Effect of different doses of dexmedetomidine on hemodynamics of coronary artery disease patients with endotracheal intubation

Objective To investigate the effect of different doses of dexmedetomidine on hemodynamics of coronary artery disease patients with endotracheal intubation. Methods Seventy-five patients with coronary artery disease scheduled for abdominal surgeries under general anesthesia were randomly divided into three groups with 25 cases for each.Patients in group L and group M received intravenuous maintenance dose of dexmedetomidine 0.5 mg/kg and 1.0 mg/kg respectively within 50 ml 0.9% saline at the 20 minutes,while patients in group C received intravenuous injection of 0.03-0.05 mg/kg midazolam before induction of anaesthesia.SBP,DBP,HR and ECG were continuously monitored at five different time which is baseline,before induction,before tracheal intubation,immediately after tracheal intubation,3 minutes after tracheal intubation.Results HR,SBP and DBP of group L and group M were significantly decreased,compared with baseline after intravenuous injection dexmedetomidine(P0.05),but there was no significant difference between group L and group M(P0.05).HR,SBP and DBP of the three groups were significantly decreased,compared with baseline before tracheal intubation(P0.05),and there was no significant difference among the three groups(P0.05).Four cases of sinus bradycardia(HR52 beats per minute) and 1 case of low blood tension(SBP decreased over 40%) were observed in group M,1 case of low blood tension in group C and no case in group L before tracheal intubation.Immediately after tracheal intubation,HR,SBP and DBP of group C were significantly increased,compared with that before anesthesia induction and these values also raised than other two groups(P0.05).At 3 minutes after tracheal intubation,HR,SBP and DBP of group C dropped,compared with immediately after tracheal intubation(P0.05) and also significantly increased than that before tracheal intubation.There was no significant difference in HR,SBP and DBP at the time before tracheal intubation,immediately after tracheal intubation,3 minutes after tracheal intubation(P0.05). Conclusion Perfusion of dexmedetomidine before induction can leads to less variation in hemodynamics during tracheal intubation in patients with coronary artery disease.It could be better option for the dose of dexmedetomidine 0.5 μg/kg.