Comparison of Intubating Conditions with Succinylcholine Versus Rocuronium in the Prehospital Setting

Abstract

Objective

Rapid sequence intubation (RSI) is frequently performed by emergency medical services (EMS). We investigated the relationship between succinylcholine and rocuronium use and time until first laryngoscopy attempt, first-pass success, and Cormack-Lehane (CL) grades.

Methods

We included adult patients for whom prehospital RSI was attempted from July 2015 through June 2022 in a retrospective, observational study with pre-post analysis. Timing was verified using recorded defibrillator audio in addition to review of continuous ECG, pulse oximetry, and end-tidal carbon dioxide waveforms. Our primary exposure was neuromuscular blocking agent (NMBA) used, either rocuronium or succinylcholine. Our prespecified primary outcome was the first attempt Cormack-Lehane view. Key secondary outcomes were first laryngoscopy attempt success rate, timing from NMBA administration to first attempt, number of attempts, and hypoxemic events.

Results

Of 5,179 patients in the EMS airway registry, 1,475 adults received an NMBA while not in cardiac arrest. Cormack-Lehane grades for succinylcholine and rocuronium were similar: grade I (64%, 59% [95% CI 0.64–1.09]), grade II (16%, 21%), grade III (18%, 16%), grade IV (3%, 3%). The median interval from NMBA administration to start of the first attempt was 57 s for succinylcholine and 83 s for rocuronium (mean difference 28 [95% CI 20–36] seconds). First attempt success was 84% for succinylcholine and 83% for rocuronium. Hypoxemic events were present in 25% of succinylcholine cases and 23% of rocuronium cases.

Conclusions

Prehospital use of either rocuronium or succinylcholine is associated with similar Cormack-Lehane grades, first-pass success rates, and rates of peri-intubation hypoxemia.

Acknowledgments

We want to acknowledge the dedicated efforts of the EMS professionals of the Seattle Medic One program and their continuous efforts to improve the care delivered to the community they serve.

Author Contributions

MRS conceived and designed the study and implemented the protocol changes and training. CRC, KMP, and JR supervised the process of data collection and analyzed the airway data and recordings. CM provided the statistical analysis of data. JR and KMP drafted the manuscript, and all authors substantially contributed to its revision. JR takes responsibility for the paper as a whole.

Disclosure Statement

No potential conflict of interest was reported by the author(s).

Funding

There is no financial support related to this work.

Presentations

• Presented at the Western Medical Research Conference, Jan 2023, Carmel, CA.

• Presented at the National Association of EMS Physicians meeting, Jan 2023, Tampa, FL.