The Effects Of Remifentanil In Various Target Plasma Concentrations In Combination Of Etomidate On Hemodynamic Response To Tracheal Intubation

Objective:To compare the effects of target-controlled infusion (TCI) of remifentanil (R) in variousdose in combination of TCI etomidate (E) on hemodynamic response to tracheal intubation.Methods: Forty ASAⅠ-Ⅱpatients aged＜65yr undergoing elective surgery under generalanesthesia were enroUed in this study.The patients were unpremedicated. Anesthesia was inducedwith remifentanil and etomidate both given by TCI simultaneously.The patients were randomizedto receive remifentanil at a fixed target plasma concentration of 2,4,6 or 8ng/ml(groupR2,R4,R6,R8).TCI etomidate was started at a target plasma concentration of 0.6ug/ml.Tracheawas intubated following intravenous rocuronium when the consciousness of patients waslost.Recording the time when the the consciousness of patients was lost and the BP and HR inthe induced process,before intubation and 1,2 min after intubation.If the consciousness of patientswas not lost,the target plasma concentrations of etomidate increased 0.1ug/ml every other one min.Results: Induction time was significantly longer in group R2,R4than that in group R6 andR8(P＜0.05).MAP increased significantly for 2 min after intubation in group R2 and R4.But MAPdid not change in group R6 and R8 after intubation.But MAP significantly declined in group R8than the foundation,and low blood pressure and bradycardia increased. Conclusion: Remifentaniland etomidate have a synergistic effect when given by TCI simultaneously for induction ofanesthesia.The target plasma etomidate concentration of 0.6 ug/ml in the presence of plasmaremifentanil concentration of 6 ng/ml can effectively attenuate the intubation response.