Accuracy of Regional Cerebral Oxygen Saturation in Predicting Postoperative Cognitive Dysfunction After Total Hip Arthroplasty

To estimate the accuracy of regional cerebral oxygen saturation (rSO₂) in predicting postoperative cognitive dysfunction (POCD) for patients undergoing total hip arthroplasty, 46 patients aged more than 50 years old were enrolled. We measured the patients’ cognitive function by using a battery of six neuropsychological tests before surgery and then 7 days after surgery again. rSO₂ was continuously monitored by near-infrared spectroscopy during surgery. POCD was present in 9 (19.6%) patients 1 week after surgery. Logistic regression analysis showed that increasing age [OR=1.224, P=0.035] and maximum percentage drop in rSO₂ (rSO_2%max) [OR=1.618, P=0.011] were significant risk factors for POCD. The area under the receiver operating characteristic curve of rSO_2%max was 0.833 [95% confidence interval (CI) 0.615–1.051] at cutoff value of 11%. The specificity and sensitivity of rSO_2%max >11% in predicting POCD were 77.8% and 86.5%, respectively. rSO_2%max more than 11% was a potential predictor for POCD.