A Systematic Review and Meta-Analysis of Risk Factors for Unplanned Intraoperative Hypothermia Among Adult Surgical Patients

Unplanned intraoperative hypothermia (UIH) is a frequent but preventable complication of surgery. Accurate identification of UIH risk factors allows nurses to minimize its negative outcomes. This study aimed to investigate the risk factors for UIH in adult surgical patients.Systematic review and meta-analysis METHODS: We comprehensively searched PubMed, Cochrane Central Register of Controlled Trials, Web of Science, Ovid Embase, and ClinicalTrials.gov from their inception until December 31, 2020 to identify available, related studies in English. Two authors independently extracted data from these studies. Data analysis was performed using Review Manager Version 5.3.This meta-analysis included 12 studies involving 15,010 patients. The combined results showed that age [mean difference (MD) = 4.85, P < .0001; I2 = 94%], body mass index (MD = - 0.76, P = .001; I2 = 59%), ambient temperature [odds ratio (OR) = 0.82, P < .001; I2 = 54%], preoperative systolic blood pressure (MD = -14.68, P < .00001; I2 = 30%), preoperative heart rate (MD = - 13.25, P < .00001; I2 = 0%), duration of anesthesia (>2 h; OR = 2.67, P < .001; I2 = 0%), and intravenous fluid administration >1,000 mL (OR = 2.02, P = .01; I2 = 77%) were significantly associated with a higher risk of UIH.Our study demonstrated that various risk factors contribute to the development of UIH. Perioperative nurses should understand these risk factors in order to apply evidence-based procedures and improve patient outcomes. Due to the substantial clinical heterogeneity across studies, further studies are needed to verify these findings.