Pathophysiology, clinical features and management of hepatorenal syndrome.

Hepatorenal syndrome (HRS) is a form of functional renal failure occurring in patients with advanced liver disease. Hypoperfusion of the kidney, due to renal vasoconstriction, is the main feature of HRS. Conversely, the extrarenal circulation is characterized by low systemic resistance, especially occurring in splanchnic vessels, and arterial hypotension. It has been postulated that renal vasoconstriction is induced either by a hepatorenal reflex related to the diseased liver or by arterial vasodilation and the subsequent baroreceptor-mediator activation of systemic vasoconstrictor factors. The diagnosis of HRS requires the exclusion of other causes of renal failure in patients with liver disease. On the basis of clinical and prognostic differences, two types of HRS have been defined. The prognosis of HRS is poor and, to date, the only effective treatment is the liver transplantation.