Effect of diuretics on cardiopulmonary performance in severe chronic airflow obstruction. A controlled clinical trial.

In a randomized, controlled trial, ten patients with pulmonary heart disease due to severe chronic airflow obstruction were stratified into two groups: group 1 had clinical features of congestive heart failure during respiratory failure and were regularly receiving diuretics; group 2 had no such clinical features and were not receiving diuretics. In group 1, when placebo was substituted for diuretics, pulmonary edema developed in three patients; exercise performance and ventricular function of the remaining two patients deteriorated. In group 2, there was no difference in exercise tolerance or ventricular function between placebo and diuretic therapy. The clinical deterioration in group 1 was related to abnormal left ventricular function. Thus, diuretics benefit only patients who have clinical features of congestive heart failure. In patients with isolated abnormal right ventricular function, diuretics may be harmful.