The effect of low flow anesthesia with sevoflurane on oxidative status: A prospective, randomized study.

OBJECTIVES: To assess the impact of low-flow, mid-flow, and high-flow sevoflurane anesthesia on the oxidative state by measuring thiol/disulfide levels in patients undergoing surgery. METHODS: The study included 99 patients randomly assigned to 3 groups. In the low-flow anesthesia group, the fresh gas flow was diminished to 1 L.min-1 for anesthesia maintenance after 6 L.min-1 was administered for the first 10 minutes. In the mid-flow anesthesia group, fresh gas flow was applied as 2 L.min-1. In the high-flow anesthesia group, the fresh gas flow was administered as 4 L.min-1 throughout the operation. Blood samples were obtained before induction, at the 60th minute after induction, and at 2 hours postoperatively. Native thiol, total thiol, disulfide analyzed and disulfide/native thiol percentage, disulfide/total thiol percentage, and native thiol/total thiol percentage were calculated. RESULTS: Disulfide values in mid-flow and low-flow anesthesia were significantly lower at the 60th minute after induction compared to the high-flow anesthesia group. In the group evaluations, intraoperative native thiol levels in the high-flow group were found to be substantialy lower than preoperative values. CONCLUSION: It was sighted that low-flow anesthesia with sevoflurane prohibited oxidative damage. It was concluded that low flow anesthesia can be utilized safely in this respect.