The liver's complex vascular supply and high metabolic activity make it particularly vulnerable to circulatory disturbances. The severity and characteristics of hepatic injury depend upon the blood vessels that are involved and the degree to which injury is related to passive congestion or diminished perfusion .
There are several well-recognized forms of vascular injury to the liver, including Budd-Chiari syndrome, hepatic sinusoidal obstruction syndrome (veno-occlusive disease), passive congestion due to heart failure, hepatic infarction, and ischemic hepatitis. (See "Pathogenesis of liver injury in circulatory failure".)
This topic review will focus on ischemic hepatitis, hepatic infarction, and ischemic cholangiopathy, while discussions on Budd-Chiari syndrome, hepatic sinusoidal obstruction syndrome, and congestive hepatopathy are presented separately. (See "Budd-Chiari syndrome: Epidemiology, clinical manifestations, and diagnosis" and "Diagnosis of hepatic sinusoidal obstruction syndrome (veno-occlusive disease) following hematopoietic cell transplantation" and "Congestive hepatopathy".)
ISCHEMIC HEPATITIS (SHOCK LIVER, HYPOXIC HEPATITIS)
Ischemic hepatitis (also referred to as shock liver, hypoxic hepatitis, and occasionally [and erroneously] acute hepatic infarction) refers to diffuse hepatic injury resulting from acute hypoperfusion . In one report, ischemic hepatitis accounted for 1 percent of patients admitted to an intensive care unit .
The term hepatitis is somewhat of a misnomer since the injury is not mediated by an inflammatory process. Nevertheless, the profound elevation in aminotransferases is similar to that seen in acute viral and toxic hepatitis (such as caused by acetaminophen), two disorders that should be considered prominently as part of the differential diagnosis. (See "Approach to the patient with abnormal liver biochemical and function tests".) The term ischemic hepatitis is preferable to "shock liver" since the syndrome can occur in the absence of shock. The diffuse nature of the injury distinguishes it from hepatic infarction, which represents focal injury.