Rocuronium dose and first-attempt intubation success in the critically ill: secondary analysis of two multicenter trials

Rationale: The neuromuscular blockade dose may affect intubation success on the first attempt, thereby impacting outcomes for patients undergoing emergency tracheal intubation. Objectives: To evaluate the association between rocuronium dose and tracheal intubation outcomes among adults undergoing emergency tracheal intubation in the emergency department (ED) and intensive care unit (ICU). Methods: We conducted a secondary analysis of data from two multicenter randomized controlled trials studying airway management in the ED and ICU. We compared patient characteristics and intubation outcomes between patients receiving high-dose (>1.2 mg/kg) versus standard-dose (≤1.2 mg/kg) rocuronium. The primary outcome was successful intubation on the first attempt. We used propensity matching to account for measured potential confounders, stratified by setting. Measurements and main results: Participating sites included 9 EDs and 24 ICUs in the United States. Among 2440 patients in the trial datasets, we included the 1822 (74.7%) patients who received rocuronium in the current analysis. Of these, 720 (39.5%) received high-dose rocuronium, and 1102 (60.5%) received standard-dose rocuronium. Participants receiving high-dose rocuronium had a higher probability of successful intubation on the first attempt (adjusted relative risk [RR] 1.07, 95% confidence interval [CI] 1.02-1.12). This difference in the primary outcome was not present for ED intubations (adjusted RR 0.97, 95% CI 0.89-1.04) but was present for ICU intubations (adjusted RR 1.13, 95% CI 1.06-1.20). Conclusions: In this secondary analysis, high-dose rocuronium (>1.2 mg/kg) was associated with higher first-attempt success. Given the potential for unmeasured confounding, these findings warrant evaluation in a randomized controlled trial.