Abstract 02: Effect of Airway Insertion First-Pass Success Upon Patient Outcomes in the Pragmatic Airway Resuscitation Trial

Introduction: The multicenter Pragmatic Airway Resuscitation Trial (PART) demonstrated better adult out-of-hospital cardiac arrest (OHCA) outcomes with initial laryngeal tube (LT) insertion than endotracheal intubation (ETI) airway management. While emphasized in clinical practice, the effect of advanced airway insertion first-pass success (FPS) upon outcomes after OHCA is unknown. We sought to determine the direct and indirect mediating effects of LT and ETI FPS upon adult OHCA in a secondary analysis of PART. HYPOTHESES: 1) FPS associated with adult OHCA outcomes. 2) FPS mediates (explains) the association between airway type (LT vs. ETI) and adult OHCA outcomes. Methods: We defined FPS as successful LT insertion or ETI on the first attempt as reported by EMS personnel. We examined the outcomes return of spontaneous circulation (ROSC), 72-hour survival, hospital survival, and hospital survival with favorable neurologic function (MRS ≤3). Using multivariable GEE, we determined the association between FPS and outcomes after OHCA, adjusting for age, sex, witnessed arrest status, bystander CPR, initial rhythm, and trial randomization. Using the method of Baron and Kenny, we used mediation analysis to explain the contribution of FPS towards differences in OHCA outcomes between LT and ETI. Results: Of 3,004 patients enrolled in the trial, 1,423 received LT, 1,227 received ETI, 354 received bag-valve-mask ventilation only. FPS was: LT 90.3% and ETI 51.5%. FPS was associated with increased ROSC (adjusted OR 1.36, 95% CI 1.04-1.78) and 72h survival (1.45; 1.20-1.74) but not hospital survival (0.94; 0.67-1.31) or hospital survival with favorable neurologic function (0.70; 0.40-1.23). FPS had a strong mediating effect on the OHCA outcome differences between LT and ETI; 72h survival (74% mediated); ROSC (53% mediated); hospital survival (52% mediated); hospital survival with favorable neurologic status (35% mediated). Conclusion: In adult with OHCA, airway insertion FPS is associated with increased ROSC and 72h survival. Differences in OHCA outcomes between LT and ETI are largely explained by differences in FPS. EMS personnel should emphasize FPS in the advanced airway management of OHCA.