How stepwise interventions in pre-hospital emergency care enhance out-of-hospital cardiac arrest management in a Megacity in China

Objective: A series of improvements have been formulated and implemented to prompt the inadequate pre-hospital care capacity for out-of-hospital cardiac arrest (OHCA) management in China. The aim of this study is to investigate the combined association of those stepwise interventions with OHCA management in Shenzhen, as a representative city in China. Methods: This registry-based retrospective study included emergency medical services (EMS)-treated adult OHCA patients with presumed cardiac etiology in Shenzhen, China, covering the period from January 1, 2011 to December 31, 2022. During this period, three key interventions were implemented sequentially: a public access defibrillation (PAD) program on October 1, 2017, a civilian cardiopulmonary resuscitation (CPR) training program on July 1, 2020, and telecommunicator cardiopulmonary resuscitation (T-CPR) on November 23, 2021. The outcomes of bystander CPR and return of spontaneous circulation (ROSC) were compared with pre-intervention controls. Results: A total of 6,571 EMS-treated presumed cardiac etiology adult OHCA patients were included, among which were 623 cases with bystander-witnessed OHCA and a shockable rhythm. Across four periods, the rates of both bystander CPR (8.55 vs. 12.60 vs. 18.31 vs. 23.10%) and ROSC (6.01 vs. 5.29 vs. 9.59 vs. 8.33%) showed an increasing trend. For the rate of bystander CPR, the likelihood was significantly increased after implementation of the PAD program (OR 1.64 [95% CI 1.21-2.23]) and civilian CPR training program (OR 2.12 [95% CI: 1.52-2.95]), and after the addition of the T-CPR application (OR 3.06 [95% CI: 2.14-4.39]), compared with the pre-period. Similarly, cumulative interventions were associated with a higher ROSC (OR 0.84 [95% CI: 0.62-1.14], OR 1.52 [95% CI: 1.07-1.89], OR 1.42 [95% CI: 1.07-1.89]) when compared with the pre-period. In subgroup analysis, cumulative interventions significantly improved the rate of bystander CPR in cases where OHCA occurred in public locations, and ROSC in cases where the time from symptom onset to calling 120 was within 10 min. Conclusion: Stepwise interventions in pre-hospital emergency care increased likelihood of bystander CPR and ROSC following pre-hospital resuscitation significantly. This improvement is attributed to the coordination and cumulative effect of multiple positive interventions for OHCA management.