Analysis of the Risk Factors for the Onset of Postoperative Hypothermia in the Postanesthesia Care Unit

Abstract

PurposeRecent studies on hypothermia typically focused on a single anesthesia method or a particular surgical procedure. Although there are multiple risk factors leading to hypothermia, such as the use of cold solutions or nonhumidified and nonheated anesthetic gases, few studies have reported the incidence of postoperative hypothermia among patients in the postanesthesia care unit (PACU). DesignThis is a retrospective analysis of patients who underwent surgery and were admitted to the PACU immediately after surgery at the Fourth Affiliated Hospital, College of Medicine, Zhejiang University, from September 2018 to March 2019. MethodsPatient data were collected and analyzed in two groups to understand the factors affecting the occurrence of hypothermia. Hypothermia was defined as a core temperature of less than 36°C. On the basis of body temperature, patients in the PACU were divided into hypothermic and nonhypothermic groups. Factors influencing hypothermia were studied by the univariate method, followed by logistic regression analysis to identify the risk factors for hypothermia onset. FindingsOf a total of 1,788 patients were enrolled in the study, 113 (6.32%) exhibited hypothermia (<36°C) in the PACU. The hypothermic and nonhypothermic groups displayed significant differences (P < .05) in the anesthesia method used as well as the American Society of Anesthesiologists physical classification status. The body temperature at the time the patients were admitted to the operating room influenced the occurrence of postoperative hypothermia (P < .01). These parameters were recognized as independent risk factors for postoperative hypothermia in the PACU. ConclusionsSignificant risk factors for the onset of hypothermia were general anesthesia and higher American Society of Anesthesiologists grade. However, epidural anesthesia was found to have a protective effect.