Dilutional hyponatremia in patients with cirrhosis and ascites.

OBJECTIVES: To analyze the predisposing factors, modifications of vasoactive systems, and prognosis of patients with cirrhosis and hyponatremia. PATIENTS AND METHODS: Fifty-four patients with hyponatremia (serum sodium level of <130 mEq/L after 5 days of hyponatremic diet and no diuretic therapy). Twenty cirrhotic patients served as controls. We measured plasma renin activity and levels of plasma aldosterone, norepinephrine, and antidiuretic hormone. Follow-up identified the development of hepatorenal syndrome and death.
RESULTS: A higher percentage of patients with hyponatremia had decreased liver size, higher levels of plasma renin activity, and higher serum concentrations of aldosterone and norepinephrine. Renal insufficiency was detected in 31 of them (57%). Precipitating factors (hemorrhage or infections) were detected in 27 patients (50%). Incidence of hepatorenal syndrome and death were higher in patients with spontaneous development of hyponatremia (n = 23 [85%] and n = 25 [93%], respectively) than in patients with precipitating factors (n = 15 [56%] and n = 12 [44%], respectively) and cirrhotic controls (n = 1 [5%] and n = 5 [25%], respectively) (P<.001). Results of multivariate analysis showed that Child-Pugh index, presence of hepatocarcinoma, and serum concentration of urea were associated with mortality. After excluding those patients with kidney failure at the time of admission, only Child-Pugh index and norepinephrine concentrations were independent predictors of mortality.
CONCLUSIONS: Hyponatremia is an alteration in patients with advanced liver disease. Although survival is significantly reduced in patients with spontaneous development of hyponatremia, a reduced sodium concentration cannot be considered as a independent predictor of the risk for death.