Effect of spinal versus general anesthesia on the postoperative cognitive function in elderly patients

ABSTRACT

The objective of this prospective randomized study was to compare the effect of general and spinal anesthesia on the cognitive function in elderly patients. Forty-two patients [male female 18 24] between the ages of 60 and 73 yr old undergoing knee arthroplasty were randomly allocated into one of two groups group I [n=20] received general anesthesia, and all of them receive the same anesthetic technique, and group II [n=22] received spinal anesthesia. Initially, all patients were assessed by Blessed dementia scale and Hamilton Depression Rating Scale. A battery of neuropsychological measures including Circle Connection, Benton visual Retention Memory, Digit Span and Controlled Word Association, were carried out before surgery and again one and seven days after surgery, then 3 months later. Analysis of data revealed that the two groups were similar in terms of demographic data, baseline cognitive function scores, duration of surgery and intraoperative mean arterial blood pressure [MAP], oxygen saturation [SpO[2]%], and the amount of fluid needed. The results indicated that there were an early postoperative cognitive dysfunction [POCD] at one day after surgery in both study groups. One week later the cognitive function returned to baseline scores. At the 3rd month follow up, the cognitive measures were normal and even showed a statistically non significant improvement in both groups. We can conclude that PO CD after general or regional anesthesia was transient and there were no POCD after 3 months in elderly patients undergoing knee arthroplasty under general or regional anesthesia