! " -sum total of abnormalities of all organ systems and their interactions that determine the outcome of an operation #$ % & -estimation using Goldman’s cardiac risk index -risk of surgical cardiac death: -no previous MI: 1.0-1.2% -MI > 6 months: 6.0% -MI (transmural) < 3 months: 16-37% -predisposing factors for perioperative cardiac death: 1. infarction within 6 months 2. congestive heart failure 3. arrhythmias 4. aortic stenosis 5. emergency or major surgery 6. age greater than 70 years 7. poor medical condition -ECG and hematocrit level are significant -stress test indicated to identify patients at risk -positive if any or all of the following: -ST depression > 0.2 mV, inadequate heart rate response to stress, or hypotension -delay surgery (if possible) to > 6 months after MI -angioplasty or CABG may be necessary before any major surgical procedure -treat CHF and a-fib #'$ ( & -risk factors: 1. smoking 2. obesity 3. advanced age 4. industrial exposure 5. PCO2 > 45 mmHg diffusion defect 6. abnormal PFTs: -FVC < 70% predicted -FEV1 < 2.0L or < 70% predicted -PEFR < 200 L/min -FEV1/FVC < 65% 7. PAP > 30 mmHg -exercise oxygen consumption (prior to thoracotomy) (VO2) > 20 ml/kg/min less likely to have post-op pulmonary complications -8 weeks smoking cessation prior to surgery beneficial #)$ * & -serum abnormalities of BUN and Cr are not manifest until > 75-90% of renal reserve lost -creatinine clearance (ml/min) = [1.23 x weight (140-age)]/creatinine in umol/L -correct reversible causes: infection, uncontrolled hypertension, obstruction, and dehydration -peritoneal, hemodialysis, or continuous ultrafiltration occasionally required #+$ * & -patients with cirrhosis -Child-Pugh criteria: based on presence of ascites, bilirubin, encephalopathy, nutritional status, albumin -class A < 5%; B 5-10%; C 20-50% mortality following non-cardiac surgery -generally die of high-output CV failure and low peripheral resistance -see Table 11-4 -measures that can be taken: -abstinence from alcohol important prior to elective procedures -improve protein tolerance by use of branched-chain amino acid -control ascites: -spironolactone and lasix combined with fluid restriction to 1500 ml/day -limit sodium to 2g/day #,$ & see Chap. 3 * #-$ . */* -difficult to assess -severely malnourished patient: -weight loss > 15% over previous 3-4 months -serum albumin < 3.0 g/dL -energy to injected skin-test antigens -serum transferring level < 200 mg/dL -if severely malnourished, then enteral or parenteral (only if severe) nutrition for 4-5 days preop -normalize retinol binding protein, thyroxin-binding prealbumin, and transferring #0$ ! &# 1 -no definite guidelines -see appendix . 3 2 * 2 $ 4 Pathophysiology: -lack of metabolically effective circulating insulin -deficient utilization of glucose by peripheral tissues -increased output of glucose by liver -increased fatty acids ketones urine -glycosuria osmotic diuresis loss of sodium and potassium -anaesthetic agents can cause an exaggerated hyperglycemic epinephrine response and an increased resistance to exogenously administered insulin -stress of operation aggravates hyperglycemia -epinephrine: glycogenolysis -glucocorticoid: mobilized protein, anti-insulin effect -growth hormone Management: -DM pts should have preference on operative schedule to minimize effects of fasting and ketosis -mild DM frequently do not require insulin; dietary control sufficient -pts using OHA should continue their use until day before operation Insulin Therapy: -see appendix for protocols Ketoacidosis: -IV hydration, insulin therapy, and electrolyte replacement (potassium) -need for potassium usually does not exceed 80 mEq Nonketotic Hyperglycemic Hyperosmolar Coma: -relatively uncommon -usually occurs in elderly diabetic or nondiabetic obese patients and those receiving TPN -treat with large amounts of hypotonic solutions and intravenous insulin (est dose of 10 U) ! Pathophysiology: -disorder of normal body thermoregulation -controlled by anterior hypothalamus -?protective mechanism to combat infection -all pyrogens evoke common mediator IL-1 (endogenous pyrogen) -alters activity of temperature-sensitive neurons raises set-point -vasoconstriction chills, shivering increased body temperature Perioperative Fever: -fever in the immediate postoperative period usually is not serious, is not very high, and is self-limited -usually ascribed to atelectasis Malignant Hyperthermia: -incidence ~ 1/100000 general anaesthetic procedures -succinylcholine, halothanes metabolic acidosis and electrolyte imbalances -hypercalcemia, hypotonicity, hyperthermia (~40OC), oxygen denaturation, hypercapnia, cardiac dysrhythmia -treat with dantrolene IV 1 mg/kg, repeat to total dose of 10 mg/kg prn -supportive measures; ventilation/oxygenation, treatment of possible myoglobinuria Fever within 24 Hours: -usually due to atelectasis or failure to clear pulmonary secretions -unnecessary to do extensive tests at this point -if high fevers with rigours, hypotension, and changes in mentation: consider severe wound complications such as necrotizing fasciitis or intestinal leak Fever at 24-48 Hours: -usually respiratory complications -catheter related problems - UTI -inspect wound for cellulitis, necrotizing fasciitis, or clostridia myositis Fever after 48-72 Hours: -thrombophlebitis -most common cause of fever after 72h is wound infection -also suspect UTI -less common infections: pneumonitis, acute cholecystitis, idiopathic postoperative pancreatitis -drug allergy -candidiasis may complicate IV TPN tx with amphotericin B -fever after 1 week leaking anastomosis, abscess, deep wound infection 5 5 . % 4 /* Predisposing Factors: -staphylococcus aureus most frequently involved offending organism -enteric organisms in bowel surgery; other less common pathogens: enterococci, Psedomonas, Proteus, Klebsiella -hemolytic strep responsible for 3% of wound infections Classification of Operative Wounds Class Wound Description I Clean Nontraumatic, uninfected operative wounds in which the respiratory, alimentary, or genitourinary tract is not entered. Usually closed without drains 1.5-3.9% II Clean-contaminated Respiratory, alimentary, or genitourinary tract is entered with only minimal contamination 3-4% III Contaminated Fresh traumatic wounds; wounds with a major break in sterile technique; wounds encountering non-purulent inflammation; wounds made in or near contaminated skin 7.4-8.5% IV Dirty Purulent infection is encountered 28-40% Factors: -type of operative wound -age: -diabetes: -steroids: -obesity: -remote infection -duration of operation: -malnutrition -others (see Table 11-9) Examples Incidence of Infection 15-24 years (4.7%); > 65 years (10%) not an independent risk factor when adjusted to age increase rates from 7 to 16% doubles rate < 30 min (3.6%); > 6 hours (18%) Prevention: -skin preparation: -bowel preparation: -prophylactic antibiotics -maintenance of temperature: -meticulous technique: -appropriate drainage -clipping (2% infection rate) preferred over shaving (5%) of hair -clear liquids, cathartics, antibiotic regimens -warming blankets, warm fluids -gentle handling of tissue, hemostasis Clinical Manifestations: -infections usually evident between 5th and 8th POD; may manifest after weeks if pt on antibiotics -necrotizing fasciitis or clostridia myositis can occur within 24 hours Management: -open incision and pack wound with gauze -cellulitis and edema add antibiotics; Gram stain may help guide treatment -if hemolytic strep penicillin for 1 week -clostridia myositis/necrotizing fasciitis surgical debridement -Fournier’s gangrene: necrotizing fasciitis of perineum or groin in diabetic patients -30-70% mortality rate 5 % * -inadequate hemostasis -provide good culture medium for bacteria -early haematomas return to OR ligate responsible vessel primary closure of wound -late haematomas manage patient expectantly with hope that haematoma has not become contaminated 5 % * -lymph collections -aspiration and pressure dressings -continuous closed-suction drainage 5 % . *1 * * -< 45ya: 1.3%; > 45ya: 5.4% -generally caused by a technical factor -contributory factors: -malnutrition, hypoproteinemia, morbid obesity, malignancy with immunologic deficiency, uraemia, diabetes, coughing with increased abdominal pressure, remote infection -local factors: hemorrhage, infection, excessive suture material, poor technique -monofilament sutures have lower incidence of disruption than braided sutures -vitamin C deficiency: 8x increase in wound dehiscence -zinc deficiency associated with poor healing -steroids interfere with wound healing; use vitamin A to counteract these effects -chemotherapeutic agents inhibit wound healing -usually wait 1-2 weeks post-op before chemotherapy started -radiation causes obliteration of small vasculature and fibrosis Clinical Manifestations: -salmon-coloured fluid draining from wound at 4th or 5th POD (85% of the time) Treatment: -depends on pt’s condition -if no evisceration non-operative treatment with sterile occlusive wound dressing and binder -evisceration moist sterile towels applied and pt returned to OR -perioperative broad-spectrum antibiotics should be given 4 4 ( ** -requires release of alpha-adrenergic receptors in SMC of bladder neck and urethra and parasympathetic stimulation to contract bladder -stress, pain, spinal anaesthesia, and various anorectal reflexes conspire to increase alpha-adrenergic stimulation -if retention urinary catheter used * * * Etiology: -inadequate resuscitation: -sympathetics decreases renal blood flow; RAA system will shunt blood away from afferent arterioles -drug toxicity: aminoglycosides, vancomycin, amphotericin B, high doses of penicillin G or sulfonamides -see Table 11-12 for other nephrotoxic drugs Pathophysiology of Renal Dysfunction: Prerenal: -BUN/Cr 20:1 -commonly observed with dehydration -hepatorenal syndrome: -two mechanisms: hypovolemia (type I) and maldistribution of blood flow (type II) -Type I: deficiency in intravascular volume secondary to blockage of liver outflow ascites -Type II: failing liver, elevated bilirubin, other stigmata of cirrhosis; CO and low PVR -kidneys are normal; recovery is rare and depends on recovery of intrinsic liver disease Intrinsic Damage: -acute tubular necrosis: -most common cause in surgical setting is renal perfusion d/t prolonged and sustained hypotension (from sepsis, blood los, hypovolemia, dehydration, or myocardial infarction) -mechanism: -kidney tries to maintain glomerular blood flow afferent dilatation and efferent constriction of arterioles -perceived hypoperfusion angiotensin by RAA system afferent constriction - sympathetics norepinephrine afferent constriction -this results in tubular ischemic and hypoperfusion of renal cortex ATN -myoglobinuria and transfusion reaction (free Hb) may complicate renal injury -other causes: -radiocontrast dyes with dehydration -atheromatous embolic during aortic vascular surgery -clamping of renal artery Postrenal Failure: -ureteral clots or stones; BPH Prevention of Acute Renal Failure: -chronic UTI treat with Abx -BPH TURP or balloon dilation -chronic renal impairment ensure adequate hydration -in low flow states, mannitol, bicarbonate, and diuresis induced by furosemide should be used -mannitol increases renal corticla blood flow and produces an osmotic diuresis Manifestations: -oliguria with u/o of 0.4-0.5 cc/kg/h in adult -anuria: uncommon; usually from ATN as a result of renal artery thrombosis or obstructive uropathy -fractional excretion of sodium (FENa) = [UNa / PNa] / [UCr/PCr] -if > 1% intrinsic renal damage -UNa < 10 mEq/L prerenal cause or intrinsic liver disease -intrinsic UNa > 40 mEq/L, FENa > 3% Management: -if diagnosis is uncertain: -volume challenge if suspect hypovolemia -once adequate volume status established furosemide (20-40 mg) to improve u/o -stop nephrotoxic drugs -established renal failure: -treat hyperkalemia: infusion of calcium, hypertonic dextrose solution, and insulin then resins -maintenance of nutrition in patients with ATN: enterally or parenterally -IV “Giordano-Giovannetti diet” of essential AA and hypertonic dextrose, with minimum of fat, decreases mortality in patients with ATN -dialysis for critical ionic excesses, volume overload, or BUN concentration > 80-100 mg/dl 4 Pathophysiology: -VC and FRC may be reduced after upper abdominal surgery (50-60% and 30% respectively) -postoperative pain alters mechanics of respiration -closing volume (lung volume at which airway closure is first detectable) decreases in the postoperative period -other physiologic causes of insufficiency: diffusion defects, abnormalities in V/Q, reduction in CO with persistent shunt, alterations in Hb level and persistent shun, and shunting that is anatomic or related to atelectasis Predisposing Factors: Smoking: Age: Obesity: COPD: Cardiac dz: -must abstain at least 8 weeks to achieve any demonstrable benefit -must look at physiologic age rather than chronological age -related to underlying pulmonary dysfunction characteristic of this patient population -decreased FRC d/t chest wall compliance -ensure adequate pain control -use gastrostomy tube rather than NG found to statistically decrease incidence of respiratory complications -beware of pulmonary edema in CHF patiens ** -collapse of alveoli resulting from anaesthesia, diaphragmatic dysfunction, postoperative incisional pain, and patient positioning -prevention is key: -coughing and deep breathing, chest physiotherapy, incentive spirometry, -intermittent positive pressure breathing, and CPAP -medication for prophylaxis: -expectorants: provide more liquid secretions -detergents and mucolytic solutions: alter surface tension of secretions and render their elimination more likely -bronchodilators: eliminate bronchospasm * -third most common nosocomial infection (after wound and UTI) -pathogens include Psueudomonas, Serratia, Klebsiella, Proteus, Enterobacter, Streptococcus -use of H2-blockers may breakdown acid barrier, allowing overgrowth and colonization of the stomach by intestinal flora (gram negatives) Clinical Manifestations: -fever, productive cough, dyspnea, pleuritic chest pain, and purulent sputum -if hypotensive, consider gram negative pneumonia Management: -cultures obtained via routine ETT suctioning have little predictive benefit in correctly identifying the pathogen responsible for noscomial pneumonia -empiric therapy with aminoglycoside and antipseudomonal penicillin initiated until definitive culture results obtained (via BAL ideally) -most likely setting is during emergency induction of anaesthesia, particularly in pts with GERD or hiatal hernia Clinical Manifestations: -presence of gastric contents in mouth followed by wheezing, hypoxia, bronchorrhea, and cyanosis -CXR: progression of local damage and infiltration accute respiratory failure results -causes chemical pneumonitis that results in bacterial colonization with subsequent development of pneumonia Management: -prevention: empty stomach and neutralization of gastric contents -suction then ETT to complete clearance of tracheobronchial tree ( %* -pulmonary-capillary hydrostatic pressure exceeds plasma oncotic pressure -most common causes: fluid overload or myocardial insufficiency secondary to MI -others: sepsis, valvular dysfunction, neurogenic stimulation, and hepatic failure -increased capillary permeability: -sepsis, ARDS, acute pancreatitis Clinical Manifestations: -two peak phases: -during resuscitation if too aggressive with fluid replacement -post-operative when fluid mobilization occurs -rales, distended neck veins, cyanosis, peripheral pitting edema -CXR: vascular redistribution, septal lines (Kerley’s B lines), peribronchial and perivascular cuffing Management: -depends on inciting cause -for overload: -pulmonary catheter may aid diagnosis and management -PAWP 18-25 mmHg; CI decreased with increased PVR -if PAWP normal or low, look for other causes -?ARDS -ECG look for evidence of pump failure -treat with diuretics, IV nitroglycerin ( venous capacitance and preload) -dobutamine or amrinone may improve cardiac output -consider afterload reduction with nitroprusside if above maneuvers fail to produce a sufficient CI 2 ( % * -fat embolism extremely common pathologic finding after trauma -26% in patients with single fracture to 44% in patients with multiple fractures -fat embolism syndrome with pulmonary dysfunction, coagulopathy, and neurologic disturbances associated with increased circulating fat globules is ncommon Pathophysiology: -long bone fractures with release of marrow fat into circulation Clinical Manifestations: -respiratory insufficiency -CXR shows characteristic bilateral alveolar infiltrates -may evolve into ARDS -CNS involvement in 86% confusion and disorientation with eventual progression to coma -characteristic petechial rash occurs in axillae, neck , and skin folds -fat globules in urine not specific for fat embolism syndrome -associated findings: -unexplained drop in hct, thrombocytopenia, hypocalcemia, and hypoalbuminemia Management: -immobilize any long bone fracture -early surgical fixation decreases incidence of pulmonary complications of fat embolism -oxygenation and supportive measures * * (. * ( % *# . $ -pt incapable of maintaining adequate oxygenation, adequate ventilation, adequate tissue delivery, or some combination of these defects -syndrome that includes: -lung injury, acute in nature -bilateral infiltrates on frontal chest radiograph -PaO2/FIO2 < 200 -PCWP < 19 mmHg with no evidence of CHF -may be due to specific single cause or may represent endpoint of a poorly understood pathway with a common final denominator of lung damage and subsequent decompensation of oxygenation and ventilation Etiology and Pathophysiology: -abnormal cytokine response to injury: -activation of complement cascade, activtionof thromboxane-leukotrienes pathway, disorders in NO production, degranulation of neutrophils, production of increased permeability factors by macrophages transudation of fluid and reactive materials into alveoli -causes V/Q mismatch -CXR shows “whiteout”; CT scan demonstrate regional changes in lung function -volutrauma: maldistribution of inspired tidal volume secondary to PPV and the heterogeneous nature of lung injury in ARDS -overdistention of alveolus beyond its normal maximum Management: -reduce volutrauma: -early use of PEEP adjusted to the inflection point (as seen on pressure-volume curve) -pressure-limited ventilation with plateau pressures less than 35 cmH2O -permissive hypercapnia -use of inhalational NO -PEEP has remained the mainstay of treatment of ARDS -recruits collapsed alveolar units -attenuates lung injury associated with PPV -may prevent loss of FRC and prevent alveolar collapse at end-expiration -permissive hypercapnia limits potentially detrimental effects of increased peak airway pressures, the number of breaths necessary per minute, which reduces the risk of barotrauma and volutrauma -inhalation of NO at mall doses has reduced pulmonary hypertension and improved oxygenation in a variety of patients -newer modalities using partial liquid ventilation (PLV) and perfluorocarbon-assisted gas exchange (PAGE) . 4( 4 % / -mortality from perioperative MI ranges from 54% to 89% -presence of coronary artery disease: risk of perioperative MI increased from 0.1-0.7% to 1.1% -patients over 40: infarction rate is 1.8% -previous MI: infarction rate 27% (within 3 months); 11% (b/n 3 and 6 months); 5% (> 6 months) Identification of the Patient at Risk: -Goldman index -look for cardiac signs, symptoms and risk factors Clinical Manifestations: -most cases occur on operative day or during first 3 PODs -most important precipitating factor is shock risk of coronary thrombosis and myocardial ischemic -chest pain only in 27% of patients b/c may be masked by narcotics -may manifest as a sudden appearance of shock, dyspnea, cyanosis, tachycardia, arrhythmia, or CHF -evaluate with ECG, serial cardiac enzymes, ABG (rule out respiratory causes) Management: -pre-operative: -optimize CHF (digitalization for pts with enlarged hearts) -treat anemia -optimize fluid and electrolyte balance -continue beta-blockers until morning of operation -operation after 6 months of an MI -intra-operative: -regulation of BP important -avoid hypoxia, hypotension, haemorrhage, dehydration, electrolyte disturbance and arrhythmias -treatment: -+/- monitoring in ICU -pain relief: morphine and sedation -+/- heparin, ASA; nitro and beta-blockers -hypoxia relief: oxygen -shock treated by vasopressor agents -early emergency cardiac catheterization, angioplasty, or stenting may reverse an evolving MI 1( 1 -sinus tachycardia (not an arrhythmia) is the most common disturbance of rhythm, followed by PVC and sinoatrial arrhythmia Etiology: -intrinsic cardiac disease -perioperative release of catecholamines d/t stress or pain -organ manipulation that stimulates reflex response -electrolyte abnormalities and metabolic disturbances: -hypokalemia PACs and PVCs -hyperkalemia conduction abnormalities -hypocalcemia QT interval ventricular arhythmias -hypercalcemia bardycardia and heart block -cardiac medications: -digitalis toxicity supraventricular-atrial flutter with varying block, PVCs, VT or VF -antihypertensive meds sinus bardycardia or induction block -anaesthetic agents: -halothanes ventricular dysrhythmias -parasympathetic stimulation (neostigmine, physostigmine, succinylcholine) bardycardia -other factors: -hypercapnia may suppress sinoatrial node function ectopic pacemaker or aberrant reentry mechanisms -thyrotoxicosis atrial fibrillation -pheochromocytoma Management of Preexisting Arrhythmias: -digoxin for patients with supraventricular tachycardia -reversible causes, such as electrolyte disturbances, drug toxicity, hypoxia, etc. should be controlled -cardiac pacing for significant conduction defects: -third degree AV block -Mobitz II block -sick sinus syndrome Management of New-onset Arrhythmias: -ECG: -P waves present supraventricular origin -variable morphology ectopic focus, MAT or SVT -P waves absent A-fib -QRS narrow supraventricular origin -QRS wide ventricular origin or supraventricular with aberrant conduction, conduction block -Acute tachyarrhythmias with hypotension cardioversion (100 360J) -Symptomatic bradycardia 0.5mg atropine IV q5min to max of 0.04 mg/kg -consider transcutaneous pacing Sinus Tachycardia: -find and treat cause: pain, hypovolemia, hypoxia, acidosis, sepsis, CHF, hypoperfusion, hypercapnia Paraoxysmal Supraventricular Tachycardia: -re-entry tachycardia -rates between 150 and 250 bpm -primary treatment with -adenosine 6 mg IV; repeat with 12 mg after 1-2 min -then verapamil 2-5 mg IV with second dose after 15-30 min -may consider cardioversion Atrial Fibrillation: -lack of “atrial kick” may result in 10-15% decrease in cardiac output -causes: -thyrotoxicosis, valvular heart disease, hypertension, CAD, PE, MI -common after pneumonectomy -cardioversion if hemodynamically unstable -anticoagulate if long standing A-fib -control rate (eg. with CCB, BB) and rhythm Sustained Supraventricular Tachycardias: -may be a result of digitalis toxicity -obtain serum potassium and digitalis levels Atrial Flutter: -if unstable cardioversion -digitalis used to maintain heart rate once controlled Ventricular Tachycardia and Fibrillation: -if pulseless precordial thump and immediate defibrillation at 200 J -(review ACLS protocols) ( * * Preoperative Hypertension: -preoperative hypertension that is untreated or poorly controlled does increase the risk of perioperative blood pressure lability, which may result in increased incidence of stroke, TIA, arrhythmias, post-op MI, and possibly post-op renal failure -postpone operation until hypertension controlled if: -previous hypertension with diastolic pressure > 110 -new-onset hypertension -sudden increases in hypertension -recent deterioration in critical end-organ status -delay operation in patients with mild or moderate hypertension with: -ECG changes of MI or ischemic -new-onset dysrhythmias -emergence of LVH on ECG -new onset or unstable angina -CHF, whether established or new -recent neurological deficit -new onset of high-grade hypertensive retinopathy -continue antihypertensive medications until day of operation Postoperative Hypertension: -systolic pressures > 200 mmHg result in bleeding from suture line, haemorrhagic cerebral infarction, myocardial ischemic or infarction, and acute renal failure -~ 80% of post-op HTN episodes occur within first 3 h of emergence form anaesthesia -d/t ETT, inadequate analgesia, acute bladder distention, fluid overload -tracheal stimulation, hypothermia, hypercapnia, hypoxemia -if uncontrollable sodium nitroprusside or labetalol is given -late post-op: -d/t hypervolemia 2o fluid mobilization into intravascular space, inadequate analgesia, or failure to resume previous antihypertensive medications 3 6 *% ( * 2* * Lupus Anticoagulant Factor (Anticardiolipin Syndrome): -antibodies that interfere with in vitro PTT by prolonging phospholipid-dependent clotting factors -increased risk of arterial and venous thrombosis -patients normally do not require anticoagulation therapy -those undergoing major procedures should receive prophylactic anticoagulation therapy and mechanical prophylaxis Heparin-Induced Thrombocytopenia: -form of consumptive platelet activation -not dose dependent -mechanism: autoantibody formation directed toward heparin and platelet surface antigens -mild: occurs 2-4 days after heparin exposure -severe: 6-12 days after exposure and associated with thrombosis -arterial thrombosis common -significant mortality rate -phlegmasia cerulea dolens amputation rate up to 30% -treatment: stop heparin; +/- surgical thrombectomy; Greenfield filter, anticoagulation with warfarin 1* *% 1 2 . %* Antithrombin-III Deficiency: -AT-III the most important inhibitor of coagulation -inactivates thrombin, Xa, IXa, XIa, plasmin, kallikrein, XIIa -deficiency is autosomal dominant -recurrent thrombosis in 60%; pulmonary embolus in 40% -treatment: heparin; if OR FFP to raise level of AT-III Protein C Deficiency: -Protein C: vit K-dependent inhibitor of procoagulant system -inactivates V and VIII -seen in 4-5% of patients < 45y with unexplained venous thrombosis -deficiency is autosomal dominant: (CRM-: lack of protein; CRM+: dysfunctional protein) -significant when serum activity < 70% -treatment: warfarin Protein S Deficiency: -Protein S: vit K-dependent; produced by hepatocytes and megakaryocyte -cofactor for Protein C -significant when serum activity < 60% ! -associated with high mortality related mainly of primary disease -75% of pts are > 70y -causes: poor oral hygiene, dehydration, use of anticholinergic agents, lack of oral intake -staphylococci infection via probable transductal inoculation of parotid gland -routes of spread for suppurative parotitis: -downward into deep fascial planes of the neck -backward into external auditory canal -outward into skin of face Clinical Manifestations: -swollen tender parotid -may progress rapidly to severe cellulitis on affected side of face and neck -may require tracheotomy if airway compromised Management: -prophylaxis: adequate hydration, good oral hygiene -start with broad spectrum Abx against staph; take C+S of pus -surgical drainage; should not be delayed beyond 5th day Prognosis: -mortality approximated 20%, but his was frequently related to the patient’s basic disease 4 * % 3 7* 2 -small bowel normally does not manifest ileus post-op, because it continues to function throughout and after operation -tube feedings may start almost immediately after operation -if inflammation or several anastomoses in small bowel 24h ileus might be experienced -gastric ileus: 24-48h -colonic ileus: 3-5 days -caused by: -surgical manipulation, inflammation, peritonitis, blood in peritonem -blood in retroperitoneum -hypokalemia, hypocalcemia, hyponatremia, hypomagnesaemia -opiates and phenothiazine -treatment: -correct underlying disorder, if any; mostly supportive treatment -long tube decompression -measure serum albumin prolonged ileus in hypoalbuminemic patients -12.5g q8-12h to raise albumin > 3.0 mg/dL often results in return of bowel function * & % General Considerations: -factors that increase likelihood of anastomotic leakage: -emergency procedures, poorly prepared patients, inadequately resuscitated patients, prolonged intraoperative hypotension, hypothermia -etiological factors: poor surgical technique, distal obstruction, inadequate proximal decompression Duodenal Stump Blowout: -disastrous complication with a high mortality -complications: peritonitis, subhepatic abscess, pancreatitis, sepsis, establishment of an external fistula wit fluid, and electrolyte abnormalities -most likely to occur between 2nd and 7th POD -adequate drainage required: incision below (R)CM and insertion of large sump catheter -fluid and electrolyte therapy, TPN instituted Intestinal Leaks and Fistulas: Leaks: -fever, leukocytosis, unexplained ileus in absence of intestinal obstruction, complicated post-op course -if patient is in jeopardy, sepsis uncontrolled, no effective drainage abdomen re-explored -anastomosis must be resected and redone -if hemodynamically unstable separation of both ends and diversion should be done Fistula: -increased wound pain and redness/drainage on POD #4-5 -usually result from operations involving inflammatory bowel disease, cancer, or lysis of adhesions -allow fistula to close spontaneously Therapy of an Established Fistula: -five phases: stabilization, identification and diagnosis, decision, operation, healing 1. Stabilization: -resuscitation using crystalloids, RBC, and albumin -Abx only if septic -sump-type drain placed around skin; skin protected with Stomadheisve and ion exchange paste to keep pH acidic and prevent activation of pancreatic enzymes that require basic pH -TPN: 5-6% AA, 15-25% dextrose, 20% fat -nutrition can be monitored with RBP, TBP, transferring -enteral feeds may be attempted but they must be supplemented with TPN 2. Identification and Diagnosis: -obtain fistulogram/sinogram -degree of bowel continuity, size and depth of defect, presence of distal obstruction, nature of bowel adjacent to fistula, presence of large abscess -fistulas unlikely to close spontaneously: -ileal, gastric, fistulas at ligament of Treitz -total anastomotic disruption; partial disruption with adjacent abscess; lateral fistula with distal obstruction; fistula in strictured intestine; end fistula with no distal communication -local sepsis or systematic sepsis -spontaneous closure usually within 5 weeks of adequate nutrition support in a patient w/o sepsis 3. Decision: -somatostatin used to promote closure -if short-turnover protein levels are increasing, the serum albumin concentration is approaching 3.0 g/dl, and the patient is maintaining the albumin level without infusions of exogenous albumin, operation can take place -failure to maintain or increase in levels of transferring, retinol-binding protein, and thyroxin-binding prealbumin indicative of mortality 4. Operation: -mortality ~10-11% if operated during first 10 days or after 4 months; ~20% between 10 days and 4months -resection and end-to-end anastomosis; protection with omentum onlay -for duodenal fistula: vagotomy and gastrojejunostomy, feeding jejunostomy and gastrostomy, area of fistula drained -chronic pancreatic fistula: -excise fistula down to pancreas, identify leak, distal pancreatectoy and splenectomy -Roux-en-Y anastomosis can be used to provide internal drainage for the pancreatic fistula 5. Healing: -feeding delayed 7-10 days -difficulties eating: -lack taste sensation: use zinc sulfate or lactate -may be necessary to allow alcohol to induce eating Colocutaneous Fistulas: -fluid and electrolyte abnormalities and skin digestion are rare, but infectious complications are significant -percuaneous drainage of intraabdominal abscesses and local care of wound infections -antibiotics as indicated -spontaneous closure likely -persistence if sepsis, distal obstruction, anastomotic dehiscence, Crohn’s disease, or carcinoma present -lack of spontaneous close by 5 weeks surgical repair -resection of fistula and affected colonic segment with primary anastomosis and temporary diversion of the fecal stream by colostomy * ( ( % * Dumping: -loss of pyloric valve that normally prevents hyperosmolar material from entering duodenum and small bowel -d/t pyloroplasty, pyloromyotomy, gastrojejunostomy, gastric resection, Billroth I or II anastomosis -results in release of vasoactive substances: -serotonin, bradykinin, substance P, peptides (VIP, pancreatic polypeptide, insulin, glucagon, neurotensin, enteroglucagon) -results in decreased plasma volume hypotension; hypokalemia -symptoms: -early postprandial bloating, borborygmus, cramps, sensation of light-headedness, palpitations, sweating, hypotension -eating solids at meal and drinking liquids afterwards diminishes symptoms -avoid carbohydrates which are more likely to provoke dumping -in severe cases, long-acting octreotide may oppose some of the action of released peptides and ameliorate the symptoms -surgical treatments: conversion of BII to BI; 6 cm reverse loop of jejunum to slow transit of hypertonic solution Postvagotomy Diarrhea: -5-20% of patients have troublesome diarrhea post-truncal vagotomy -factors: -dysmotility or dysfunction of small bowel motility stasis and overgrowth of bacteria, malabsorption of fat, increased and incoordinate bile flow into small bowel -treatment difficult: -antibiotics have little success -10-cm reversed jejunal loop 100 cm distal to ligament of Treitz has been advocated Afferent Loop Syndrome: -syndrome almost always occurs when the afferent loop is anastomosed to the greater curve after a BI gastrectomy -obstruction of afferent loop from adhesions, kinking, intussusception, volvulus of afferent loop, stomal ulcer, or obstruction of the efferent limb -duodenal secretions increases in afferent loop regurgitated into stomach -haemorrhagic pancreatitis or perforation can occur -symptoms: -eating is regularly followed by RUQ epigastric distention and pain, borborygmus, and cramps relieved by projectile vomitus of clear bile that is never mixed with food -operation require for relief of these symptoms: -afferent loop is anastomosed into Roux-en-Y efferent loop ~60 cm downstream to prevent reflux of bile into stomach -vagotomy to prevent marginal ulcer Alkaline Reflux Gastritis: -stomach sensitive to bile; eating associated with burning epigastric pain -large amounts of bile emanating form afferent loop -acute and chronic inflammation, evidence of decreased parietal cells, and increase in mucous-secreting cells, and intestinalization of the gastric glands -most effective treatment: cholestyramin and sucralfate -if medically unmanageable: Tanner-19 procedure with vagotomy and long bile-containing loop anastomosed 60 cm down stream Nutritional Complications: -fat malabsorption chronic nutritional deficiency, failure of absorption of fat-soluble vitamins, chronic bile salt diarrhea -iron and calcium absorbed primarily in duodenum -after BII many pts hypocalcemic and iron-deficiency anemic -loss of intrinsic factor monthly B12 injections required -may require conversion of BII to BI Recurrence of Disease: -complications for ileostomies: ulcerative colitis 4%; Crohn’s disease 30% -Crohn’s: granulomatous, ulcerations; peristomal fistulas -ciprofloxacin and metronidazole should be initiated -no point in resiting stoma recurrence will likely happen again Stomal Necrosis and Retraction: -necrosis or retraction superficial to fascia no immediate action required -necrosis extends below fascia immediate laparotomy and reconstruction of stoma -retraction below level of fascia immediate laparotomy to prevent further fecal contamination of peritoneal cavity Skin Complications: -usually result of siting and inability to obtain appropriate seal around stoma -Caraya powder, ion exchange paste, +/- nystatin powder and systemic fluconazole (if yeast) are helpful -cellulitis requires antibiotics Stomal Stricture: -development of serositis in immediate postoperative period -most common cause of stricture is necrosis or retraction, resulting in mucocutaneous separation, exposure of the serosa, and subsequent serositis -tx: stoma separated from skin, skin opening enlarged, new maturation performed -if stricture at fascial level, fascial opening enlarged Peristomal Hernias and Prolapse: -prolapse occurs when there is vigorous peristalsis and insufficient fixation of bowel to underside of anterior abdominal wall 4 ( % 3 4 * / * * * / -most common metabolic complication after surgery % * *# . $ -may result in CNS damage, seizures and death -secretion of ADH is more prolonged or more intense than after normal operative procedures -management: -if slight edema and [Na] ~125-130 fluid restriction is all that is required -if CNS disturbance: -symptoms not severe mannitol given slowly provokes diuresis of excess water secreted with minimum of sodium; furosemide can be added -if severe 3% saline; small increments 50-100 ml over 3-4 hours -permanent CNS damage can occur if rapid correction of hyponatremia -prevention: avoid overresuscitation of patients; limit free water . %* / 1( %4* 2 Thyroid Storm: -mortality of 10-20% -occurs in patients with existing thyrotoxicosis that is unrecognized or uncontrolled -any traumatic event, such as surgery, infection, or embolism, may complicate thyrotoxicosis and provoke thyroid storm -once hypotension supervenes, it is a preterminal event -irreversible cardiac failure usually is the mode of death -tx: -control of catecholamine-induced cardiac symptoms: propranolol IV 1mg/min to max of 10 mg to control HR -dobutamine may be necessary -PTU 200 mg and KI 5-10 gtts given to decrease T3 and T4 release -hydrocortisone 200 mg IV followed by 100 mg q8h diminishes thyroid hormone release Myxedema Coma: -pts with chronic hypothyroidism that is unrecognized or inadequately controlled; provoked by stress of operation -inciting factors: trauma, infection, GIB, surgery, narcotics and phenothiazine -tx: -warming, hydration, assisted ventilation -L-thyroxine 300-500 mg IV then 50-100 mg/d %* // * ( -d/t suppression of pituitary-adrenal axis by previous administration of steroids or destruction or exhaustion of adrenal glands -in patients with carcinoma, bilateral adrenal metastasis may occur -symptoms: -unexplained hypotension, fever, abdominal pain, light-headedness, weakness, palpitations, mental status changes, nausea, and vomiting -lab findings: -hypoglycemia, hyponatremia, occasionally hyperkalemia -tx: -measure serum cortisol and initiate treatment -hydrocortisone 200 mg IV -hypotension should resolve in 1-2h if dx is correct -400 mg hydrocortisone in divided doses over 24h should b given if hypotension not resolved 8* * -most common cause is pre-existing liver disease -cirrhosis, alcoholic hepatitis, fatty infiltration -general anaesthesia should be avoided in patients with established liver dz: -portal vein’s contribution is diminished and hepatic artery supplies at least 50% of hepatic flow -splanchnic vasoconstriction of hepatic artery markedly decreases hepatic flow -therefore, regional or epidural anaesthetic is preferred -liver failure usually on 3rd or 5th POD -somnolence, jaundice, u/o, ascites -treatable reversible causes: -hypovolemia, hypokalemia, hypomagnesaemia, GIB, constipation, remote infection -must r/o SBP -tx: -correct lytes, administration of neomycin, cathartic, or lactulose, and provision of nutritional support -enteral feeds preferred: -modified low aromatic, high branched-chain amino acid formulation -hepatorenal syndrome type II can complicate hepatic failure; if liver does not recover post-op death 4 -delirium (20%), depression (9%), dementia (3%), functional psychosis (2%) of elderly post-op patients Clinical Manifestations: -manifestations are extremely variable -delirium: occurs most commonly in elderly patients and those who are immobilized for long periods -depressive reactions: pt characteristically uncooperative or recovery may be impeded by listlessness, anorexia, and disinterest -suicide a major risk in pts with depressive reaction -paranoid psychotic disorder Management: -efforts should be directed at removing toxic causes of the acute brain syndrome, removing unnecessary stimuli without isolating the patient, and providing psychologic or pharmacologic tranquillization -consultation with psychiatry is indicated in the case of any acute and severe emotional disturbance .* * * % 1* /. * -delirium usually follows operation within 48h but may be delayed -hyperactivity with irritability, delusions, hallucinations, restlessness, and agitation -cause is multifactorial -Haldol 2-15 mg PO bid or 1-5 mg IV followed by 5-10 mg/h may help agitation -prophylactic medication with lorazepam should be administered in the perioperative period to patients with severe alcoholic histories who are candidates for DTs .* * -characteristically occurs late in the post-op period -use of SSRIs are useful * -very yound gan old patients are particularly vulnerable to the development of psychiatric complications after surgical treatment Pediatric Surgery: -severe anxiety states may be precipitated by the shock of operation -emotional needs must be attended to -maturity is important and decreases post-op anxiety reactions Surgery in the Aged: -more prone to become emotionally disturbed when confronted with new situations, esp. if inadequate comprehension and generalized feeling of insecurity Gynecologic and Breast Surgery: -high incidence of depression, anxiety and sexual difficulties -contact with other mastectomy patients expedites psychologic rehabilitation -the more the procedure antedates menopause, the greater the likelihood of associated psychologic disturbance (ie. hysterectomy) Cancer Surgery: -two major threats: disease and extensive surgical treatment -depression is related to an anticipated interference with valued activities -tendency toward seclusion, withdrawal, and nonparticipation -depression frequent Cardiac Surgery: -serious psychiatric disturbances observed with considerable frequency afte mitral valvulotomy and openheart surgery -manifestations usually after initial lucid interval of 3-5 days; resolve shortly after transfer from CICU to ward -postoperative incapacitation and increased time on heart-lung machine are factors increasing the likelihood of delirium ?organic brain damage from operation Dialysis and Transplantation: -suicide rate is 300 times greater in dialysis and transplantation patients -uraemia, debilitating disease, and the undergoing of repeated procedures are contributing factors
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