Endotracheal intubation without the use of muscle relaxants: Comparisons three different remifentanil bolus doses following propofol induction

Endotracheal intubation without neuromuscular blockade has been performed using several doses of propofol and remifentanil. In this study we investigated the effects of three different doses of remifentanil on endotracheal intubation following propofol induction. Forty-five healthy patients were randomly assigned to one of three equal groups. After intravenous bolus doses of propofol 2.5 mg kg-1, Group I, II and III received intravenous remifentanil 0.5 mg kg-1, 1 mg kg-1 and 2 mg kg-1 respectively. Remifentanil was injected in 30 seconds. Laryngoscopy and intubation was performed sixty seconds after remifentanil injection. Intubation conditions were assessed on the basis of the case of ventilation, jaw relaxation, position of vocal cords, and patients'response to intubation and inflation of endotracheal tube cuff. Hemodynamic responses to intubation were also recorded. Total intubation quality scores in Group III were higher than those of Group I and II (p<0.05). Mean arterial pressures after anaesthesia induction were lower than the control values in all groups (p<0.05). In Group I and Group II; heart rates after intubation were found to be significantly higher when compared with the pre-induction values (p<0.05). Heart rates in Group III were significantly lower at after induction periods when compared with the pre-induction values (p<0.05). It is concluded that; bolus of remifentanil 2 ?g kg-1 after propofol induction provides better intubation conditions without the use of muscle relaxants.