Postoperative cognitive dysfunction in adult and elderly patients--general anesthesia vs subarachnoid or epidural analgesia.

This study compared the effect of general anesthesia or regional vertebral analgesia (subarachnoid or epidural) on postoperative cognitive function in 60 young adult (group A) and 60 elderly (group E) patients undergoing orthopedic and urologic surgery. Wechsler Adult Intelligence Scale-Revised for cognitive functions assessment was done preoperatively, and postoperatively; one day and three days after surgery. Variations in heart rate, blood pressure, arterial oxygen and carbon dioxide tensions, and pH as well as serum bicarbonate, sodium and potassium levels, were assessed at the same time intervals.