|EEG-guided anesthesia in postoperative delirium|
|Elderly patients are more susceptible to delirium after major surgery with yet-unclear mechanisms, which is correlated with poor outcomes. It has been reported that EEG-guided anesthetic administration reduced the incidence of postoperative delirium as a result of avoidance of burst suppression. Meanwhile, EEG suppression during surgery is also associated with postoperative delirium, but this correlation has not been determined as a cause-effect relationship. The ENGAGES trial investigators conducted this trial to determine whether reducing anesthetic administration and minimizing EEG suppression during surgery can lower the incidence of postoperative delirium and published the data in JAMA (here).
In this single-center, randomized trial, patients older than 60 years old undergoing major surgery with general anesthesia were enrolled. All patients were measured EEG to measure anesthetic depth on a scale of 0 to 100 (values lower than 40 suggest excessive depth or EEG suppression). In the usual care group (n=609), no EEG data were available to clinicians except the signal quality. In the guided group (n=604), EEG data were displayed to clinicians and interventions were deployed in order to decrease volatile anesthetic administration. The primary endpoint was delirium incidence between days 1 and 5 after surgery.
In the guided group, 157 patients (26.0%) experienced postoperative delirium; in the usual care group, 140 participants (23.0%) experienced postoperative delirium. There was no difference in the incidence of delirium, as well as other outcomes, between the two groups.
Therefore, EEG-guided anesthetic administration during major surgery in elderly patients did not decrease the incidence of postoperative delirium.