Treatment of dilutional hyponatremia in congestive heart failure.

Water restriction is a slow and difficult way to treat dilutional hyponatremia during diuretic therapy of congestive heart failure. An i.v. infusion of 400-1 400 mmol hypertonic saline combined with repeated i.v. injections of loop diuretics was used instead in 9 cases (6 patients). In 4 cases with dominating left heart failure the serum sodium concentration increased and the heart failure was not aggravated as judged from pulmonary rales and body weight. Two of the five cases with dominating right heart failure responded in the same favourable way, but body weight increased 1-2 kg and hyponatremia reappeared in three. The only difference observed between responders and non-responders was that the responders were free from leg edema. This treatment of dilutional hyponatremia seems worth further cautious use in situations in which water restriction is troublesome, but it should probably be reserved for patients without severe right heart failure.