Effect Of Etomidate On Postoperative Delirium In Elderly Patients Undergoing Orthopedic Surgery With Total Intravenous Anesthesia

Objective：To observe the effect of etomidate on postoperative delirium inelderly orthopedic patients with total intravenous anesthesia, and to discuss thefeasibility of etomidate maintenance in total intravenous anesthesia.Method：Ninety nine patients aged more than60years with ASAⅠ-Ⅲ,scheduled for orthopedic surgery with total intravenous anesthesia, were randomlydivided into three groups (n=33): etomidate induction/maintenance group (groupEE), etomidate induction group (group EP) and propofol control group (group PP).After exclusion, ninety four patients were included in this study. Anesthesiainduction: after all the patients were given an intravenous injection of midazolam0.03mg/kg, fentanyl4ug/kg and cisatracurium1.5mg/kg, etomidate wasadministered at a dosage of0.3mg/kg to the patients in group EE and group EP,while propofol was administered at a dosage of1.5-2.0mg/kg to the patients ingroup PP. Anesthesia maintenance: the patients in group EE were given a continuousintravenous infusion of etomidate at0.5-0.8mg·kg-1·h-1, while the patients in groupEP and group PP were given a infusion of propofol at4-10mg· kg-1·h-1. All thepatients were given a infusion of remifentanil at0.2-0.3ug·kg-1·min-1. Perioperativehemodynamic changes, recovery time, extubation time, occurrence of intraoperativeawareness and emergence agitation were recorded. The intravenous blood sampleswere collected before anesthesia, after extubation and at24h after operation,respectively. The concentration of serum cortisol was detected usingradioimmunoassay (RIA). The confusion assessment method-chinese revision(CAM-CR) scale was applied to evaluate postoperative delirium at1h,1and3dafter operation, and the occurrence of postoperative nausea and vomiting wasrecorded at the same time.Result：(1) There were no significant statistical differences of preoperative,intraoperative and postoperative systolic blood pressure, diastolic blood pressure and heart rate among three groups during perioperative period (P＞0.05). Compared withgroup PP, intraoperative use of vasopressors reduced significantly in group EE (P＜0.0167).(2) The concentrations of serum cortisol after extubation decreasedsignificantly in all groups (P＜0.05), while compared with those before anesthesia.Compared with group PP, the concentrations of serum cortisol after extubationdecreased significantly in group EP and group EE (P＜0.05); compared with group EP,the concentration of serum cortisol after extubation decreased significantly in groupEE (P＜0.05). The concentrations of serum cortisol after extubation were normal inall groups, but the concentrations of serum cortisol at24h after operation were higherthan those before anesthesia in group EE and group EP (P＜0.05).(3) Recovery timeand extubation time of the patients were prolonged significantly in group EE (P＜0.05), while compared with group EP and group PP.(4) Compared with group PP, theoccurrence of postoperative delirium were significantly increased in EE group (P＜0.0167).Conclusion：(1) Continuous infusion of etomidate showed slightly inhibitiveeffect on the cardiovascular system, and its adrenal suppression is transient andreversible which allows it used safely for the elderly orthopedic patients withoutadrenal insufficiency within four hours.(2) Etomidate maintenance in totalintravenous anesthesia prolongs the recovery time of elderly orthopedic patients.(3)Etomidate maintenance in total intravenous anesthesia can increase postoperativedelirium of elderly orthopedic patients.