Protocol for the Electroencephalography Guidance of Anesthesia to Alleviate Geriatric Syndromes (ENGAGES) study: a pragmatic, randomised clinical trial

Abstract

IntroductionPostoperative delirium, arbitrarily defined as occurring within 5 days of surgery, affects up to 50% of patients older than 60 after a major operation. This geriatric syndrome is associated with longer intensive care unit and hospital stay, readmission, persistent cognitive deterioration and mortality. No effective preventive methods have been identified, but preliminary evidence suggests that EEG monitoring during general anaesthesia, by facilitating reduced anaesthetic exposure and EEG suppression, might decrease incident postoperative delirium. This study hypothesises that EEG-guidance of anaesthetic administration prevents postoperative delirium and downstream sequelae, including falls and decreased quality of life.Methods and analysisThis is a 1232 patient, block-randomised, double-blinded, comparative effectiveness trial. Patients older than 60, undergoing volatile agent-based general anaesthesia for major surgery, are eligible. Patients are randomised to 1 of 2 anaesthetic approaches. One group receives general anaesthesia with clinicians blinded to EEG monitoring. The other group receives EEG-guidance of anaesthetic agent administration. The outcomes of postoperative delirium (≤5 days), falls at 1 and 12 months and health-related quality of life at 1 and 12 months will be compared between groups. Postoperative delirium is assessed with the confusion assessment method, falls with ProFaNE consensus questions and quality of life with the Veteran's RAND 12-item Health Survey. The intention-to-treat principle will be followed for all analyses. Differences between groups will be presented with 95% CIs and will be considered statistically significant at a two-sided p<0.05.Ethics and disseminationElectroencephalography Guidance of Anesthesia to Alleviate Geriatric Syndromes (ENGAGES) is approved by the ethics board at Washington University. Recruitment began in January 2015. Dissemination plans include presentations at scientific conferences, scientific publications, internet-based educational materials and mass media.Trial registration numberNCT02241655; Pre-results.

Delirium in Older Persons

“…51,52 In a recent innovation, bispectral EEG monitoring and adjustment of anesthetic depth has been shown to be associated with a marked reduction in postoperative delirium 53,54 and is currently under investigation in a large clinical trial. 55 …”

Electroencephalogram dynamics during general anesthesia predict the later incidence and duration of burst-suppression during cardiopulmonary bypass

“…Rather, burst-suppression may be more evident, at clinically relevant anesthetic doses, in patients that possess an underlying vulnerability to POD. Results from trials, such as the ENGAGES study (Wildes et al , 2016), are expected to make clear the effect of principled low dose anesthetic protocols on POD and other clinically relevant outcomes.…”

Assessing method agreement for paired repeated binary measurements administered by multiple raters

“…The usage of GLMMs is motivated by the need of addressing several challenges simultaneously: 1) incorporating the influence of raters into assessing method agreement; 2) categorical outcomes; 3) longitudinal data; 4) missing or unbalanced data. We will illustrate our approach using a clinical research study [30] in which surgical patients are evaluated for post-operative delirium using two assessment tools, i.e., the CAM and the 3D-CAM. In this illustration, all the aforementioned challenges are encountered.…”