Abstract: ObjectiveTo observe the effecte of different doses of dexmedetomidine (DEX) on hemodynamics changes and stress response when inserted with Supreme laryngeal mask airway (LMA Suprem) before anesthesia. MethodsA total of 60 ASAⅠ-Ⅱ patients who were scheduled for general anesthesia were randomly divided into three groups (n=20): a control group (Group C), a DEX intravenous infusion 1 group (Group D1) and a DEX intravenous infusion 2 group (Group D2). Patients did not received any medication before surgery. Groups D1 and D2 were administrated with 0.5 and 1 μg·kg-1 of DEX (diluted to 4 mg·L-1 with normal saline) over 10 min, which Group C was administrated with the equal volume of normal saline. Then, patients underwent intravenous induction using 0.2 mg·kg-1 etomidate, 0.15 μg·kg-1 sufentanil and 0.5 mg·kg-1 atracurium. All patients were inserted with LMA Supreme under pharyngeal surface anesthesia of lidocaine. Based on body weight and basic physical condition, proper types of Supreme LMA were chosen. The changes of heart rate (HR) and mean blood pressure (MAP) before, immediately after and 1 min after LMA Supreme insertion were recorded. ResultsCompared with Group C, Groups D1 and D2 showed remarkably decreased hemodynamic changes before, immediately and 1 min after LMA Supreme insertion (P<0.05). However, Compared with Group D1, the change of HR was increased in Group D2 before, immediately and 1 min after LMA Supreme insertion (P<0.05). ConclusionsDEX (0.5 or 1 μg·kg-1) intravenous infusion before anesthesia combined with pharyngeal surface anesthesia can significantly suppress hemodynamic changes after the LMA Supreme insertion. Administration of 0.5 μg·kg-1 DEX can successfully reduce the hemodynamic changes. HR is suppressed after 1 μg·kg-1 DEX infusion under pharyngeal surface anesthesia.