The effects of active warming on perioperative inadvertent hypothermia in patients undergoing vitreoretinal surgery under local anesthesia

Abstract

Purpose: Perioperative inadvertent hypothermia (PIH) is the decrease in core temperature below 36°C. We aimed to assess whether PIH develops in patients operated under local anesthesia (ULA) for vitreoretinal surgery in the operating room and investigate active warming efficacy. Methods: Seventy-two patients were divided into two groups: Group 1 contained unwarmed patients ( n = 36), and Group 2, warmed patients ( n = 36). The core temperatures, heart rate (HR), and mean arterial pressure (MAP) of the patients were measured at the beginning of surgery, after 20 min, 40 min, 1 h, at the end of the operation, and during the postoperative period. Results: PIH incidence was 44.6% in Group 1, whereas no hypothermia was observed in Group 2. Patient temperatures at 20 min ( P = 0.001), 40 min ( P < 0.001), 1 h ( P < 0.001), the end of the operation ( P < 0.001), and the postoperative period ( P < 0.001) were significantly higher in Group 2 than in Group 1. Patient HRs at the end of the operation and during the postoperative period were significantly lower in Group 2 ( P = 0.005) than in Group 1 ( P < 0.001). The intraoperative 40 th ( P = 0.044) and 60 th ( P < 0.001) minutes, end of operation ( P < 0.001), and postoperative MAP ( P < 0.001) values of Group 1 were significantly higher than those of Group 2. Conclusion: PIH may develop in patients operated ULA, especially with a low ambient temperature. Actively warming may help prevent the harmful effects of PIH.

The Effect of Using a Normothermia Checklist on Awakening Time From Anesthesia and Coagulation Disorder: A Randomized Controlled Trial

“…The combination of active warming and passive insulation methods applied in this study in accordance with NC guidelines was effective in preventing IPH in 100% of the control group. Although no similar studies have been conducted in Turkey, a recent Turkish study (Urfalioglu et al, 2021) reported active heating methods to have positive effects on IPH. Another study (Tunc et al, 2022) that compared active heating and passive insulation methods determined active heating to be effective in preventing IPH.…”

Effect of Aggressive Warming versus Routine Thermal Management on the Incidence of Perioperative Hypothermia in Patients Undergoing Thyroid Surgery: A Prospective, Randomized, Double-Blind Controlled Trial

“…10 The occurrence of perioperative hypothermia may be related to the operation time > two hour, the intraoperative blood loss, the size of surgical wound, the use of anesthetic drugs, an age of > 60 years, or a low body mass index (BMI). 2,11,12 Current research on hypothermia primarily focuses on high-risk patients or specific types of surgery, such as hip replacement and thoracic surgeries. 13 The thermal management of thyroid surgery is often overlooked because of its small incisions, less trauma, and less bleeding.…”