Original Investigation
June 10, 2024
Electroencephalography-Guided Anesthesia and Delirium in Older Adults After Cardiac Surgery: The ENGAGES-Canada Randomized Clinical Trial
Alain Deschamps, Arbi Ben Abdallah, Eric Jacobsohn, et al
JAMA. Published online June 10, 2024. doi:10.1001/jama.2024.8144
Question Does electroencephalography-guided anesthetic administration to minimize electroencephalography suppression decrease the incidence of postoperative delirium in older patients undergoing cardiac surgery?
Findings In this multicenter randomized clinical trial involving 1140 patients aged 60 years and older undergoing cardiac surgery, postoperative delirium occurred in 18.15% of participants in the electroencephalography-guided anesthetic group and 18.10% in the usual care group, a difference that was not statistically significant.
Meaning These findings do not support the use of electroencephalography-guided anesthetic administration for the prevention of postoperative delirium among older adults undergoing cardiac surgery.
Abstract
Importance Intraoperative electroencephalogram (EEG) waveform suppression, suggesting excessive general anesthesia, has been associated with postoperative delirium.
Objective To assess whether EEG-guided anesthesia decreases the incidence of delirium after cardiac surgery.
Design, Setting, and Participants Randomized, parallel-group clinical trial of 1140 adults 60 years or older undergoing cardiac surgery at 4 Canadian hospitals. Recruitment was from December 2016 to February 2022, with follow-up until February 2023.
Interventions Patients were randomized in a 1:1 ratio (stratified by hospital) to receive EEG-guided anesthesia (n = 567) or usual care (n = 573). Patients and those assessing outcomes were blinded to group assignment.
Main Outcomes and Measures The primary outcome was delirium during postoperative days 1 through 5. Intraoperative measures included anesthetic concentration and EEG suppression time. Secondary outcomes included intensive care and hospital length of stay. Serious adverse events included intraoperative awareness, medical complications, and 30-day mortality.
Results Of 1140 randomized patients (median [IQR] age, 70 [65-75] years; 282 [24.7%] women), 1131 (99.2%) were assessed for the primary outcome. Delirium during postoperative days 1 to 5 occurred in 102 of 562 patients (18.15%) in the EEG-guided group and 103 of 569 patients (18.10%) in the usual care group (difference, 0.05% [95% CI, −4.57% to 4.67%]). In the EEG-guided group compared with the usual care group, the median volatile anesthetic minimum alveolar concentration was 0.14 (95% CI, 0.15 to 0.13) lower (0.66 vs 0.80) and there was a 7.7-minute (95% CI, 10.6 to 4.7) decrease in the median total time spent with EEG suppression (4.0 vs 11.7 min). There were no significant differences between groups in median length of intensive care unit (difference, 0 days [95% CI, −0.31 to 0.31]) or hospital stay (difference, 0 days [95% CI, −0.94 to 0.94]). No patients reported intraoperative awareness. Medical complications occurred in 64 of 567 patients (11.3%) in the EEG-guided group and 73 of 573 (12.7%) in the usual care group. Thirty-day mortality occurred in 8 of 567 patients (1.4%) in the EEG-guided group and 13 of 573 (2.3%) in the usual care group.
Conclusions and Relevance Among older adults undergoing cardiac surgery, EEG-guided anesthetic administration to minimize EEG suppression, compared with usual care, did not decrease the incidence of postoperative delirium. This finding does not support EEG-guided anesthesia for this indication.
Trial Registration ClinicalTrials.gov Identifier: NCT02692300
