Review article: hepatorenal syndrome--definitions and diagnosis.

Hepatorenal syndrome (HRS) is a severe complication of cirrhosis that develops in the final phase of the disease. Two types of HRS exist. Type 1 is defined by a rapid reduction of renal function and in type 2 HRS the reduction of renal function is slowly progressive. Type 1 HRS is diagnosed when the serum creatinine level increases by more than 50% of the baseline value to above 133 micromol/L. According to the International Ascites Club, HRS is defined by the presence of five criteria: (1) severe cirrhosis; (2) glomerular hypofiltration; (3) no other functional or organic causes; (4) failure of plasma volume expansion; (5) no proteinuria. Additional diagnostic criteria may be present. The diagnosis of HRS may be difficult in patients with severe cirrhosis. Other types of acute renal failure may occur. For example, ischaemic or toxic tubular necrosis or sepsis may cause renal failure in these patients. Furthermore, uncontrolled HRS may lead to ischaemic tubular necrosis; thus, these patients must be managed as soon as possible in an intensive care unit.