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Randomized Controlled Trial
. 2024 Jul 9;332(2):112-123.
doi: 10.1001/jama.2024.8144.

Electroencephalography-Guided Anesthesia and Delirium in Older Adults After Cardiac Surgery: The ENGAGES-Canada Randomized Clinical Trial

Alain Deschamps  1 , Arbi Ben Abdallah  2 , Eric Jacobsohn  3 , Tarit Saha  4 , George Djaiani  5 , Renée El-Gabalawy  6 , Charles Overbeek  1 , Jennifer Palermo  1 , Athanase Courbe  1 , Isabelle Cloutier  7 , Rob Tanzola  4 , Alex Kronzer  2 , Bradley A Fritz  2 , Eva M Schmitt  8 , Sharon K Inouye  8 , Michael S Avidan  2 ; Canadian Perioperative Anesthesia Clinical Trials Group
Collaborators, Affiliations
Randomized Controlled Trial

Electroencephalography-Guided Anesthesia and Delirium in Older Adults After Cardiac Surgery: The ENGAGES-Canada Randomized Clinical Trial

Alain Deschamps et al. JAMA. .

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.

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Conflict of interest statement

Conflict of Interest Disclosures: Dr Palermo reported grants from CIHR during the conduct of the study. Dr Avidan reported grants from Canadian Institute for Health Research (CIHR) during the conduct of the study. No other disclosures were reported.

Figures

Figure 1.
Figure 1.. Flow of Participants in a Trial of Electroencephalography (EEG)-Guided Anesthesia in Cardiac Surgery
aRandomization was stratified by site and patients were randomized in a 1:1 ratio to receive usual care or to EEG-guided anesthesia. bThese deviations are due to EEG malfunctioning, “off-pump” coronary artery bypass graft, patient taken back to the operating room on postoperative day 1, and use of circulatory arrest. cDeviation of anesthesia protocol includes EEG guidance in a patient randomized to the blinded protocol or no EEG in a patient randomized to the guided protocol.
Figure 2.
Figure 2.. Cumulative Incidence of Delirium Through Postoperative Day 5
The shaded areas indicate 95% CIs. EEG indicates electroencephalography.
See this image and copyright information in PMC

Comment in

References

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