Comparison of full-dose succinylcholine and rocuronium for rapid sequence intubation in an academic emergency department: a retrospective cohort study.

BACKGROUND Succinylcholine and rocuronium are the principal neuromuscular blocking agents used for rapid sequence intubation (RSI). Prior studies comparing these agents have shown conflicting results, although a Cochrane review suggested that succinylcholine may provide superior intubating conditions. This study aimed to compare the first-pass success rate, intubating conditions, and peri-intubation safety between full-dose succinylcholine (1.5 mg/kg) and rocuronium (1.2 mg/kg) during RSI. METHODS This retrospective cohort study was conducted in a single academic emergency department between 2017 and 2021. Adult patients who underwent RSI with either succinylcholine or rocuronium were included. The primary outcome was the first-pass success rate. The secondary outcome was clinically acceptable intubating conditions, and exploratory safety outcomes included hypoxia, hemodynamic change, vasopressor use, and post-intubation adverse events. Logistic regression was performed to identify independent predictors of the first-pass success rate. RESULTS A total of 342 patients were included, with 201 receiving succinylcholine (1.5 mg/kg) and 141 receiving rocuronium (1.2 mg/kg). There was no statistically significant difference detected on the first-pass success rates between succinylcholine and rocuronium (81.6% vs. 79.4%; absolute risk difference 2.2%; 95% confidence interval [95% CI] -6.4 to 10.7; P=0.31). No statistically significant differences were observed in exploratory peri-intubation safety outcomes, including hypoxia, hemodynamic changes, or adverse events between the groups. Rocuronium was more frequently used in patients with endocrine comorbidities, which is consistent with confounding by indication (30.5% vs. 13.9%; P=0.03). Independent predictors of the first-pass success rates included the use of video laryngoscopy (adjusted odds ratio [aOR] 1.59; 95% CI 1.22-4.09, P=0.02) and greater physician experience (aOR 2.12; 95% CI 1.09-5.21, P=0.04). CONCLUSION In this single-center retrospective cohort study, there was no statistically significant difference observed in the first-pass success rates, intubation conditions, and peri-intubation safety outcomes between succinylcholine and rocuronium during RSI in the emergency department. However, clinically relevant differences cannot be excluded because the study was not designed to establish equivalence.