Abstract: Objective To analyze the effect of continuous intravenous injection of different doses on dexmedetomidine on the recovery period of general anesthesia in patients undergoing thyroid surgery. Methods A total of 120 patients with thyroidectomy admitted to the First Affiliated Hospital of Army Medical University from November 2017 to November 2019 were randomly divided into a control group (60 patients) with continuous intravenous injection of 0.8 μg/kg dexmedetomidine. The observation group (60 patients) were given 0.4 μg/kg dexmedetomidine. The SBP, DBP, HR, Ramsay, VAS score, arousal index and adverse reactions were compared between the two groups at different time periods. Results The scores of SBP, DBP, HR and VAS, the incidence of nausea, vomiting, laryngospasm and choking cough in the observation group were not different from those in the control group at different time periods. The Ramsay scores of the observation group at different time periods were significantly lower than those of the control group(P＜0.05). The time of eye opening, extubation and directional force recovery in the observation group were significantly shorter than those in the control group (P＜0.05). The incidence of bradycardia in the observation group was 1.67%, which was significantly lower than that in the control group(6.68%) (P＜0.05). Conclusions 0.4 and 0.8 μg/kg dexmedetomidine can maintain hemodynamic stability in the recovery period of general anesthesia in patients undergoing thyroid surgery, but 0.8 μg/kg has more sedative effect and higher incidence of bradycardia, so it is recommended to use 0.4 μg/kg dexmedetomidine.

Key words: different doses, dexmedetomidine, continuous intravenous injection, thyroid surgery, recovery period of general anesthesia