Analysis of risk factors and development of a predictive model for postoperative delirium in elderly patients undergoing cardiac surgery with general anesthesia

Postoperative delirium (POD) is a common and serious complication in elderly patients undergoing general anesthesia, particularly with cardiac surgery. Identifying risk factors for POD and developing predictive tools are essential for improving patient outcomes. This retrospective cohort study analyzed data from 238 consecutive elderly patients (aged 60 or older) who underwent elective cardiac surgery at our hospital between January 2021 and December 2024. The study aimed to identify factors contributing to postoperative delirium and to develop a predictive nomogram. Patients were divided into delirium and non-delirium groups based on the occurrence of delirium within 72 hours post-surgery. Statistical analysis was performed using multivariate logistic regression, and a nomogram was developed to predict the risk of POD. Significant factors associated with postoperative delirium included age, Charlson Comorbidity Index, cardiopulmonary bypass, and intraoperative hypotension. The nomogram based on these factors demonstrated strong discriminatory ability with an area under the curve of 0.869 and a sensitivity of 76.21% and specificity of 88.51%. The internal validation showed a high C-index of 0.889, indicating excellent calibration. Decision curve analysis confirmed the model's clinical utility. The study identified key risk factors for POD in elderly cardiac surgery patients and developed a nomogram with strong discriminatory ability and clinical applicability. This tool could help clinicians identify high-risk patients and improve management to reduce the incidence of POD.