Perioperative Risk Factors for Intraoperative Hypothermia in Adult Patients Undergoing Elective Surgery at Jigme Dorji Wangchuk National Referral Hospital, Bhutan : a Prospective Observational Study

Abstract

BACKGROUND: Intraoperative hypothermia is commonly encountered in anesthetic practice. It is related to several risk factors and can lead to various adverse events. It is important to detect it early and prevent the complications related to it. Thus, this study was done to identify the incidence and perioperative risk factors for intraoperative hypothermia at a National Referral Hospital in Bhutan. METHODS: A prospective observational study was conducted in adult patients who underwent elective surgery lasting more than 30 minutes at the National Referral Hospital in Bhutan from August 2017 to November 2017. Patient characteristics, incidence of hypothermia, and any interventions for treatment of hypothermia during operation were recorded. Hypothermia was defined as core body temperature less than 36°C measured with an esophageal probe. RESULTS: Data were obtained from 91 patients with the mean (SD) age of 42.3 (17.2) years (range 18-75 years) and ASA scores of 1 and 2 in 57 and 34 of the patients, respectively. The patients underwent elective surgery with a mean (SD) duration of 73.2 (48.1) minutes and a mean (SD) duration of anesthesia of 80.9 (49.2) minutes. The incidence of intraoperative hypothermia was 61.5% (56/91). Preoperative heart rate more than 80 bpm (hazard ratio [HR] 0.45, 95% confidence interval [CI], 0.26-0.77) was a protective factor and duration of anesthesia more than 60 minutes (HR 1.82, 95% CI, 0.98-3.38) was a risk factor for intraoperative hypothermia. Hypothermic patients were managed with cotton blankets,air forced warmer and warmed IV fluids. CONCLUSIONS: Patients undergoing elective surgery lasting more than 30 minutes with preoperative heart rate less than 80 beats per minute and undergoing duration of anesthesia more than 60 minutes should be assessed properly from the preoperative period. Furthermore, the core body temperature of these patients should be continuously monitored throughout the operation period to detect intraoperative hypothermia and to intervene early.