The challenges of providing renal replacement therapy in decompensated liver cirrhosis.

Development of renal failure requiring renal replacement therapy (RRT) in the cirrhotic patient is a devastating complication. Survival without RRT is less than 10% on average at 6 months. However, it is now appreciated that all renal failure in this group of patients is not due solely to hepatorenal syndrome, and the cause of the renal failure affects the prognosis. This paper reviews the prognosis depending on cause and points out the difficulty in making the correct diagnosis. Provision of RRT is difficult in this group of patients due to hypotension and coagulopathy which is highly prevalent. Survival with RRT is still poor with only 30-60% of patients surviving to liver transplant. Provision of RRT should be offered as a bridge to patients awaiting liver transplant or those undergoing liver transplant evaluation. Provision of long-term RRT is usually not indicated in other cirrhotic patients who develop a need for RRT except as a trial to see if renal function will return. The decision between intermittent hemodialysis or continuous renal replacement therapy (CRRT) is usually based on the clinical characteristics of the patient. Neither has been demonstrated to be superior to the other, although CRRT may be better tolerated in the unstable patient. CRRT is clearly indicated in cases of fulminant hepatic failure as it does not raise intracranial pressure. Provision of intraoperative CRRT during liver transplant may be indicated to help control volume and electrolytes in those patients presenting for liver transplant with renal failure. Newer extracorporeal support systems, such as extracorporeal albumin dialysis (MARS) and fractional plasma separation and adsorption with hemodialysis (Prometheus), have recently been developed to provide both renal and liver support in this group of patients. These are still considered experimental, although the MARS system has been utilized to treat patients with hepatorenal syndrome, and is available outside the United States.