Abstract
BACKGROUND: Postoperative delirium (POD) and emergence delirium (ED) commonly occur in elderly and pediatric patients undergoing anesthesia. Electroencephalography (EEG)-based monitoring technologies, including Bispectral Index (BIS), SedLine EEG monitoring, and other EEG techniques, have been proposed as potential strategies for reducing delirium risk, but current evidence remains controversial. Therefore, this systematic review and meta-analysis aimed to evaluate the impact of EEG-guided anesthesia on delirium incidence in patients of various age groups. METHODS: PubMed, Embase, Web of Science, and the Cochrane Library were searched upto August 2025 for studies investigating EEG-guided anesthesia depth and delirium outcomes. The primary outcomes included incidence of POD and Pediatric Anesthesia Emergence Delirium (PAED) scores. Meta-analysis and subgroup analyses based on EEG monitoring techniques were conducted using Stata software. Publication bias was assessed with Begg's and Egger's tests. RESULTS: Twenty studies involving 7344 adult patients and 463 pediatric patients were included. Pooled analyses indicated that deep anesthesia significantly increased POD risk in elderly patients (P = 0.008). For adult patients, EEG-guided anesthesia was associated with a significant reduction in POD compared with usual care (P = 0.001). In elderly patients, EEG-guided anesthesia was associated with a non-significant trend toward lower postoperative delirium (P = 0.123). For pediatric patients, EEG monitoring did not significantly affect PAED scores overall (P = 0.143); however, subgroup analysis revealed that non-BIS modality may have reduced PAED scores (P < 0.001). CONCLUSIONS: The effectiveness of EEG-guided anesthesia in reducing delirium risk varies across age groups. EEG monitoring effectively decreases POD incidence in adults. Among elderly patients, EEG-guided anesthesia did not significantly reduce the risk of POD, whereas non-BIS modality may confer greater benefit for pediatric emergence delirium. These findings are hypothesis-generating; future studies should define age-tailored EEG monitoring strategies and clarify indications across patient groups.