Diuretic treatment and diuretic resistance in heart failure

Diuretic therapy decreases capillary wedge pressure and improves New York H eart Association (NYHA) functional class both in acute and chronic heart fa ilure. In advanced symptomatic heart failure, loop diuretics are generally necessary to improve symptoms of congestion. Diuretic resistance in the ede matous patient has been defined as a clinical state in which diuretic respo nse is diminished or lost before the therapeutic goal of relief from edema has been reached. The major causes of diuretic resistance are functional re nal failure (prerenal azotemia), hyponatremia, altered diuretic pharmacokin etics, and sodium retention caused by counterregulatory mechanisms intended to reestablish the effective arterial blood volume. Therapeutic approaches to combat diuretic resistance include restriction of fluid and sodium inta ke, use of angiotensin-converting-enzyme (ACE) inhibitors, changes in route (oral, intravenous) and timing (single dose, multiple doses, continuous in fusion) of diuretic therapy, and use of diuretic combinations. Am J Med. 19 99;106:90-96. (C) 1999 by Excerpta Medica, Inc.