Transcranial Doppler and Artificial Intelligence Prediction of Postoperative Delirium in Heart Valve Surgery

Postoperative delirium is a frequent complication after cardiac surgery. This prospective observational study will evaluate whether cerebral blood flow velocity measured by transcranial Doppler before and during elective heart valve surgery is associated with delirium during the first five postoperative days. Bispectral index, near-infrared spectroscopy, and arterial blood gas data will also be recorded. Delirium will be assessed daily by an independent evaluator who is blinded to the intraoperative measurements and artificial intelligence predictions, using CAM-ICU for mechanically ventilated patients or the Turkish 3D-CAM for patients on the ward. The study will also compare zero-shot delirium risk predictions from five general-purpose large language models (Claude, GPT, Gemini, Grok, and Kimi) with the blinded clinical assessments. The models will not be trained on data from the study cohort.