Summary

Background and objective: In our algorithm for management of the anticipated difficult airway the induction agent (etomidate) is administered after the tip of the fibreoptic is placed in the trachea but before the tube is advanced over it. In a previous investigation we demonstrated the safety of this method. Due to its popularity as an induction agent, some would like to replace etomidate with propofol. However, because rapid recovery of spontaneous breathing is crucial with this technique, substitution might not be advisable. We compared the speed of recovery of spontaneous breathing after fibreoptic intubation between etomidate and propofol. Methods: In this prospective, randomized, double-blind study we used either 0.2 mg kg−1 etomidate or 2 mg kg−1 propofol for induction. Our technique of nasotracheal fibreoptic intubation consists of using fentanyl, cocaine instillation into the lower nasal canals, cricothyroid injection of lidocaine, performing bronchoscopy, administration of etomidate and advancing the tube after loss of consciousness. We measured time to loss of consciousness, time to recovery of spontaneous breathing, lowest bispectral index value and time to lowest value. Results: Time to loss of consciousness did not differ. The time to recovery of spontaneous breathing differed significantly: the median time (interquartile range [range]) for etomidate was 81 s (62–102 [0–166]), and for propofol 146 s (95–260 [65–315]); P = 0.001. The lowest bispectral index values were not different. The time of the lowest bispectral index values differed significantly: for etomidate 58 s (51–68 [38–100]), and for propofol 90 s (52–125 [38–172]); P = 0.015. Conclusion: For nasotracheal fibreoptic intubation, where the tube is advanced after induction of anaesthesia, we still recommend etomidate because spontaneous breathing recovers faster than with propofol.