Etomidate versus midazolam for out-of-hospital intubation: a prospective, randomized trial

The primary objective of this study is to compare the intubation success rates of etomidate and midazolam when used for sedative-facilitated intubation, without paralytics, in out-of-hospital adult patients.

This prospective, double-blind, randomized trial was conducted with 2 ground out-of-hospital advanced life support systems (ALS); all patients aged 18 or older who required out-of-hospital sedative-facilitated intubation were eligible for participation. The ambulances were stocked with blinded numbered syringes containing either 7 mg of midazolam or 20 mg of etomidate. No paralytics were used. If sedation was not achieved with the study drug, medics could request additional sedation from a medical command physician; only midazolam or diazepam were available outside of the study.

One hundred ten patients were enrolled in the study; 55 patients received midazolam and 55 patients received etomidate. The 2 groups were similar with regard to age, sex, initial vital signs, and reasons for intubation or sedation. The overall intubation success rate was 76% (95% confidence interval [CI] 68% to 84%); 75% (41/55) for midazolam (95% CI 64% to 86%) and 76% (42/55) for etomidate (95% CI 65% to 87%). There was also no difference in incidence of hypotension, number of intubation attempts, or perceived difficulty of intubation. Additional sedation was requested almost equally for the 2 groups: 14 patients in the midazolam group and 12 patients in the etomidate group. A benzodiazepine was successful for rescue of a failed etomidate intubation 10 of 12 times (83%; 95% CI 62% to 100%). When used for rescue of failed midazolam intubations, benzodiazepines were effective in only 5 of 14 (36%, 95% CI 11% to 61%) attempts.

There were no observed differences between midazolam and etomidate in sedation-facilitated intubation success rates; we could not fully evaluate global outcomes of these agents or the sedative-facilitated intubation strategy itself.