Evaluation of the optimal timing for advanced airway management for adult patients with out-of-hospital cardiac arrest: A retrospective observational study from a multicenter registry.

Aim: We aimed to investigate the appropriate timing for advanced airway management (AAM) in witnessed adult non-traumatic out-of-hospital cardiac arrest (OHCA) by adjusting for resuscitation time bias and limiting the analysis to witnessed OHCA. Methods: This retrospective observational study used a multicentre OHCA registry involving 99 participating hospitals in Japan and included adult patients with witnessed non-traumatic OHCA who underwent AAM during resuscitation. The primary and secondary outcomes were favourable 30-day neurological outcomes and survival, respectively. The time from emergency medical service contact to AAM was categorised as follows: 1-5, 6-10, 11-15, 16-20, 21-25, and 26-30 min. In each group, we calculated the time-dependent propensity score using a Fine-Gray regression model. After propensity score matching, we used a generalised estimating equation (GEE). Results: A total of 16,448 patients who underwent AAM were matched with patients at risk of requiring AAM. AAM was associated with favourable 30-day neurological outcomes when performed at 6-10 and 16-20 min with RRs (95% CIs) of 1.41 (1.12-1.78), but not at 16-20 min (0.74 [0.56-0.99]), respectively. AAM was associated with improved 30-day survival at 1-5 and 6-10 min (1.22 [1.05-1.41], 1.33 [1.16-1.54], respectively), but not at 16-20 min (0.78 [0.62-0.97]. Conclusions: Performing AAM within 10 min was associated with improved outcomes compared with those at risk of receiving AAM. However, the results were not consistent across all groups, therefore, careful interpretation is required.