Survival after dispatcher-assisted cardiopulmonary resuscitation in out-of-hospital cardiac arrest

Aim: Strategies to increase provision of bystander CPR include mass education of laypersons. Additionally, programs directed at emergency dispatchers to provide CPR instructions during emergency calls to untrained bystanders have emerged. The aim of this study was to evaluate the association between dispatcher-assisted CPR (DA- CPR) and 30-day survival compared with no CPR or spontaneously initiated CPR by lay bystanders prior to emergency medical services in out of hospital cardiac arrest (OHCA).

Methods: Nationwide observational cohort study including all consecutive lay bystander witnessed OHCAs reported to the Swedish Register for Cardiopulmonary Resuscitation in 2010-2017. Exposure was categorized as: no CPR (NO-CPR), DA-CPR and spontaneously initiated CPR (SP-CPR) prior to EMS arrival. Propensity-score matched cohorts were used for comparison between groups. Main Outcome was 30-day survival.

Results: A total of 15 471 patients were included and distributed as follows: NO-CPR 6440 (41.6%), DA-CPR 4793 (31.0%) and SP-CPR 4238 (27.4%). Survival rates to 30 days were 7.1%, 13.0% and 18.3%, respectively. In propensity-score matched analysis (DA-CPR as reference), NO-CPR was associated with lower survival (conditional OR 0.61, 95% CI 0.52-0.72) and SP-CPR was associated with higher survival (conditional OR 1.21 (95% CI 1.05-1.39).

Conclusions: DA-CPR was associated with a higher survival compared with NO-CPR. However, DA-CPR was associated with a lower survival compared with SP-CPR. These results reinforce the vital role of DA-CPR, although continuous efforts to disseminate CPR training must be considered a top priority if survival after out of hospital cardiac arrest is to continue to increase.