Loop Diuretics in Acute Oliguric and Pre-renal States

Oliguria is common in critically ill patients, the most common cause being a reduction of the effective intravascular volume. Oliguric patients are almost universally treated with escalating doses of loop diuretics in the hope of increasing urine output. However, in the setting of a reduced effective intravascular volume loop diuretics cause a marked fall in glomerular filtration rate with an acute decline in renal function. In this paper we demonstrate that there is no scientific rationale or clinical evidence to support the use of loop diuretics in patients with oliguria and pre-renal azotemia, prophylactically in patients at risk of developing acute renal failure and in patients with established acute renal failure.