Succinylcholine and rocuronium are the most commonly utilized neuromuscular blocker agents (NMBAs) for rapid sequence intubation (RSI) in the emergency department (ED). The duration of action of rocuronium is significantly longer (∼30 min) compared to succinylcholine (∼10 min) and previous studies have shown that patients receiving rocuronium are more likely to have longer time to sedation initiation following RSI. Furthermore, patients receiving rocuronium may be more likely to experience awareness with paralysis than those receiving succinylcholine. The primary goal for this study was to evaluate the association between NMBA use during RSI and post-intubation sedation and analgesia practices in the ED.

This was a retrospective, multicenter cohort study including patients 18 years and older that received succinylcholine or rocuronium during RSI in the ED between September 1, 2020 and August 31, 2021. Patients were excluded if they were intubated prior to ED arrival, experienced an out-of-hospital or in ED cardiac arrest, or received sugammadex within 60 min of rocuronium administration. Patients were screened in reverse chronological order until the targeted sample size was achieved and all data was abstracted from the electronic health record. The primary outcome was the time to initiation of analgesia or sedation. Secondary outcomes included dose of sedatives or analgesia administered at 30- and 60 min, and medications administered for post-intubation sedation or analgesia.

A total of 200 ED patients were included of which 100 received succinylcholine and 100 received rocuronium. There was no difference in the median time to initiation of analgesia or sedation between the succinylcholine and rocuronium groups (10 vs 8.5 min, p = 0.82) or in Kaplan-Meier cumulative probabilities (p = 0.17). At 60 min post-RSI, those receiving succinylcholine received significantly higher median doses of propofol (20 μg/kg/min vs. 10 μg/kg/min; p = 0.02) and fentanyl [100 μg vs. 84.2 μg; p = 0.02].

While no differences were observed in the time to initiation of post-intubation sedation or analgesia in ED patients receiving succinylcholine compared to rocuronium, differences in the intensity of post-intubation regimens was observed. Further investigation is needed to evaluate the adequacy of sedation following RSI in the ED.