Questionable value of furosemide in preventing renal failure

The effects of furosemide on renal function and hemodynamics were evaluated in 54 critically ill surgical patients. Standard clearance techniques were used to measure glomerular filtration rate (GFR), renal plasma flow (RPF), osmolar clearance (COsm), sodium clearance (CNa), and renal blood flow (RBF). RBF distribution to outer cortex, inner cortex-outer medulla, and inner medulla was measured by the radioactive xenon disappearance technique. Furosemide produced a marked rise in urine output, COsm, and CNa; it produced no change in GFR, RPF, RBF, and RBF distribution. Twelve of the 54 patients received furosemide for therapy not related to the study; six patients developed renal failure and five became hypotensive 2 to 10 hours after administration of furosemide. These data demonstrate that furosemide does not protect against renal failure by altering or increasing RBF but may cause renal failure by producing hypovolemia.