Hepatorenal syndrome: new perspectives in pathophysiology and management.

Hepatorenal syndrome (HRS) is a unique form of acute renal failure occurring in patients with advanced liver disease. Despite the severe derangement of renal function and ominous prognosis, minimal pathologic abnormalities of the kidneys are found at autopsy. The kidneys, if transplanted, are capable of normal function, which supports the concept that renal failure is functional and potentially reversible. The pathogenesis of HRS is not completely known, but it is probably the result of an extreme underfilling of the arterial circulation secondary to an arterial vasodilation located in splanchnic circulation. Besides the renal circulation, all other extrasplanchnic vascular beds also appear to be vasoconstricted. The diagnosis of HRS is currently based on several widely accepted diagnostic criteria aimed at excluding nonfunctional causes of renal failure. Recently initiated therapeutic approaches lend a note of optimism to the future management of HRS. These include liver transplantation as definitive treatment for patients with end-stage liver disease, and introduction of new vasoconstrictor drugs with the preferential effect on the splanchnic circulation. The development of HRS after spontaneous bacterial peritonitis may be effectively prevented by the administration of albumin together with antibiotic therapy.