Effects Of Dexmedetomidine On Hemodynamics During Induction Of Anesthesia In Patients With Atrial Fibrillation

Objective To evaluate the effects of dexmedetomidine on hemodynamics during induction of anesthesia in the patients with atrial fibrillation.Methods Fifty patients with rheumatic valvular heart disease complicated with atrial fibrillation,aged 45-64 yr,weighing 50-75kg,with ventricular rate≥90bpm,of ASA physical statusⅡorⅢ（NYHAⅡorⅢ）,scheduled for elective surgery,were randomly divided into 2 groups（n=25 each）using a random number table:control group（group C）and dexmedetomidine group（group D）.Dexmedetomidine 0.6μg/kg was infused intravenously at 10min prior to induction of anesthesia in group D.Anesthesia was induced with iv midazolam 0.06mg/kg,sufentanil 0.6μg/kg,and vecuronium 0.12mg/kg.Tracheal intubation was performed when the BIS value≤55.After admission to operating room（T0,baseline）,immediately after the end of dexmedetomidine infusion（T₁）,immediately before intubation（T₂）,and at 1,3 and 5 min after intubation（T₃、T₄、T₅）,SP,DP,mean arterial pressure（MAP）and HR were recorded.The adverse cardiovascular events were recorded staring from induction of anesthesia to 5 min after intubation.Results Compared with the baseline value at T0,HR was significantly decreased at T_2,T₅,while increased at T₃,T₄in group C,and HR was decreased at T₁-T₅in group D;SP,DP and MAP at T₂,T₅were decreased at T_2,T₅,while increased at T₃in group C,and no significant changes were found in the indices mentioned above in group D.Compared with group C,the incidence of hypotension,hypertension and tachycardia was significantly decreased,and no significant changes were found in the incidence of bradycardia in group D.Conclusion Dexmedetomidine 0.6μg/kg infused intravenously can effectively alleviate the cardiovascular response in patients with atrial fibrillation during anesthesia induction.