RÉSUMÉ
Objective To evaluate the effects of different depths of sedation on serum adiponectin (ADP) concentrations in elderly patients undergoing general anesthesia.Methods A total of 120 elderly patients of both sexes,aged 65-83 yr,weighing 45-75 kg,of American Society of Anesthesiologists physical status Ⅱ or Ⅲ,undergoing elective noncardiac surgery under general anesthesia,were divided into Ⅰ and Ⅱ groups (n =60 each) using a random number table.Propofol was given by closed-loop target-controlled infusion,and bispectral index value was maintained at 40-50 in group Ⅰ and at 50-60 in group Ⅱ.The cognitive function was assessed by the Montreal Cognitive Assessment at 1 day before operation ant 1 and 7 days after operation.Blood samples were collected from the internal jugular vein immediately before surgery,at 2 h after the beginning of surgery and at 1 and 7 days after surgery for determination of serum ADP and S-100β protein concentrations.Results Compared with group Ⅰ,Montreal Cognitive Assessment scores were significantly increased at 1 and 7 days after surgery,the serum concentrations of ADP were increased and S-100β protein concentrations in serum were decreased at 1 and 7 days after surgery,and the intraoperative requirement for ephedrine and atropine and incidence of postoperative cognitive dysfunction were decreased during surgery in group Ⅱ (P＜0.05).Conclusion Maintaining BIS value at 50-60 can reduce the development of postoperative cognitive dysfunction,which is related to the increased concentration of serum ADP in elderly patients undergoing general anesthesia.