Use of rapid sequence intubation predicts improved survival among patients intubated after out-of-hospital cardiac arrest

Objective: Some observational studies indicate that endotracheal intubation is associated with a worse outcome compared to bag-mask ventilation after out-of-hospital cardiac arrest in emergency medical services (EMS) systems without rapid sequence intubation (RSI). We evaluated the role of RSI in airway management following cardiac arrest.

Methods: We conducted a cohort study of all non-traumatic arrest patients treated by a metropolitan EMS system from 2007 to 2011. Advanced airway management information was obtained from a prospective airway registry and linked to a cardiac arrest registry. We used multivariate logistic regression to estimate the association between attempted intubation status and survival to hospital discharge.

Results: Of 3133 patients, 82% underwent attempted intubation without RSI, 15% underwent attempted RSI, and 3% experienced no intubation attempt. Survival to hospital discharge differed by attempted intubation status: 11% (n=291/2576) for intubation without RSI, 48% (n=226/471) for RSI, and 71% (n=61/86) for "no intubation." Compared to the intubation without RSI group, the adjusted odds ratios of survival were 5.6 (95% CI 4.3, 7.2) for the RSI group and 15 (95% CI 9, 27) for the "no intubation" group.

Conclusion: In this population-based cohort of out-of-hospital cardiac arrest, RSI was used in 15% of patients and associated with a better prognosis than intubation attempted without paralytics. Because this subset with a favorable prognosis may not be readily intubated in systems without paralytics, these findings could help to explain the adverse relationship between intubation and survival observed in prior studies.