serum cholesterol should be less than 5.0 mmol/L and LDL-cholesterol should be less than 3.0 mmol/L. For patients with clinically established cardiovascular disease and patients with diabetes the treatment goals should be lower: total cholesterol < 4.5 mmol/L and LDL-cholesterol < 2.5 mmol/L. Treatment goals are not defined for HDL-cholesterol and triglycerides, but HDLcholesterol < 1.0 mmol/L in men and < 1.2 mmol/L in women, and fasting triglyceride > 1.7 mmol/L are markers of increased cardiovascular risk. In asymptomatic individuals the decision to start treatment depends not only on the serum lipid levels but also on an assessment of total cardiovascular risk. 5 HIAA Specimen type: 24-hour urine collection with 20 mL of 6N HCI as preservative. The presence of acid preservative is essential. Special requirements or comments: Appropriate clinical details and a list of all current medication are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. HMMA (=VMA) Specimen type: 24-hour urine collection with 20 mL of 6N HCI as preservative. The presence of acid preservative is essential. Special requirements or comments: Appropriate clinical details and a list of all current medication are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 156 04–Biochem pp69-228 13/7/10 11:58 AM Page 157 CLINICAL BIOCHEMISTRY TEST DIRECTORY Homocysteine Special requirements or comments: Specimen should be delivered to the laboratory immediately after collection (within 15 minutes). It is necessary for General Practitioners requiring this test to arrange for their patient to attend the Laboratory’s Phlebotomy Department at the Mid-Western Regional Hospital. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Human Chorionic Gonadotrophin (hCG) Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Nonpregnant females: Males: less than 5.3 U/L less than 5.3 U/L Gestational age (weeks) Weeks since last menstrual period Serum hCG U/L 1.3 – 2 3.3 – 4 16 – 156 2–3 4–5 101 – 4870 3–4 5–6 1110 – 31500 4–5 6–7 2560 – 82300 5–6 7–8 23100 – 151000 6–7 8–9 27300 – 233000 7 – 11 9 – 13 20900 – 291000 11 – 16 13 – 18 6140 – 103000 16 – 21 18 – 23 4720 – 80100 21 – 39 23 - 41 2700 - 78100 157 CLINICAL BIOCHEMISTRY Specimen type: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. At least 2 mL of blood in a lithium heparin tube. 04–Biochem pp69-228 13/7/10 11:58 AM Page 158 CLINICAL BIOCHEMISTRY TEST DIRECTORY Hydroxyindole acetic acid (HIAA) CLINICAL BIOCHEMISTRY Specimen type: 24-hour urine collection with 20 mL of 6N HCI as preservative. The presence of acid preservative is essential. Special requirements or comments: Appropriate clinical details and a list of all current medication are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Hydroxymethoxymandelic acid (HMMA or VMA) Specimen type: 24-hour urine collection with 20 mL of 6N HCI as preservative. The presence of acid preservative is essential. Special requirements or comments: Appropriate clinical details and a list of all current medication are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 17-Hydroxy progesterone Specimen type: Serum: The specimen (1.0 – 1.5 mL of blood) should be drawn between 8 and 9 am and before the day’s medication is taken. Note that serum assay is required for initial diagnosis of congenital adrenal hyperplasia. Newly-born should be at least 48 hours old before being tested. Saliva (for monitoring adequacy of therapy but not for initial diagnosis): For saliva assay, special collection devices, tubes and instructions are available from the Clinical Biochemistry Laboratory or the Paediatric Secretaries, Children’s Ark, Mid-Western Regional Hospital. Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. Blood spot samples on special filter paper cards (for monitoring adequacy of therapy but not for initial diagnosis): Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. Special requirements or comments: Appropriate clinical details and a list of all current medication are required. Newly-born should be at least 48 hours old before being tested. 158 04–Biochem pp69-228 13/7/10 11:58 AM Page 159 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Requests for this test are referred to an external specialist laboratory. Hydroxproline Specimen type: 24-hour urine collection with 20 mL of 6N HCI as preservative. The presence of acid preservative is essential. Special requirements or comments: The patient must avoid food containing gelatin, meat and fish for 24 hours prior to and during the test. These foods include gelatin-based deserts, ice creams and sweets. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. IgE (total) Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Availability of assay: allow three working days for receipt of report. Reference range: Adults: < 87 IU/mL Children: 0-1 years 1-2 years 2-3 years 3-9 years < 29 IU/mL < 49 IU/mL < 45 IU/mL < 52 IU/mL IgE (allergen specific) Specimen type: Serum Special requirements or comments: Requests for allergen-specific IgE must be accompanied by completed allergy questionnaire. Appropriate clinical details are required. 159 CLINICAL BIOCHEMISTRY Reference range: The referral laboratory report provides appropriate reference values. 04–Biochem pp69-228 13/7/10 11:58 AM Page 160 CLINICAL BIOCHEMISTRY TEST DIRECTORY CLINICAL BIOCHEMISTRY Note: These tests should not be considered diagnostic for a given allergen - they are merely assays for specific IgE. The medical history and clinical judgment are essential for assessing the significance and relevance of positive and negative test results. Turnaround time: Requests for this test are referred to an external specialist laboratory. Allow two/three weeks for receipt of report. Reference range: The laboratory report provides appropriate reference values. IGF-1 (insulin-like growth factor-1, somatomedin C) Specimen type: Serum Special requirements or comments: The specimen should be brought to the laboratory without delay. Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. IGF Binding Protein-3 Specimen type: Serum Special requirements or comments: The specimen should be brought to the laboratory without delay. Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. IgG, IgA, IgM Specimen type: Serum Special requirements or comments: Appropriate clinical details required. Turnaround time: Availability of assay: Monday – Friday during core working hours. 160 04–Biochem pp69-228 13/7/10 11:58 AM Page 161 CLINICAL BIOCHEMISTRY TEST DIRECTORY CLINICAL BIOCHEMISTRY Reference range: Adults: IgG: 5.3 – 16.5 g/L IgA: 0.8 – 4.0 g/L IgM: 0.5 – 2.0 g/L Age-related ranges: Age range (males and females) IgG (g/L) IgA (g/L) IgM (g/L) Birth – 2 weeks 5.0 – 17.0 0.01 – 0.08 0.05 – 0.20 2 – 6 weeks 3.9 – 13.0 0.02 – 0.15 0.08 – 4.00 6 – 8 weeks 2.1 – 7.7 0.05 – 0.40 0.15 – 0.70 2 – 6 months 2.4 – 8.8 0.10 – 0.60 0.20 – 1.00 6 – 9 months 3.0 – 9.0 0.15 – 0.70 0.40 – 1.60 9 – 12 months 3.0 – 10.0 0.20 – 0.70 0.60 – 2.10 1 – 2 years 3.1 – 13.8 0.30 – 1.20 0.50 – 2.20 2 – 3 years 3.7 – 15.8 0.30 – 1.30 0.50 – 2.20 3 – 6 years 4.9 – 16.1 0.40 – 2.00 0.50 – 2.00 6 – 9 years 4.9 – 16.1 0.50 – 2.40 0.50 – 1.80 9 – 12 years 4.9 – 16.1 0.70 – 2.50 0.50 – 1.80 12 – 15 years 4.9 – 16.1 0.80 – 2.80 0.50 – 1.90 15 – 45 years 5.4 – 16.1 0.90 – 3.40 0.50 – 2.00 Over 45 years 5.3 – 16.5 0.80 – 4.00 0.50 – 2.00 IgG Subclasses Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Immunofixation (serum protein) Specimen type: Serum 161 04–Biochem pp69-228 13/7/10 11:58 AM Page 162 CLINICAL BIOCHEMISTRY TEST DIRECTORY Special requirements or comments: Appropriate clinical details required. CLINICAL BIOCHEMISTRY Turnaround time: Availability of assay: allow three working days for receipt of report. Reference range: The laboratory report provides appropriate information. Immunofixation (urine protein) Specimen type: Urine, No preservative required: keep refrigerated. Special requirements or comments: Appropriate clinical details required. Turnaround time: Availability of assay: allow three working days for receipt of report. Reference range: The laboratory report provides appropriate information. Immunoreactive trypsin Specimen type: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. Serum specimen. Special requirements or comments: Specimen must be delivered to the Clinical Biochemistry within one hour of collection. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Industrial toxicology The Clinical Biochemistry Laboratory does not provide an assay service for environmental, industrial or occupational toxic agents or chemicals. The most appropriate agency to contact regarding these matters is the Environmental Protection Agency.; contact details: EPA Headquarters, PO Box 3000, Johnstown Castle Estate, Co. Wexford, Tel: 0539160600; Fax:053-9160699; Email: [email protected]; Lo Call: 1890 335599. Web site: www.epa.ie 162 04–Biochem pp69-228 13/7/10 11:58 AM Page 163 CLINICAL BIOCHEMISTRY TEST DIRECTORY Insulin CLINICAL BIOCHEMISTRY Specimen type: Serum. Specimen for glucose assay must be drawn at same time. Special requirements or comments: Record specimen collection time. The specimen should be delivered to the Clinical Biochemistry Laboratory within two hours of collection. Haemolysed specimens are unsuitable for insulin assay. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Insulin antibodies Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Insulin C-peptide Specimen type: Serum. Specimen for glucose assay must be drawn at same time. Special requirements or comments: Record specimen collection time. Specimen should be delivered to the laboratory within four hours of venepuncture. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Insulin-like growth factor-1 (IGF-1 or somatomedin C) Specimen type: Serum. 163 04–Biochem pp69-228 13/7/10 11:58 AM Page 164 CLINICAL BIOCHEMISTRY TEST DIRECTORY CLINICAL BIOCHEMISTRY Special requirements or comments: The specimen should be brought to the laboratory without delay. Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Insulin-like growth factor-1 binding protein-3 (IGF-1 BP3) Specimen type: Serum. Special requirements or comments: The specimen should be brought to the laboratory without delay. Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Iron Specimen type: Serum Special requirements or comments: A fasting specimen is required. Iron specimens must be sent to the Clinical Biochemistry Laboratory. Blood should be drawn before other specimens that require anticoagulated tubes. Serum iron displays a marked circadian rhythm. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Adults Males: 8.1 – 32.6 umol/L Females: 5.0 – 30.4 umol/L Iron studies profile Specimen type: Serum. Patient must be fasting. 164 04–Biochem pp69-228 13/7/10 11:58 AM Page 165 CLINICAL BIOCHEMISTRY TEST DIRECTORY CLINICAL BIOCHEMISTRY Special requirements or comments: Includes iron, transferrin, TIBC and transferrin saturation. Blood should be drawn before other specimens that require anticoagulated tubes. Serum iron displays a marked circadian rhythm. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: See ranges for individual analytes: Iron Males: Females: 8.1 – 32.6 umol/L 5.0 – 30.4 umol/L Transferrin Males: Females: 1.8 – 3.3 g/L 1.9 – 3.8 g/L TIBC Adults: 42 – 80 umol/L Transferrin saturation Adults: 15 – 45% Islet cell antibodies Specimen type: Serum Please refer to Serology/Immunology section of this manual. Kappa and Lambda Free Light Chains in serum This assay is available to consultant haematologists and their teams. The assay should be regarded as experimental. Important diagnostic and patient management decisions should not be made on the basis of serum free light chain assay results only. Specimen type: Serum only. Assay is not available for urine. Special requirements or comments: Appropriate clinical details are required including reason for request. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 165 04–Biochem pp69-228 13/7/10 11:58 AM Page 166 CLINICAL BIOCHEMISTRY TEST DIRECTORY Keppra® (Levetiracetam) CLINICAL BIOCHEMISTRY Specimen type: Serum. Special requirements or comments: Serum levetiracetam concentrations increase linearly with dose and it is not bound to plasma proteins. The drug’s elimination is primarily renal, but some non-hepatic enzyme dependent metabolism occurs that produces pharmacologically inactive metabolites. The relationship between levetiracetam serum concentrations and clinical effect has not yet been ascertained, however, the measurement of serum or plasma levetiracetam concentrations seems to be an aid to individualisation of treatment with this anticonvulsant drug. Large inter-individual differences exist between the dose/plasma concentration response of levetiracetam and there is a concentration range within which the drug is generally effective and unlikely to cause toxicity. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Ketones Specimen type: Urine. Special requirements or comments: Test immediately after collection. This test is performed as a ward/surgery side-room test. Use ward-based urine analysers. Lactate Specimen type: Plasma (fluoride EDTA anticoagulant). i.e. use the same tube as for glucose specimens. Special requirements or comments: Specimen should be sent to the laboratory immediately after being drawn. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: 0.5 – 2.2 mmol/L Lactate dehydrogenase (LD or LDH) Specimen type: Serum; Pleural fluid, ascitic fluid Special requirements or comments: Note: haemolysis invalidates the assay. 166 04–Biochem pp69-228 13/7/10 11:58 AM Page 167 CLINICAL BIOCHEMISTRY TEST DIRECTORY daily, throughout 24 hours. Monday – Friday during core working hours. Reference range: Serum: 98 – 192 U/L Lambda and Kappa Free Light Chains in serum This assay is available to consultant haematologists and their teams. The assay should be regarded as experimental. Important diagnostic and patient management decisions should not be made on the basis of serum free light chain assay results only. Specimen type: Serum only. Assay is not available for urine. Special requirements or comments: Appropriate clinical details are required including reason for request. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Lamictal® (Lamotrigine) Specimen type: Serum Special requirements or comments: Specimen drawn before the next oral dose with the patient at steady state. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Lamotrigine (Lamictal®) Specimen type: Serum Special requirements or comments: Specimen drawn before the next oral dose with the patient at steady state. Turnaround time: Requests for this test are referred to an external specialist laboratory. 167 CLINICAL BIOCHEMISTRY Turnaround time: Availability of assay: Serum: Pleural fluid, ascitic fluid: 04–Biochem pp69-228 13/7/10 11:58 AM Page 168 CLINICAL BIOCHEMISTRY TEST DIRECTORY Reference range: The referral laboratory report provides appropriate reference values. CLINICAL BIOCHEMISTRY L.A.T.S. replaced by TBII (TSH-binding inhibiting immunoglobulin) Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Laxatives screen Specimen type: 20 mL of urine, ideally from three consecutive days. Stool specimens may also be used. Special requirements or comments: Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. LD or LDH (Lactate dehydrogenase) Specimen type: Serum; Pleural fluid, ascitic fluid Special requirements or comments: Note: haemolysis invalidates the assay. Turnaround time: Availability of assay: Serum: Pleural fluid, ascitic fluid: Reference range: Serum: 98 – 192 U/L LDL-Cholesterol Specimen type: Serum 168 daily, throughout 24 hours. Monday – Friday during core working hours. 04–Biochem pp69-228 13/7/10 11:58 AM Page 169 CLINICAL BIOCHEMISTRY TEST DIRECTORY Special requirements or comments: Fasting specimen Reference range: General population reference values: 2.5 – 3.5 mmol/L In general, total serum cholesterol should be less than 5.0 mmol/L and LDL-cholesterol should be less than 3.0 mmol/L. For patients with clinically established cardiovascular disease and patients with diabetes the treatment goals should be lower: total cholesterol < 4.5 mmol/L and LDL-cholesterol < 2.5 mmol/L. Treatment goals are not defined for HDL-cholesterol and triglycerides, but HDLcholesterol < 1.0 mmol/L in men and < 1.2 mmol/L in women, and fasting triglyceride > 1.7 mmol/L are markers of increased cardiovascular risk. In asymptomatic individuals the decision to start treatment depends not only on the serum lipid levels but also on an assessment of total cardiovascular risk. Lead Specimen type: Whole blood in trace metal-free tube. Trace metal-free needle must be used in conjunction with trace metal-free tube. Special requirements or comments: This specimen should be collected first if other tests are requested to avoid contamination. Please contact Clinical Biochemistry Laboratory for trace metal-free specimen collection tube and needle. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Levetiracetam (Keppra®) Specimen type: Serum. Special requirements or comments: Serum levetiracetam concentrations increase linearly with dose and it is not bound to plasma proteins. The drug’s elimination is primarily renal, but some non-hepatic enzyme dependent metabolism occurs that produces pharmacologically inactive metabolites. The relationship between levetiracetam serum concentrations and clinical effect has not yet been ascertained, however, the measurement of serum levetiracetam concentrations seems to be an aid to individualisation of treatment with this anticonvulsant drug. Large inter-individual differences exist between the dose/plasma concentration response of levetiracetam and there is a concentration range within which the drug is generally effective and unlikely to cause toxicity. 169 CLINICAL BIOCHEMISTRY Turnaround time: Availability of assay: Monday – Friday during core working hours. 04–Biochem pp69-228 13/7/10 11:58 AM Page 170 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Requests for this test are referred to an external specialist laboratory. CLINICAL BIOCHEMISTRY Reference range: The referral laboratory report provides appropriate reference values. Levodopa Specimen type: Serum, specimen must be delivered to the laboratory immediately. Special requirements or comments: Appropriate clinical details are required including a summary of prescribed medication. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. LFT profile Specimen type: Serum Special requirements or comments: Includes bilirubin, alkaline phosphatase, gamma GT, and ALT. Please ensure that specimens for the assay of transaminase activity (ALT) are delivered to the Laboratory within 24 hours of sample collection. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: See ranges for individual analytes Total bilirubin reference range: Adults: 7 – 34 µmol/L Paediatric values: Up to 24 hours: 24 – 48 hours: 3 – 5 days: 1 month to adult: <100 µmol/L <140 µmol/L <200 µmol/L <34 µmol/L Gamma GT (GGT) Reference range: 7 – 50 U/L ALT reference range: 14 – 63 U/L 170 04–Biochem pp69-228 13/7/10 11:58 AM Page 171 CLINICAL BIOCHEMISTRY TEST DIRECTORY Alkaline phosphatase reference range: Adults: 38 – 126 U/L CLINICAL BIOCHEMISTRY Age range Serum alkaline phosphatase (U/L) Males Females Birth - 4 weeks 75 – 316 48 – 406 1 month – 1 year 82 – 383 124 – 341 1 – 3 years 104 – 345 108 – 317 3 – 6 years 93 – 309 96 – 297 6 – 9 years 86 – 315 69 – 325 9 – 12 years 42 – 362 51 – 332 12 – 15 years 74 – 390 50 – 162 15 – 18 years 52 – 171 47 – 119 18 – 100 years 30 – 120 30 – 120 LH Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Serum LH (U/L) Females Follicular phase 0.5 - 18 Mid-cycle 15 - 80 Mid-luteal phase 0.5 - 18 Post-menopausal Males Adult male 16 - 64 0.8 – 7.6 Lipase Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. 171 04–Biochem pp69-228 13/7/10 11:58 AM Page 172 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Requests for this test are referred to an external specialist laboratory. CLINICAL BIOCHEMISTRY Reference range: The referral laboratory report provides appropriate reference values. Lipid profile (fasting specimens only) Specimen type: Serum: see special requirements Special requirements or comments: The patient must be fasting for 10 hours and have been on a stable diet for the previous two to three weeks Alcohol should not be consumed in the three days before the test. The profile includes; total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglyceride. Turnaround time: Availability of assay: Monday – Friday during core working hours. General population reference values Total Cholesterol Reference Range: 4.0 – 6.7 mmol/L HDL-Cholesterol Reference Range: 1.0 – 2.2 mmol/L LDL-Cholesterol Reference Range: 2.5 – 3.5 mmol/L Triglyceride Reference Range: 0.5 – 2.1 mmol/L Note: reference ranges for lipids: In general, total serum cholesterol should be less than 5.0 mmol/L and LDL-cholesterol should be less than 3.0 mmol/L. For patients with clinically established cardiovascular disease and patients with diabetes the treatment goals should be lower: total cholesterol < 4.5 mmol/L and LDL-cholesterol < 2.5 mmol/L. Treatment goals are not defined for HDL-cholesterol and triglycerides, but HDLcholesterol < 1.0 mmol/L in men and < 1.2 mmol/L in women, and fasting triglyceride > 1.7 mmol/L are markers of increased cardiovascular risk. In asymptomatic individuals the decision to start treatment depends not only on the serum lipid levels but also on an assessment of total cardiovascular risk. Lipoprotein(a) Specimen type: Serum Special requirements or comments: The patient should be fasting for 10 hours. Turnaround time: Requests for this test are referred to an external specialist laboratory. 172 04–Biochem pp69-228 13/7/10 11:58 AM Page 173 CLINICAL BIOCHEMISTRY TEST DIRECTORY Reference range: The referral laboratory report provides appropriate reference values. Specimen type: Serum Special requirements or comments: Draw specimen at a consistent interval from the last dose, 6-12 hours is recommended. Turnaround time: Availability of assay: Monday – Friday during core working hours. Therapeutic range: The generally accepted therapeutic range is 0.4 – 1.5 mmol/L. The range for maintenance therapy is 0.4 – 0.8 mmol/L, but it is lower in the elderly (0.3 – 0.4 mmol/L) and higher in younger patients (0.9 – 1.1 mmol/L). The range for acute management of manic episodes is 0.8 – 1.3 mmol/L. Luteinising hormone (LH) Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Serum LH (U/L) Females Follicular phase 0.5 - 18 Mid-cycle 15 - 80 Mid-luteal phase 0.5 - 18 Post-menopausal Males Adult male 16 - 64 0.8 – 7.6 Lysosomal enzyme analysis (White cell enzyme analysis) Specimen type: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. 173 CLINICAL BIOCHEMISTRY Lithium 04–Biochem pp69-228 13/7/10 11:58 AM Page 174 CLINICAL BIOCHEMISTRY TEST DIRECTORY CLINICAL BIOCHEMISTRY Special requirements or comments: 5 mL blood in potassium EDTA tube; do not refrigerate or centrifuge, deliver to laboratory without delay. Monday – Wednesday (only) dispatch to Manchester. Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Macroprolactin Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Macroprolactin is a molecular complex of prolactin and an IgG antibody. It is cleared from the circulation more slowly than monomeric prolactin. Because of its molecular mass, is confined to the vascular system and exhibits little biological activity in vivo. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Magnesium Specimen type: Serum. For urine assay a 24-hour urine collection is required with 20mL of 6N HCI as preservative. Special requirements or comments: Blood specimens for magnesium assay must be collected free of haemolysis. Turnaround time: Availability of assay: Serum: daily, throughout 24 hours. Urine: Monday – Friday during core working hours. Reference range: Serum: 0.74 – 1.03 mmol/L Urine: 3.0 – 4.25 mmol/24 hours 174 04–Biochem pp69-228 13/7/10 11:58 AM Page 175 CLINICAL BIOCHEMISTRY TEST DIRECTORY Manganese Special requirements or comments: This specimen should be collected first if other tests are requested to avoid contamination. Please contact Clinical Biochemistry Laboratory for trace metal-free specimen collection tube and needle. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Mercury Specimen type: Whole blood in trace metal-free tube. Trace metal-free needle must be used in conjunction with trace metal-free tube. This specimen should be collected first if other tests are requested to avoid contamination. Urine: 24-hour collection in metal-free container, no preservatives required. Special requirements or comments: Please contact Clinical Biochemistry Laboratory for trace metal-free specimen collection tube and needle. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Metanephrines Specimen type: 24-hour urine collection with 20 mL of 6N HCI as preservative. The presence of acid preservative is essential. Special requirements or comments: Appropriate clinical details and a list of all current medication are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 175 CLINICAL BIOCHEMISTRY Specimen type: Whole blood in trace metal-free tube. Trace metal-free needle must be used in conjunction with trace metal-free tube. 04–Biochem pp69-228 13/7/10 11:58 AM Page 176 CLINICAL BIOCHEMISTRY TEST DIRECTORY Methadone CLINICAL BIOCHEMISTRY Specimen type: Random urine specimen collected without any preservative. Special requirements or comments: The assay is intended to assist in the clinical management of the patient and is not provided for medico-legal purposes. The requesting doctor may need to consider whether a patient might avail of opportunities to alter or interfere with the integrity of the specimen. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: The cut-off threshold for a positive result for methadone is 300 ng/mL. A positive result for methadone e indicates only the presence of methadone and does not necessarily correlate with the extent of physiological and psychological effects. A negative result indicates that methadone is either not present or is present at levels below the cut-off threshold for this test. Methaemoglobin Specimen type: Arterial blood in air-free heparinised syringe. Blood gas analysis sampling kits are available in each ward. Once the sample has been drawn, the blood gas syringe must be labelled with the patient’s full name, chart number, ward, date and time of collection. Immediately after collection, expel any air from the sample and seal the syringe with the stopper provided in the sampling kit. Special requirements or comments: The specimen should be brought to the laboratory immediately. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: 0.4 – 1.5% Methanol Specimen type: Whole blood or serum or plasma. Special requirements or comments: Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Toxicology Laboratory, Beaumont Hospital, Beaumont, Dublin 9. Tel: 01 809 2673; 01 809 2671; 01 809 2675 176 04–Biochem pp69-228 13/7/10 11:58 AM Page 177 CLINICAL BIOCHEMISTRY TEST DIRECTORY Beaumont Laboratory operates a strict policy of not transmitting reports by fax. Reference range: The referral laboratory report provides appropriate reference values. Methotrexate Specimen type: Serum Special requirements or comments: Sampling time will vary according to the dosing protocol. Details of specimen collection time, dosage regimen and mode of administration must be included with request. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Microalbumin Specimen type: 24-hour urine collection without preservative. Early morning urine specimen. Special requirements or comments: 24-hour urine collection is recommended. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: 0 – 20 mg/L Less than 30 mg/24 hours 0 – 20 µg/minute Microalbumin/creatinine ratio Specimen type: Early morning urine specimen 177 CLINICAL BIOCHEMISTRY The current out-of-hours toxicology call service at Beaumont Hospital is available to all hospitals in the Republic of Ireland. “The service is restricted to checking only for drugs, which if taken in overdose require a specific antidote or treatment. It is not an aid to diagnosis nor to allow a patient to be discharged.” If the assay is required outside of normal working hours the Toxicologist on-call at Beaumont Hospital must be contacted at 087 2590749. Consultant: Dr. W. Tormey 04–Biochem pp69-228 13/7/10 11:58 AM Page 178 CLINICAL BIOCHEMISTRY TEST DIRECTORY Special requirements or comments: CLINICAL BIOCHEMISTRY Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Albumin excretion Normal Microalbuminuria Clinical albuminuria 24-hour collection mg/24 hours Spot collection (SI Units) mg/mmol creatinine < 30 < 3.4 30 - 300 3.4 – 34.0 > 300 > 34.0 Note: Because of variability in urinary albumin excretion, two or three specimens collected within a three-month period should be abnormal before considering a patient to have crossed one of these diagnostic thresholds. Exercise within 24 hours, infection, fever, congestive heart failure, marked hyperglycaemia and marked hypertension may elevate urinary albumin over baseline values. Mucopolysaccharides Specimen type: 1-5 mL of urine. Specimen should be sent to the laboratory immediately. Special requirements or comments: The initial screen (at the Children’s Hospital, Temple Street, Dublin) is for total glycosaminoglycans. If positive, or if a clinical suspicion exists, electrophoresis is carried out. Enzyme analysis is performed at The Willink Biochemical Genetics Unit, Royal Manchester Children’s Hospital (Tel 00 44 161 7272137 or 7272138) when an abnormal mucopolysaccharide pattern has been identified in urine. For these investigations, 5 mL of blood in a potassium EDTA tube is required. Do not refrigerate and deliver to the Clinical Biochemistry Laboratory immediately. Note that dispatch to Manchester needs to be on Monday – Wednesday (only). Full clinical details must accompany these requests. Contact the Clinical Biochemistry Laboratory before initiating such a request so that all collection requirements can be met. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 178 04–Biochem pp69-228 13/7/10 11:58 AM Page 179 CLINICAL BIOCHEMISTRY TEST DIRECTORY Mycophenolate (CellCept®) Special requirements or comments: Special request form for immunosuppressant drug monitoring should be used. The date and time of specimen collection and the date, time and dosage of the last mycophenolate dose must be recorded on the request form. Appropriate clinical details are also required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Myoglobin Specimen type: Serum. Note assay is not validated for urine myoglobin. Special requirements or comments: Appropriate clinical details required. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Males: 28 – 72 ng/mL Females: 25 – 58 ng/mL Mysoline® (Primidone) Specimen type: Serum Special requirements or comments: Specimen should be drawn before the next oral dose with the patient at a steady state. When making comparative measurements, it is important that the sampling time be consistent. Phenobarbital should also be measured since it is an active metabolite of primIdone. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 179 CLINICAL BIOCHEMISTRY Specimen type: EDTA plasma 2 mL of whole blood in potassium EDTA specimen tube. Send specimen to laboratory immediately so that plasma can be separated within two hours. 04–Biochem pp69-228 13/7/10 11:58 AM Page 180 CLINICAL BIOCHEMISTRY TEST DIRECTORY Neurontin® (Gabapentin) CLINICAL BIOCHEMISTRY Specimen type: Serum Special requirements or comments: Specimen drawn before the next oral dose with the patient at steady state. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Nicotine metabolite (Cotinine) Specimen type: 10 mL of urine collected without a preservative. Special requirements or comments: Cotinine is the major nicotine metabolite found in urine. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. N-Telopeptide (NTx) Specimen type: Urine; specimen must be delivered to laboratory without delay. Special requirements or comments: It is recommended that a carefully monitored second void collection is made; patients should be asked to empty their bladders on waking and discard the urine. Then they should collect the next specimen (the second morning void) in the urine container (plain container, no additives). To minimise the influence of day-to-day variability, it is important to maintain the same collection protocol. Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 180 04–Biochem pp69-228 13/7/10 11:58 AM Page 181 CLINICAL BIOCHEMISTRY TEST DIRECTORY Occult blood CLINICAL BIOCHEMISTRY Specimen type: Stool specimen Special requirements or comments: The following food should not be consumed in the 3 days before the test: red meat, radish, and liver. Turnaround time: Availability of assay: allow three working days for receipt of report. Reference range: Negative result. Oestradiol / estradiol Specimen type: Serum Special requirements or comments: Appropriate clinical details required. This assay has not been validated for use on neonatal samples. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Serum Oestradiol (pmol/L) Females Follicular phase Mid-cycle Mid-luteal phase Males 110 – 551 550 – 1835 110 – 734 Post-menopausal < 92 Adult males <206 Note: lower limit of detection of assay is approximately 73 pmol/L. Oligoclonal IgG banding (CSF) Specimen type: CSF and serum obtained at the same time. Special requirements or comments: Appropriate clinical details required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 181 04–Biochem pp69-228 13/7/10 11:58 AM Page 182 CLINICAL BIOCHEMISTRY TEST DIRECTORY OM-MA (alternative: CA125) CLINICAL BIOCHEMISTRY Specimen type: Serum Special requirements or comments: IMPORTANT WARNING: This assay is not validated for use as a screening test for cancer. The regulatory body approval for this assay states that it is intended strictly for in vitro diagnostic use as an aid in monitoring the response to therapy for patients with epithelial ovarian cancer, and in detecting residual ovarian cancer in patients who have undergone first-line therapy and would be considered for diagnostic second-look procedures. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: 0 – 48 U/mL Opiate Specimen type: Random urine specimen collected without any preservative. Special requirements or comments: The assay is intended to assist in the clinical management of the patient and is not provided for medico-legal purposes. The requesting doctor may need to consider whether a patient might avail of opportunities to alter or interfere with the integrity of the specimen. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: The cut-off threshold for a positive result for opiate is 300 ng/mL. A positive result for opiate indicates only the presence of opiate and does not necessarily correlate with the extent of physiological and psychological effects. A negative result indicates that opiates are either not present or are present at levels below the cut-off threshold for this test. Organic Acids Specimen type: At least 2 mL and ideally 5 mL of urine collected without preservative. The specimen must be sent to the laboratory immediately so that it can be frozen at minus 25 degrees Celsius as soon as possible. Special requirements or comments: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. 182 04–Biochem pp69-228 13/7/10 11:58 AM Page 183 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Requests for this test are referred to an external specialist laboratory. CLINICAL BIOCHEMISTRY Reference range: The referral laboratory report provides appropriate reference values. Organophosphate and carbamate poisoning Specimen type: 2 mL of whole blood in fluoride-EDTA tube (glucose specimen tube) Assay: cholinesterase Special requirements or comments: Specimen should be sent to the laboratory without delay. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Orosomucoid (alpha-1-acid glycoprotein) Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate referance values. Osmolality Specimen type: Serum; urine (in a plain container without preservative) Special requirements or comments: Specimen should be sent to the laboratory without delay. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: Serum: 282 – 300 mOsm/kg. Urine osmolality results should be interpreted in conjunction with the patient’s renal function, serum osmolality and clinical condition. 183 04–Biochem pp69-228 13/7/10 11:58 AM Page 184 CLINICAL BIOCHEMISTRY TEST DIRECTORY Osteocalcin CLINICAL BIOCHEMISTRY Specimen type: Serum Special requirements or comments: To minimise the influence of day-to-day variability, it is important to maintain the same collection protocol. Serial samples should be collected at the same time of day on each occasion, e.g. mid-morning. Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Oxalate Specimen type: Urine: 24-hour urine collection is required with 20mL of 6N HCI as preservative. Special requirements or comments: Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Oxcarbazepine (Trileptal®) Specimen type: Serum/plasma Special requirements or comments: Specimen drawn before the next oral dose with the patient at steady state. Store specimen at approximately 4 degrees Celsius prior to preparation for dispatch to referral laboratory. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 184 04–Biochem pp69-228 13/7/10 11:58 AM Page 185 CLINICAL BIOCHEMISTRY TEST DIRECTORY Pancreatic Polypeptide Special requirements or comments: Patient should be fasting overnight. The specimen should be surrounded with ice and brought to the laboratory immediately. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Pancreolaurly test Please consider the more convenient alternative investigation: stool Elastase-1 (Pancreatic) Specimen type: A pancreolaurlyl test pack is available from the Pharmacy or from Allphar Services Ltd., Belgard Road, Tallaght, Dublin 24. Tel (01) 4041600. A detailed test protocol for the requesting doctor accompanies the test pack. A comprehensive patient information sheet is also included in the test pack. Special requirements or comments: At the end of the test, the Clinical Biochemistry Laboratory should receive two ten-hour urine collections – one for Day 1 (the test day) and one for Day 2 (the control day). Turnaround time: Availability of assay: allow three working days for receipt of report. Reference range: The laboratory report provides appropriate reference values. Paracetamol (Acetaminophen) Specimen type Serum: see special requirements. Special requirements or comments: Specimen should be drawn four hours post-overdose and preferably not later than 16 hours. Serum values taken less than four hours post-ingestion are difficult to interpret due to the possibility of continuing absorption and distribution of the drug and may not represent the peak level. Note that results are reported in ug/mL. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: 0 – 5 µg/mL (0 – 5 mg/L) 185 CLINICAL BIOCHEMISTRY Specimen type: Collect 5 mL of blood into an ice-cold lithium heparin tube containing 0.1 mL of TRASYLOL (aprotinin: 20,000 KlU/mL). Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. 04–Biochem pp69-228 13/7/10 11:58 AM Page 186 CLINICAL BIOCHEMISTRY TEST DIRECTORY CLINICAL BIOCHEMISTRY Plasma paracetamol (mg/L) TREATMENT LINES Hours after ingestion Paraprotein studies Specimen type: Serum and urine (no preservative required; keep refrigerated). Special requirements or comments: Appropriate clinical details. Turnaround time: Availability of assay: allow three working days for receipt of report. Reference range: The laboratory report provides appropriate information. 186 Plasma paracetamol (mmol/L) 04–Biochem pp69-228 13/7/10 11:58 AM Page 187 CLINICAL BIOCHEMISTRY TEST DIRECTORY Paraquat Screen (dithionite test) Special requirements or comments: This is a qualitative test and can detect the presence of paraquat in urine down to a level of approximately 2 mg/L Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: Negative. Paraquat (quantitative) Specimen type: Serum, urine; see special requirements. Special requirements or comments: This assay is available at the Toxicology Laboratory, Beaumont Hospital, Dublin. (Telephone 01 809 2673 or 01 809 2675). The current out-of-hours call service at Beaumont Hospital is available to all hospitals in the Republic of Ireland. “The service is restricted to checking only for drugs, which if taken in overdose require a specific antidote or treatment. It is not an aid to diagnosis nor to allow a patient to be discharged.” If the assay is required outside of normal working hours the Toxicologist on-call at Beaumont Hospital must be contacted at 087 2590749. Reference range: The laboratory report provides appropriate information. Parathyroid hormone (PTH) intact Specimen type: Serum Special requirements or comments: Specimen should be sent to the laboratory immediately Serum must be stored at minus 25 degrees Celsius while awaiting analysis. Turnaround time: Availability of assay: allow three working days for receipt of report. Reference range: 15 – 65 ng/L. 15 – 65 pg/mL. 187 CLINICAL BIOCHEMISTRY Specimen type: Urine. 04–Biochem pp69-228 13/7/10 11:58 AM Page 188 CLINICAL BIOCHEMISTRY TEST DIRECTORY Parathyroid hormone Related Protein (PTHrP) CLINICAL BIOCHEMISTRY This assay is only performed on requests authorised by a consultant. Specimen type: Contact the Biochemistry Laboratory before initiating the request so that all the collection requirements can be met. Special requirements or comments: The specimen must be collected into a special PTHrP Cocktail Tube (Nichols Ref No 38-2182) obtainable from the referral laboratory. On receipt the tube must be stored at minus 20 degrees Celsius or colder until required for use. Place the cocktail tube on ice prior to drawing the sample. Do not use the cocktail tube as a collection tube. Collect the whole blood into a syringe and transfer the sample to the cocktail tube. Mix thoroughly by inversion. Immediately send the specimen to the laboratory so that the plasma can be separated from the cells using a refrigerated centrifuge. Freeze the separated plasma immediately at minus 20 degrees Celsius or colder. It is essential that the sample reaches the referral laboratory in a frozen state. The specimen must be stored at minus 20 degrees Celsius or cooler while awaiting analysis. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Paroxetine (Seroxat®) Specimen type: Serum Special requirements or comments: Details of dosage regimen required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. PCP (Phencyclidine) Specimen type: Random urine specimen collected without any preservative. Special requirements or comments: The assay is intended to assist in the clinical management of the patient and is not provided for medico-legal purposes. The requesting doctor may need to consider whether a patient might avail of opportunities to alter or interfere with the integrity of the specimen. 188 04–Biochem pp69-228 13/7/10 11:58 AM Page 189 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Requests for this test are referred to an external specialist laboratory. pCO2 Specimen type: Arterial blood in air-free heparinised syringe. Blood gas analysis sampling kits are available in each ward. Immediately after collection, expel any air from the sample and seal the syringe with the stopper provided in the sampling kit. Once the sample has been drawn, the blood gas syringe must be labelled with the patient’s full name, chart number, ward, date and time of collection. Labels suitable for affixing to blood gas syringes are made available to each ward. These labels display the URGENT alert message in a prominent manner. Special requirements or comments: The specimen should be brought to the Laboratory immediately. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: Adult pH pCO2 pO2 Base Excess Actual Bicarbonate Standard Bicarbonate Oxygen Saturation 7.35 - 7.45 4.26 - 5.99 kPa 11.04 - 14.36 kPa -2.0 - +2.0 22.0 - 26.0 mmol/L 22.0 - 26.0 mmol/L 96 - 97 % pH (BGA) Specimen type: Arterial blood in air-free heparinised syringe. Blood gas analysis sampling kits are available in each ward. Immediately after collection, expel any air from the sample and seal the syringe with the stopper provided in the sampling kit. Once the sample has been drawn, the blood gas syringe must be labelled with the patient’s full name, chart number, ward, date and time of collection. Labels suitable for affixing to blood gas syringes are made available to each ward. These labels display the URGENT alert message in a prominent manner. Special requirements or comments: The specimen should be brought to the Laboratory immediately. 189 CLINICAL BIOCHEMISTRY Reference range: The cut-off threshold for a positive result for phencyclidine is 25 ng/mL. A positive result for phencyclidine indicates only the presence of phencyclidine and does not necessarily correlate with the extent of physiological and psychological effects. A negative result indicates that phencyclidine is either not present or is present at levels below the cut-off threshold for this test. 04–Biochem pp69-228 13/7/10 11:58 AM Page 190 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Availability of assay: daily, throughout 24 hours. CLINICAL BIOCHEMISTRY Reference range: Adult pH pCO2 pO2 Base Excess Actual Bicarbonate Standard Bicarbonate Oxygen Saturation 7.35 - 7.45 4.26 - 5.99 kPa 11.04 - 14.36 kPa -2.0 - +2.0 22.0 - 26.0 mmol/L 22.0 - 26.0 mmol/L 96 - 97 % pH (miscellaneous fluids) Specimen type and special requirements or comments: Pleural and peritoneal fluids: Collect the sample of fluid in a syringe pre-rinsed with 0.2 mL of heparin or in a syringe from the BGA sampling kit available in wards. Immediately after collection, expel any air from the sample and seal the syringe with the stopper provided in the BGA sampling kit. The Laboratory will not, for safety reasons, accept syringes with any form of needle or resheathed needle attached. Once the sample has been drawn, the syringe must be labelled with the patient’s full name, chart number, ward, date and time of collection. Labels suitable for affixing to blood gas syringes are made available to each ward. These labels display the URGENT alert message in a prominent manner. The specimen should be surrounded with ice-water and brought to the Laboratory without delay. Urine: Random urine specimen collected without preservative and transported to the laboratory on ice-water. Stool: Fresh stool specimen transport to the Laboratory on ice-water (methodology: aqueous stool suspension measured with pH indicator paper). Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: The laboratory report provides appropriate reference values. Phencyclidine (PCP) Specimen type: Random urine specimen collected without any preservative. Special requirements or comments: The assay is intended to assist in the clinical management of the patient and is not provided for medico-legal purposes. The requesting doctor may need to consider whether a patient might avail of opportunities to alter or interfere with the integrity of the specimen. Turnaround time: Requests for this test are referred to an external specialist laboratory. 190 04–Biochem pp69-228 13/7/10 11:58 AM Page 191 CLINICAL BIOCHEMISTRY TEST DIRECTORY Phenobarbital Specimen type: Serum Special requirements or comments: Specimen drawn before the next oral dose with the patient at steady state. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Therapeutic guide: 65 – 170 µmol/L Phenylalanine Specimen type: Serum; 24-hour urine collected without preservative. Special requirements or comments: Specimen should be sent to the laboratory immediately Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Phenytoin (Epanutin®) Specimen type: Serum Special requirements or comments: Specimen drawn before the next oral dose with the patient at steady state. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Therapeutic guide: 40 – 79 umol/L Note: Approximately 92% of serum/plasma phenytoin is bound to protein. The binding of phenytoin to serum proteins may decrease in conditions associated with hypoalbuminaemia. Some drugs, most notably, valproate may displace phenytoin from serum proteins and increase its free fraction. 191 CLINICAL BIOCHEMISTRY Reference range: The cut-off threshold for a positive result for phencyclidine is 25 ng/mL. A positive result for phencyclidine indicates only the presence of phencyclidine and does not necessarily correlate with the extent of physiological and psychological effects. A negative result indicates that phencyclidine is either not present or is present at levels below the cut-off threshold for this test. 04–Biochem pp69-228 13/7/10 11:58 AM Page 192 CLINICAL BIOCHEMISTRY TEST DIRECTORY Phosphate CLINICAL BIOCHEMISTRY Specimen type: Serum. Urine: a 24-hour urine collection is required with 20mL of 6N HCl as preservative. Special requirements or comments: Blood specimens for phosphate assay must be collected free of haemolysis. The serum must be separated within a period of two hours from venepuncture, since phosphate is released from red blood cells during the transport and storage of whole blood specimens thus causing a falsely raised serum phosphate concentration. Turnaround time: Availability of assay: Serum: daily, throughout 24 hours. Urine: Monday – Friday during core working hours. Reference range: Serum: 0.78 – 1.53 mmol/L Urine: 15 – 50 mmol/24 hours. Phytanic acid Specimen type: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. Special requirements or comments: 5 mL blood in potassium EDTA tube; do not refrigerate, deliver to laboratory without delay. Monday-Wednesday (only) dispatch to Manchester. Clinical details required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Placental alkaline phosphatase isoenzyme Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 192 04–Biochem pp69-228 13/7/10 11:58 AM Page 193 CLINICAL BIOCHEMISTRY TEST DIRECTORY pO2 Special requirements or comments: The specimen should be brought to the Laboratory immediately. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: Adult pH pCO2 pO2 Base Excess Actual Bicarbonate Standard Bicarbonate Oxygen Saturation 7.35 - 7.45 4.26 - 5.99 kPa 11.04 - 14.36 kPa -2.0 - +2.0 22.0 - 26.0 mmol/L 22.0 - 26.0 mmol/L 96 - 97 % Porphoblinogen Specimen type: Urine; keep cool and protect from light using e.g. aluminium kitchen foil. Special requirements or comments: Specimen should be sent to the laboratory without delay. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Pophyrins “The key to effective investigation of the porphyrias is the appropriate analysis of correctly chosen samples taken when the patient is symptomatic, taking into account the clinical presentation.” All Wales Clinical Biochemistry Audit Group: Standards for Investigation of Porphyria Specimen type: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. Appropriate clinical details are required. 193 CLINICAL BIOCHEMISTRY Specimen type: Arterial blood in air-free heparinised syringe. Blood gas analysis sampling kits are available in each ward. Immediately after collection, expel any air from the sample and seal the syringe with the stopper provided in the sampling kit. Once the sample has been drawn, the blood gas syringe must be labelled with the patient’s full name, chart number, ward, date and time of collection. Labels suitable for affixing to blood gas syringes are made available to each ward. These labels display the URGENT alert message in a prominent manner. 04–Biochem pp69-228 13/7/10 11:58 AM Page 194 CLINICAL BIOCHEMISTRY TEST DIRECTORY CLINICAL BIOCHEMISTRY Special requirements or comments: The following specimens are required. Urine: 20 mL of fresh early morning urine and a 24-hour collection, keep refrigerated and protect from light using e.g. aluminium kitchen foil. Stools: 5 – 10 grams specimen, refrigerate and protect from light using e.g. aluminium kitchen foil. Blood: Two 2.7 mL blood specimens in potassium EDTA tubes and 2.6 mL blood in one lithium heparin tube; protect from light using e.g. aluminium kitchen foil. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Potassium Specimen type: Serum, plasma. For urine a 24-hour collection is recommended. Special requirements or comments: Blood specimens for potassium assay must be collected free of haemolysis. The serum must be separated within a period of two hours from venepuncture, since potassium is released from red blood cells during the transport and storage of whole blood specimens thus causing a falsely raised serum potassium concentration. Turnaround time: Availability of assay: Serum, plasma: daily, throughout 24 hours. Urine: Monday – Friday during core working hours. Reference range: Serum: 3.6 – 5.1 mmol/L Urine: 30 – 100 mmol/24 hours Primidone (Mysoline®) Specimen type: Serum Special requirements or comments: Specimen should be drawn before the next oral dose with the patient at a steady state. When making comparative measurements, it is important that the sampling time be consistent. Phenobarbital should also be measured since it is an active metabolite of primIdone. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 194 04–Biochem pp69-228 13/7/10 11:58 AM Page 195 CLINICAL BIOCHEMISTRY TEST DIRECTORY Procollagen peptide Type 3 (P111NP) Special requirements or comments: Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Progesterone Specimen type: Serum Special requirements or comments: Appropriate clinical details required. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Adult females: Follicular phase: Mid-luteal: Post-menopausal: 0.6 – 4.7 nmol/L 18 – 89 nmol/L < 2 nmol/L Males: <1.6 nmol/L 17-Hydroxy progesterone Specimen type: Serum: The specimen (1.0 – 1.5 mL of blood) should be drawn between 8 and 9 am and before the day’s medication is taken. Note that serum assay is required for initial diagnosis of congenital adrenal hyperplasia. Newly-born should be at least 48 hours old before being tested. Saliva (for monitoring adequacy of therapy but not for initial diagnosis): For saliva assay, special collection devices, tubes and instructions are available from the Clinical Biochemistry Laboratory or the Paediatric Secretaries, Children’s Ark, Mid-Western Regional Hospital. Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. Blood spot samples on special filter paper cards (for monitoring adequacy of therapy but not for initial diagnosis): Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. 195 CLINICAL BIOCHEMISTRY Specimen type: Clotted blood sample. The specimen should be sent to the laboratory immediately. The sample should be centrifuged and the serum separated within 1-2 hours of collection (maximum no more than 4 hours). 04–Biochem pp69-228 13/7/10 11:58 AM Page 196 CLINICAL BIOCHEMISTRY TEST DIRECTORY Special requirements or comments: Appropriate clinical details and a list of all current medication are required. CLINICAL BIOCHEMISTRY Prograf® (FK 506, Tacrolimus) Specimen type: Whole blood in specimen tube with potassium EDTA as anticoagulant. Special request form for immunosuppressant drug monitoring should be used. Special requirements or comments: Trough levels should be monitored. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Prolactin Specimen type: Serum Special requirements or comments: Appropriate clinical details and a list of all current medication are required. Prolactin levels are increased by stress and by drugs that deplete dopamine or block its action. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Females: 40 – 530 mU/L Males: 53 – 360 mU/L Prostate Specific Antigen (PSA) Specimen type: Serum; specimen should reach laboratory within eight hours of venepuncture. Special requirements or comments: This assay has regulatory body approval for the quantitative measurement of PSA in human serum, as an aid in the detection of prostate cancer when used in conjunction with digital rectal examination in men aged 50 years or older. This assay is also likely to be of value as an adjunctive test to aid in the management of prostate cancer patients. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Males Siemens Medical Second Generation Total PSA Assay: 0 – 4.0 ng/mL Siemens Medical Third Generation Total PSA Assay: 0 – 3.2 ng/mL 196 04–Biochem pp69-228 13/7/10 11:58 AM Page 197 CLINICAL BIOCHEMISTRY TEST DIRECTORY Prostate Specific Antigen, Free (fPSA) This assay is only performed on requests authorised by a consultant. Specimen must be delivered to the laboratory within four hours of venepuncture. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Protein Specimen type: Serum, plasma; Urine: untimed urine collection, 24-hour urine collection (no preservative is required but urine should be kept cool); Protein may also be assayed in other fluids such as CSF, pleural fluid, ascitic fluid. Special requirements or comments: Prolonged venous compression during blood collection will increase serum protein. Turnaround time: Availability of assay: Serum: daily, throughout 24 hours. Urine: Monday – Friday during core working hours. Reference range: Serum: 61 – 79 g/L Urine: 0.03 – 0.15 g/24 hours Protein/creatinine ratio (urine) Specimen type: Urine: untimed urine collection, 24-hour urine collection. Special requirements or comments: No preservative is required but urine should be kept cool. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Urine protein/creatinine ratio: < 35 mg/mmol 197 CLINICAL BIOCHEMISTRY Specimen type: Serum; specimen must be delivered to the laboratory immediately. 04–Biochem pp69-228 13/7/10 11:58 AM Page 198 CLINICAL BIOCHEMISTRY TEST DIRECTORY Protein (CSF) CLINICAL BIOCHEMISTRY Specimen type: CSF. Special requirements or comments Appropriate clinical details required. Note that it is Laboratory Policy that all CSF specimens must be delivered to the Microbiology Department for initial examination and processing. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: 0.150 – 0.450 g/L Protein Electrophoresis (Serum) Specimen type: Serum Special requirements or comments: Appropriate clinical details required. Turnaround time: Availability of assay: allow three working days for receipt of report. Reference range: The laboratory report provides appropriate information. Protein Electrophoresis (Urine) Specimen type: Untimed urine collection or a 24-hour collection. No preservative is required. Keep specimen refrigerated. Special requirements or comments: Appropriate clinical details are required. Turnaround time: Availability of assay: allow three working days for receipt of report. Reference range: The laboratory report provides appropriate information. Prozac® (Fluoxetine) Specimen type: Serum 198 04–Biochem pp69-228 13/7/10 11:58 AM Page 199 CLINICAL BIOCHEMISTRY TEST DIRECTORY Special requirements or comments: Details of dosage regimen required. CLINICAL BIOCHEMISTRY Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. PSA (Prostate Specific Antigen) Specimen type: Serum; specimen should reach laboratory within eight hours of venepuncture. Special requirements or comments: This assay has regulatory body approval for the quantitative measurement of PSA in human serum, as an aid in the detection of prostate cancer when used in conjunction with digital rectal examination in men aged 50 years or older. This assay is also likely to be of value as an adjunctive test to aid in the management of prostate cancer patients. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Males Siemens Medical Second Generation Total PSA Assay: 0 – 4.0 ng/mL Siemens Medical Third Generation Total PSA Assay: 0 – 3.2 ng/mL PSA (Prostate Specific Antigen) Free Specimen type: Serum; specimen must be delivered to the laboratory immediately. This assay is only performed on requests authorised by a consultant. Specimen must be delivered to the laboratory within four hours of venepuncture. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. PTH (intact) Specimen type: Serum Special requirements or comments: Specimen must be delivered to the laboratory immediately. Serum must be stored at minus 25 degrees Celsius while awaiting analysis. 199 04–Biochem pp69-228 13/7/10 11:58 AM Page 200 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Availability of assay: allow three working days for receipt of report. CLINICAL BIOCHEMISTRY Reference range: 15 – 65 ng/L. 15 – 65 pg/mL. PTHrP (Parathyroid hormone Related Protein) This assay is only performed on requests authorised by a consultant. Specimen type: Contact the Biochemistry Laboratory before initiating the request so that all the collection requirements can be met. Special requirements or comments: The specimen must be collected into a special PTHrP Cocktail Tube (Nichols Ref No 382182) obtainable from the referral laboratory. On receipt the tube must be stored at minus 20 degrees Celsius or colder until required for use. Place the cocktail tube on ice prior to drawing the sample. Do not use the cocktail tube as a collection tube. Collect the whole blood into a syringe and transfer the sample to the cocktail tube. Mix thoroughly by inversion. Immediately send the specimen to the laboratory so that the plasma can be separated from the cells using a refrigerated centrifuge. Freeze the separated plasma immediately at minus 20 degrees Celsius or colder. It is essential that the sample reaches the referral laboratory in a frozen state. The specimen must be stored at minus 20 degrees Celsius or cooler while awaiting analysis. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Pyruvate Specimen type: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. Special requirements or comments: Add 3 mL of 5.1% perchloric acid to specimen tube. Weigh tube. Add 0.5 – 1.0 mL of whole blood to the weighed tube. Mix thoroughly by inverting several times. Weigh tube again and calculate the exact weight of blood added. Centrifuge tube at 4 degrees Celsius. Remove supernatant and store at minus 25 degrees Celsius pending dispatch to Reference Laboratory. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 200 04–Biochem pp69-228 13/7/10 11:58 AM Page 201 CLINICAL BIOCHEMISTRY TEST DIRECTORY Rapamune® (Sirolimus) Special requirements or comments: Special request form for immunosuppressant drug monitoring should be used. The date and time of specimen collection and the date, time and dosage of the last sirolimus dose must be recorded on the request form. Appropriate clinical details are also required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Reducing substances (semi-quantitative test) Specimen type: Stool: fresh random stool specimen. Urine: fresh random urine. Special requirements or comments: Transport specimen(s) to the laboratory as soon as possible; delay may cause falsely low results. Freeze specimen if testing is delayed. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Negative. Renal profile Specimen type: Serum Special requirements or comments: Includes electrolytes, urea, creatinine, calcium, phosphate, albumin. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: See ranges for individual analytes: Serum, plasma Sodium 136 – 144 mmol/L Potassium 3.6 – 5.1 mmol/L Chloride 101 – 111mmol/L 22 – 32 mmol/L CO2 Urea 2.9 – 7.1 mmol/L Creatinine Calcium Phosphate Albumin 35 – 106 µmol/L 2.23 – 2.56 mmol/L 0.78 – 1.53 mmol/L 35 – 48 g/L 201 CLINICAL BIOCHEMISTRY Specimen type: Whole blood in a potassium EDTA tube (=FBC tube). 04–Biochem pp69-228 13/7/10 11:58 AM Page 202 CLINICAL BIOCHEMISTRY TEST DIRECTORY Renin CLINICAL BIOCHEMISTRY Specimen type: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. Special requirements or comments: Collect specimen in an ice-cold potassium EDTA tube (=FBC tube). The specimen should be surrounded with ice and brought to the laboratory immediately (<10 minutes). Record details of specimen collection time, whether the patient was ambulant or recumbent, and list of all current medication. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Rhinorrhoea Fluid Analysis (Beta 2 transferrin; Tau Protein) Specimen type: Nasal fluid accompanied by 1 mL of serum. Special requirements or comments: Appropriate clinical details are also required. This assay differentiates CSF from other biological fluids. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Sabril® (Vigabatrin) Specimen type: Serum Special requirements or comments: Specimen drawn before the next oral dose with the patient at steady state. Note: the serum level correlates with the dose administrated but not with the therapeutic benefit. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 202 04–Biochem pp69-228 13/7/10 11:58 AM Page 203 CLINICAL BIOCHEMISTRY TEST DIRECTORY Salicylate Special requirements or comments: Peak serum level is reached 1-2 hours after oral administration. Note results are reported as mmol/L. Turnaround time: Availability of assay: daily, throughout 24 hours. Reference range: Therapeutic guide: Toxic range: < 1.45 mmol/L > 2.3 mmol/L Seroxat® (Paroxetine) Specimen type: Serum Special requirements or comments: Details of dosage regimen required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Serum Protein Electrophesis Specimen type: Serum Special requirements or comments: Appropriate clinical details required. Turnaround time: Availability of assay: allow three working days for receipt of report. Reference range: The laboratory report provides appropriate information. Sex hormone binding globulin (SHBG) Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. 203 CLINICAL BIOCHEMISTRY Specimen type: Serum 04–Biochem pp69-228 13/7/10 11:58 AM Page 204 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Availability of assay: allow seven days for receipt of report. CLINICAL BIOCHEMISTRY Reference range: Adult females (non-pregnant): Adult males: 18 – 114 nmol/L 13 – 71 nmol/L SHBG (sex hormone binding globulin) Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Adult females (non-pregnant): Adult males: 18 – 114 nmol/L 13 – 71 nmol/L Sirolimus (Rapamune®) Specimen type: Whole blood in a potassium EDTA tube (=FBC tube). Special requirements or comments: Special request form for immunosuppressant drug monitoring should be used. The date and time of specimen collection and the date, time and dosage of the last sirolimus dose must be recorded on the request form. Appropriate clinical details are also required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Sodium Specimen type: Serum, plasma; Urine: Random urine, 24-hour urine collection, no preservative required. Special requirements or comments: Blood specimen should be collected free of haemolysis. Turnaround time: Availability of assay: Serum, plasma: daily, throughout 24 hours. Urine: Monday – Friday during core working hours. 204 04–Biochem pp69-228 13/7/10 11:58 AM Page 205 CLINICAL BIOCHEMISTRY TEST DIRECTORY 136 – 144 mmol/L 80 – 250 mmol/24 hours CLINICAL BIOCHEMISTRY Reference range: Serum, plasma: Urine: Solvent screen for toluene (glue), trichloroethane (Tipex®) and butane Specimen type: Whole blood or serum or plasma. Special requirements or comments: Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Toxicology Laboratory, Beaumont Hospital, Beaumont, Dublin 9. Tel: 01 809 2673; 01 809 2671; 01 809 2675 Beaumont Laboratory operates a strict policy of not transmitting reports by fax. The current out-of-hours toxicology call service at Beaumont Hospital is available to all hospitals in the Republic of Ireland. “The service is restricted to checking only for drugs, which if taken in overdose require a specific antidote or treatment. It is not an aid to diagnosis nor to allow a patient to be discharged.” If the assay is required outside of normal working hours the Toxicologist on-call at Beaumont Hospital must be contacted at 087 2590749. Consultant: Dr. W. Tormey Reference range: The referral laboratory report provides appropriate reference values. Somatomedin C (IGF-1, insulin-like growth factor-1) Specimen type: Serum. Special requirements or comments: The specimen should be brought to the laboratory without delay. Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Spiked drink (suspected case of spiked drink) Important notes: (1) Requests for analyses relating to a case of alleged spiking of drink must be made by a registered medical practitioner. 205 04–Biochem pp69-228 13/7/10 11:58 AM Page 206 CLINICAL BIOCHEMISTRY TEST DIRECTORY CLINICAL BIOCHEMISTRY (2) The biochemistry service is provided to assist in the clinical management of the patient and is not provided for forensic purposes or as part of a criminal investigation. (3) Specimens should be collected within 24 hours of the alleged incident. Specimens collected more than 24 hours after the alleged incident are unlikely to yield significant findings. (4) The measurement of the subject’s serum or plasma alcohol should be considered a prerequisite to any biochemistry investigations of alleged spiking of drink. Specimen type: Serum or plasma and urine Special requirements or comments: Specimens must be collected within 24 hours of the alleged incident. Specimen collected more than 24 hours after the event are unlikely to yield significant findings. Appropriate clinical details are required including a summary of prescribed medication. No preservative is required for the urine specimen. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Steroid Profile This assay is only performed on requests authorised by a consultant. Specimen type: Urine: 24-hour urine collection Special requirements or comments: No preservative is required but urine should be kept cool. Store specimen at approximately 4 degrees Celsius prior to preparation for dispatch to referral laboratory. Appropriate clinical details must accompany the request. Note: this assay is expensive (€300). Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Stone analysis (stone with details of source) Specimen type: Stone(s). 206 04–Biochem pp69-228 13/7/10 11:58 AM Page 207 CLINICAL BIOCHEMISTRY TEST DIRECTORY CLINICAL BIOCHEMISTRY Special requirements or comments: Specimen should be washed free of tissue and blood, and submitted in a clean dry container. Include relevant clinical information. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Sweat Test Specimen type: Sweat. Special requirements or comments: Bookings for sweat tests may be made with the Laboratory Phlebotomist at (061) 482270 Turnaround time: Sweat tests are usually performed within one week of booking. Reference range: Sweat chloride: A sweat chloride of less than 40 mmol/L is normal and there is a low probability of cystic fibrosis. A sweat chloride concentration between 40 and 60 mmol/L is suggestive but not diagnostic of cystic fibrosis. A sweat chloride of greater than 60 mmol/L supports the diagnosis of cystic fibrosis. These guidelines should be interpreted in the context of the patient’s age and medical history. Sweat conductivity using Wescor Sweat-Chek: Normal: 0 – 60 mmol/L; Borderline: 60 – 90 mmol/L; Abnormal: > 90 mmol/L. T3 (triiodothyronine), free hormone Specimen type: Serum. Special requirements Appropriate clinical details and a list of all current medication are required. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: 2.7 – 7.0 pmol/L 207 04–Biochem pp69-228 13/7/10 11:58 AM Page 208 CLINICAL BIOCHEMISTRY TEST DIRECTORY T4 (thyroxine), free hormone CLINICAL BIOCHEMISTRY Specimen type: Serum Special requirements or comments: Appropriate clinical details and a list of all current medication are required. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: 9.9 – 20.1 pmol/L Tacrolimus (Prograf®, FK 506) Specimen type: Whole blood in specimen tube with potassium EDTA as anticoagulant. Special requirements or comments: Special request form for immunosuppressant drug monitoring should be used. Trough levels should be monitored. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Tambocor® (Flecainide) Specimen type: Serum Special requirements or comments: Appropriate clinical details required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Tau Protein (Rhinorrhoea Fluid Analysis; Beta 2 transferrin) Specimen type: Nasal fluid accompanied by 1 mL of serum. Special requirements or comments: Appropriate clinical details are also required. This assay differentiates CSF from other biological fluids. 208 04–Biochem pp69-228 13/7/10 11:58 AM Page 209 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Requests for this test are referred to an external specialist laboratory. CLINICAL BIOCHEMISTRY Reference range: The referral laboratory report provides appropriate reference values. TBG (thyroxine binding globulin) Specimen type: Serum Special requirements or comments: With appropriate clinical details. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. TBII (TSH-binding inhibiting immunoglobulin) Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Tegretol® (Carbamazepine) Specimen type: Serum Special requirements or comments: Specimen should be drawn before the next oral dose with the patient at steady state. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Therapeutic Guide: 17 - 51µmol/L 209 04–Biochem pp69-228 13/7/10 11:58 AM Page 210 CLINICAL BIOCHEMISTRY TEST DIRECTORY Testosterone: males CLINICAL BIOCHEMISTRY Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Adult males: Males 20-49 years: Males over 50 years: 8.5 – 42.0 nmol/L 9.9 – 52.4 nmol/L 7.4 – 25.7 Testosterone: females Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Availability of assay: allow seven days for receipt of report. Reference range: Adult females: 0.2 – 3.0 nmol/L Testosterone/sex hormone binding globulin (SHBG) ratio Specimen type: Serum Special requirements or comments: This ratio is only applicable to female patients. Appropriate clinical details are required. Turnaround time: Availability of assay: allow seven days for receipt of report. Reference range: Adult females: Theophylline Specimen type: Serum 210 1.0 – 5.2 04–Biochem pp69-228 13/7/10 11:58 AM Page 211 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: 40 – 110 µmol/L Thiopurine S-Methyltransferase (Red Blood Cell Thiopurine S-Methyltransferase; TPMT) Specimen type: Two specimens of whole blood in potassium EDTA tubes. Specimen should be sent to the Clinical Biochemistry Laboratory. Special requirements or comments: Appropriate clinical details are required. For patients about to commence azathioprine (Imuran®) therapy. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Thyroglobulin Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Thyroid hormone profile Specimen type: Serum 211 CLINICAL BIOCHEMISTRY Special requirements or comments: Sampling times: Oral trough: immediately before the next oral dose. Oral peak: 2 hours after administration of a product with rapid release properties; 4-8 hours after administration of a product with sustained release properties. Intravenous: (a) prior to intravenous infusion (b) 30 minutes after completion of loading dose to measure the adequacy of dose; (c) 4-6 hours after beginning continuous infusion therapy (pre steady state but used to establish a trend) or before the next infusion. 04–Biochem pp69-228 13/7/10 11:58 AM Page 212 CLINICAL BIOCHEMISTRY TEST DIRECTORY CLINICAL BIOCHEMISTRY Special requirements or comments: Appropriate clinical details are required. Panel includes TSH and free T4. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: TSH: 0.15 – 3.2 mU/L Free T4 9.9 – 20.1 pmol/L Thyroid Stimulating Hormone (TSH) Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: 0.15 – 3.2 mU/L Thyroid stimulating immunoglobulin (TBII, TSH-binding inhibiting immunoglobulin) Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Thyroxine, free hormone (free T4) Specimen type: Serum Special requirements or comments: Appropriate clinical details and a list of all current medication are required. Turnaround time: Availability of assay: Monday – Friday during core working hours. 212 04–Biochem pp69-228 13/7/10 11:58 AM Page 213 CLINICAL BIOCHEMISTRY TEST DIRECTORY Reference range: 9.9 – 20.1 pmol/L CLINICAL BIOCHEMISTRY Thyroxine binding globulin (TBG) Specimen type: Serum Special requirements or comments: With appropriate clinical details. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. TIBC (calculated) Specimen type: Serum Special requirements or comments: A fasting specimen is required. TIBC specimens must be sent to the Clinical Biochemistry Laboratory Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Adults: 42 – 80 µmol/L Tocopherol (Vitamin E) Specimen type: Serum Special requirements Protect from light, keep refrigerated. Specimen should be sent to the laboratory immediately Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Topamax® (Topiramate) Specimen type: Serum 213 04–Biochem pp69-228 13/7/10 11:58 AM Page 214 CLINICAL BIOCHEMISTRY TEST DIRECTORY Special requirements or comments: Specimen drawn before the next oral dose with the patient at steady state. CLINICAL BIOCHEMISTRY Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Topiramate (Topomax®) Specimen type: Serum Special requirements or comments: Specimen drawn before the next oral dose with the patient at steady state. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Toxicology: Environmental The Clinical Biochemistry Laboratory does not provide an assay service for environmental, industrial or occupational toxic agents or chemicals. The most appropriate agency to contact regarding these matters is the Environmental Protection Agency. Contact details: EPA Headquarters, PO Box 3000, Johnstown Castle Estate, Co. Wexford, Tel: 053-9160600; Fax:053-9160699; Email: [email protected]; Lo Call: 1890 335599. Web site: www.epa.ie. Toxicology: Food The Clinical Biochemistry Laboratory does not provide an assay service for toxic agents or chemicals in food or food products. The most appropriate agency to contact regarding these matters is the Food Safety Authority of Ireland; contact details: Food Safety Authority of Ireland, Abbey Court. Lower Abbey Street, Dublin 1 Phone 01 817 1300 ; Fax 01 817 1301; Email [email protected] Web address www.fsai.ie Toxicology: Industrial The Clinical Biochemistry Laboratory does not provide an assay service for environmental, industrial or occupational toxic agents or chemicals. The most appropriate agency to contact regarding these matters is the Environmental Protection Agency.; contact details: EPA Headquarters, PO Box 3000, Johnstown Castle Estate, Co. Wexford, Tel: 053-9160600; Fax:053-9160699; Email: [email protected]; Lo Call: 1890 335599. Web site: www.epa.ie 214 04–Biochem pp69-228 13/7/10 11:58 AM Page 215 CLINICAL BIOCHEMISTRY TEST DIRECTORY Toxins TPMT (Thiopurine S-Methyltransferase) Specimen type: Two specimens of whole blood in potassium EDTA tubes. Specimen should be sent to the Clinical Biochemistry Laboratory. Special requirements or comments: Appropriate clinical details are required. For patients about to commence azathioprine (Imuran®) therapy. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Trace Metal Monitoring (in patients on nutrition support, especially parenteral nutrition) Specimen type: Whole blood in trace metal-free tube. Trace metal-free needle must be used in conjunction with trace metal-free tube. Please contact Clinical Biochemistry Laboratory for trace metal-free specimen collection tube and needle. Special requirements or comments: This specimen should be collected first if other tests are requested to avoid contamination. Do not open or centrifuge the specimen tube. Trace element Frequency of testing Zinc Baseline, then every 2-4 weeks depending on results Copper Baseline, then every 2-4 weeks depending on results Selenium Baseline if risk of depletion. Need for further testing depends on baseline value Manganese Every 3-6 months if on home parenteral nutrition Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 215 CLINICAL BIOCHEMISTRY Toxins are poisons produced by living organisms, especially bacteria, Investigations relating to toxins do not fall within the area of responsibility of the Clinical Biochemistry Laboratory. 04–Biochem pp69-228 13/7/10 11:58 AM Page 216 CLINICAL BIOCHEMISTRY TEST DIRECTORY Transferrin CLINICAL BIOCHEMISTRY Specimen type: Serum Special requirements or comments: A fasting specimen is required. Transferrin specimens must be sent to the Clinical Biochemistry Laboratory Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Adults Males: 1.8 – 3.3 g/L Females: 1.9 – 3.8 g/L Transferrin saturation Specimen type: Serum Special requirements or comments: A fasting specimen is required. Iron studies specimens must be sent to the Clinical Biochemistry Laboratory Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Adults: 15 – 45% Transglutaminase antibodies, Tissue (anti-tTG) Please refer to Serology/Immunology Laboratory. Tricyclic antidepressants (semi-quantitative, serum) Specimen type: Serum Special requirements or comments: The cut-off threshold for a positive result for tricyclic antidepressants is 100 ng/mL. A positive result for tricyclic antidepressants indicates only the presence of tricyclic antidepressants and does not necessarily correlate with the extent of physiological and psychological effects. Pharmokinetic studies have shown that there is a marked interindividual variation in the therapeutic and toxic response to tricyclic antidepressants at similar blood concentrations. 216 04–Biochem pp69-228 13/7/10 11:58 AM Page 217 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Triglyceride Specimen type: Serum Special requirements or comments: Serum triglyceride is subject to major increases following meals and may also be released after prolonged fasting. A 12-hour fast is essential for meaningful triglyceride measurements. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Triglyceride Reference Range: General population reference values: 0.5 – 2.1 mmol/L Note: reference ranges for lipids: In general, total serum cholesterol should be less than 5.0 mmol/L and LDL-cholesterol should be less than 3.0 mmol/L. For patients with clinically established cardiovascular disease and patients with diabetes the treatment goals should be lower: total cholesterol < 4.5 mmol/L and LDL-cholesterol < 2.5 mmol/L. Treatment goals are not defined for HDL-cholesterol and triglycerides, but HDLcholesterol < 1.0 mmol/L in men and < 1.2 mmol/L in women, and fasting triglyceride > 1.7 mmol/L are markers of increased cardiovascular risk. In asymptomatic individuals the decision to start treatment depends not only on the serum lipid levels but also on an assessment of total cardiovascular risk. Triidothyronine, free hormone (Free T3) Specimen type: Serum. Special requirements Appropriate clinical details and a list of all current medication are required. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: 2.7 – 7.0 pmol/L 217 CLINICAL BIOCHEMISTRY A negative result indicates that tricyclic antidepressants are either not present or are present at levels below the cut-off threshold for this test. This assay is designed to detect the four major tricyclic antidepressants: amitriptyline, nortriptyline, imipramine, and desipramine. 04–Biochem pp69-228 13/7/10 11:58 AM Page 218 CLINICAL BIOCHEMISTRY TEST DIRECTORY Trileptal® (Oxcarbazepine) CLINICAL BIOCHEMISTRY Specimen type: Serum/plasma Special requirements or comments: Specimen drawn before the next oral dose with the patient at steady state. Store specimen at approximately 4 degrees Celsius prior to preparation for dispatch to referral laboratory. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Troponin I Troponin T assay is available – see below. Troponin T (cTnT) Specimen type: Serum. Special requirements or comments: Two samples should be collected, at admission and 8-12 hours later. The date and time of the suspected cardiac event should be stated on the request to assist interpretation. Turnaround time: Availability of assay: 7.00am to 11.30pm each day. Reference range: Less than 0.01 ng/mL A Troponin T concentration greater than 0.1 ng/mL twelve hours after the onset of chest pain is suggestive of myocardial infarction. An increased Troponin T concentration indicates myocardial damage, but not its cause. The diagnosis of ACS/AMI must be supported with appropriate symptoms and/or ECG changes. In the absence of supportive clinical findings, other causes of myocardial damage should be considered. Trypsin, immunoreactive Specimen type: Serum. Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. Special requirements or comments: Specimen must be delivered to the Clinical Biochemistry within one hour of collection. 218 04–Biochem pp69-228 13/7/10 11:58 AM Page 219 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Requests for this test are referred to an external specialist laboratory. CLINICAL BIOCHEMISTRY Reference range: The referral laboratory report provides appropriate reference values. Tryptase Assay (plasma) Adverse (Anaphylactoid) Reactions to Intravenous Drugs Specimen type: The preferred specimen is EDTA plasma (at least 1 mL). It is possible to measure tryptase in serum if EDTA plasma is not available. Special requirements or comments: The first sample should be taken as soon as possible after commencement of the reaction and ideally within the first 30 minutes. Further samples should be taken 3, and 24 hours after reaction. Documentation required This should be comprehensive, but brief, and should include the following (although any other factor which the anaesthetist thinks could be a cause of the reaction should be indicated, eg surgical stimulation, undiagnosed hypovolaemia etc). • Surgical procedure, • Date of reaction, • Drugs administered (including premedication and sequences where possible), • Clinical manifestations, • Management of reaction and outcome (eg residual effects or death), • Previous medical and anaesthetic history if known, • Any particular risk factors? (eg known asthmatic, penicillin allergy, anaesthetic reaction or extremely anxious patient etc), • The haematological data (‘routine haematology’ including full differential white cell count and haematocrit), if available. This documentation should accompany the plasma samples. Telephone contact: At any stage of the reaction the user of the service is encouraged to telephone the Protein Reference Unit in Sheffield (00 44 114 271 5552) for advice. This advice is based on the cumulative experiences of NARCOS in the assessment of emergency situations. NARCOS provides a 24 hour advisory service via the Hospital switchboard (00 44 114 243 4343). Store specimens at approximately +4 degrees Celsius prior to preparation for dispatch to referral laboratory. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 219 04–Biochem pp69-228 13/7/10 11:58 AM Page 220 CLINICAL BIOCHEMISTRY TEST DIRECTORY TSH (Thyroid Stimulating Hormone) CLINICAL BIOCHEMISTRY Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: 0.15 – 3.2 mU/L TSH-binding inhibiting immunoglobulin (TBII) Specimen type: Serum Special requirements or comments: Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Type 3 procollagen peptide (P111NP) Specimen type: Serum The specimen should be sent to the laboratory immediately. The sample should be centrifuged and the serum separated within 1-2 hours of collection (maximum no more than 4 hours). Special requirements or comments: Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. U & E Profile (urea and electrolytes) Specimen type: Serum, Plasma Special requirements or comments: The U + E panel includes sodium, potassium, chloride, carbon dioxide and urea. 220 04–Biochem pp69-228 13/7/10 11:58 AM Page 221 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Availability of assay: daily, throughout 24 hours. CLINICAL BIOCHEMISTRY Reference range: Reference ranges for serum or plasma urea and electrolytes Serum, plasma Urea Sodium Potassium Chloride Carbon dioxide mmol/L mmol/L mmol/L mmol/L mmol/L 2.9 – 7.1 136 – 144 3.6 – 5.1 101 – 111 22 - 32 Urea Specimen type: Serum, plasma; Urine: 24-hour collection (no preservative required). Special requirements or comments: This assay is also available as part of the U+E test profile (serum or plasma) Turnaround time: Availability of assay: Serum, plasma: daily, throughout 24 hours. Urine: Monday – Friday during core working hours. Reference range: Serum, plasma: Urine: 2.9 – 7.1 mmol/L 430 – 710 mmol/24 hours. Uric Acid (Urate) Specimen type: Serum, plasma; Urine: a 24-hour collection is required ( no preservative, keep cool); Joint fluid: send specimen to the Microbiology Department for Microscopy (detection of uric acid crystals). Special requirements or comments: Turnaround time: Availability of assay: Serum, plasma: daily, throughout 24 hours. Urine: Monday – Friday during core working hours. Reference range: Serum: Males: 286 – 518 umol/L Females: 155 – 476 umol/L Urine: 2.8 – 4.4 mmol/24 hours 221 04–Biochem pp69-228 13/7/10 11:58 AM Page 222 CLINICAL BIOCHEMISTRY TEST DIRECTORY Urine Protein Electrophoresis CLINICAL BIOCHEMISTRY Specimen type: Untimed urine collection or a 24-hour collection. No preservative is required. Keep specimen refrigerated. Special requirements or comments: Appropriate clinical details are required. Turnaround time: Availability of assay: allow three working days for receipt of report. Reference range: The laboratory report provides appropriate information. Valproate (valproic acid, Epilim®) Specimen type: Serum Special requirements or comments: Specimen drawn before the next oral dose with the patient at steady state. There is no evidence that monitoring serum valproate levels can be valuable in the management of patients with epilepsy. Studies indicate that concentrations are no better a guide to clinical response than is dose. Measurement of serum levels may be useful in the assessment of compliance. Turnaround time: Availability of assay: Monday – Friday during core working hours. Reference range: Therapeutic guide: 347 – 693 umol/L Vasoactive intestinal polypeptide (VIP) Specimen type: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. Special requirements or comments: Patient should be fasting overnight. Collect 3 mL of blood into an ice-cold potassium EDTA specimen tube. The specimen should be surrounded with ice and brought to the laboratory immediately. Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 222 04–Biochem pp69-228 13/7/10 11:58 AM Page 223 CLINICAL BIOCHEMISTRY TEST DIRECTORY Very long chain fatty acids (VLCFA) CLINICAL BIOCHEMISTRY Specimen type: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. Special requirements 5 mL blood in potassium EDTA tube; do not refrigerate, deliver to laboratory without delay. Monday- Wednesday (only) dispatch to Manchester. Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Vigabatrin (Sabril®) Specimen type: Serum Special requirements or comments: Specimen drawn before the next oral dose with the patient at steady state. Note: the serum level correlates with the dose administrated but not with the therapeutic benefit. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. VIP (vasoactive intestinal polypeptide) Specimen type: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. Special requirements or comments: Patient should be fasting overnight. Collect 3 mL of blood into an ice-cold potassium EDTA specimen tube. The specimen should be surrounded with ice and brought to the laboratory immediately. Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 223 04–Biochem pp69-228 13/7/10 11:58 AM Page 224 CLINICAL BIOCHEMISTRY TEST DIRECTORY Viscosity, plasma CLINICAL BIOCHEMISTRY Please refer to Haematology Section of this Handbook. Vitamin A Specimen type: Serum Special requirements or comments: Protect from light using e.g. aluminium kitchen foil. Keep refrigerated. Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Vitamin B6: Pyridoxine Specimen type: Whole blood in K-EDTA specimen tube. Special requirements or comments: Specimen must be sent to the laboratory immediately. Protect from light, Keep refrigerated. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Vitamin B12 Please refer to Haematology Section of this Handbook. Vitamin C Specimen type: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. Note that Vitamin C is highly reactive and easily oxidised. Special requirements Collect blood into two 2.6 mL lithium heparin tubes. Deliver the specimen to laboratory immediately so that further processing can take place to stabilise Vitamin C. This stabilisation must be completed within 30 minutes of specimen collection. 224 04–Biochem pp69-228 13/7/10 11:58 AM Page 225 CLINICAL BIOCHEMISTRY TEST DIRECTORY Turnaround time: Requests for this test are referred to an external specialist laboratory. CLINICAL BIOCHEMISTRY Reference range: The referral laboratory report provides appropriate reference values. Vitamin D (25-Hydroxy vitamin D3; 25-Hydroxycholecalciferol) Specimen type: Serum Special requirements or comments: Protect from light using e.g. aluminium kitchen foil. Keep refrigerated. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Vitamin D (1,25 dihydroxy) (=1,25 Dihydroxy cholecalciferol) Specimen type: Serum. See special requirements. Special requirements or comments: A fasting specimen is required. The specimen should be protected from light using e.g. aluminium kitchen foil and brought to the laboratory immediately. Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Vitamin E (Tocopherol) Specimen type: Serum Special requirements Protect from light using e.g. aluminium kitchen foil. Keep refrigerated. Specimen should be sent to the laboratory immediately. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 225 04–Biochem pp69-228 13/7/10 11:58 AM Page 226 CLINICAL BIOCHEMISTRY TEST DIRECTORY VMA CLINICAL BIOCHEMISTRY Specimen type: 24-hour urine collection with 20 mL of 6N HCI as preservative. Special requirements or comments: Appropriate clinical details and a list of all current medication are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Volume Specimen type: Various Reference range: The laboratory report provides appropriate reference values. Weight Specimen type: Various Reference range: The laboratory report provides appropriate reference values. White cell cystine Specimen type: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. Special requirements or comments: 1-2 mL blood in lithium heparin tube; do not refrigerate or centrifuge, deliver to laboratory without delay. Monday – Wednesday (only) dispatch to Manchester. Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 226 04–Biochem pp69-228 13/7/10 11:58 AM Page 227 CLINICAL BIOCHEMISTRY TEST DIRECTORY White cell enzyme analysis (Lysosomal enzyme analysis) Special requirements or comments: 5 mL blood in potassium EDTA tube; do not refrigerate or centrifuge, deliver to laboratory without delay. Monday – Wednesday (only) dispatch to Manchester. Appropriate clinical details are required. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Zarontin® (Ethosuximide) Specimen type: Serum Special requirements Specimen should be drawn before the next oral dose with the patient at steady state. Due to the long half-life of ethosuximide, fluctuations in serum concentration are relatively minor. However, when making comparative measurements, it is advisable that the sampling time be consistent. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. Zinc Specimen type: Whole blood in trace metal-free tube. Trace metal-free needle must be used in conjunction with trace metal-free tube. Special requirements or comments: This specimen should be collected first if other tests are requested to avoid contamination. Please contact Clinical Biochemistry Laboratory for trace metal-free specimen collection tube and needle. Turnaround time: Requests for this test are referred to an external specialist laboratory. Reference range: The referral laboratory report provides appropriate reference values. 227 CLINICAL BIOCHEMISTRY Specimen type: Contact the Clinical Biochemistry Laboratory before initiating the request so that all collection requirements can be met. 04–Biochem pp69-228 228 13/7/10 11:58 AM Page 228
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