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.