Risk factors for postoperative delirium in adult patients undergoing cardiopulmonary bypass in cardiac surgery.

Objective: To identify risk factors for postoperative delirium in adult patients undergoing cardiopulmonary bypass.

Methods: The medical records of 214 patients who underwent cardiopulmonary bypass at the First Affiliated Hospital of Hunan Normal University from January 2022 to January 2024 were retrospectively analyzed. Based on the occurrence of postoperative delirium, patients were divided into a delirium group (49 cases) and a non-delirium group (165 cases). Outcome measures, including clinical baseline data, preoperative left ventricular ejection fraction (LVEF), preoperative Acute Physiology and Chronic Health Evaluation II (APACHE II) score, anesthesia duration, surgery duration, aortic cross-clamp duration, intraoperative mean arterial pressure (MAP), intraoperative blood loss, length of intensive care unit (ICU) stay, postoperative mechanical ventilation duration, as well as postoperative MAP, were compared between the two groups. Logistic regression analysis was performed to identify the potential factors associated with post-operative delirium in patients.

Results: Of the included 214 patients, 49 patients experienced delirium, resulting in an incidence of 22.90%. The delirium group had significantly lower LVEF and significantly higher APACHE II scores compared to the non-delirium group (all P<0.001). No significant difference was observed between the two groups in terms of anesthesia duration, surgery duration, aortic cross-clamp duration, intraoperative MAP, and intraoperative blood loss (all P>0.05). The delirium group experienced significantly longer length of ICU stay and postoperative mechanical ventilation duration as compared to the non-delirium group (all P<0.001), but no significant difference was observed in terms of postoperative MAP between the two groups (P>0.05). Logistic regression analysis identified preoperative New York Heart Association classification (NYHA) (OR: 6.755, 95% CI: 2.529-18.039, P<0.001), preoperative LVEF (OR: 6.886, 95% CI: 2.383-19.899, P<0.001), preoperative APACHE II score (OR: 7.788, 95% CI: 2.740-22.135, P<0.001), length of ICU stay (OR: 9.463, 95% CI: 3.563-25.135, P<0.001), and postoperative mechanical ventilation duration (OR: 9.744, 95% CI: 3.419-27.768, P<0.001) as independent factors influencing the occurrence of delirium in adult patients undergoing cardiopulmonary bypass.

Conclusion: Postoperative delirium is a prevalent complication among patients undergoing cardiac surgery. Independent risk factors for postoperative delirium in adult patients undergoing cardiopulmonary bypass during cardiac surgery include preoperative NYHA class III or IV, lower LVEF, higher APACHE II score, an extended length of stay in the ICU, and prolonged postoperative mechanical ventilation duration.