Study objective: To examine the association between the neuromuscular blocking agent received (succinylcholine versus rocuronium) and the incidences of successful intubation on the first attempt and severe complications during tracheal intubation of critically ill adults in an emergency department (ED) or ICU.

Methods: We performed a secondary analysis of data from 2 multicenter randomized trials in critically ill adults undergoing tracheal intubation in an ED or ICU. Using a generalized linear mixed-effects model with prespecified baseline covariates, we examined the association between the neuromuscular blocking agent received (succinylcholine versus rocuronium) and the incidences of successful intubation on the first attempt (primary outcome) and severe complications during tracheal intubation (secondary outcome).

Results: Among the 2,440 patients in the trial data sets, 2,339 (95.9%) were included in the current analysis; 475 patients (20.3%) received succinylcholine and 1,864 patients (79.7%) received rocuronium. Successful intubation on the first attempt occurred in 375 patients (78.9%) who received succinylcholine and 1,510 patients (81.0%) who received rocuronium (an adjusted odds ratio of 0.87; 95% CI 0.65 to 1.15). Severe complications occurred in 67 patients (14.1%) who received succinylcholine and 456 patients (24.5%) who received rocuronium (adjusted odds ratio, 0.88; 95% CI 0.62 to 1.26).

Conclusion: Among critically ill adults undergoing tracheal intubation, the incidences of successful intubation on the first attempt and severe complications were not significantly different between patients who received succinylcholine and patients who received rocuronium.