Pre-hospital advanced airway management for adults with out-of-hospital cardiac arrest: nationwide cohort study

OBJECTIVE: To determine survival associated with advanced airway management (AAM) compared with no AAM for adults with out-of-hospital cardiac arrest. DESIGN: Cohort study between January 2014 and December 2016. SETTING: Nationwide, population based registry in Japan (All-Japan Utstein Registry). PARTICIPANTS: Consecutive adult patients with out-of-hospital cardiac arrest, separated into two sub-cohorts by their first documented electrocardiographic rhythm: shockable (ventricular fibrillation or pulseless ventricular tachycardia) and non-shockable (pulseless electrical activity or asystole). Patients who received AAM during cardiopulmonary resuscitation were sequentially matched with patients at risk of AAM within the same minute on the basis of time dependent propensity scores. MAIN OUTCOME MEASURES: Survival at one month or at hospital discharge within one month. RESULTS: Of the 310 620 patients eligible, 8459 (41.2%) of 20 516 in the shockable cohort and 121 890 (42.0%) of 290 104 in the non-shockable cohort received AAM during cardiopulmonary resuscitation. After time dependent propensity score sequential matching, 16 114 patients in the shockable cohort and 236 042 in the non-shockable cohort were matched at the same minute. In the shockable cohort, survival did not differ between patients with AAM and those with no AAM: 1546/8057 (19.2%) versus 1500/8057 (18.6%) (adjusted risk ratio 1.00, 95% confidence interval 0.93 to 1.07). In the non-shockable cohort, patients with AAM had better survival than those with no AAM: 2696/118 021 (2.3%) versus 2127/118 021 (1.8%) (adjusted risk ratio 1.27, 1.20 to 1.35). CONCLUSIONS: In the time dependent propensity score sequential matching for out-of-hospital cardiac arrest in adults, AAM was not associated with survival among patients with shockable rhythm, whereas AAM was associated with better survival among patients with non-shockable rhythm.