Practical applications of intravenous diuretic therapy in decompensated heart failure

Intravenous (IV) loop diuretics play an important role in the treatment of decompensated heart failure (DHF). They inhibit the Na(+)-K(+)-2Cl(-) reabsorptive pump in the thick ascending limb of the loop of Henle, and the resultant natriuresis and diuresis decreases volume load, improves hemodynamics, and reduces DHF symptoms. However, loop diuretics have a short half-life and their efficacy may be limited by postdiuretic sodium rebound during the period between doses in which the tubular diuretic concentration is subtherapeutic. Moreover, they can produce electrolyte abnormalities, neurohormonal activation, intravascular volume depletion, and renal dysfunction. Several studies have reported an association between diuretic therapy and increased morbidity and mortality. In addition, many patients, especially those with more advanced forms of heart failure (HF), are resistant to standard doses of loop diuretics. These high-risk, resistant patients may benefit from pharmacologic and/or nonpharmacologic interventions to improve hemodynamic performance, treatment of renovascular disease, discontinuation of aspirin and other sodium-retaining drugs, manipulation of the route of delivery or combination of diuretic classes, or hemofiltration. Despite >50 years of use, many questions regarding the use of intravenous diuretic agents in patients with DHF are still unanswered, and there remains a compelling need for well-designed randomized, controlled clinical trials to establish appropriate treatment regimens that maximize therapeutic benefit while minimizing morbidity and mortality.