Abstract 232: Out-of-Hospital Airway Management and Cardiac Arrest Outcomes: A Propensity Score Matched Analysis

Abstract

Objective: This study aimed to determine whether EMT-intermediate ETI or LMA comparing with bag-valve mask ventilation is associated with improved OHCA outcomes in Korea. Methods: We used a Korean national OHCA cohort database composed of hospital and ambulance data. We included all EMS-treated OHCA with presumed cardiac etiology for the period Jan. 2006 to Dec. 2008. We excluded cases not receiving continued resuscitation in the emergency department (ED), as well as those without available hospital outcome data. The primary exposure was airway management technique during ambulance transport (endotracheal tube (ETI), laryngeal mask airway (LMA) or bag-valve-mask (BVM)). The primary outcomes were survival to admission and hospital discharge. We compared outcomes between each airway management group using multivariable logistic regression, adjusting for sex, age, witnessed, prehospital defibrillation, bystander cardiopulmonary resuscitation (CPR), call to ambulance arrival time to the scene, call to ambulance arrival time to ED, initial ECG, metropolitan, and level of ED. We repeated the analysis using propensity-score matched subsets. Results: Of 54,496 patients with OHCA, we included 5,278 (9.7%). Overall survival to admission and to discharge was 20.2% and 6.9%, respectively. ETI and LMA was performed in 250 (4.7%) and 391 (7.4%), respectively. In the full multivariable models using total patients, adjusted survival to admission and discharge were similar for ETI and BVM; OR 0.91 (0.66-1.27) and 1.00 (0.60-1.66), respectively. Adjusted survival to admission and discharge were significantly lower in LMA than BVM: OR 0.72 (0.54-0.95) and 0.52 (0.32-0.85), respectively. In the full multivariable models using propensity matched samples, adjusted survival to admission and discharge were similar for ETI and BVM; OR 1.32 (0.81-2.16) and 1.44 (0.66-3.15), respectively. Adjusted survival to admission was similar for LMA and BVM: OR 0.72 (0.50-1.02). However, survival to discharge was significantly lower for LMA than BVM: OR 0.45(0.25- 0.82). Conclusions: In Korea, EMT-I placed LMA during ambulance transport was associated with worsened OHCA survival to discharge than BVM. Outcomes were similar between EMT-I ETI and BVM ventilation.