Phase-Specific Electroencephalography Monitoring: A Dynamic Approach to Predict Postoperative Delirium During Aortic Surgery

BACKGROUND: Static or averaged electroencephalography (EEG) metrics may fail to capture dynamic cerebral changes during surgery. We assessed the EEG features during aortic arch surgery with cardiopulmonary bypass (CPB) and total circulatory arrest (TCA) to identify key EEG predictors of postoperative delirium (POD). METHODS: This retrospective study analyzed intraoperative EEG data from 233 patients across 5 phases: pre-CPB, CPB initiation, TCA, post-TCA, and post-CPB. The predictive potential of EEG parameters was assessed using logistic regression, and phase-specific nomogram models were developed. The primary analysis included emergency cases; elective cases were included in sensitivity analyses. RESULTS: POD occurred in 78 patients (44.8%). Phase-specific models showed high predictive performance. Independent predictors of POD included reduced alpha power during the post-CPB phase (odds ratio [OR]=0.76, 95% CI: 0.67-0.87, P