Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (179 page)

   Acute fulminant hepatitis is associated with failure of liver function. Patients present with hepatic encephalopathy and hepatic synthetic dysfunction. The manifestations of encephalopathy may range from drowsiness and confusion to stupor and coma. Synthetic dysfunction is usually manifested by coagulopathy. Multiorgan failure may ensue. Ascites is typical. Bacterial superinfection, especially with streptococci and
S. aureus
, may occur.

   ALF is more common with coinfection with two hepatitis viruses, like HBV and HDV, or with hepatitis infections in patients with preexisting liver disease. HBV infection is the most common cause of ALF (approximately 1–3% of adults). HAV is associated with ALF only in adults and occurs in 1.8% of patients >60 years of age. ALF after HEV is rare, except for pregnant women, where up to 20% of patients may develop ALF. ALF is an extremely rare complication of acute HCV infection. ALF may occur as a complication of systemic HSV infection. There is a high mortality associated with ALF, but if the patient survives, complete biochemical and histologic recovery are the rule.

   In addition to clinical signs of hepatic failure, significant metabolic derangement and laboratory abnormalities are common:

   As the patient’s condition deteriorates, titers of HBsAg and HBeAg often fall and disappear.

   Serum bilirubin progressively increases and may reach very high levels.

   Increased serum AST and ALT levels are seen, but levels may fall abruptly terminally; serum ALP and GGT may be increased.

   Serum cholesterol and cholesterol esters are markedly decreased.

   Albumin and total protein levels are decreased.

   Increased ammonia level in blood.

   Hematologic abnormalities.

   Evidence of DIC is common.

•   Decreased factors II, V, VII, IX, and X cause prolonged PT and aPTT.

•   Decreased antithrombin III.

•   Platelet count <100,000 in two thirds of patients.

•   Hemorrhage, especially in the GI tract.

   Metabolic markers are typically abnormal, including