Ischemic Hepatitis : Clinical and Laboratory Observations of 34 Patients

Acute hepatocellular injury, whether due to viral hepatitis, hepatic ischemia, or drug hepatotoxicity, results in elevated levels of serum aminotransferases (AST and ALT). Serum lactate dehydrogenase (LD) is reported to be markedly elevated in ischemic hepatitis. Thus, comparisons of the degree of elevation of serum levels of LD, ALT, and AST may be helpful in the differential diagnosis of acute liver injury. To study this, we reviewed serum enzyme patterns early in the course of acute liver injury in patients with acute viral hepatitis A and B (n = 51), ischemic hepatitis (n = 20), and acetaminophen injury (n = 26). All patients had serum ALT and/or AST at least five times the upper limit of normal. For a given ALT and AST level, LD was higher in ischemic hepatitis and acetaminophen injury than in viral hepatitis. The mean ALT/LD ratio for acute viral hepatitis was 4.65, for ischemic hepatitis 0.87, and for acetaminophen injury 1.46. Mean ALT/LD ratio for viral hepatitis was significantly higher (p < 0.0001) than for the other two groups combined. An ALT/LD ratio of 1.5 differentiated acute viral hepatitis from ischemic hepatitis and acetaminophen injury with a sensitivity of 94% and a specificity of 84%.

The incidence of hypoxic hepatitis was prospectively studied for 1 year in a group of high-risk patients suffering from low cardiac output in a coronary care unit. Hypoxic hepatitis, defined as an increase in serum aminotransferase activity of at least 20 times the upper limit of normal without any other cause for hepatic necrosis, was observed in 20 patients. This represents 2.6% of the 766 patients admitted to the unit during this period and 21.9% of the 91 patients suffering from low cardiac output. Clinical, biological and hemodynamic data were compared between 20 patients with low cardiac output and hypoxic hepatitis, and 48 patients with low cardiac output but without hypoxic hepatitis who survived more than 24 h. In these two groups of patients, hepatic blood flow was measured by galactose clearance at low concentration. Patients with hypoxic hepatitis exhibited a higher central venous pressure (90% versus 38%-p < 0.001) as well as a lower hepatic blood flow (867 +/- 377 ml/min versus 1429 +/- 644 ml/min-p = 0.001). In conclusion, although it is considered a rare hepatic disorder, hypoxic hepatitis is frequent in patients with low cardiac output admitted to the coronary care unit, and is associated with a decrease in hepatic blood flow and passive hepatic venous congestion.