Prevalence of postoperative delirium according to the intraoperative general anesthetic agents in patients undergoing cardiac surgery: A retrospective and propensity-score matched study

Abstract

Background: Postoperative delirium (PD) is still an issue in post-cardiac surgery patients despite the constant efforts to reduce it. Although various risk factors for PD after cardiac surgery have been identified, there is limited clinical data regarding the effect of intraoperative anesthetic agents on the PD.Methods: The medical records of 534 patients, who had undergone heart valve surgery or coronary artery bypass graft surgery with cardiopulmonary bypass (CPB) between January 2012 and August 2017, were investigated. They were divided into two groups according to the main anesthetic agent: sevoflurane with dexmedetomidine (sevo-dex group, n = 340) and propofol (propofol group, n = 194). The incidence of PD was evaluated as the primary outcome. PD was defined as the positive Confusion Assessment Method for the Intensive Care Unit during the intensive care unit stay. Patient-, surgery-, and anesthesia-related factors and postoperative complications were investigated as secondary outcomes. To reduce the risk of confounder effects between the two groups, 194 patients were selected from the sevo-dex group after propensity-score matching.Results: After propensity-score matching, the incidence of PD was not significantly different between the sevo-dex (6.2%) and propofol (10.8%) groups (P = 0.136). In comparison of the incidence of each type of PD, only hyperactive PD occurred significantly less in the sevo-dex group than in the propofol group (P = 0.021). Older age, lower preoperative albumin levels, and emergency surgery were significant risk factors for PD.Conclusions: The overall incidence of PD after cardiac surgery with CPB is not associated with the main anesthetic agents, sevoflurane and dexmedetomidine-based vs. propofol-based anesthesia. Only hyperactive PD occurred less frequently after in patients receiving sevoflurane and dexmedetomidine-based anesthesia.