Outcomes With the Use of Bag-Valve-Mask Ventilation During Out-of-hospital Cardiac Arrest in the Pragmatic Airway Resuscitation Trial

Abstract

Background: While emergency medical services (EMS) often use endotracheal intubation (ETI) or supraglottic airways (SGA), some patients receive only bag-valve-mask (BVM) ventilation during out-of-hospital cardiac arrests (OHCA). Our objective was to compare patient characteristics and outcomes for BVM ventilation to advanced airway management (AAM) in adults with OHCA.

Methods: Using data from the Pragmatic Airway Resuscitation Trial, we identified patients receiving AAM (ETI or a SGA), BVM ventilation only (BVM-only), and BVM ventilation as a rescue after at least one failed attempt at advanced airway placement (BVM-rescue). The outcomes were return of spontaneous circulation (ROSC), 72-hour survival, survival to hospital discharge, neurologically intact survival (Modified Rankin Scale ≤ 3), and the presence of aspiration on a chest radiograph. Comparisons were made using generalized mixed-effects models while adjusting for age, sex, initial rhythm, EMS-witnessed status, bystander cardiopulmonary resuscitation, response time, study cluster, and advanced life support first on scene.

Results: Of 3,004 patients enrolled, there were 282 BVM-only, 2,129 AAM, and 156 BVM-rescue patients with complete covariates. Shockable initial rhythms (34% vs. 18.6%) and EMS-witnessed arrests (21.6% vs. 11.3%) were more likely in BVM-only than AAM but similar between BVM-rescue and AAM. Compared to AAM, BVM-only patients had similar ROSC (odds ratio [OR] = 1.29, 95% confidence interval [CI] = 0.96 to 1.73), but higher 72-hour survival (OR = 1.96, 95% CI = 1.42 to 2.69), survival to discharge (OR = 4.47, 95% CI = 3.03 to 6.59), and neurologically intact survival (OR = 7.05, 95% CI = 4.40 to 11.3). Compared to AAM, BVM-rescue patients had similar ROSC (OR = 0.73, 95% CI = 0.47 to 1.12) and 72-hour survival (OR = 1.08, 95% CI = 0.66 to 1.77) but higher survival to discharge (OR = 2.15, 95% CI = 1.17 to 3.95) and neurologically intact survival (OR = 2.64, 95% CI = 1.20 to 5.81). Aspiration incidence was similar.

Conclusions: Bag-valve-mask-only ventilation is associated with improved OHCA outcomes. Despite similar rates of ROSC and 72-hour survival, BVM-rescue ventilation was associated with improved survival to discharge and neurologically intact survival compared to successful AAM.