Timing of Prehospital Advanced Airway Management for Adult Patients With Out‐of‐Hospital Cardiac Arrest: A Nationwide Cohort Study in Japan

BACKGROUND: The timing of advanced airway management (AAM) on patient outcomes after out‐of‐hospital cardiac arrest has not been fully investigated. We evaluated the association between the timing of prehospital AAM and 1‐month survival. METHODS AND RESULTS: We conducted a secondary analysis of a prospective, nationwide, population‐based out‐of‐hospital cardiac arrest registry in Japan. We included emergency medical services–treated adult (≥18 years) out‐of‐hospital cardiac arrests from 2014 through 2017, stratified into initial shockable or nonshockable rhythms. Patients who received AAM at any minute after emergency medical services–initiated cardiopulmonary resuscitation underwent risk‐set matching with patients who were at risk of receiving AAM within the same minute using time‐dependent propensity scores. Eleven thousand three hundred six patients with AAM in shockable and 163 796 with AAM in nonshockable cohorts, respectively, underwent risk‐set matching. For shockable rhythms, the risk ratios (95% CIs) of AAM on 1‐month survival were 1.01 (0.89–1.15) between 0 and 5 minutes, 1.06 (0.98–1.15) between 5 and 10 minutes, 0.99 (0.87–1.12) between 10 and 15 minutes, 0.74 (0.59–0.92) between 15 and 20 minutes, 0.61 (0.37–1.00) between 20 and 25 minutes, and 0.73 (0.26–2.07) between 25 and 30 minutes after emergency medical services–initiated cardiopulmonary resuscitation. For nonshockable rhythms, the risk ratios of AAM were 1.12 (1.00–1.27) between 0 and 5 minutes, 1.34 (1.25–1.44) between 5 and 10 minutes, 1.39 (1.26–1.54) between 10 and 15 minutes, 1.20 (0.99–1.45) between 15 and 20 minutes, 1.18 (0.80–1.73) between 20 and 25 minutes, 0.63 (0.29–1.38) between 25 and 30 minutes, and 0.44 (0.11–1.69) after 30 minutes. CONCLUSIONS: In this observational study, the timing of AAM was not statistically associated with improved 1‐month survival for shockable rhythms, but AAM within 15 minutes after emergency medical services–initiated cardiopulmonary resuscitation was associated with improved 1‐month survival for nonshockable rhythms.