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    Ch35. Anesthesia for Patients with

    Liver Disease

    R1

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    Liver has remarkable functional reservez Hepatic disease clinical manifestation extensive

    damage

    z little reserve marginal patient OR

    further hepatic decompensation overt hepatic failure

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    HEPATITIS

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    ACUTE HEPATITIS

    z viral infection, drug reaction, exposure tohepatotoxin

    z Acute hepatocellular injury with variable amounts of cell

    necrosis

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    Viral hepatitis

    Transmissionz Hepatitis A & E : oral-fecal route

    z Hepatitis B & C : percutaneously & by contact with body fluids

    z Hepatitis D : host hepatitis B virus

    Clinical manifestionsz 1- to 2-week mild prodromal illness

    ~ Fatigue, malaise, low-grade fever, vausea, vomiting

    z Jaudice , ~ 2-12 wks , 4 mns

    ~ Hepatitis B & C : cholestasis, fulminant hepatic failure

    Prognosisz

    Chronic active hepatitis : hepatitis B 3-10%, C 50%z Asymptomatic infectious carriers

    ~ HBsAg(+) Pt 0.3-30%, hepatitis C 0.5-1%(hepatitis C viral RNA )

    Immunizationz Highly effective against hepatitis B infection

    z Postexposure prophylaxis with hyperimmune globulin is effective for hepatitis B

    z Hepatitis C vaccine, prophylaxis

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    Drug-induced hepatitis

    Cause

    z Direct dose-dependent toxicity of adrug

    z Idiosyncratic drug reaction

    Alcoholic hepatitis

    z Chronic alcohol ingestion fattyinfiltration hepatomegaly

    ~ Impaired fatty acid oxidation

    ~ Increased uptake & esterification of

    fatty acid~ Diminished lipoprotein synthesis &

    secretion

    Acetaminophen ingestion

    z Ingestion of 25G or more fatalfulminant disease

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    Preoperative considerations

    Elective surgery acute hepatitis resolve z LFT normalization

    z Periop. Morbidity(12%), mortality(10% with laparotomy)

    z Acute alcohol toxicity : greatly complicated

    ~ alcohol withdrawal mortality rate 50% Lab. Evaluationz BUN, s-electrolyte, creatinine, glucose, transaminases, alkaline phosphatase,

    albumin, PT, platelet count

    z Alcoholic hepatitis ALT AST z PT : best indicator of hepatic synthetic function

    ~ Vit. K PT 3 sec (INR >1.5) : severe hepatic dysfunction

    z drug exposure, transfusion, prior enesthetics

    z Dehydration & electrolyte abNL

    z Coagulopathy Vit. K, FFP z Premedi

    ~ Acute withdrawal alcoholic Pt. benzodiazepine & thiamine

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    Intraoperative considerations

    Goalz Preserve existing hepatic function

    z Avoid factors that may be detrimental to the liver

    Alcoholic Ptz Cross-tolerance to anesthetics

    z Close cardiovascular monitoring~ Alcohol cardiac depression, alcoholic cardiomyopathy

    IV inhalation anesthetics z Standard induction doses of IV agents

    ~ Metabolism or excretion redistribution

    Isoflurane is the volatile agent of choicez Hepatic blood flow

    z Hepatic blood flow ~ Hypotension, excessive sympathetic activation, high mean airway pr.

    z Coagulopathy regional anesthetia ~ Hypotension

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    CHRONIC HEPATITIS

    Persistent hepatic inflammation for longer than 6 monthsz Evidenced by elevated serum aminotransferases

    Liver biopsy 1. Chronic persistent hepatitis

    ~ cellular architecture portal tract chronic inflammation

    2. Chronic lobular hepatitis~ Resolve acute hepatitis, but recurrent exacerbations

    ~ Hepatic lobule inflammation necrosis foci

    3. Chronic active hepatitis~ chronic hepatic inflammation

    ~ LC : 20-50%

    ~ hepatitic B or C sequelae

    ~ Fatigue, recurrent jaundice

    ~ Only a mild elevation in serum aminotransferase activityz Often correlate poorly with disease severity

    ~ Chr. hepatitis B or C

    Anesthetic managementz Chronic persistent or lobular hepatitis acute hepatitis

    z Chronic active hepatitis cirrhosis

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    CIRRHOSIS

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    Cirrhosis

    m/c cause in US : alcohol

    z chronic active hepatitis, chronic biliary inflammation or obx.,chronic Rt-sided CHF, autoimmune hepatitis, hemochromatosis,Wilsons disease, 1-antitrypsin deficiency, nonalcoholic steatohepatitis,

    cryptogenic cirrhosis Hepatocyte necrosis, fibrosis, nodular regeneration

    z , portal venous flow

    z Signs Symptoms disease severity

    ~ Jaundice, ascites

    ~ Spider angiomas, palmar erythema, gynecomastia, splenomegalyz 3 Major complications

    ~ Variceal hemorrhage from portal hypertension

    ~ Intractable fluid retention in ascites, hepatorenal syndrome

    ~ Hepatic encephalopathy, coma

    z 10% spontaneous bacterial peritonitis, HCC

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    Preoperative considerationsb. hematological manifestations

    z Anemia

    ~ Blood loss, RBC destruction , bone barrow

    suppression, nutritional deficiencies

    z Thrombocytopenia, leukopenia~ Congestive splenomegaly (from portal HTN)

    z Coagulation factor deficiencies

    ~ Decreased hepatic synthesis

    Preop. Blood transfusion

    z Nitrogen load encephalopathy

    z coagulopathy

    ~ FFP, cryoprecipitate

    ~ platelet < 100,000/ platelet

    transfusion

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    Preoperative considerationsc. circulatory manifestations

    Cirrhosis : hyperdynamic circulatory stateArteriovenous shunt

    z Systemic & pulm. circulation

    z Anemia blood viscosity filling

    pr. systemic vascular resistance

    cardiac output cirrhotic cardiomyopathy

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    Preoperative considerationsd. respiratory manifestations

    Hyperventilation

    z

    Primary respiratory alkalosis Hypoxemia

    z Rt-to-Lt shunting (up to 40% of cardiac

    output)

    z Shunt pulm. A-V communications, V-Q

    mismatching Ascites diaphragmatic elevation

    lung volume

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    Preoperative considerationse. renal manifestations and fluid balance

    Ascites

    z Portal HTN hydrostatic pr. intestine peritoneal cavity fluid transudation

    z Hypoalbuminemia plasma oncotic pr. fluid transudation

    z Protein-rich lymphatic fluid serosal surface ofliver

    z Renal sodium retention

    ~ e Underfillingf theory : effective plasma volume

    ~ e Oveflowf theory : renal sodium retention

    transudation ascites Cirrhosis & ascites

    z Renal perfusion , intrarenal hemodynamics , proximal & distal sodium reabsorption ,free water clearance

    hyponatremia (dilutional), hypokalemia (excessive

    urinary potassium losses)

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    Preoperative considerations

    e. renal manifestations and fluid balance

    Hepatorenal syndrome

    z Progressive oliguria, avid sodium retention,azotemia, intrractable ascites

    z Very high mortality rate

    z Liver transplantation

    Judicious periop. fluid managementz diuresis

    z Acute intravascular fluid deficit colloid infusion

    z Ascites pph. Edema diuresis 1/d

    z Loop diuretics~ Bed rest, sodium restriction(

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    Preoperative considerationsf. central nervous system manifestations

    Hepatic encephalopathyz Alterations in mental status

    z With fluctuating neurological signs~ Asterixis, hyperreflexia, inverted plantar reflex)

    z EEG changes

    ~ Symmetric high-voltage, slow-wave activityz ICP

    Factors precipitate hepatic encephalopathyz G-I cleeding

    z Increased dietary protein intake

    z Hypokalemic alkalosis (from vomiting or diuresis)

    z Infectionsz Worsening liver function

    aggressive z Oral lactulose 30-50mL every 8h or neomycin

    500mg every 6h

    reduce intestinal ammonia absorptionz Avoidance of sedatives

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    Intraoperative considerations

    Hepatitis B or C carrier : blood & body fluid

    Drug responsesz Unpredictable for response to anesthetic agents

    z NMBAs highly ionized drug volume of distribution

    ~ Hepatic elimination (pancuronium, rocuronium, vecuronium) Anesthetic techniquez Hepatic a. blood flow

    z Regional anesthesia : thrombocytopenia, coagulopathy ~ Hypotension

    z General anesthesia~ Induction : barbiturate or propofol induction

    ~ Maintenance : isoflurane in oxygen or oxygen-air mixture~ Opioid supplementation : half-life prolonged resp. depression

    ~ Cisatracurium : NMBA of choice (unique nonhepatic metabolism)

    z Preoxygenation & rapid-sequence induction with cricoid pressure

    z Unstable pt. & active bleeding ~ Awake intubation

    ~ Rapid-sequence induction with cricoid pr., using ketamine (or etomidate) & succinylcholijne

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    Intraoperative considerations (2)

    Monitoringz Vasopressin 5-lead ECG MI

    z ABGA : acid-base status

    z Large Rt-to-Lt intrapulm. Shunt~ Nitrous oxide

    ~ PEEP : V-Q mismatch, hypoxemia

    z Intraarterial pr. Monitoring

    z Intravascular volume status : CVP, pulm. a. pr. Monitoring

    z Urinary output

    Fluid replacement

    z intravascular volume & urinary output z Colloid iv fluid(albumin)

    ~ Sodium overload , oncotic pressure

    ~ Ascitic fluid iv colloid fluid replacement

    z Transfusion~ citrate toxicity

    z Hypocalcemia

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    HEPATOBILIARY DISEASE

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    Hepatobiliary disease

    Cholestasis

    z Progressive jaundice, dark urine with pale stool, pruritus

    z Extrahepatic obx of biliary tract : m/c cause

    ~ Gallstone, stricture, tumor in common hepatic ductz Intrahepatic cholestasis

    ~ Viral hepatitis, idiosyncratic drug reaction (phenothiazine, oral

    contraceptives)

    Cholelithiasis

    z Cholecystitis : RUQ tenderness, fever, leukocytosisz Cholangitis : chill or high fever

    z Acute cholecystitis 75% medical treatment 2-7

    z 5-10% acalculous cholecystitis

    ~ Serious trauma, burns, prolonged labor, major surgery, critical illness

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    Hepatobiliary disease (2)

    Preoperative considerations

    z Acute cholecystitis medically stabilized cholecystectomy (LC)

    ~ Nasogastric suction, iv fluids, antibiotics, opioid analgesics

    z Acalculous cholecystitis~ critically ill pt. gangrene & perf.

    ~

    z Extrahepatic biliary obx. vit.K deficiency

    ~ Vit.K , PT FFP

    z

    Generous preop. HydrationIntraoperative considerations

    z Intraop. Cholangiogram opioid

    ~ False-positive

    ~ Opioid-induced sphincter spasm naloxone or glucagon

    z

    Renal elimination

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    HEPATIC SURGERY

    Common hepatic procedures

    z Repair of lacerations, drainage of abscesses, resections for

    tumors

    Hepatic surgery

    z Multiple large-bore iv catheters

    z Fluid(blood) warmers

    z Arterial pr., CVP monitoring

    z Antifibrinolytics

    ~ Aprotinin, -aminocaproic acid, tranexamic acid

    Postop Cx

    z Bleeding, sepsis, hepatic dysfunction