RESUMO
Objective To investigate the relationship between postoperative cognitive dysfunc-tion and plasma cortisol levels in aged patients undergoing total hip replacement surgery. Methods Ninety patients aged 65-75 years old,scheduled for total hip replacement surgery under general anesthesia were enrolled in the present study.Cognitive state was tested by mini-mental state examination (MMSE).The patients were divided into two groups,POCD group and non-POCD group.Perioperative plasma levels of cortisol were determined on 2 d preoperative,2 d postoperative and 7 d postoperative.Results Incidence of POCD after 7 d in aged patients undergoing total hip re-placement surgery was 37.8%.Compared with day 2 d preoperative,plasma cortisol levels in POCD patients significantly increased on 2 d and 7 d post operation (P <0.01 or P <0.05).Compared with non-POCD patients,cortisol levels on the 2 d and 7 d postoperative day significantly increased in POCD patients (P <0.05).Plasma cortisol levels showed a negative correlation with MMSE scores on postoperative 2 d and 7 d(P <0.01).Conclusion Elderly patients have a relatively higher incidence of POCD after hip replacement surgery.POCD may be caused by high plasma cortisol levels in elderly patients following hip replacement surgery under general anesthesia.