Effect of intraoperative warming on delirium during emergence from general anesthesia in elderly patients

Abstract

Objective To evaluate the effect of intraoperative warming on delirium during emergence from general anesthesia in elderly patients. Methods Eighty elderly patients of both sexes, aged≥65 yr, of American Society of Anesthesiologists physical statusⅠ-Ⅲ, scheduled for elective total hip replacement, were assigned to routine group (group R, n=40) and warming group (group W, n=40). The non-operated site was covered using the sterile cloth, and no other active warming measurements were given in group C. Fluid was infused and warmed to 37 ℃, the non-operated site was covered using the forced-air warming system, and the temperature of the forced-air warming system was maintained at 38-42 ℃ in group W. The tympanic membrane temperatures was recorded at 5 min after anesthesia induction, at 30, 60 and 90 min after beginning of surgery, at the end of surgery and at 30 min after emergence from anesthesia, and the difference between monitored values and monitored values on admission to operating room (△T) was recorded at each time point. The intraoperative volume of fluid infused, operation time, extubation time, duration of postanesthesia care unit stay and development of delirium during emergence and shivering were recorded. Results Compared with group R, △T was significantly decreased at 60 and 90 min after beginning of surgery, the incidence of delirium during emergence and shivering was decreased, the extubation time and duration of postanesthesia care unit stay were shortened in group W (P<0.05). Conclusion Intraoperative warming can decrease the development of delirium during emergence from general anesthesia and is helpful in improving the quality of recovery from anesthesia in elderly patients. Key words: Body temperature; Aged; Anesthesia recovery period; Delirium