Etomidate as a sole agent for endotracheal intubation in the prehospital air medical setting.

INTRODUCTION: Etomidate is an anesthetic agent with rapid onset, short duration of action, a generally stable hemodynamic profile, and cerebroprotective effects. It is used in the hospital setting to facilitate emergency endotracheal intubation. This helicopter EMS used etomidate as an intubating agent without paralytics for 2 years.

METHODS: Intubations performed by the helicopter crew using etomidate alone were reviewed. Intubation was classified as successful or unsuccessful. Successful intubations requiring three or more attempts or repeated doses of etomidate were interpreted as difficult.

RESULTS: Fifty patients received etomidate to facilitate orotracheal intubation. Etomidate was the sole agent in 44 of these cases. Mean age was 31 years (range 4-79); 35 patients (80%) were men. Most patients (79%) were victims of blunt trauma. The mean dose of etomidate was 0.5 mg/kg (range 0.3-1.1). Hemodynamic parameters remained stable. Intubation was successful in 39 patients (89%). Intubation was difficult in seven patients (16%) and unsuccessful in five (11%). Masseter muscle spasm was noted in three of the five patients for whom intubation was unsuccessful. Other complications included emesis in eight patients and seizure-like activity in one patient.

CONCLUSION: Etomidate can be used to facilitate emergency endotracheal intubation in the prehospital air medical setting, with a success rate of 89%. At the doses used in the study, hemodynamic parameters remained stable, but intubation was difficult or unsuccessful in 27% of patients. Masseter muscle spasm, which may represent orofacial myoclonus or inadequate relaxation, is common in patients who cannot be intubated with etomidate. Etomidate is recommended as a sole agent for facilitating intubation only when rapid sequence intubation with paralysis is contraindicated or otherwise undesirable.