ORIGINAL CONTRIBUTION Diuretics, Mortality, and Nonrecovery of Renal Function in Acute Renal Failure

ACUTE RENAL FAILURE (ARF) IN hospitalized patients may be associated with low, normal, or excess extracellular volume, depending on the cause of the ARF, accompanying conditions (eg, heart failure, liver disease), and patterns of administration of crystalloids and colloids. Diuretic agents are frequently given to augment renal salt and water excretion in the setting of extracellular volume overload. Diuretics are also frequently given during ARF in an effort to “convert” oliguric to nonoliguric ARF, since oliguria has been recognized as a proxy for the severity of ARF and the likelihood of requiring dialysis. Despite the ubiquity of this practice, there is scant evidence that diuretics provide any material benefit to patients with ARF. Indeed, the “conversion” of oliguric to nonoliguric ARF may reflect the severity of disease (diuretic-responsive ARF) rather than a valid (and favorable) response to therapy. Moreover, the use of diuretics may increase the risk of ARF when given before radiocontrast exposure and in other clinical settings, raising the possibility that diuretics may be harmful in patients with established ARF. Several randomized clinical trials have explored the use of diuretics in established ARF and have not shown benefit in survival or recovery of renal function, although all studies were hampered by low statistical power. We hypothesized that the use of diuretics during ARF would be associated with an increase in mortality, hospital length of stay, and nonrecovery of renal function in critically ill patients with ARF due to either direct effects or indirect effects of delaying dialytic sup-