The Effect of Sevoflurane Low-Flow Anesthesia on Preserving Patient Core Temperature

Abstract

Introduction: Low-flow anesthesia (LFA) reduces the fresh gas flow (FGF) entering the anesthesia circuit and saves on the volatile agent used. In this study, the effect of LFA with sevoflurane on core temperature and the incidence of perioperative hypothermia were investigated. Methods: According to the FGF applied, patients were classified into three groups: LFA (1 L/min), medium-flow anesthesia (MFA = 2 L/min), and high-flow anesthesia (HFA = 4 L/min). Patients’ demographic data and the initial (T1) and final (T2) core temperatures during the operation were compared. Results: A total of 160 patients were included in the study. The T2 value of the HFA group was significantly lower than the LFA group (p = 0.028). Different flow values were found to have a significant effect on temperature change (F = 21.630, p < 0.001, partial eta squared = 0.216). There was a significant difference between the mean temperatures measured at two different times (F = 301.064, p < 0.001, partial eta squared = 0.657). The overall incidence of hypothermia was 32.5%, with 52 patients. Hypothermia (T²<36°C) incidences were not different between the LFA group and the MFA and HFA groups (p = 0.682). However, perioperative core temperature loss was significantly lower in the LFA group (p = 0.001). Conclusions: LFA using sevoflurane was not sufficient alone to significantly reduce the incidence of hypothermia. However, we have demonstrated that it may also have a beneficial effect on reducing perioperative temperature loss.