Acute Renal Failure

Twenty-two hundred sixty-two consecutive medical and surgical admissions were evaluated prospectively to determine the contribution of iatrogenic factors to the development of renal insufficiency in hospital. Of 2,216 patients at risk, some degree of renal insufficiency developed in 4.9 percent. Decreased renal perfusion, postoperative renal insufficiency, radiographic contrast media, and aminoglycosides accounted for 79 percent of the episodes. Iatrogenic factors, broadly defined, accounted for 55 percent of all episodes. Poor prognostic indicators included oliguria, urine sediment abnormalities and, most importantly, severity of renal insufficiency; with an increase in serum creatinine of 3 mg/dl or greater, the mortality rate was 64 percent. Age, admission serum creatinine levels, and the number of episodes of renal insufficiency did not significantly affect outcome. We conclude that there is a substantial risk of the development of renal failure in hospital and that the mortality rate due to hospital-acquired renal insufficiency remains high.

Injections of radiocontrast agents are a frequent cause of acute decreases in renal function, occurring most often in patients with chronic renal insufficiency and diabetes mellitus. We prospectively studied 78 patients with chronic renal insufficiency (mean [+/- SD] serum creatinine concentration, 2.1 +/- 0.6 mg per deciliter [186 +/- 53 mumol per liter]) who underwent cardiac angiography. The patients were randomly assigned to receive 0.45 percent saline alone for 12 hours before and 12 hours after angiography, saline plus mannitol, or saline plus furosemide. The mannitol and furosemide were given just before angiography. Serum creatinine was measured before and for 48 hours after angiography, and urine was collected for 24 hours after angiography. An acute radiocontrast-induced decrease in renal function was defined as an increase in the base-line serum creatinine concentration of at least 0.5 mg per deciliter (44 mumol per liter) within 48 hours after the injection of radiocontrast agents. Twenty of the 78 patients (26 percent) had an increase in the serum creatinine concentration of at least 0.5 mg per deciliter after angiography. Among the 28 patients in the saline group, 3 (11 percent) had such an increase in serum creatinine, as compared with 7 of 25 in the mannitol group (28 percent) and 10 of 25 in the furosemide group (40 percent) (P = 0.05). The mean increase in serum creatinine 48 hours after angiography was significantly greater in the furosemide group (P = 0.01) than in the saline group. In patients with chronic renal insufficiency who are undergoing cardiac angiography, hydration with 0.45 percent saline provides better protection against acute decreases in renal function induced by radiocontrast agents than does hydration with 0.45 percent saline plus mannitol or furosemide.