On the Concentrating Defect in Cirrhosis of the Liver*

Abstract

The characteristics of the urine concentrating system of 27 patients with cirrhosis were studied. The patients received adaquate dietary protein and sodium and had no clinical evidence of renal disease. The mean Umax for the group was 651 [plus or minus] 25 mOsm/L (1 SE) which was significantly lower than the mean Umax (812 [plus or minus] 31 mOsm/L) in a comparable group of chronically ill patients without cirrhosis. The mean TCH2O was 4.8 [plus or minus] 0.44 ml/min which is within normal limits. The Umax defect was not correlated with severity of disease, GFR, urinary sodium, urea or serum potassium. Further studies provided evidence that decreased sodium delivery to the ascending loop of Henle was not a sufficient explanation for the Umax defect. Increased medullary blood is postulated as the explanation for the low Umax and normal TcH2O in this disease.