Dexmedetomidine for Prevention of Cardiovascular Response to Tracheal Intubation during General Anesthesia

Objective To observe the effects of dexmedetomidine on cardiovascular response to tracheal intubation during general anesthesia.Methods Thirty patients(ASA classⅠ-Ⅱ) scheduled for elective operations under general anesthesia,who had normal physical examination(electrocardiogram,liver and kidney function and electrolytes) without a history of anesthesia exception,were randomly assigned to receive either intravenous infusion of 1μg·kg-1 dexmedetomidine(dexmedetomidine group,n=15)or intravenous infusion of the same amount of normal saline(controlled group,n=15).Anesthesia was induced with midazolam 0.1 mg·kg-1,fentanyl 4 μg·kg-1,vecuronium 0.1 mg·kg-1 and etomidate 0.3 mg·kg-1 in both groups.Systolic blood pressure(SBP),diastolic blood pressure(DBP) and heart rate(HR) were recorded before infusion,after infusion,before intubation,during intubation,and 1,3 and 5 minutes after intubation.Results Blood pressure(BP) and HR increased during intubation and 1 minute after intubation in both groups(P0.01),but the increase in dexmedetomidine group was smaller than that in control group(P0.01).After infusion,before intubation,and 3 and 5 minutes after intubation,HR significantly decreased in dexmedetomidine group,compared with the control value and the value before infusion(P0.01).Bradycardia occured in 1 patient after dexmedetomidine infusion,but reverted to normal after administration of 0.5 mg atropine.Conclusion Dexmedetomidine can effectively reduce cardiovascular responses to tracheal intubation during general anesthesia.