Rescue-Breathing Versus Chest Compression-Only Bystander Cardiopulmonary Resuscitation in Non-Cardiac Out-of-Hospital...

The role of rescue-breathing cardiopulmonary resuscitation (RB-CPR) remains controversial following guideline recommendations emphasizing chest compression-only CPR (CO-CPR). This study evaluated the associations of bystander-performed RB-CPR with mortality and unfavorable neurological outcomes in Japanese patients with non-cardiac out-of-hospital cardiac arrest (OHCA).

This retrospective nationwide cohort study included patients identified in the All-Japan Utstein Registry with non-cardiac OHCA between 2012 and 2023. Patients with a cardiac etiology or traumatic cause and those in whom resuscitation was not initiated were excluded. The analysis was restricted to patients who received bystander CPR with documented chest compressions and available information on rescue breathing. Adjusted risk ratios (RRs) were estimated using modified Poisson regression with robust variance. Prespecified subgroup and sensitivity analyses were performed.

Among 154,137 patients, 20,124 (13.1%) received RB-CPR and 134,013 (86.9%) received CO-CPR. RB-CPR was associated with modestly lower risks of both 30-day mortality (adjusted RR 0.98, 95% CI 0.98-0.99) and 30-day unfavorable neurological outcomes (adjusted RR 0.99, 95% CI 0.99-0.99). RB-CPR was associated with lower risks of both outcomes in pediatric patients but no clear differences were observed among adult or elderly patients. Associations were strongest for pediatric patients and drowning-related arrests and modest in patients with asphyxia.

Thirty-day mortality and unfavorable neurological outcomes were lower after RB-CPR than after CO-CPR for non-cardiac OHCA, particularly in pediatric patients. Although CO-CPR remains important in bystander CPR, rescue breathing may still have benefit, particularly in pediatric patients and those with cardiac arrest related to drowning or asphyxia.