Association between endotracheal intubation and outcomes of nonshockable out-of-hospital cardiac arrest in Japan.

Background: Patients with nonshockable out-of-hospital cardiac arrest (OHCA) have poor outcomes compared with those with shockable rhythm. The optimal strategy for advanced airway management (AAM) for these patients remains controversial. This study aimed to compare outcomes between prehospital endotracheal intubation (ETI) and supraglottic airway (SGA) for adults with witnessed and nonshockable OHCA.

Methods: We compared the outcomes according to airway management using a nationwide, population-based Japanese registry (All-Japan Utstein Registry) between 2005 and 2021. The study population included adults with witnessed, nontraumatic, nonshockable OHCA who received prehospital AAM by emergency medical service (EMS) personnel. The outcomes were return of spontaneous circulation (ROSC), 1-month overall survival, and 1-month survival with a favorable neurological outcome, defined as a Cerebral Performance Category score of 1 or 2. To adjust for confounding factors between the ETI and SGA groups, we used propensity score analysis with inverse probability of treatment weighting (IPTW) and performed a sensitivity analysis using overlap weighting.

Results: A total of 147,088 patients were included: 30,797 (20.9%) received ETI and 116,291 (79.1%) received SGA. After IPTW adjustment, patients receiving ETI had significantly higher rates of ROSC (19.3% vs. 11.1%; odds ratio [OR] 1.51; 95% confidence interval [CI] 1.48-1.54), 1-month survival (6.4% vs. 4.5%, OR 1.44; 95%CI 1.40-1.49), and 1-month survival with favorable neurological outcomes (1.0% vs. 1.0%, OR 1.11; 95%CI 1.04-1.20) than those receiving SGA. The sensitivity analysis confirmed robust associations for ROSC (OR 1.53; 95%CI 1.45-1.61) and 1-month survival (OR 1.48; 95%CI 1.36-1.60), but the association with favorable neurological outcome was not statistically significant (OR 1.11; 95%CI 0.93-1.34).

Conclusion: In this Japanese nationwide Utstein registry cohort study with IPTW adjustment, for adult witnessed OHCA patients with initial nonshockable rhythm, prehospital ETI was associated with significantly higher rates of ROSC and 1-month survival, compared to prehospital SGA. These findings suggest that ETI, when performed by EMS personnel, has the potential to improve outcomes in these patients with OHCA.