EEG-guided anesthesia fails to prevent delirium in older adults after cardiac surgery: JAMA

The multicenter randomized clinical trial involving 1140 patients aged 60 years and older undergoing cardiac surgery suggests against using electroencephalography-guided anesthetic administration for preventing postoperative delirium.

"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," the researchers reported.

Intraoperative electroencephalogram (EEG) waveform suppression, suggesting excessive general anesthesia, has been associated with postoperative delirium. Alain Deschamps, Université de Montreal, Montreal, Quebec, Canada, and colleagues aimed to assess whether EEG-guided anesthesia reduces = the incidence of delirium after cardiac surgery.

For this purpose, the researchers performed a randomized, parallel-group clinical trial comprising 1140 adults 60 years or older undergoing cardiac surgery at 4 Canadian hospitals. Participants were recruited from 2016 to 2022. Patients were randomized in a 1:1 ratio to receive EEG-guided anesthesia (n = 567) or usual care (n = 573).

The primary outcome was delirium during postoperative days 1 through 5. Intraoperative measures were EEG suppression time and anesthetic concentration. Secondary outcomes included hospital length of stay and intensive care. Serious adverse events included medical complications, intraoperative awareness, and 30-day mortality.

The study led to the following findings:

• Of 1140 randomized patients (median age, 70 years; 24.7% women), 99.2% were assessed for the primary outcome.
• Delirium during postoperative days 1 to 5 occurred in 18.15% of patients in the EEG-guided group and 18.10% in the usual care group (difference, 0.05%).
• In the EEG-guided group compared with the usual care group, the median volatile anesthetic minimum alveolar concentration was 0.14 lower, and there was a 7.7-minute decrease in the median total time spent with EEG suppression (4.0 versus 11.7 min).
• There were no significant differences between groups in the median length of intensive care unit (difference, 0 days) or hospital stay (difference, 0 days).
• No patients reported intraoperative awareness.
• Medical complications occurred in 11.3% of patients in the EEG-guided group and 12.7% in the usual care group.
• Thirty-day mortality occurred in 1.4% of patients in the EEG-guided group and 2.3% in the usual care group.

"EEG-guided anesthetic administration to minimize EEG suppression, compared with usual care, did not reduce the incidence of postoperative delirium among older adults undergoing cardiac surgery," the researchers wrote. "This finding does not support EEG-guided anesthesia for this indication."

Reference:

Deschamps A, Ben Abdallah A, Jacobsohn E, et al. Electroencephalography-Guided Anesthesia and Delirium in Older Adults After Cardiac Surgery: The ENGAGES-Canada Randomized Clinical Trial. JAMA. Published online June 10, 2024. doi:10.1001/jama.2024.8144