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

Abstract

Background: Low flow anesthesia reduces the fresh gas flow (FGF) entering the anesthesia circuit and saves on the volatile agent used. In this study, the effect of low-flow anesthesia with sevoflurane on core temperature and the incidence of perioperative hypothermia were investigated.Methods: Records of patients who underwent general anesthesia with sevoflurane were analyzed retrospectively. According to the fresh gas flow applied, the patients were divided into three groups: Low flow anesthesia (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) temperatures during the operation were compared.Results: A total of 160 patients were included in the study. There was no significant difference in T1 temperature values between the groups. 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 degrees) 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: Low flow anesthesia using sevoflurane was not sufficient alone to reduce the incidence of hypothermia. However, the LFA technique preserved the patient’s core temperature better than the MFA and HFA techniques. Therefore, in addition to low-flow anesthesia being a cost-oriented technique, we have demonstrated that it may also have a beneficial effect on reducing perioperative temperature loss.Trial Registration: Researchregistary.com/6840Ethics committee: Yozgat Bozok University 2017-KAEK-25122019.1