Comparison of etomidate and midazolam for prehospital rapid-sequence intubation.

Objective: This study compares etomidate with midazolam for prehospital rapid-sequence intubation (RSI).

Methods: The authors conducted a retrospective review of consecutive intubations at a university-based air medical program from January 1995 to December 2000. Exclusion criteria were patients not undergoing RSI, age <15 years, and incomplete chart data. Outcome measures included intubation success, incidence of hypotension, and percentage of change in heart rate (HR) and systolic blood pressure (SBP).

Results: The intubation success rate was 110 out of 112 (98%) with etomidate, and 96 out of 97 (99%) with midazolam. Mean ages, patient gender distributions, and initial SBPs and HRs did not differ between the two groups. The mean dose of etomidate was 24 mg, the mean percentage of change in HR was -1% (95% confidence interval [CI], -6 to 4), and the mean percentage of change in SBP was 2% (95% CI, -3 to 7). The mean dose of midazolam was 3.5 mg, the mean percentage of change in HR was 1% (95% CI, -5 to 7), and the mean percentage change in SBP was 3% (95% CI, -3 to 9). The number of hypotensive episodes with etomidate (7 out of 74) compared with midazolam (3 out of 56) did not differ significantly (Fisher's exact test, p=0.51).

Conclusion: Intubation success rate was very high with both etomidate (98%) and midazolam (99%). There was no statistically significant mean percentage of change in SBP or HR with either agent. The authors found a low incidence of hypotension with both agents, although the mean dose of midazolam used was considerably less than typically recommended for induction.