Effect of Electroencephalography-Guided Anesthetic Administration on Postoperative Delirium Among Older Adults Undergoing Major Surgery

Abstract

IMPORTANCE Intraoperative electroencephalogram (EEG) waveform suppression, often suggesting excessive general anesthesia, has been associated with postoperative delirium. OBJECTIVE To assess whether EEG-guided anesthetic administration decreases the incidence of postoperative delirium. DESIGN, SETTING, AND PARTICIPANTS Randomized clinical trial of 1232 adults aged 60 years and older undergoing major surgery and receiving general anesthesia at Barnes-Jewish Hospital in St INTERVENTIONS Patients were randomized 1:1 (stratified by cardiac vs noncardiac surgery and positive vs negative recent fall history) to receive EEG-guided anesthetic administration (n = 614) or usual anesthetic care (n = 618). MAIN OUTCOMES AND MEASURES The primary outcome was incident delirium during postoperative days 1 through 5. Intraoperative measures included anesthetic concentration, EEG suppression, and hypotension. Adverse events included undesirable intraoperative movement, intraoperative awareness with recall, postoperative nausea and vomiting, medical complications, and death. RESULTSOf the 1232 randomized patients (median age, 69 years [range, 60 to 95]; 563 women [45.7%]), 1213 (98.5%) were assessed for the primary outcome. Delirium during postoperative days 1 to 5 occurred in 157 of 604 patients (26.0%) in the guided group and 140 of 609 patients (23.0%) in the usual care group (difference, 3.0% [95% CI, −2.0% to 8.0%]; P = .22). Median end-tidal volatile anesthetic concentration was significantly lower in the guided group than the usual care group (0.69 vs 0.80 minimum alveolar concentration; difference, −0.11 [95% CI, −0.13 to −0.10), and median cumulative time with EEG suppression was significantly less (7 vs 13 minutes; difference, −6.0 [95% CI, −9.9 to −2.1]). There was no significant difference between groups in the median cumulative time with mean arterial pressure below 60 mm Hg (7 vs 7 minutes; difference, 0.0 [95% CI, −1.7 to 1.7]). Undesirable movement occurred in 137 patients (22.3%) in the guided and 95 (15.4%) in the usual care group. No patients reported intraoperative awareness. Postoperative nausea and vomiting was reported in 48 patients (7.8%) in the guided and 55 patients (8.9%) in the usual care group. Serious adverse events were reported in 124 patients (20.2%) in the guided and 130 (21.0%) in the usual care group. Within 30 days of surgery, 4 patients (0.65%) in the guided group and 19 (3.07%) in the usual care group died.CONCLUSIONS AND RELEVANCE Among older adults undergoing major surgery, EEG-guided anesthetic administration, compared with usual care, did not decrease the incidence of postoperative delirium. This finding does not support the use of EEG-guided anesthetic administration for this indication. 40. Muhlhofer WG, Zak R, Kamal T, et al. Burst-suppression ratio underestimates absolute duration of electroencephalogram suppression compared with visual analysis of intraoperative electroencephalogram.

Guidelines for perioperative care in gynecologic/oncology: Enhanced Recovery After Surgery (ERAS) Society recommendations—2019 update

“…In the elderly, there is increased focus on using this tool to reduce the dose of inhalational anesthetic to avoid the risk of post-operative cognitive dysfunction and delirium133; a recent randomized controlled trial, however, has called this into question 134…”

State of the clinical science of perioperative brain health: report from the American Society of Anesthesiologists Brain Health Initiative Summit 2018

“…One explanation for the difference in findings is that, in the ENGAGES study, anaesthetic concentrations were reduced by only 0.11 minimum alveolar concentration (MAC). 115 By comparison, in the CODA trial, anaesthetic concentrations were reduced by 0.36 MAC in the EEG-guided treatment group. 114 This could be interpreted that, if EEG-guided anaesthesia guidance does not markedly reduce anaesthetic dosage, then it will not reduce delirium.…”

“…The recent Effect of Electroencephalography-Guided Anesthetic Administration on Postoperative Delirium Among Older Adults Undergoing Major Surgery The ENGAGES Randomized Clinical Trial was a large RCT of intraoperative EEG guidance protocol designed to reduce time in burst suppression, and the prior Cognitive Dysfunction after Anesthesia (CODA) trial randomised patients to receive care guided by the BIS monitor processed number or standard of care. 114,115 The ENGAGES EEG-based intervention was not associated with a reduction in delirium; in contrast, the Cognitive Dysfunction after Anesthesia (CODA) Trial (Centre for Clinical Trials number, CUHK_ CCT00141) did show a reduction in the incidence of delirium. One explanation for the difference in findings is that, in the ENGAGES study, anaesthetic concentrations were reduced by only 0.11 minimum alveolar concentration (MAC).…”

Complexity measures of the electroencephalograph capture loss and recovery of consciousness in patients anesthetized with propofol

“…Additionally, monitoring anesthetic depth is becoming increasingly important, since lighter planes of anesthesia speed recovery times, decrease operative costs (Dexter, Macario, Manberg, & Lubarsky, 1999) and reduce morbidity, including the potential for post-operative delirium and cognitive dysfunction in vulnerable populations of surgical patients (B.A. Fritz, Maybrier, & Avidan, 2018;Bradley A. Fritz et al, 2016;Kertai et al, 2011;Petsiti et al, 2015;Tarnal, Vlisides, & Mashour, 2015); though see also (Kalkman, Peelen, Moons, Group, & Group, 2011;Wildes et al, 2019) for limitations. However, lighter planes of anesthesia impart a greater risk of intraoperative recall in patients (Avidan et al, 2013;G.…”