Investigation of the effect of minimal, LW and HİGH flow anesthesia on body temperature and tissue oxygenation in elective nasal surgeries

Objective: Inadvertent perioperative hypothermia (IPH) is frequently observed in patients undergoing general anesthesia. Intraoperative high fresh gas flow (FGF), dry and cold air can contribute to IPH. Therefore, low and minimal flow anesthesia methods are used in today's practice. There are implementation reservations due to the risk of hypoxia. In our study, we aimed to investigate the effect of minimal, low and high flow anesthesia on body temperature and tissue oxygenation in patients undergoing elective nasal surgery. Material and Methods: With the permission of Recep Tayyip Erdoğan University NonInvasive Clinical Trials Ethics Committee dated 23.12.2016 and 2016/39, in this prospective randomized controlled study, under hypotensive anesthesia, elective nasal surgery planned, aged 18-60, BMI 19-27, ASA 1-2 risk group, the operation time between 1 and 4 hours patients were included. The patients were divided into groups as minimal (0.5L / min), low (1L / min) and high (2L / min) flow anesthesia. Demographic data of the patients such as age, gender, BMI and operative data (duration of anesthesia, operation time, iv total fluid) were recorded. Preoperative waiting room temperature, intraoperative operating room room temperature and intraoperative body temperature, anesthesia respiratory circuit humidity and VIII temperature, tissue oxygen saturation and tissue hemoglobin index were recorded at 0, 15, 30, 60, 90, 120 and 150 minutes. In the postoperative period, shivering and body temperatures of the patients, Alderete score, room temperature of the recovery unit were recorded. Results: Data of 92 patients were analyzed. IPH was observed in patients (p = 0.001; p <0.01). There was no significant difference in demographic data, perioperative hemodynamic parameters and body temperature of the patients (p> 0.05). Tissue oxygen saturation (p = 0.033, p = 0.028, p = 0.011, p = 0.02; p <0.05) and postoperative Aldrete score (p = 0.002; p <0.01) were found to be significantly higher in the minimal flow group at 15th, 60th, 90th and 120th minutes. A correlation was found between body temperature and postoperative recovery temperatures and operating room temperature (r = .446, r = .531; p <0.05). Conclusion: IPH was detected in patients who underwent elective nasal surgery. It was observed that 0.5, 1 and 2 L / min FGF rates had no effect on body temperature and at the same time, the humidity and temperature of the anesthesia circuit were maintained. However, it was found tissue oxygen saturation at 0.5 L / min FGF and Aldrete score in the postoperative recovery unit were higher. Body temperature was correlated with preoperative waiting room, operating room and postoperative recovery room temperature. Keywords: Minimal Flow Anesthesia, Low Flow Anesthesia, İnadvertent Perioperative Hypothermia, Tissue Oxygen Saturation (StO2)