The Impact of Anesthetic Techniques on Cognitive Functions after Urological Surgery.

BACKGROUND Postoperative cognitive dysfunction (POCD) is a well-recognized complication of cardiac and noncardiac surgery. However, contradictory results concerning postoperative mental function have been reported. The aim is to determine the effect of anesthetic techniques (general or spinal) on cognitive functions using more sensitive neuropsychological tests in patients undergoing urological surgery. MATERIAL AND METHODS A total of thirty patients were enrolled in the study and assigned to receive either general (n = 15) or spinal (n = 15) anesthesia. A battery of neuropsychological tests including Wisconsin Card Sorting Test, Iowa Gambling Task, Stroop Color-Word Test, N-back Task and Continuous Performance Test was performed preoperatively and three days later. RESULTS The two experimental groups were similar at baseline assessment of cognitive function. Although there were no statistically significant differences between general and spinal anesthetic groups with respect to Wisconsin Card Sorting Test and Iowa Gambling Task, a significant intergroup difference between pre-and postoperative N-back scores was detected in the general anesthesia group (p = 0.001 & p = 0.004). In addition, patients within this group had significantly higher error rates on the Stroop Color-Word (p = 0.019) and Continuous Performance Tests (p = 0.045). In contrast, patients receiving spinal anesthesia exhibited little change or marginal improvement on all subscales of the battery. CONCLUSIONS Our findings indicate significant decline in specific aspects of mental function among patients who were administered general anesthesia compared with the other technique. It seems that spinal anesthesia contributes to lower disturbance after surgery.