# Effects of EEG-based monitoring of depth of anesthesia on postoperative delirium, cognitive dysfunction, and long-term neurocognitive outcomes: a meta-analysis

## TL;DR

This study finds that monitoring depth of anesthesia during surgery may help reduce long-term cognitive issues but doesn't affect short-term outcomes like delirium or patient satisfaction.

## Contribution

The novel contribution is identifying a protective effect of depth-of-anesthesia monitoring on long-term neurocognitive outcomes.

## Key findings

- Monitoring depth of anesthesia significantly reduces long-term neurocognitive disorders.
- No significant impact on short-term cognitive function or delirium incidence was observed.
- High heterogeneity suggests variability in study results.

## Abstract

To evaluate the impact of monitoring depth of anesthesia on postoperative delirium, long-term cognitive function, and patient satisfaction through a comprehensive meta-analysis.

We conducted a systematic review and meta-analysis of studies that assessed the effects of depth of anesthesia monitoring on various postoperative outcomes. Studies were identified through electronic databases, and data were extracted on the duration of anesthesia, early postoperative Mini-Mental State Examination (MMSE) scores, incidence of postoperative delirium, long-term neurocognitive disorders, and patient satisfaction. Pooled standardized mean differences (SMD) and relative risks (RR) were calculated using random-effects models. Heterogeneity was assessed using I2 statistics, and publication bias was evaluated using funnel plots and Egger’s test.

A total of 17 studies were included, encompassing 5,684 patients. Monitoring depth of anesthesia did not significantly affect the duration of anesthesia or early postoperative MMSE scores. Similarly, no significant difference was observed in the incidence of postoperative delirium before discharge. However, a significant reduction in the incidence of postoperative neurocognitive disorder was noted in long-term follow-up. No significant differences were found in patient satisfaction. High heterogeneity was observed in some analyses, indicating variability across studies.

Monitoring depth of anesthesia appears to have a protective effect against long-term neurocognitive disorders but does not significantly impact short-term cognitive function, delirium incidence, or patient satisfaction. These findings suggest that depth of anesthesia monitoring may be particularly beneficial in high-risk patient populations.