Forced-Air Warming in Patients Undergoing Endovascular Procedures: Comparison between 2 Thermal Blanket Models

Abstract

The purpose of this study was to compare the efficiency between 2 thermal blanket models: the upper blanket and the underbody blanket in patient heating and hypothermia prevention during endovascular surgery. Fifty patients, American Society of Anesthesiologists physical status 2-4, receiving endovascular surgery repair of infrarenal abdominal aortic aneurysm or lower limb angioplasty by endovascular technique were studied. Primary outcome was to determine which forced-air blanket is more warming effective during the surgeries. Age, type of surgery, gender, body mass index, surgery duration, and initial patient temperature were analyzed to determine possible hypothermia association as secondary outcomes. Patients were randomized and split into 2 groups based on blanket model. All patients received general anesthesia, and temperature was obtained by an esophageal thermometer inserted after tracheal intubation and registered at intervals of 15 min until extubation. Groups significantly differed in body temperature (P = 0.006) and hypothermia occurrence (P = 0.020). The underbody blanket group hada higher ratio of hypothermic patients and a lower average temperature at the end of surgery. The average temperature after 60 min in the underbody blanket group was lower than the upper blanket group,although this difference was only significant after 150 min (P = 0.020). We conclude that upper thermal blanket is more effective thanunderbody thermal blanket in patient warming and hypothermia prevention during endovascular abdominal aortic aneurysm repair and lower limb angioplasty after 150 min of anesthetic-surgical time duration.