Comparison of renal function following anesthesia with low-flow sevoflurane and isoflurane

Study Objective: To evaluate postoperative renal function after patients we re administered sevoflurane under conditions designed to generate high conc entrations of compound A. Study Design and Setting: A multicenter (11 sites), multinational, open-lab el, randomized, comparative study of perioperative renal function in patien ts who have received low-flow (less than or equal to 1 L/min) sevoflurane o r isoflurane. Patients: 254 ASA physical status I, II and III patients requiring endotrac heal intubation for elective surgery lasting more than 2 hours. Interventio ns: After induction, low-flow anesthesia was initiated at a flow rate less than or equal to 1 L/min. Blood and urine samples were studied to assess po stoperative renal function. Measurements and Main Results: Measurements of serum BUN and creatinine, an d urine glucose, protein pH and specific gravity were used to assess renal function preoperatively and up to 3 days postoperatively. Serum inorganic f luoride ion concentration was measured at preinduction, emergence, and 2, 2 4 and 72 hours postoperatively. Compound A concentrations were measured at two sites far those patients receiving sevoflurane. Adverse experience data were analyzed. One hundred eighty-eight patients were considered evaluable (98 sevoflurane and 90 isoflurane). Peak serum fluoride concentrations wer e significantly higher after sevoflurane (40 +/- 16 mu M) than after isoflu rane (3 +/- 2 mu M). Serum creatinine and BUN decreased in both groups post operatively; glucosuria and proteinuria occurred in 15% to 25% of patients. There were no clinically significant differences in BUN, creatinine, gluco suria, and proteinuria between the low-flow sevoflurane and low-flow isoflu rane patients. Conclusions: There were no statistically significant differences in the ren al effects of sevoflurane or isoflurane in surgical patients undergoing low -flow anesthesia for up to 8 hours. I,ow-flow sevoflurane anesthesia under clinical conditions expected to produce high levels of compound A appears a s safe as low-flow isoflurane anesthesia. (C) 1999 by Elsevier Science Inc.