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Anesthetic Management for Acute Hepatitis
Preoperative Management
Intraoperative Management

Anesthetic Management for Chronic Hepatitis

Anesthetic Management for Cirrhosis
Preoperative Management
Intraoperative Management

PREOPERATIVE MANAGEMENT

General

-elective surgery is to be postponed until the acute hepatitis has resolved
-resolution of hepatitis is followed by normalization of liver function tests
-surgery during acute viral hepatitis may have increased perioperative morbidity of about 12%
-acute alcohol withdrawl during surgery may be associated with high rate of mortality of upto 50%
-hepatitis is involved with decreased hepatic function and may lead to hepatic failure
-associated complications of hepatic failure: encephalopathy, coagulopathy, or hepatorenal syndrome

Laboratory evaluation should include:

-BUN
-creatinine
-serum electrolyes
-glucose
-complete blood count
-transaminases
-bilirubin
-alkaline phosphatase
-albumin
-coagulation profile
-if alcoholic history suggestive: alcohol blood level may be indicated
-hypokalemia and metabolic alkalosis may be associated with nausea and vomiting
-hypomagnesia may be associated with increased risk of dysrhythmias esp in alcoholics
-AST is generally higher than ALT in alcoholics
-ALT is generally higher than AST in other forms of hepatitis apart from alcohol induced hepatitis
-PT is the best indicator of hepatic synthetic function which is associated with the extrinsic coagulation cascade
-severe hepatic dysfunction: associated with persistent INR > 1.5 following Vit K administration

INTRAOPERATIVE MANAGEMENT

goal: preserve existing hepatic function and avoid other factor which may intiate new injury to the liver
-drug selection varies because of different causal factors of hepatitis
-ex.chronic alcoholics often have cross tolerance to anesthetics there may require higher doses
-viral hepatitis may be involved with increased CNS sensitivity to anesthetics therefore may require smaller doses
-chronic alcoholics often have cardiomyopathy which combined with cardiodepressant effects of anesthetics may be detrimental
-to help asses and avoid the deterioration of cardiac function, these patients should be observed with close cardiac monitoring
-Inhalational anesthetics are preferred over intravenous anesthetics because of less hepatic metabolism and elimination
-induction doses of intravenous anesthetics are generally the same since the termination of action is mainly redistribution
-large or frequent doses of i.v. anesthetics may be prolonged because action is no longer terminated by redistribution
-metabolism and excretion become dependant on the liver with larger and frequent doses of i.v anesthetics
ISOFLURANE is the agent of choice in hepatic patients because of its least effect on the blood flow to the liver

Factors associated with decreased blood flow to the liver:
-hypotension
-increased sympathetic stimulation
-controlled ventilation with high mean airway pressures
regional anesthesia can usually be safely administered assuming coagulation profile is normal and hypotension avoided

Anesthetic Management in Chronic Hepatitis

Anesthetic Management

-chronic persistent and chronic lobular hepatitis have similar anesthetic management as acute hepatitis
-patients with chronic active hepatitis are presumed to have cirrhosis and are treated according to management of cirrhosis

Anesthetic Management in Cirrhosis

PREOPERATIVE MANAGEMENT

-due to limited functional hepatic reserve, cirrhotic patients are at increased risk of deterioration
-successful anesthetic management is highly dependant on recognizing and controlling the multisystemic nature of cirrhosis

INTRAOPERATIVE MANAGEMENT

-patients who are carriers of hepatitis B or hepatitis C may be infectious therefore extra care should be performed

Drug Responses

-cirrhotic patients have unpredicatable responses to drugs

Possible alterations may occur in:

-CNS sensitivity
-volume of distribution
-protein binding
-drug metabolism
-drug elimination
-increased volume of distribution for highly ionized agents (ex. nondepolarizing muscle relaxants) may require larger initial dose
-increased volume of distribution may occur because of the expanded extracellular fluid compartment
-decreased metabolic functions in cirrhotic patients may require smaller maintence doses of certain medications
-decreased metabolic functions may accumulate metabolites which are active and lead to prolonged duration of action
-decreased synthetic funtion of the liver may lead to decreased levels of pseudocholinesterase
-decreased levels of pseudocholinesterase may lead to increased duration of action of succinlycholine

Anesthetic Technique

-liver becomes more dependant on hepatic arterial perfusion as the portal venous blood flow is reduced
-critical to maintain and preserve hepatic arterial blood flow
-regional anesthesia may be used if coagulopathy and thrombocytopenia are absent. Avoid hypotension
-barbituate induction followed by isoflurane in air is most common anesthetic maintenance for cirrhotic patients
-halothane is generally avoided in cirrhotic patients
-opiods may reduce the volatile anesthetic requirements but frequent doses of opiods may accumulate and prolong duration
-prolonged duration of action of opiods due to frequent dosing may impair respiratory efforts
-cisatracuronium may be the muscle relaxant of choice due to its nonenzymatic degradation independent of the liver

Rapid sequence induction and intubation are generally needed due to increased risk:

-preoperative nausea and vomiting
-upper GI bleeding
-abdominal distention
-possible ascites

Monitoring

-respiratory and cardiac monitoring should be closely monitored especially in abdominal procedures
-electrocardiogram (5 lead) in patients receiving vasopressin recommended to detect cardiac ischemia from cor art vasoconstriction
-pulse oximetry and blood gas samples should help asses oxygenation and acid/base status of the cirrhotic patient
-cirrhotic patients with large right to left intrapulmonary shunts may not tolerate the administratio of nitrous oxide well
-cirrhotic patients with large right to left intrapulmonary shunts may require PEEP to treat V/Q abnormalities
-A-line is usually indicated in cirrhotic patients especially in cases with large fluid shifts ex. expectant bleeding
-urine output is closley monitored to help assess perfusion of vital organs
-if urine output is decreased then mannitol or low dose ('renal 'dose) dopamine may be indicated

Fluid Replacement

-cirrhotic patients are often already on sodium restriction preoperatively
-intraoperatively preservation of intravascular volume and urinary output is of prime importance
-colloid i.v. fluids may be preferred which helps to avoid sodium overload and also increases oncotic pressure
-abdominal procedure in cirrhotic patients usually encompass excessive bleeding and fluid shifts
-excessive bleeding and fluid shifts in cirrhotic patients should be replaced with intravenous fluids administration
-I.V. colloid fluid replacement is often required to prevent profound hypotension and renal deterioration