Causes of Liver Dysfunction in Critical Illness

ACUTE LIVER FAILURE Acute hepatitis with jaundice and coagulopathy without hepatic encephalopathy is referred to as severe acute hepatitis. The prognosis is generally good. The term fulminant hepatic failure (FHF) was originally defi ned as a clinical syndrome developing as a result of massive necrosis of liver cells or any other sudden and severe impairment of hepatic function (Trey and Davidson, 1970). This defi nition included the stipulation that there should be no history or evidence of pre-existing liver disease and that the signs of encephalopathy should appear within 8 weeks of the onset of the fi rst symptoms. Late-onset hepatic failure was diagnosed when the onset of encephalopathy was delayed by 8–26 weeks from the onset of symptoms. More recently, in an attempt to standardize the nomenclature a different terminology has been proposed. This is based on the interval between jaundice and encephalopathy, the terms hyperacute, acute or subacute liver failure being applied depending on whether this interval is 0–7 days, 8–28 days or 29 days to 12 weeks respectively (O’Grady et al., 1993). In this classifi cation, in contrast to Trey and Davidson’s original defi nition, cases with pre-existing chronic liver disease are included, although when the acute and chronic phases are due to the same process those with a previous history of symptomatic liver disease are normally excluded. This new terminology did not, however, receive universal approval (Bernuau and Benhamou, 1993). These authors suggest that patients with encephalopathy developing within 2 weeks of the onset of jaundice should be categorized as FHF, whereas the term subfulminant hepatic failure (SFHF) should be applied to those in whom the onset of encephalopathy is delayed for 2–12 weeks.