Tracheal intubation without the use of muscle relaxants: remifentanil or alfentanil in combination with propofol

Background: Alfentanil-propofol combination provides adequate conditions fo r tracheal intubation without neuromuscular blocking drugs in most patients . Providing an option for intense opioid effect without compromising recove ry after short operations, remifentanil might offer benefits over alfentani l, especially in ambulatory surgery. In this study incubating conditions af ter remifentanil-propofol were compared to those after alfentanil-propofol. Methods: In a randomized, double-blind study 60 healthy patients were assig ned to one of three groups (n=20). After intravenous atropine, remifentanil 3 or 4 mu g kg(-1) (Rem3 or Rem4) or alfentanil 30 mu g kg(-1) (Alf30) was injected over 30 s followed by propofol 2.5 mg kg(-1). Sixty seconds after the administration of propofol, laryngoscopy and intubation were attempted . Intubating conditions were assessed as excellent, good or poor on the bas is of ease of ventilation, jaw relaxation, position of the vocal cords, and patient response to intubation and slow inflation of the endotracheal tube cuff. Results: Overall conditions at intubation were significantly (P<0.05) bette r, and the frequency of excellent conditions was significantly (P<0.05) hig her in the Rem4 group compared with the Alf30 group. Intubation was judged to be impossible in 20%, 25% or 5% of the patients in the Alf30, Rem3 or Re m4 groups, respectively No patient manifested signs of opioid-induced muscu lar rigidity. In terms of arterial pressures or heart rate, there were no d ifferences between the groups. Conclusion: The best method was the combination of remifentanil 4 mu g kg(- 1) and propofol 2.5 mg kg(-1). This provided satisfactory intubating condit ions in 93%, and prevented cardiovascular intubation response. (C) Acta Anaesthsiologica Scandinavica 44 (2000).