- Postoperative delirium is common in older patients and associated with poor outcomes, including long-term worsening of cognitive impairment.
- Several previous studies have suggested that avoiding deep general anesthesia may decrease the risk of postoperative delirium, while other studies have not shown a similar association.
- This multicenter, pragmatic, evaluator- and patient-blinded randomized clinical trial sought to correlate EEG suppression (an accepted marker of deep anesthesia) with postoperative delirium in elderly patients undergoing cardiac surgery.
- 1,140 adults aged 60 years or older undergoing cardiac surgery were randomized to receive either EEG-guided anesthesia (n = 567) or usual care (n = 573).
- In the EEG-guided group, anesthesia providers were encouraged to decrease volatile anesthetic administration to limit EEG suppression, resulting in an overall 66% decrease in time in EEG suppression in the EEG-guided group compared to the usual care group (median time in EEG suppression 4.0 vs 11.7 minutes).
- Primary outcome: No significant differences were observed between groups in the incidence of postoperative delirium. Delirium 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, with a difference of 0.05% (95% CI, −4.57% to 4.67%).
- Secondary outcomes: No significant differences were observed between groups in median ICU stay, hospital length of stay, medical complications, or 30-day mortality. In addition, no patients in either group reported intraoperative awareness.
- The authors concluded that EEG-guided anesthetic management to minimize EEG suppression did not significantly reduce the incidence, duration, or severity of postoperative delirium among older adults undergoing cardiac surgery.
Summary of "Electroencephalography-Guided Anesthesia and Delirium in Older Adults After Cardiac Surgery: The ENGAGES-Canada Randomized Clinical Trial"
Summary published February 24, 2025
