Studies on the renin-angiotensin-aldosterone system in patients with cirrhosis and ascites: Effect of saline and albumin infusion

Abstract

In patients with cirrhosis of the liver and ascites the reason for the elevated plasma renin activity (PRA) and aldosterone is not known. The objectives of this study were to determine: (a) whether acute suppression of these hormones was possible in this chronic disease state, and (b) whether decrease in “effective blood volume” was responsible for the elevated PRA and aldosterone. Six patients with cirrhosis of the liver and ascites and nine normal volunteers were studied. To avoid individual variations all cirrhotic patients and four normal controls received 50 g albumin infusion after they achieved sodium-balance on a 10-meq sodium 100 meq potassium diet followed by saline infusion (0.9% at 500 ml/hr for 4 hr) when sodium balance was again achieved. Despite significant differences in baseline of PRA (16.9 ± 6.4 vs. 4.1 ± 1.5 SEM ng/ml/hr) and plasma aldosterone (200 ± 57 vs. 56.2 ± 14.6 SEM ng/100 ml) between cirrhotic patients and normal controls, the responses (in percentage change from baseline) to albumin infusion were strikingly similar. The response to saline infusion in the cirrhotic patients, however, was blunted when compared to normals, whether they had prior infusion of albumin or not. In normal controls, saline infusion caused a significantly greater decrease in PRA and plasma aldosterone at all intervals studied when compared to albumin infusion. In patients with cirrhosis, however, the suppressive effect of albumin and saline were not statistically different. This study demonstrates that the elevated PRA and plasma aldosterone in patients with cirrhosis of the liver and ascites are acutely suppressible by both albumin and saline infusion. These findings are consistent with the hypothesis that in these patients, decrease in “effective blood volume” is the most important reason for the elevated PRA and plasma aldosterone.