Prevention of peri-anesthetic hypothermia by regulating cutaneous micro-circulation: A rodent model

Objectives: Patients undergoing surgery involving general anesthesia often suffer from hypothermia, which is associated with various complications. External heating and warming are used to combat hypothermia throughout surgery; however their effectiveness is often limited. In this study we investigated a unique approach utilizing a natural physiological mechanism; protective cutaneous vasoconstriction for reducing peri-anesthetic hypothermia. The concept is based on the dermal application of a cream with vasoconstrictive alpha adrenergic agonist properties designed for this purpose; "thermal cream" (TC). Topical application of the cream was tested in a rodent model. The aim of the present study was to test the efficacy of a topical vasoconstrictive application in reducing peri-anesthetic hypothermia. Materials and Methods: Adult Wistar rats were divided into two experimental arms: application of thermal cream was compared to application of a base cream without any active compound (control) under the same conditions. The rats were exposed to an ambient temperature of 21°C. Their skin and core temperatures were measured and compared before, during and after anesthesia. Results: The rats underwent rapid hypothermia immediately after the induction of anesthesia. The rats treated with thermal cream had a significantly higher core body temperature than the controls throughout the entire anesthetic period. This difference was even greater when the cream had been applied before the animal underwent anesthesia. Conclusions: The thermal cream was effective in attenuating peri-anesthetic-induced hypothermia in a rodent model. It was easy to apply with no immediate mortality or other major adverse events.