Objective: To investigate the relationship between apolipoprotein e4 allele and emergence agitation (EA) in patients undergoing general anesthesia.
Methods: A nested cohort study was conducted in elderly patients (over 60 years old) scheduled for major abdominal surgery requiring general anesthesia. A structured interview was conducted in PACU to determine EA, defined using the Sedation-Agitation Scale (SAS). Blood samples were obtained for measurement of the apolipoprotein genotypes.
Results: Of the 196 patients studied, 22.4% developed EA. Thirty-eight patients (19.4%) had the apolipoprotein e4 allele. The presence of the e4 allele and low level of education were both associated with an increased risk of EA (36.9% vs15.8%, P=0.005; 30% vs 14.3%, P=0.01). After adjustment for covariates, the patients with the copy of e4 allele were shown to have a greater likeliness of an increased risk of EA (odds ratio: 4.32; 95% CI: 1.75-10.05) than those without the e4 allele.
Conclusion: Apolipoprotein e4 carrier status is associated with an increased risk for EA.