Altered metabolism of anesthetics
Although both propofol and etomidate are metabolized by the liver, their actions are terminated by redistribution, making them reasonable anesthetics to use in patients with liver disease. Benzodiazepines, barbiturates, and most opioids however may have prolonged effects, as a result of both decreased clearance and an increase in the free active fraction of these drugs, in patients with marked hypoalbuminemia. Remifentanil clearance is not affected by liver dysfunction.
Patients with liver disease often need a higher initial dose of nondepolarizing neuromuscular blockers, probably because of increased volume of distribution or increased neuromuscular receptors. However, for some, a slower elimination time may decrease the requirement for maintenance dosing. Vecuronium and rocuronium are highly dependent on hepatobiliary excretion and metabolism and show a decreased clearance and a prolonged effect in patients with liver disease. Cisatracurium and atracurium are degraded via Hofmann elimination and are unaffected by liver disease. Succinylcholine and mivacurium (not available in the United States) are completely metabolized in the plasma by pseudocholinesterase, which may be depressed in severe liver disease, prolonging their duration of action.
Acetaminophen and Nonsteroidal Anti-inflammatory Drugs
Acetaminophen is deemed safe in total daily doses of less than 2000 mg. Nonsteroidal anti-inflammatory drugs (NSAIDs) may exacerbate risk of surgical bleeding, gastrointestinal bleeding, and renal injury but should be utilized on a case-by-case basis.