Page 1 of 1 i-STAT G3+, G7+, 6+, Glu, Crea Cartridges PRINCIPLE: I. The i-STAT Portable Clinical Analyzer, in conjunction with the i-stat Test Cartridges, performs blood analysis at the point of care. Just 2-3 drops of fresh whole blood is all that is required, and the portable, battery-powered analyzer displays quantitative test results in approximately 2 minutes. Portable printers and infrared communication devices allow all patient information obtained at the bedside to be printed on demand and transmitted to centralized information systems for record keeping and billing. Quantitative determination of Sodium (Na+), Potassium (K+), Chloride (Cl-), Glucose (Glu), Urea Nitrogen (BUN), and Hematocrit(Hct) in whole blood is performed using the 6+cartridge. Hemoglobin is mathematically derived based on the hematocrit value. The 6+ cartridge is used in the ED, CCU, ICU, OR, and the CATH Lab. The G cartridge for glucose only is used in the OR and the CATH LAB, for patients with glucose >200 mg/dL and Hematocrit <25 %. Quantitative determination of Creatinine is performed using the Creatinine cartridge in the ED and Radiology. Arterial Blood Gas testing is performed using the EG7+ cartridge in the ED, ICU, CCU, SCN, OR, PACU, and the CATH LAB. The parameters that may be measured are: Sodium(Na), Potassium(K), Ionized calcium(iCa), pH, pCO2, pO2,and HCT. TCO2, HCO3, BE, sO2 and Hemoglobin are calculated results. Arterial Blood Gas testing is performed using the G3+ cartridge in the Emergency Department, SCN CCU, ICU, OR, the CATH LAB and on the patient service/ nursing units. The parameters that may be measured are: pH, pCO2,and pO2. TCO2, HCO3, BE, and sO2 are calculated results. II. Specimen A. i-STAT orders All i-STAT orders must be written on the patient’s chart. DO NOT PERFORM AN ARTERIAL BLOOD GAS WITHOUT A WRITTEN ORDER. Check the patient’s chart for anticoagulant therapy or diagnosis which would indicate the necessity for increasing the pressure holding time on the puncture site. B. Patient Preparation: -Verify patient identification by checking the patient’s name and social security number and/or patient account number on the arm band. -Explain the purpose of the test and the steps of the procedure to the patient prior to performing the test. -The operator’s hands must be washed before and after testing. SD/ISTABG/OUTREA Page 2 of 2 -Because of the hazardous nature of handling blood products, it is required that disposable latex gloves or an acceptable substitute be used when collecting specimens and test procedures. Standard precautions shall be observed for all blood specimens and they should be handled at Biosafety Level 2 as recommended for any potentially infectious material in the Centers for Disease Control/National Institutes of Health manual, Biosafety in Microbiological and Biomedical Laboratories, 1988 or in the National Committee for Clinical Laboratory Standard Document M29, Protection of Laboratory Workers from Infectious Disease Transmitted by Blood, Body Fluids, and Tissue, 1991. C. Sample volume (size): 65 uL for 6+ and G, cartridges 95 uL for EG7+,G3+, and Crea cartridges D. Sample Type: Fresh whole blood from venous, arterial puncture, skin, or indwelling line. Venipuncture: Observe the following precautions: -Avoid drawing from an arm with an IV line. IV solutions will dilute the sample and may interfere with the tests. -Avoid localized stasis which can increase potassium and pH results and decrease ionized calcium results. If a tourniquet is applied for more than one minute while looking for a vein, release and reapply after two to three minutes. -Allow the tourniquet to remain in place until all blood is withdrawn to prevent changes in ionized calcium and pH results. -Avoid extra muscle activity, such as clenching and unclenching the fist, which may increase potassium results. -Avoid hemolysis by allowing residual alcohol to dry over the puncture site. Hemolysis will cause an increase in potassium results and a decrease in calcium results. -If the cartridge cannot be filled immediately, collect a sample into an evacuated blood collection tube or a syringe containing heparin ( sodium, lithium or balanced) anticoagulant. For ionized calcium measurements, balanced heparin or <10 IU/ml of sodium or lithium heparin is recommended. Balanced heparin or low volume heparin is used in some commercially available blood gas syringes. Becton-Dickenson’s lithium heparin evacuated tubes contain approximately 15 IU/ml when filled to capacity. SD/ISTABG/OUTREA Page 3 of 3 -Fill evacuated tubes and syringes with anticoagulant to capacity. Incomplete filling will cause higher heparin to blood ratios which will decrease ionized calcium results and may affect other results. -Gently mix blood and anticoagulant immediately to avoid clotting: invert an evacuated tube 5 to 10 times and roll a syringe between the palms for at least five seconds in two directions. -Collect vacuum tubes in the prescribed sequence to avoid interference due to carry over of anticoagulant from one tube to the next: blue, red, gold, green, lavender, grey. If a blue stoppered tube is drawn, draw a 1 ml blue stoppered discard tube before drawing the blue stoppered tube. -For the most accurate results, test samples immediately after draw. If testing is delayed, remix evacuated tubes by gentle inversion and syringes by rolling between the palms for 5 seconds. Test samples within 10 minutes after draw. Arterial : Observe the following precautions: -Evacuated tubes are not recommended for blood gas analysis. -Follow the directions carefully when using pre-prepared blood gas kits and syringes. Fill syringes to the recommended capacity or use the least amount of liquid heparin anticoagulant that will prevent clotting. Under filling syringes which contain liquid heparin will decrease results due to dilution and will decrease ionized calcium results due to binding. -For ionized calcium, use balanced or low volume heparin blood gas syringes. -Wait 15 minutes before specimen collection when there has been a change in ventilator setting or the FIO2. -Mix blood and anticoagulant by rolling between the palms for at least 5 seconds. Then invert the syringe repeatedly for at least 5 seconds. -Do not expose the sample to air when testing for ionized calcium , pH, pCO2 or pO2. -Avoid or remove immediately any air drawn into the syringe and maintain anaerobic conditions. -For the most accurate results, test samples immediately after draw. If testing is delayed, remix. Test samples within 10 minutes. SD/ISTABG/OUTREA Page 4 of 4 -Fill the cartridge before icing the sample for transportation. Icing will increase potassium and will affect oxygen levels in samples collected in plastic syringes. In-Dwelling Line : Follow the following precautions: -Withdraw slowly three to six times the volume of the catheter, connectors, and needle to remove intravenous solution, heparin, or medications that may contaminate the sample. Samples collected without anticoagulant should be tested within 3 minutes. Samples collected in lithium heparin syringes should be tested within 10 minutes and well mixed before use. E. Collection Options: Evacuated tubes (for Venous samples only) -without anticoagulant -with lithium heparin anticoagulant). Syringes Venous samples : -without anticoagulant -with lithium heparin anticoagulant Arterial samples: -balanced or low heparin -Blood Gas Syringe Kit F. Test Within Time Frames: 3 minutes -evacuated tubes or syringes without anticoagulant 10 minutes -for evacuated tubes or syringes with anticoagulant (Maintain anaerobic conditions when using syringes) (Evacuated tubes and syringes must be well mixed before testing) G.. Handling Conditions SD/ISTABG/OUTREA Page 5 of 5 If the i-STAT cartridge is not filled immediately after collection, the blood must be thoroughly mixed. Mix tubes by gentle inversion 7 times. Mix syringes by rolling between the palms 5 times in three directions. H. Criteria For Specimen Rejection -Evidence of clotting. -Specimens collected in anticoagulant other than lithium heparin. -Syringe for pH, PCO2, and PO2 with air bubbles in sample. -Other sample types such as urine, CSF and pleural fluid. -Samples not collected according to the specimen type precaution guidelines. I. Sample Transfer Device Blunt End Dispensers -To avoid the use of needles when transferring a blood sample from an evacuated tube, a dispenser can be used. Do not use dispensers because that would introduce air into the sample when ionized calcium, pH or pCO2 are being measured. J. Specimen Labeling Unless the specimen is analyzed immediately after collection and then discarded, the specimen container must be labeled with the following information. -Patient's name -Patient's social security number -Time and date of collection -Phlebotomist/collector ID III. Reagent and Supplies A. Reagents Test Cartridges The i-STAT Test Cartridge is a self contained testing system. Each cartridge is considered a "run", with no reuse of reagents or carry-over of specimen. The 6+ cartridge contains the following tests: 1. SD/ISTABG/OUTREA Sodium Page 6 of 6 2. 3. 4. 5. 6. 7. Potassium Chloride Glucose BUN Hematocrit Hemoglobin (calculated) The Arterial Blood Gas Cartridge, EG7+, performs the following tests: 1. 2. 3. Sodium 8. Potassium Ionized Calcium HCO3 (calculated) 9. TCO2 (calculated) 10. BE (calculated) 4. 5. 6. 7. pH PCO2 PO2 Hematocrit 11. 12. sO2 (calculated) Hemoglobin (calculated) The Arterial Blood Gas Cartridge, G3+, performs the following tests: 1. 2. 3. pH PCO2 PO2 4. 5. 6. 7. HCO3 (calculated) TCO2 (calculated) BE (calculated) sO2 (calculated) The Glucose cartridge performs only glucose. The Creatinine cartridge performs only creatinine. Each i-STAT Test Cartridge contains a buffered calibrant containing known concentrations of each analyte; a sample handing system; an array of unauthorized sensors; and conductive pads to make electrical contact with the analyzer. The sensors are electrodes which are micro-fabricated onto silicon chips. Sensing functionality is imparted to the electrodes by coating of chemically sensitive films such as ion-selective membranes and enzyme layers. Each sensor is connected to a contact pad by a signal line. Reagent Storage Test cartridges are stored in their sealed foil pouches at 2-8o C. Do not allow the cartridge to freeze. Cartridges are usable until the expiration date printed on the foil pouch if stored at 2-8o C. Cartridges may be stored at room temperature (18-30o) for a maximum of fourteen (14) days. If the cartridges are stored at room temperature, use the calendar on the cartridge box to indicate the room temperature expiration date. Do not use the SD/ISTABG/OUTREA Page 7 of 7 cartridges if the 14 day time has expired. Do not store cartridges at temperatures exceeding 30oC. 6+ and Glucose cartridges do not require thermal control and may be used after standing just 5 minutes at room temperature. An entire box should stand at room temperature for one hour. EG7+ and G3+,and Creatinine cartridges require thermal control (37 ) and may be used after standing just 5 minutes at room temperature. An entire box should stand at room temperature for one hour. DO NOT RETURN CARTRIDGES TO THE REFRIGERATOR ONCE THEY HAVE COME TO ROOM TEMPERATURE. Cartridges must be used immediately after they have been removed from the foil pouch. B. Supplies 1. i-STAT System Components a. b. c. d. e. f. 2. Blood Collection Supplies a. b. c. d. e. f. IV. Portable Clinical Analyzer Electronic Simulator Reagent Cartridge Printer (hand held) IR Interface Cradle Disposables (as appropriate for sample application) 2 x 2 Gauze Alcohol Pads Tourniquet Venipuncture Supplies (Needles, Syringes) Vacutainer Tubes (Lithium Heparin) Arterial Blood Gas Supplies (Needles, Syringes, low volume heparin blood gas syringes Quality Control A. Calibration and Linearity Calibration is performed internally each time a test cartridge is inserted into the i-STAT analyzer with no intervention required on the part of the operator. Each cartridge includes a sealed foil pack which contains a calibrant solution with a known concentration of each analyte. During the first part of the testing cycle the calibrator is automatically forced out of the foil pack and over the sensors. The signals produced by the sensors in response to the calibrant solution are stored. If the calibration fails, the i-STAT analyzer will give a code and results will not be calculated. SD/ISTABG/OUTREA Page 8 of 8 Calibration verification is performed by the Laboratory Department every six months. Linearity is performed by the Laboratory Department initially on each analyte tested. B. Quality Control Quality control (QC) is the process designed to ensure that a test system is working properly. The i-STAT system daily quality control is an electronic simulator. Liquid control and calibration verification solutions for verification of cartridges are tested by the laboratory for each new lot number of cartridges received. 1. Electronic Simulator a. External Electronic Simulator The Electronic Simulator is a stable electronic device which verifies the electrical measurement circuits by producing signals at two levels to check the accuracy and integrity of the circuits and the electrical isolation between individual measurement channels. The results of the Electronic Simulator are "PASS" or "FAIL". External Electronic Simulator is used to verify a failed internal simulator test. Remove the external Electronic Simulator from storage. Insert the external Electronic Simulator into the cartridge door to the i-STAT instrument. CONTRACTING CARTRIDGES will be displayed. Wait 70 seconds. PASS or FAIL will be displayed at the end of the simulator test. The acceptable limits for the simulator are set internally; FAIL will be displayed if the limits are exceeded. If PASS is displayed, patient testing may be initiated. If FAIL is displayed on the analyzer screen: Repeat the procedure with the same external Electronic Simulator. If PASS is displayed use the analyzer as required. If FAIL is displayed repeat the procedure with a different external Electronic Simulator. If PASS is displayed with the second external Electronic Simulator: Use the analyzer as required. Deliver the SD/ISTABG/OUTREA Page 9 of 9 questionable external Electronic Simulator to the Laboratory Department. If FAIL is DISPLAYED with the second external Electronic Simulator: DO NOT analyze patient samples with the analyzer. Transmit the results to the Central Data Station. Deliver the faulty analyzer to the laboratory. The Point of Care Coordinator will record the failure along with the action taken. Remove the external Electronic Simulator after the locked message “LCK” is no longer displayed and return to storage. The results of the external Electronic Simulator, the date, time and operator ID will be transmitted by a Respiratory Therapist to the Central Data Station via the infrared cradle for review and record keeping. Radiology and the CATH LAB will transmit their i-STAT analyzer each day at the end of 1st shift. Perform the Electronic QC in the following situations: 1) 2) 3) b. When an internal Electronic Simulator fails. When an analyzer is brought from a cold environment to a hot, humid environment to insure that any moisture that may have condensed on the internal connector has evaporated before performing patient tests. When the analyzer's batteries are changed. Internal Electronic Simulator The internal Electronic Simulator is selected on an 8/24 hour schedule. The internal Electronic Simulator will run every 8 hours for pH, pCO2, pO2, hematocrit and ACT channels and every 24 hours for all other channels. QC Lockout is enabled on all analyzers. This setting prevents analyzers from running a cartridge after a failed internal Electronic Simulator test. An internal Electronic Simulator is a circuit in the Analyzer which verifies the performance of each Analyzer by testing signals consistent with both very low and very high concentrations of each of the analytes. The software in the analyzer and module measure these signals as it would measure signals from a cartridge. The software checks the SD/ISTABG/OUTREA Page 10 of 10 measurements against predetermined thresholds and indicates their acceptability to the use via a PASS/FAIL message. ACT analyte has quality control tested every 8 hours. The internal Electronic Simulator is triggered by inserting a cartridge. If the software detects that the specified time has elapsed since the last Electronic Simulator test (internal or external), it will automatically perform the internal test before the sample is tested, adding about 15-20 seconds to the testing cycle. A failed Simulator test stops the cycle, the FAIL simulator result will be displayed on the screen, and the sample will not be analyzed. If the test passes, the cartridge cycle continues to completion and the cartridge results are displayed. What to do if the Electronic Simulator Fails: Rerun the cartridge in the same Analyzer to ensure the FAIL was not due to a one-time spike of electrical noise. If the test fails again, rerun the cartridge in another Analyzer if immediately available. Note that the cartridge should not be run if there is more than a three minute delay from the time it is filled. If the cartridge fails in more than one Analyzer, use another cartridge. In all cases, an external Electronic Simulator can be used to verify proper performance of Analyzer. Failed analyzers are to be brought to the laboratory for replacement. 2. Verification of Cartridges a. SD/ISTABG/OUTREA Verification of newly received cartridges (performed by the Laboratory Department) i) Verify that the transit temperatures of each shipment were satisfactory using the four window temperature indicator strip affixed to the cartridge box. ii) From each lot of cartridges received, analyze three levels of i-STAT and Meter Trax Controls each in duplicate, using any verified analyzer. iii) From each new lot number of cartridges received, analyze i-STAT calibration verification solutions one, three, and five to ensure that patient reference ranges (or reportable ranges) are acceptable from lot to lot. Hematocrit calibration verification is performed as a separate procedure at a minimum every 6 months (see i-STAT Calibration Verification Procedure). iv) Perform a parallel reagent check by comparing the quality calibration verification ranges from the previous lot numbers. Page 11 of 11 Perform QC on the old cartridge lot number along with the new cartridge lot number and record results. b. Storage Conditions i) Refrigerated Cartridges a) Verify that the cartridges stored in the designated Chemistry refrigerator are all within the expiration date printed on the boxes. Deliver any expired cartridges to the Laboratory Point of Care office. b) Verify that the Chemistry refrigerator did not exceed the limits of 2-8oC (25-46oF). c) Chemistry will document the refrigerator temperature daily. If the temperature of the cartridge storage refrigerator is within the range of 2-8oC (35-46oF) use cartridges as required. If the temperature is outside the range of 2-8oC (2546oF) quarantine the cartridges in the storage refrigerator. Notify the Point of Care Coordinator, Laboratory Manager, or Supervisor immediately. DO NOT USE the cartridges from the out-of-control refrigerator. Record the QC failure with the action taken via a Laboratory Incident report form. ii. SD/ISTABG/OUTREA Room Temperature Cartridges a) Verify that all boxes of cartridges at room temperature have been out of the refrigerator less than two weeks. Deliver any expired cartridges to the Laboratory Point of Care office. b) If the measured temperature of the room has been continuously below 30oC (86oF) use cartridges as required. Page 12 of 12 If the measured room temperature has exceeded 30o (86oF) for any period of time: Quarantine the cartridges. Notify the Laboratory Point of Care Coordinator, Laboratory Manager, or Supervisor immediately. DO NOT use the cartridges. Record the out of control event and the action taken via a Laboratory Incident report form. 3. Comparison of test methods for Sodium, Potassium, Chloride, BUN, Glucose, Hematocrit, and Creatinine is performed by the Laboratory Point of Care office every 6 months. (See Comparison of Test Methods procedure). 4. Proficiency Testing is performed on 6+, Creatinine and EG7+ cartridge using CAP’s AQ2 Survey. Laboratory Point of Care performs 6+ proficiency testing and Respiratory Therapy performs EG7+ proficiency testing. Proficiency testing samples are shipped three times during the year and include five challenges for each analyte or test. Samples are tested exactly like patient samples and the results are returned to CAP within 10 working days of receipt for grading. 5. If any QC result is not within range, take corrective action before any patient samples are tested. a. Repeat the test. b. c. If QC is within range, patient testing may proceed. If QC is not within range, DO NOT PERFORM PATIENT TESTING. The Point of Care Coordinator will notify i-STAT Technical Service. Corrective action taken is recorded in the i-STAT Central Data Station and noted on the i-STAT System QC Log. V. PROCEDURE A. Select the Cartridge to be used. 6+ Cartridge is used for stat Electrolytes, BUN, Glucose, and Hematocrit testing in ED, CCU, ICU, OR and the CATH Lab.. Creatinine cartridge is used for stat Creatinine in ED and Radiology. EG7+ Cartridge is used for ABG in Critical Care areas: ED, ICU, CCU, SCN, OR, PACU, and the CATH LAB.. G3+ Cartridge is used for ABG in SCN, ED, ICU, CCU, OR, PACU,the CATH LAB and on nursing floors/patient care units. SD/ISTABG/OUTREA Page 13 of 13 Glucose Cartridge is used in the Operating Room, and CATH LAB for patients with glucose concentrations above 200 mg/d and hematocrits below 25%. The cartridge should be handled as follows to avoid difficulty in filling or rejection by the analyzer: -Do not contaminate the contact pads with finger prints or talc from gloves as the analyzer may not be able to make proper contact with the cartridge. -Do not exert excessive pressure over the central area of the label as the calibrant pack underneath could burst prematurely. -Do not block the air vent as the sample will not be able to flow to the fill mark and the calibrant solution will not be able to flow to the sensors. -Do not use a cartridge on which blood or any other fluid is spilled, as the analyzer’s connector may be contaminated. B. Fill Test Cartridge 1. C. Remove the cartridge from the protective foil pouch after it has come to room temperature. 2. Place cartridge on a flat surface or hold it horizontally. Do not hold cartridge between the fingers if using a syringe with needle to fill the sample well. 3. Collect the blood specimen. 4. Direct the pipette tip, capillary tube, or needle into the sample well. 5. Dispense sample slowly and steadily until it reaches the FILL TO mark (tilt cartridge slightly if necessary). Avoid the introduction of air bubbles into the sample well. 6. Fill the sample well 1/3 to 2/3 full. 7. Once the cartridge is full, complete the procedure without delay. Seal Test Cartridge 1. Fold the plastic snap closure over the sample well. 2. Press on the rounded end of the closure until it snaps into place. SD/ISTABG/OUTREA Page 14 of 14 3. D. Failure to seal the cartridge will prevent patient testing. Insert Test Cartridge into the i-STAT Analyzer 1. Hold the analyzer firmly in one hand. Grasp the test cartridge by the sides, label facing up, with the other hand. 2. Push the cartridge slowly and smoothly through the cartridge door until it will go no further. The cartridge activates the analyzer. The analyzer displays "CONTACTING CARTRIDGE" then a time-to-result bar, the cartridge type, "LCK" prompt, and an area in which to enter operator and patient identification numbers. Do not attempt to remove a test cartridge while the "LCK" prompt is displayed indicating that the cartridge should not be removed. The force necessary to remove the cartridge would damage the analyzer and invalidate the results. E. Enter Identification Numbers 1. Enter your assigned operator identification number. Respiratory Therapists use your LIS numerical Tech Code. All other operators use the first 6 digits of your social security number. Use the numerical keypad to enter the number. Press the "CLR" key to backspace and erase a wrong number. Press the "ENT" key to enter the completed number. 2. After the ENT key is pressed, the prompt "Repeat #, ENT" appears in the box. Repeat the operator identification number as above and press ENT to signal the analyzer that the last digit has been entered. 3. Enter the patient's account number, not the patient social security number, in the same manner as the operator ID number. 4. If either the operator identification or the patient identification numbers are not entered correctly in duplicate, the message "ID DID NOT MATCH START AGAIN" will display. Re-enter the ID number that was in error. Operating rooms and “codes” present a unique testing situation in that tests are run repeatedly on the same patient. Pressing the DIS key when prompted for Patient ID will recall the last Patient ID entered into the analyzer. The repeat request for Patient ID may also be entered by pressing the Display key. F. Enter Blood Gas and Patient Information SD/ISTABG/OUTREA Page 15 of 15 After the patient identification number is entered, the PAGE key is activated allowing access to an additional data entry screen. (If results are already displayed, press the PAGE key twice to access the data entry screen). The cursor will be flashing at the first input area. Use the numbered keys to input information and press the ENT key to advance to the next input area (or to return to the first area from the last input area). Invalid numbers will be ignored, and incorrect inputs can be corrected using the CLR key as a backspace. Pt Temp Enter the patient’s temperature in degrees Fahrenheit or Centigrade. Use the * key to enter a decimal point. The analyzer will interpret numbers between 50.0 and 110.0 as degrees Fahrenheit and between10.0 and 45.0 as degrees Centigrade. FIO2 Enter the FIO2 value as a whole number from 0 to 100, representing the number of liters or a percentage of the oxygen the patient is receiving. Use the * key to enter a decimal point. Free Field 1:(6 spaces) DEL MODE RATE PRESSURE SYS SUPPORT Delivery System:(1 space) 0= room air 1= nasal can 2= fac tent 3= hood 4= CPAP 5= trach 6= mask 7= vent 8= croup tent Free Field 2: (5 spaces) TIDAL VOLUME SD/ISTABG/OUTREA Mode:(1 space) Rate:(2 spaces) 1= AC 0-99 2= SIMV if RR<10 use a 0 3= CPAP to precede # 4= P/C PEEP PS:(2 spaces) Page 16 of 16 Tidal Volume (3 spaces) PEEP (2 spaces) Free Field 3: (4 spaces) SITE DRAWN BY ALLENS TEST Collection Site 1= R Rad Drawn By Allens Test MD NOTIFIED 2= L Rad 2=RN MD Notified 1= operator 1= yes 1= yes 2= no 2= no 3= R Brach 3=RT 4= L Brach 4= MD 5= R Fem 6= L Fem 7= art line 8= UAC 9= UVC Sample TYPE Enter the number corresponding to the sample type: 1 ART(arterial) 4 CORD 2 VEN (venous) 3 CAP (capillary) 5 MXVN(mixed venous) 6 CPB (cardiopulmonary bypass) When 6(CPB) is chosen as the sample type, a special algorithm for hematocrit values is used. The algorithm infers a total protein level, assuming the pump priming solution dilutes the hematocrit and total protein equally. An adjusted hematocrit value is reported Hct,CPB on both the analyzer display and printout. After data entry is completed the free fields may be edited until the results are printed or transmitted to the Central Data Station or until a new cartridge or external Electronic Simulator is run. G. View Results The Portable Clinical Analyzer will display test results once the cartridge has been unlocked and the LCK prompt disappears. Results will be displayed for 45 seconds . Results can be recalled to the display screen by pressing the display key. H. Results should either be transcribed onto the patient’s medical record or transmitted to the portable printer or the Central Data Station I. Remove the Test Cartridge SD/ISTABG/OUTREA Page 17 of 17 1. VII. Remove the cartridge any time after the "LCK" prompt disappears from the display screen. Discard the cartridge in an appropriate Biohazard Waste receptacle. 2. The analyzer display will deactivate after 45 seconds to save the battery. The last results can be recalled by pushing "DISPLAY". 3. Once a cartridge is removed, even if results are still displayed, the analyzer is ready to accept another cartridge. Calculations The i-STAT Portable Clinical Analyzer contains a microprocessor that performs all calculations required for reportable results. VIII. Reporting Results The i-STAT Analyzer will produce an audible beep as soon as the results are displayed. The results are displayed in numerical and bar graph forms. Results may be recorded on the patient's chart directly from the i-STAT LED display or printed and the printout placed on the patient's chart until the patient's laboratory cumulative summary is charted. The i-STAT will accumulate a total of 50 test records (patients, control material, and electronic simulator tests). All information will be transmitted to the Central Data Station, located in the Laboratory, via the IR Cradle. Test results are displayed showing numerical concentration values. Bar graphs which depict the values in relation to reference ranges are also displayed. Blood gas results are not displayed with reference ranges. The reference range is marked on the bar by tick marks. When all test values are within their reference ranges, the tick marks will be centrally aligned. The bar graphs can be used as a visual cue for distinguishing between “normal” and “abnormal” results. A. Linearity The reportable range for i-STAT constituents are as follows: TESTS Na K Cl BUN SD/ISTABG/OUTREA Page 18 of 18 Glu Hct Hgb (calculated) Crea iCA pH PO2 PCO2 HCO3 TCO2 Base Excess/BE Result Out of Reportable (Linear) Range: 1. 2. B. If a "<" or ">" sign precedes a value or if a "< >" sign is displayed, the value exceeded the linear range of measurement for that particular test. Report the “< or >” result immediately to the patient’s attending physician or nurse. 6+cartridge results must be repeated by laboratory analysis. A lithium heparin (green stoppered) tube must be collected for Electrolyte, BUN , and Glucose verification. An EDTA (lavender stoppered) tube must be collected for Hematocrit verification. The test to be repeated must be ordered in SMS as STAT. The patient will be credited by Laboratory Point of Care for all verification repeats. Results Displayed 1. Test results are displayed in numerical concentrations and on the bar graph. Results are direct readout; no calculation is necessary. There are four exceptions to the direct readout when the results are not reportable: a. SD/ISTABG/OUTREA Uncharacteristic Results Page 19 of 19 [****] is displayed in place of one or more results when a signal from a sensor is uncharacteristic. This may be due to a defective sensor or an interferant in the sample. If [****] is displayed repeat the test with a fresh cartridge. If [****] is still displayed on the 6+cartridge result, the physician may request a repeat by laboratory analysis. Follow steps VIII, A, 2 for repeating an i-STAT result by laboratory analysis. b. Results Out of Reportable (Linear) Range See above section on Linearity. c. Results Which Exceed Critical Limits (Alert Values) i. Results which exceed the laboratory established "Alert Values" represent an emergency condition. ii. If critical test result for venous Electrolytes or Hematocrit is within the i-STAT Analyzer's reportable range repeat the test for verification with a fresh test cartridge and report the result. Glucose >350 mg/dL must be verified by repeat in the laboratory except for OR patients. The physician will determine if repeat verification is to be done. Follow step VIII, A,2 for repeating an i-STAT result by laboratory analysis. ABG alert values are NOT repeated. Arterial electrolytes, ionized Calcium, and Hematocrit are NOT repeated. iii. All results which exceed Critical Limits must be brought to the physician or RN responsible’s attention immediately either by phone call or direction notification. Physician or RN notification of the Alert Value must be documented on the patient's chart. Respiratory Therapists will give all results directly to the physician or RN. Physician/RN notification is entered into the i-STAT analyzer and reported on the ABG patient report. Alert values repeated by i-STAT only will have a Critical Value Documentation Verification form sent to the nurse manager or designee. The form must be completed and returned to Laboratory Point of Care. The established Alert Values are as follows: SD/ISTABG/OUTREA Page 20 of 20 Na K Glu Hct iCa pH PO2 PCO2 Any neonate glucose result below 45 mg/dL or above 150mg/dL should be followed up according to the Neonate Blood Glucose Testing procedure located in the Nursing unit procedure manual. d. 2. Test cycle not completed due to problem with the sample, calibrant solution, sensors, mechanical or electrical functions of the analyzer: take the action displayed with the message that identifies the problem. Refer the problem to the Laboratory Point of Care Coordinator if necessary. Display Stored Results: To recall a stored test record to the display screen, press the MENU soft key and select STORED RESULTS by pressing the "2" key, from the STORED RESULTS menu, select DISPLAY A RESULT by pressing the "1" key. Select the record to be displayed by pressing the key (1 to 5) on the pages (1 to 10) corresponding to the test record. The list of stored results can be listed with Cartridge Type or Date/Time. Use the DIS key to toggle between these display modes. C. Printing Results: 1. SD/ISTABG/OUTREA Place the analyzer in the printer cradle. Turn the printer on (printer light green) or press the paper advance key to reactivate. Page 21 of 21 2. To print the displayed test record, press the PRT key on the analyzer. The most recent test record can be printed only if a patient identification number has been entered or actively bypassed. 3. Do not move the analyzer while "Printing" is displayed. Note: Results printed on thermal paper will fade with time and, therefore, not acceptable as permanent chartable record. 4. Write the patient's name on the Pt name line, the physician's name on the Physician line, and the Sample type on the Sample type line. 5. A stored test record can be printed without recalling the results to the screen. Press the MENU soft key, select STORED RESULTS by pressing the "2" key. From the STORED RESULTS Menu select PRINT RESULTS by pressing the "2" key. Use the soft keys to page up or down through the 10 pages of stored test records, press the 1 to 5 keys to select the desired records on each page. When a key is pressed, the number selected will reserve video (dark background, light lettering). To deselect a record, re-press the key, the number will return to light background, dark lettering. The list of stored results can be listed with Cartridge Type or Date/Time. Use the DIS key to toggle between these display modes. When all the test records desired are selected, press the PRT key. The message "PRINTING..." will be displayed while the records are transmitted to the printer. Each record will take about 45 seconds to print. D. 6. To stop printing before all test records are printed, press the * key. 7. A test record cannot be printed from a position displaying INVALID or NO DATA, an Electronic Simulator test or an error code. Transmitting Results to the Central Data Station 1. i-STAT operators will transmit Arterial Blood Gas (ABG) results immediately after completion of each ABG test. Respiratory Therapy will transmit all results from each analyzer that ABGs are performed on at the beginning of each shift. Radiology will transmit all results at the end of first shift, Monday through Friday. The Cardiac Cath Lab will transmit all results at the end of each case. 2. SD/ISTABG/OUTREA Place the analyzer in the IR Interface cradle. The IR Interface light must be green. Page 22 of 22 E. 3. To transmit all stored test records, press the * key or access STORED RESULTS from the menu. Press the "3" key on the analyzer to transmit all test records. 4. Do not move the analyzer while "Transmitting" is displayed. 5. During transmission the IR Interface light will blink alternately red and green. If transmission is successful, the interface will emit a single high pitched beep, and the light will return to green. An unsuccessful transmission is indicated by three low tone beeps. In this case repeat the transmission process. If unsuccessful the second time, notify the Laboratory Point of Care Coordinator. Transmitting Results from the Central Data Station to the Lab Computer. Test records will be routinely transmitted to LIS automatically via an AME interface. The Laboratory Point of Care Office will transmit results manually from the Central Data Station to the Laboratory Information System when AutoSend is off: F. 1. Use the up and down arrow keys on the Central Data Station to highlight the patient test record to be transmitted. 2. Press the F9 key. 3. "_ _ _" indicates that the record is in queue. 4. ". . ." indicates the record is being transmitted. 5. A check mark in the Central Data Station SENT column indicates that the results have been transmitted. 6. Activate the Auto Send "on" to resume automatic transmission. Reference Range The i-STAT Reference Ranges have been derived from the literature and are programmed into the i-STAT Analyzer. The reference ranges are as follows: Na SD/ISTABG/OUTREA Page 23 of 23 K Cl BUN Glu Hct Hgb Crea iCA pH PO2 sO2 PCO2 HCO3 TCO2 Base Excess/BE The reference ranges listed below are those used by Durham Regional Hospital Laboratory (serum/plasma samples for chemistries). Sodium, Potassium, Chloride, BUN, Glucose, Hematocrit, Hemoglobin, and Creatinine values have been established by in-house normal range studies and available literature. Arterial Blood Gases and ionized Calcium have been derived from the literature. SD/ISTABG/OUTREA Page 24 of 24 Na K Cl BUN Glu Hct- SD/ISTABG/OUTREA Page 25 of 25 Hgb Hgb Crea iCa pH PO2 SD/ISTABG/OUTREA Page 26 of 26 PCO2 sO2 IX. Clinical Significance Sodium Test for sodium in the blood are important in the diagnosis and treatment of patients suffering from hypertension, renal failure or impairment, cardiac distress, disorientation, dehydration, nausea and diarrhea. Some causes of increased values for sodium include dehydration, diabetes insipidus, salt poisoning, skin losses, hyperaldosteronism and CNS disorders. Some causes for decreased values for sodium include delusional hyponatremia (cirrhosis), depletional hyponatremia and syndrome of inappropriate ADH. Potassium Tests for potassium in the blood are important in the diagnosis and treatment of patients suffering from hypertension, renal failure or impairment, cardiac distress, disorientation, dehydration, nausea and diarrhea. Some causes of increased values for potassium include renal glomerular disease, adrenocortical insufficiency, diabetic ketoacidosis (DKA), sepsis and in vitro hemolysis. Some causes of decreased values for potassium include renal tubular disease, hyperaldosteronism, treatment of DKA, hyperinsulinism, metabolic alkalosis and diuretic therapy. Chloride Tests for chloride in the blood are important in the diagnosis and treatment of patients suffering from hypertension, renal failure of impairment, cardiac distress, disorientation, dehydration, nausea and diarrhea. Some causes of increased values for chloride include prolonged diarrhea, renal tubular disease, hyperparathyroidism and dehydration. Some causes for decreased values for chloride include prolonged vomiting, burns, salt-losing renal disease, overhydration and thiazide therapy. Urea Nitrogen/BUN An abnormally high level of urea nitrogen in the blood is an indication of kidney function impairment or failure. Some other causes of increased values for urea nitrogen include prerenal azotemia (e.g. shock), postrenal azotemia, GI bleeding and high protein diet. Some causes of decreased values of urea nitrogen include pregnancy, severe liver insufficiency, overhydration and malnutrition. Glucose Glucose is a primary energy source for the body and the only source of nutrients for the brain issue. Measurements for determination of blood glucose levels are important in the diagnosis and treatment of patients suffering from diabetes and hypoglycemia. Some causes for increased values of glucose include diabetes mellitus, pancreatitis, endocrine disorders (e.g. Cushings syndrome), drugs (e.g. steroids, thyrotoxicosis), chronic renal failure, stress, or I.V. glucose infusion. Some causes of decreased values of glucose include insulinoma, adrenocortical insufficiency, hypopituitarism, massive liver disease, ethanol ingestion, reactive hypoglycemia, and glycogen storage disease. SD/ISTABG/OUTREA Page 27 of 27 Hematocrit Hematocrit is a measurement of the volume of red blood cells. This is a key indicator of the body's state of hydration, anemia or severe blood loss, as well as the blood's ability to transport oxygen. Some causes of increased values of hematocrit include dehydration,burns, impaired ventilation and renal disorders. Some causes for decreased values of hematocrit include hemolytic anemias, iron deficiency, marrow depression or blood loss. Creatinine Elevated levels of creatinine are mainly associated with abnormal renal function and occur whenever there is a significant reduction in glomerular filtration rate or when urine elimination is obstructed. The concentration of creatinine is a better indicator of renal function than urea or uric acid because it is not affected by diet, exercise or hormones. Ionized Calcium Although most of the calcium in blood is bound to protein or complexed to smaller anionic species, the biologically active fraction of calcium is free ionized calcium. Through its role in a number of enzymatic reactions and in membrane transport mechanisms, ionized calcium is vitally important in blood coagulation, nerve conduction, neuromuscular transmission and in muscle contraction. Increased ionized calcium (hypercalcemia) may result in coma.Other symptoms reflect neuromuscular disturbances, such as hyperreflexia and/or neurologic abnormalities such as neurasthenia, depression or psychosis. Decreased ionized calcium often results in cramps (tetany), reduced cardiac stroke work and depressed left ventricular function. Prolonged hypocalcemia may result in bone demineralization (osteoporosis) which can lead to spontaneous fractures. Measurments of ionized calcium have proven of value under the following clinical conditions: transfusion of citrated blood, liver transplantation, open heart surgery, neonatal hypercalcemia, renal disease, hyperparathyroidism, malignancy, hypertension, and pancreatitis. pH pH is an index of the acidity or alkalinity of the blood with an arterial pH of <7.35 indicating an acidemia and >7.45 alkalemia. PO2 PO2 (partial pressure of oxygen) is a measurement of the tension or pressure of oxygen dissolved in blood. Some causes for decreased values of PO2 include decreased pulmonary ventilation, impaired gas exchange between alveolar air and pulmonary capillary blood, and alteration in the flow of blood within the heart or lungs. PCO2 PCO2 along with pH is used to assess acid-base balance. PCO2 (partial pressure of carbon dioxide), the respiratory component of acid-base balance, is a measure of the tension or pressure of carbon dioxide dissolved in the blood. Causes of primary respiratory acidosis (increase in PCO2 ) are airway obstruction, sedatives and anesthetics, respiratory distress syndrome, and chronic obstructive pulmonary disease. Causes of primary respiratory alkalosis (decreased PCO2) are hypoxia due to chronic heart failure, edema and neurologic disorders, and mechanical hyperventilation. HCO3 (bicarbonate) SD/ISTABG/OUTREA Page 28 of 28 HCO3 (bicarbonate) is an indicator of the buffering capacity of blood. Regulated primarily by the kidneys, HCO3 is the metabolic component of acid-base balance. Causes of primary metabolic acidosis are ketoacidosis , lactate acidosis, and diarrhea. Causes of primary metabolic alkalosis are vomiting and antacid treatment. TCO2 (total carbon dioxide) TCO2 (total carbon dioxide) is a measure of carbon dioxide which exists in several states: CO2 in physical solution or loosely bound to proteins. Bicarbonate ions make up all but approximately 2mmol/L of the total carbon dioxide of plasma. Measurement of TCO2 as part of an electrolyte profile is useful chiefly to evaluate HCO3 concentration. TCO2 and HCO3 are useful in the assessment of acid-base imbalance (along with pH and PCO2) and electrolyte imbalance. Base Excess/BE Base excess remains virtually constant during acute changes in the PCO2 and reflects only nonrespiratory component of pH disturbances. X. Limitations of Procedure Proper venipuncture technique must be followed to avoid hemolysis of the sample or tissue fluid contamination. Interferences: Hydroxurea (Droxia, Hydrea) Hydroxyurea can cause significant errors in the measurement of Glucose, and Creatinine with the i-STAT system. An alternate method must be used to measure Glucose and Creatinine when patient’s have been administered hydroxyurea.. Hemodilution of the plasma by more than 20% associated with priming cardiopulmonary bypass pumps, plasma volume expansion or other fluid administration therapies using certain solutions may cause clinically significant error on Sodium, Chloride, Ionized Calcium, and pH results. These errors are associated with solutions that do not match the ionic characteristics of plasma. These errors can be avoided if when hemodiluting by more than 20%, physiologically balanced multi-electrolyte solutions containing low-mobility anions (e.g. gluconate) such as Normosol-R (Abbott Laboratories). Plasma-Lyte-A (Baxter Healthcare Corporation), and Isolyte-S (B Braun Medical) are used. Thiocyanate Thiocyanate is a degradation product product of nitroprusside treatment and also a product of thiosulphate treatment of cyanide poisoning. It may cause falsely elevated Chloride results, or may cause chloride results to be suppressed (“star out”). SD/ISTABG/OUTREA Page 29 of 29 It can cause falsely decreased BUN/urea, and Glucose results. Preliminary studies indicated that 140mg/dL (24mmol/L) thiocyanate decreased BUN/urea results approximately 21%, and decreased Glucose results approximately 23%. Bromide 37.5 mmol/L bromide will increase Sodium results by 5 mmol/L, and decrease Glucose by 30mg/L.. 12.5mmol/L (100mg/dL) bromide will increase Chloride results by 30 mmol/L, and will increase Creatinine by 0.8mg/dL (71 umol/L) from an initial creatinine concentration of 1.0 mg/dL (88 umol/L). Lactate 20 mmol/L lactate will decrease Sodium results by 5 mmol/L, and decrease Ionized Calcium results by 0.05 mmol/L.. 11 mmol/L (100 mg/dL) lactate will increase Chloride results by 3.5 mmol/L. B-hydroxybutyrate 16 mmol/L (166 mg/dL) B-hydroxybutyrate will decrease Sodium results by 5 mmol/L, and will increase Chloride results by 3 mmol/L.. 20 mmol/L B-hydroxybutyrate will decrease Ionized Calcium results by 0.1 mmol/L. Salicylate 4 mmol/L salicylate will increase Chloride results by 5 mmol/L. 4.34 mmol/L salicylate will decrease Ionized Calcium results by 0.1 mmol/L. Magnesium 1.0 mmol/L magnesium above normal will increase Ionized Calcium results by 0.04 mmol/L. Ascorbate 11 mmol/L ascorbate will cause a 0.7 mg/dL increase in Creatinine. A. Sodium The use of blood collection tubes containing sodium heparin as an anticoagulant may increase sodium results up to 1 mmol/L. SD/ISTABG/OUTREA Page 30 of 30 B. Potassium If heparanized whole blood is allowed to stand before testing, potassium values will first decrease slightly, then increase over time. Potassium will increase in iced specimens. Potassium values from anticoagulated samples are preferred to serum values because 0.1 to 0.7 mmol/L potassium can be released from platelets and red blood cells during the clotting process. Potassium values obtained from skin puncture samples may vary due to hemolysis or an increase in tissue fluid from improper technique during the collection procedure. E. Glucose Glucose values will decrease in whole blood samples over time. Venous blood glucose is as much as 7 mg/dL less in capillary blood glucose as a result of tissue utilization. pH Values below 7.4 at 37 Cdecrease results by approximately 0.9 mg/dL (0.05 mmol/L) per 0.1 pH units. Values above 7.4 at 37 C increase results by approximately 0.8 mg/dL (0.04 mmol/L) per 0.1 pH units. PO2 Oxygen levels of less than 20mmHg (2.66 kPa) at 37 C may decrease results. . F. Hematocrit Grossly elevated WBC counts may increase results. High Hematocrit results can be caused by settling of red blood cells in the sample. Low hematocrit results can be caused by contamination from flush solutions in an arterial or venous line. Hematocrit results are affected by the level of total protein as follows: For HCT values below 40%PCV: For Total Protein values below 6.5g/dL, HCT decreased by 1% PCV for each decrease of 1g/dL TP. For Total Protein values above 8.0g/dL, HCT increased by 1% PCV for each increase of 1g/dL TP. For HCT values above 40%PCV: SD/ISTABG/OUTREA Page 31 of 31 For Total Protein values below 6.5g/dL, HCT decreased by 0.75% PCV for each decrease of 1g/dL TP. For Total Protein values above 8.0g/dl, HCT increased by 0.75%PCV for each increase of 1g/dL TP. Abnormally high lipids may increase results. Interference from lipids will be about two thirds the size of the interference from protein. The sample electrolyte concentration is used to correct the measured conductivity prior to reporting hematocrit results. Factors that affect sodium will therefore also affect hematocrit. G. Ionized calcium Venous stasis (prolonged tourniquet application) and forearm exercise may increase ionized calcium due to a decrease in pH caused by localized production of lactic acid. Exposing the sample to air will cause an increase in pH due to the loss of CO2 which will decrease ionized calcium. Heparin binds calcium. Each unit of heparin added per mL of blood will decrease ionized calcium by 0.01mmol/L. The correct ratio of heparin anticoagulant to blood must be achieved during sample collection. Intravenous injection of 10,000 units of heparin has been shown in adults to cause a significant decrease of ionized calcium of about 0.03mmol/L. Affect of Freezing: Cartridges should be stored between 2 and 8 C. Freezing should be avoided. Freezing will cause the ionized calcium in the calibrant fluid to precipate, which will cause sample results to be falsely elevated. To help avoid freezing, do not store cartridges against the walls of the refrigerator. If freezing is suspected, test a sample of the cartridges using i-STAT controls. H. pH Venous stasis and forearm exercise may decrease pH due to localized production of lactic acid. Exposing the sample to air will cause an increase in pH due to the loss of CO2. pH decreases on standing anaerobically at room temperature at a rate of 0.03 pH units per hour. I. PO2 Exposure of the sample to air will cause an increase in PO2 when values are below 150 mmHg and a decrease in PO2 when values are above 150 mmHg (approximate PO2 of room air). SD/ISTABG/OUTREA Page 32 of 32 Standing anaerobically at room temperature will decrease pH at a rate of 0.03 per hour, will increase PO2 by approximately 4mmHg per hour and will decrease PO2 at a rate of 2-6 mmHg per hour. Do not ice samples before testing-PO2 results may be falsely elevated in cold samples. Do not use a cold cartridge.-PO2 results may be falsely decreased if the cartridge is cold. sO2 values calculated from a measured PO2 and an assumed oxyhemoglobin dissociation curve may differ significantly from the direct measurement. J. PCO2, TCO2,HCO3 Exposing the sample to air allows CO2 to escape which causes PCO2 to decrease and pH to increase and HCO3 and TCO2 to be under-estimated. Allowing blood to stand (without exposure to air) before testing allows PCO2 to increase and pH to decrease which will cause HCO3 and TCO2 to be overestimated due to metabolic processes. K. Creatinine For Creatinine values below 2 mg/dL: For PCO2 values above 40, creatinine values are increased by 6.9% for every 10 mmHg For PCO2 values below 40, creatinine values are decreased by 6.9% for every 10 mmHg. For Creatinine values above 2 mg/dL: For PCO2 values above 40, creatinine values are decreased by 3.7% for every 10 mmHg For PCO2 values below 40, creatinine values are increased by 3.7% for every 10 mmHg. A creatine level of 5 mg/dL will cause a 0.20 mg/dL increase in Creatinine. Creatine may be elevated in patients using creatine supplements, experiencing muscle trauma or other primary or secondary myopathies, taking statins for hyperlipidemia control, or in patients with hypothyroidism or a rare genetic defect of the creatine transporter protein. XI. Reference A. B. SD/ISTABG/OUTREA i-STAT Cartridge and Test Information Sheets for Sodium, Potassium, Chloride, Glucose, BUN, Hematocrit, revised November 1996. The i-STAT Corporation, Princeton, New Jersey. i-STAT System Manual, revised October 2003. The i-STAT Corporation, Princeton, New Jersey Page 33 of 33 C. Tietz, Norbert W., Clinical Guide to Laboratory Tests, pp. 446-447, pp 398399, pp. 110-111, pp. 230-231, pp. 492-493, pp. 258-259, W. B Saunders company, Philadelphia, PA., 1983. Procedure Written By: Kathryn Winston, 10/04 Procedure Revised By: Kathryn Winston, 10/94, 11/95, 8/96, 6/97, 10/97,5/98,7/98,11/98,11/99, 2/00,3/00,10/00,1/01,6/01,11/01, Susan Montsinger 4/04, 5/05 Procedure Reviewed By: ________________________________ John T. Daly, M.D. Date DRH Laboratory Director __________________________________ Mark Powers, M.D. Date Director of Arterial Blood Gas Laboratory ________________________________ Susan Montsinger BS,MT(ASCP) Date Point of Care Coordinator _________________________________ Charles Alford, RRT Director of Cardiopulmonary Services SD/ISTABG/OUTREA
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