Sodium excretion in 13 patients with decompensated cirrhosis was measured under baseline conditions of water loading (n = 13) and during conditions designed to improve effective blood volume including: head-out water immersion alone (n = 13); norepinephrine infusion alone (n = 6), and combined norepinephrine and head-out water immersion (n = 6). All 13 patients were in positive sodium balance under baseline conditions, with a mean plasma aldosterone concentration of 78.7 +/- 15.6 ng per dl. In only four patients was plasma aldosterone less than 50 ng per dl. During head-out water immersion alone, 5 patients achieved negative sodium balance and, in all 5, plasma aldosterone was less than 50 ng per dl (mean = 23.0 +/- 5.3 ng per dl). However, the mean plasma aldosterone during head-out water immersion in the eight patients who remained in positive sodium balance during this maneuver was 64.0 +/- 11.9 ng per dl (p less than 0.01). During norepinephrine alone, positive sodium balance was maintained in all patients, and plasma aldosterone was not significantly different from baseline. Combining norepinephrine and head-out water immersion resulted in the largest and most consistent negative sodium balance. The mean plasma aldosterone concentration was decreased significantly (78.7 +/- 15.6 to 32.6 +/- 9.9 ng per dl (p less than 0.05). Regardless of the maneuver performed, no patient in whom aldosterone exceeded 50 ng per dl achieved negative sodium balance. Furthermore, only in those studies utilizing head-out water immersion, with or without norepinephrine, was negative sodium balance seen.(ABSTRACT TRUNCATED AT 250 WORDS)