Influence Of Etomidate On Stress Response And Early Postoperative Cognitive Dysfunction In Elderly Orthopedic Patients Under Totol Introvenous Anesthesia

Objective To investigate the incidence of postoperative cognitivedysfunction using etomidate and to clarify the incidence of postoperativecognitive dysfunction and stress response in elderly orthopedic patientsunder total intravenous anesthesia.Methods91patients(ASAⅠ-Ⅲ) aged more than60yearsunderwent elective orthopedic surgery were randomly divided intoetomidate induction/maintainence group (EE, n=31), etomidate inductiongroup (EP, n=30) and propofol control group (PP, n=30).The patients in each group were administered an intravenousinjection of midazolam0.03mg· kg-1, fentanyl3~5μg· kg-1,cisatracurium1.5mg· kg-1in turn; the patients in EE group and EP groupwere administered an intravenous injection of etomidate at a dosage of0.2-0.3mg· kg-1and the patients in PP group were administered anintravenous injection of propofol at a dosage of1.5-2.5mg· kg-1. Thepatients in EE group were given a continuous intravenous infusion ofetomidate at0.6-1.2mg· kg-1·h-1while the patients in EP group and PPgroup were infused propofol at4-8mg· kg-1·h-1.The venous blood samples were drawn at the time of before anesthesia, after extubation and24h after operation respectively, the levelof serum cortisol was detected using radioimmunoassay (RIA). Themini-mental state examination (MMSE) was applied to evaluatepostoperative cognitive dysfunction at1d and7d after operation.Result：At1d,7d after operations the incidence of POCD were26.7%and13.3%in PP group;30%and10%in EP group;25.5%and12.9%in EE group. The incidence of POCD among the three groups at1,7d after operation had no significant differences (P>0.05).The serum cortisol levels had no significant difference amongvarious groups before operation (P>0.05). Compared with beforeanesthesia, the levels of serum cortisol after extubation were decreasedsignificantly in all groups (P＜0.05).The level of serum cortisol after extubation was decreasedsignificantly in EE group (P＜0.05).The levels of serum cortisol at24h after operation went back tonormol level in three group.Conclusion: Both etomidate and propofol reduce stress effect ofelderly orthopedic patients under total introvenous anesthesia inoperations, and the effect is significant in EP and EE group.There is no difference between etomidate and propofol onpostoperative cognitive dysfunction in elderly orthopedic patientsunder total introvenous anesthesia.