hepatic coma, a neuropsychiatric manifestation of extensive liver damage caused by chronic or acute liver disease. Either endogenous or exogenous waste toxic to the brain is not neutralized in the liver before being shunted back into the peripheral circulation of the blood, or substances required for cerebral function are not synthesized in the liver and therefore are not available to the brain. Commonly, ammonia, a by-product of protein metabolism that is toxic to the brain, is not converted to urea by the liver. The condition is characterized by variable consciousness, including lethargy, stupor, and coma; a tremor of the hands; personality change; memory loss; hyperreflexia; and hyperventilation. Respiratory alkalosis, mania convulsions, and death may occur. The outcome varies according to the pathogenesis of the condition and the treatment. Also called portal-systemic encephalopathy. See also cirrhosis, hepatitis. ▪ INTERVENTIONS: Treatment in most cases includes cleansing enemas, low-protein diet, parenteral hydration with a balanced electrolyte solution, and specific treatment for the underlying cause. It may also include the use of neomycin orally to kill off bacteria and thus prevent elevated blood urea nitrogen levels.
