Intraoperative EEG Monitoring and Postoperative Delirium in Frail Older Adults: A Scoping Review

Background: Postoperative delirium (POD) is a severe neurological complication that disproportionately affects older adults, particularly those with baseline biological frailty or pre-existing cognitive vulnerability. While intraoperative processed electroencephalogram (EEG) monitoring (e.g., BIS, SEDline) is increasingly utilized to guide anesthetic depth and avoid burst suppression, the specific utility and outcomes of this intervention in the highly vulnerable frail population remain poorly defined. Objective: The primary objective of this scoping review is to systematically map and synthesize the existing literature surrounding the use of intraoperative EEG monitoring and its impact on postoperative delirium in frail and cognitively vulnerable older adults undergoing major non-cardiac surgery. Methods: This scoping review is conducted in strict adherence to the Joanna Briggs Institute (JBI) methodology and the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews) guidelines. Comprehensive, systematic searches were executed on May 11, 2026, across three major electronic databases: MEDLINE (PubMed), Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL). The inclusion criteria follow the PCC (Population, Concept, Context) framework, focusing on adults >60 years with identified frailty/cognitive impairment (Population), the use of processed intraoperative EEG monitoring (Concept), and the setting of major non-cardiac surgery (Context). Title, abstract, and full-text screening will be conducted independently and in duplicate using Covidence, followed by standardized data charting to identify current evidence gaps and inform future perioperative care guidelines.