Intraoperative thermal dynamics

Abstract

The role of anaesthesiologists is to maintain physiologic homeostasis during the peri operative period, a time when alteration in body temperature is common. Anesthetics create a state ofpoikilotherrnia in which body temperature tends to equilibrate with ambient temperature. Nearly all patients under general anaesthesia become hypothermic, typically by 1-3°e,1 depending on the type and dose of anesthetic. amount of surgical exposure, 23. an d am bilent temperature. 2-4 r ;. • Body temperature should be managed in a similar fashion as the other vital signs, with efforts made to maintain normothermia. An observational cross-sectional study was conducted at the Kcnyatta National Hospital main theatre. In this study all patients over the age of 12 years undergoing general or regional anaesthesia for orthopaedic procedures had their core temperatures measured immediately pre-operatively. every 15 minutes intra-operatively and immediately postoperatively. Ambient temperature within the operating room was measured and recorded every 15 minutes intra-operatively. Amount of intravenous fluids and type of surgery were also recorded with the raw data being captured on a standard questionnaire. , Perioperative hypothermia was found to be a common occurrence particularly intraoperatively and postoperatively. Large amounts of intravenous fluids infused at room temperature were also found to negatively impact on patients' core temperatures. Relatively cool operating environments were found to also cause significlIlt lowering of patients' core temperatures. 81% of patients in this study were found to be hypothermic in the immediate postoperative period but only 45% reported actually feeling cold while in the recovery room.