[Effects of different methods of anesthesia and analgesia on early postoperative cognitive dysfunction after non-cardiac surgery in the elderly]

Abstract

Objective: To determine if different methods of anesthesia and analgesia will influence the incidence of early postoperative cognitive dysfunction (POCD) after non-cardiac surgery in the elderly.

Methods: One hundred and three elderly patients undergoing elective abdominal surgery were randomly allocated to receive either general anesthesia followed with postoperative intravenous analgesia (general anesthesia group, 53 cases) or combined general-epidural anesthesia followed with postoperative epidural analgesia (combined general-epidural anesthesia group, 50 cases). Cognitive function was assessed preoperatively and 7 days postoperatively using a battery of nine neuropsychological tests. A postoperative deficit in any test was defined when decline by more than or equal to 20% of the preoperative value of that test occurred. Any patient showing deficit in 2 or more tests was defined as having postoperative cognitive dysfunction.

Results: Ninety-two patients completed both preoperative and postoperative neuropsychological tests. On day 7, POCD occurred in 20/45 patients (44.4%) in the general anesthesia group and in 23/47 patients (48.9%) in the combined general-epidural anesthesia group. No significant difference was found between the two groups. Logistic regression analysis showed that short duration of education and operation of general surgery were independent risk factors of the occurrence of early POCD.

Conclusion: Early POCD occurred in 46.7% of the elderly patients undergoing abdominal surgery. However, there was no significant difference between the effects of two different methods of anesthesia and postoperative analgesia on the incidence of POCD. Short duration of education and operation of general surgery were risk factors of early POCD.