Relationship between apolipoprotein e4 allele and emergence agitation in patients undergoing general anesthesia

Objective To investigate the relationship between apolipoprotein e4 allele and emergence agitation(EA) in patients undergoing general anesthesia.Methords 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.