Background: While pre-hospital personnel typically perform advanced airway management (endotracheal intubation (ETI) or supraglottic airway (SGA)) on adult out-of-hospital cardiac arrests (OHCA), some patients may receive only bag-valve-mask (BVM) ventilation. Our objective was to compare effects of BVM ventilation with advanced airway management upon outcomes for adult OHCA patients.
Methods: This is a secondary analysis of patients enrolled in the Pragmatic Airway Resuscitation Trial. We identified patients receiving advanced airway management (AAM - ETI or LT), BVM ventilation only (BVM-only), and BVM as a rescue after at least one failed attempt at advanced airway placement (BVM-rescue). The primary outcomes were return of spontaneous circulation (ROSC), 72-hour survival, survival to discharge, neurologically intact survival (Modified Rankin Scale ≤ 3), and aspiration. Using generalized mixed effects models, we assessed the associations between OHCA outcomes and airway type, adjusting for age, sex, shockable initial rhythm, EMS witnessed arrest, bystander CPR, dispatch to arrival time, and ALS first on scene.
Results: Out of 3004 patients enrolled, there were 352 BVM-only, 2463 advanced airway, and 189 BVM-rescue patients. ROSC was cited as the reason for not attempting an advanced airway in 28.7% of BVM-only patients. 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 exhibited similar rates of ROSC [OR 1.29 (95% CI: 0.96, 1.73)], but higher rates of 72-hour survival [1.96 (1.42, 2.69)], survival to discharge [4.47 (3.03, 6.59)], and neurologically intact survival [7.05 (4.40, 11.3)]. Compared to AAM, BVM-rescue patients exhibited similar rates of ROSC [OR 0.73 (95% CI: 0.47, 1.12)] and 72-hour survival [1.08 (0.66, 1.77)], but higher rates of survival to discharge [2.15 (1.17, 3.95)] and neurologically intact survival [2.64 (1.20, 5.81)]. Aspiration was similar across airway groups.
Conclusions: Compared with AAM, BVM-only is associated with improved OHCA outcomes. Despite similar rates of ROSC and 72-hour survival, BVM-rescue was associated with improved survival to discharge and neurologically intact survival compared to successful AAM in PART.