Inadvertent Postoperative Hypothermia at Post-Anesthesia Care Unit: Incidence, Predictors and Outcome

Background: Inadvertent postoperative hypothermia (IPH) is known to be associated with various adverse effects. The aim of this study was to evaluate the incidence, predictors and outcome of core inadvertent hypothermia on admission in the post-anesthesia care unit. Methods: Observational, prospective study in a Post-Anesthesia Care Unit. The study population consisted of adult patients after non-cardiac and non-neurologic surgery. Patients’ demographics, intraoperative and postoperative data were collected. Descriptive analysis of variables was used to summarize data and the Mann-Whitney U test, Fisher’s exact test or Chi-square test was used. Univariate and multivariate analyses were done with logistic binary regression with calculation of an Odds Ratio (OR) and its 95% Confidence Interval. Results: The incidence of IPH on admission was 32%. In univariate analysis: age, body mass index (BMI), high risk surgery, revised cardiac risk index (RCRI), type of anesthesia, use of forced-air warming, amount of intravenous crystalloids administrated, duration of anesthesia, duration of surgery and admission visual analogue scale (VAS) for pain > 3 were considered predictors of hypothermia. In multiple logistic regression analysis, age (OR 1.7, P = 0.045, for age > 65 years), RCRI (OR 3.18, P = 0.041, for RCRI > 2), duration of anesthesia (OR 1.52, P < 0.001) and admission VAS for pain (OR 2.05, P = 0.007) were considered independent predictors of IPH. Patients with IPH at PACU admission stay longer in the PACU. Conclusions: IPH was associated with a longer stay in the PACU. Age, comorbidities duration of anesthesia and pain at PACU admission were considered independent predictors for IPH.