A 58-year-old man with cirrhosis complains of worsening fatigue and confusion over the past 5 days. He also reports that over the past 48 hours he has had a declining urinary output. On examination, he is gaunt and jaundiced. He has tense ascites and a liver span of 7 cm in the midclavicular line. Lab result reveal a WBC 4600/mm3, Hb 9.4 g/dL, and PCB 29%. BUN of 34 mg/dL and a creatinine of 3.1 mg/dL. A urinary Na <10 mEq/L. Most appropriate treatment for his elevated BUN and creatinine?

This patient with well advanced cirrhosis and portal hypertension has developed the onset of renal insufficiency consistent with hepatorenal syndrome. This occurs during the end stages of cirrhosis and is characterized by diminished urine output and low urinary sodium. In the setting of end-stage liver disease, renal vasoconstriction occurs, and the distal convoluted tubule responds by conserving sodium. Unless the renal function is allowed to deteriorate further, liver transplantation will reverse this vasoconstriction and kidney function will return to normal. A large volume paracentesis may relieve the ascites but will have no significant benefit on the impaired renal function. There are no indications in this question to suggest that the patient requires acute hemodialysis.  A mesocaval shunt  is a surgical procedure that may decompress the portal pressure but will not have any benefit on renal function. Renal transplantation is of no value in this patient since the underlying lesion is in the liver; the kidneys will return to normal function if there is improvement in hepatic function.