Electroencephalography Monitoring for Preventing Postoperative Delirium and Postoperative Cognitive Decline in Patients Undergoing Cardiothoracic Surgery: A Meta-Analysis

Abstract

Background: Patients undergoing cardiothoracic surgery frequently encounter perioperative neurocognitive disorders (PND), which can include postoperative delirium (POD) and postoperative cognitive decline (POCD). Currently, there is not enough evidence to support the use of electroencephalograms (EEGs) in preventing POD and POCD among cardiothoracic surgery patients. This meta-analysis examined the importance of EEG monitoring in POD and POCD.

Methods: Cochrane Library, PubMed, and EMBASE databases were searched to obtain the relevant literature. This analysis identified trials based on the inclusion and exclusion criteria. The Cochrane tool was used to evaluate the methodological quality of the included studies. Review Manager software (version 5.3) was applied to analyze the data.

Results: Four randomized controlled trials (RCTs) were included in this meta-analysis, with 1096 participants. Our results found no correlation between EEG monitoring and lower POD risk (relative risk (RR): 0.81; 95% CI: 0.55-1.18; p = 0.270). There was also no statistically significant difference between the EEG group and the control group in the red cell transfusions (RR: 0.86; 95% CI: 0.51-1.46; p = 0.590), intensive care unit (ICU) stay (mean deviation (MD): -0.46; 95% CI: -1.53-0.62; p = 0.410), hospital stay (MD: -0.27; 95% CI: -2.00-1.47; p = 0.760), and mortality (RR: 0.33; 95% CI: 0.03-3.59; p = 0.360). Only one trial reported an incidence of POCD, meaning we did not conduct data analysis on POCD risk.

Conclusions: This meta-analysis did not find evidence supporting EEG monitoring as a potential method to reduce POD incidence in cardiothoracic surgery patients. In the future, more high-quality RCTs with larger sample sizes are needed to validate the relationship between EEG monitoring and POD/POCD further.

Keywords: cardiothoracic surgery; cognition disorders; cognitive dysfunction; delirium; electroencephalography monitoring; postoperative cognitive complications; postoperative cognitive decline; postoperative delirium.

Fig. 1.

Flow diagram of the literature search. RCTs, randomized controlled trials.

Fig. 2.

Risk of bias graph for all included studies.

Fig. 3.

Risk of bias for each included study.

Fig. 4.

Forest plots of postoperative delirium for the EEG group vs. control group. EEG, electroencephalography; M–H, Mantel–Haenszel; CI, confidence interval.

Fig. 5.

Sensitivity analysis for postoperative delirium for the EEG group vs. control group. EEG, electroencephalography; M–H, Mantel–Haenszel; CI, confidence interval.

Fig. 6.

Forest plots of secondary outcomes for the EEG group vs. control group. (A) Forest plots of red cell transfusions; (B) forest plots of the length of ICU stay (days). (C) Forest plots of the length of hospitalization (days). (D) Forest plots of mortality. EEG, electroencephalography; M–H, Mantel–Haenszel; IV, inverse variance; CI, confidence interval; ICU, intensive care unit.