Objective: To compare postoperative renal injury in low-flow sevoflurane anesthesia between more and less than two MAC-hours, and to determine the potential predisposing factors of postoperative renal injury.

Materials and Methods: The present study was a retrospective cohort study that included 400 patients who underwent low-flow general anesthesia with sevoflurane, determining maintenance of fresh gas flow not exceeding one liter per minute. All subjects were classified into two groups, those exceeding two MAC-hours and those receiving less than two MAC-hours. The diagnosis of postoperative renal injury followed the Kidney Disease Improving Global Outcomes criteria. The multivariable logistic regression analysis was performed to identify independent risk factors for postoperative acute kidney injury.

Results: The incidences of postoperative acute kidney injury among the patients received more and less than two MAC-hours groups were 20.1% and 21.5%, respectively (p=0.876). Factors found to be associated with postoperative acute kidney injury were ASA classification 2 (adjusted OR 7.82, 95% CI 1.0 to 59.2), ASA physical status 3 or higher (adjusted OR 9.85 95% CI 1.3 to 76.4), and obesity (adjusted OR 5.74, 95% CI 2.0 to 16.4). Exposure to low-flow sevoflurane for more than two MAC-hours was not associated with postoperative renal injury (adjusted odds ratio 0.89, 95% CI 0.5 to 1.5, p=0.666).

Conclusion: Exposure to low-flow sevoflurane exceeding two MAC-hours did not increase the risk of postoperative acute kidney injury.

Keywords: Acute kidney injury; Low flow general anesthesia; Sevoflurane

DOI: 10.35755/jmedassocthai.2022.06.13326

Received 25 October 2021 | Revised 21 December 2021 | Accepted 22 December 2021