Early Cognitive Changes After General Versus Spinal Anesthesia in Older Adults Undergoing Total Knee Arthroplasty

This prospective observational study investigated early postoperative cognitive changes in older adults undergoing elective total knee arthroplasty under general or spinal anesthesia. Patients aged 65 years or older who were considered suitable for either anesthetic technique were prospectively enrolled. The anesthetic technique was determined according to patient preference, clinical characteristics, surgical considerations, and the attending anesthesiologist's judgment and was not assigned by the investigators. Cognitive function was assessed using the Mini-Mental State Examination (MMSE) preoperatively and 24 h after surgery. Serum S100B concentrations were measured preoperatively and at 6 and 24 h postoperatively. The primary objective was to compare changes in MMSE scores between the general and spinal anesthesia groups. Secondary objectives were to compare perioperative changes in serum S100B concentrations and to evaluate their association with postoperative changes in cognitive performance.