Background: The contributing factors that result in significant, postoperative proteinuria and glucosuria after low-flow isoflurane and sevoflurane anesthesia are unknown. The present study compared renal responses after anesthesia with desflurane (negligible metabolism), sevoflurane, or intravenous propofol.
Methods: Informed consent was obtained from 52 patients with American Society of Anesthesiologists physical status I-III (aged 36-81 yr). Patients with diabetes or renal insufficiency were excluded. Desflurane (n = 20) or sevoflurane (n = 22), without nitrous oxide, was given at 1 l/min fresh gas flow for elective surgical procedures lasting more than 2 h; 10 patients received propofol without nitrous oxide as the primary anesthetic. Blood and urine chemistries were obtained before surgery. Blood and 24-h urine collections were obtained for 3 days after surgery and were analyzed for liver and renal indices.
Results: Length of surgery averaged approximately 300 min (range, 136-750 min), minimum alveolar concentration-hour averaged 4.3 (range, 1.2-11.0), and infusion rates of propofol were 99-168 microg x kg(-1) x min(-1). Plasma creatinine concentration did not change, plasma blood urea nitrogen decreased significantly, and significant increases in urine glucose, protein, and albumin occurred similarly in all groups. Mean (+/- SD) postoperative urine glucose values for day 1 after desflurane, sevoflurane, and propofol were 1.4 +/- 3.0, 1.1 +/- 2.1, and 1.9 +/- 2.6 g/d (normal, < 0.5 g/d). The average daily protein/creatinine ratios for postoperative days 2-3 after desflurane, sevoflurane, and propofol were 240 +/- 187, 272 +/- 234, and 344 +/- 243 (normal, < 150 mg/g). Regardless of anesthetic, there were significantly greater urine protein concentrations after surgical procedures in central versus peripheral regions.
Conclusions: Alterations in postoperative renal function were common and unrelated to the choice of anesthetic. These findings implicate nonanesthetic factors in producing changes in biochemical indices of renal excretory function.