Background and Goal of Study: The perioperative hypothermia is a common perioperative complication of surgery, as the incidence of perioperative hypothermia ranges from 44% to 60%. Furthermore, intraoperative hypothermia often leads to postoperative hypothermia in the Post-Anesthesia Care Unit (PACU) with a rate of approximately 60%. The aim o the study was to explore the factors that affects the core body temperature in admission and at discharge of Post-Anesthesia Care Unit.
Materials and methods: This was a prospective, randomized and controlled clinical trial conducted in a large general hospital of Athens, Greece. The sample of the study consisted of 952 patients who underwent different type of surgeries. Hypothermia was defined when the tympanic temperature of patients was under 36oC. The temperature of patients was measured at the middle of the surgery (intraoperative), at the admission in the PACU and before the discharge of the PACU. The statistical analysis of the results was performed by x2 test and Student t test using the statistical package SPSS for Windows (version 21) and the statistical significance was set to p=0.05. 
Results and discussion: Hypothermia rate of patients when admitted in PACU was 62.8%. Factors affecting the hypothermia (vs normothermia) rate in PACU were female gender (59.7 vs 27.2%, p=0.001), low weight (74.6±12.7 vs 86.7±21.4 kg, p=0.004), duration of surgery (134.7±58.7 vs 119.7±49.7 min, p=0.021), the subarachnoid anaesthetic technique (21.1 vs 5.7%, p=0.034), and the perioperatine temperature of patients (35.2 vs 35.9%, p=0.004). The hypothermia on discharge from PACU was affected by low weight (74.6±12.7 vs 86.7±21.4 kg, p=0.004), major surgery (79.6 vs 58.7%, p=0.008), prolonged surgery (139.4±61.7 vs 119.1±51.1 min, p=0.016), administration of propofol (76.9 vs 87.2%, p=0.012), and muscle relaxants (70.9 vs 79.5%, p=0.007), subarachnoid anaesthetic technique (19.3 vs 4.8%, p=0.001) and systolic blood pressure on discharge from PACU (131.9±24.5 vs 129.4±14.9 mmHg, p=0.014). 
Conclusion(s): Female gender, low weight, duration of surgery, the anaesthetic technique, and the perioperatine temperature of patients influences the body temperature of surgical patients in the PACU. All patients should be actively warmed both PACU and surgery, in order to avoid hypothermia and achieve normothermia. 
References: Kim et al., 2014, Cobb et al., 2016, Stewart et al., 2016

Intraoperative factors affecting the core body temperature in admission and at discharge of post-anesthesia care unit