ObjectiveTo observe the effect of dexmedetomidine combined with etomidate on the clinical safety and the tracheal extubation response after general anesthesⅠa in elderly patient undergoing thyroidectomy. MethodsFifty patients (aged between 65 and 75 years, ASAⅠor Ⅱ) scheduled for thyroid surgery between July 2012 and January 2013 were randomly divided into two groups:dexmedetomidine group (group D) and control group (group C) with 25 patients in each group. Group D received dexmedetomidine of 0.5 μg/(kg·h) through intravenous infusion after anesthesia induction, and the intravenous infusion was stopped five minutes before the end of surgery. Normal saline was infused at the same volume in group C at the same time. Patients were induced with etomidate at 0.2 mg/kg for anesthesia, and etomidate and remifentanil were used for the anesthesia maintenance during the operation. Heart rate (HR), systolic blood pressure SBP), diastolic blood pressure (DBP) and bispectral index (BIS) were recorded 5 (T1), 15 (T2) and 30 (T3) minutes after the beginning of the operation, and 15 (T4) and 5 (T5) minutes before the end of the operation. Moreover, the time of eye opening, time of extubation, the number of patients with restlessness and etomidate requirement were recorded. ResultsCompared with group C, HR and MAP at the time points of T2 and T5 in group D did not obviously change, but the number of restlessness patients in group D was significantly less than in group C (P<0.05). There was no statistically significant difference in time of eye opening and time of extubation between the two groups (P>0.05). Etomidate requirement in group D was[(8.6±2.1) μg/(kg·min)], which was significantly lower than that in group C[(14.4±3.4) μg/(kg·min)] (P<0.05). ConclusionDexmedetomidine combined with etomidate is efficient and safe for elderly patients undergoing thyroidectomy, and this method can effectively reduce cardiovascular responses to tracheal extubation, decrease the incidence of postoperative restlessness, and reduce the requirement of etomidate during the operation.