Comparison of Dual-Dispatch Protocols on Return of Spontaneous Circulation in Patients with Out-of-Hospital Cardiac Arrest: A Nationwide Observational Study.

Objective:In South Korea, the National Fire Agency (NFA) conducted a pilot project on the advanced life support (ALS) protocol, including epinephrine administration, to improve the survival rate of out-of hospital cardiac arrest (OHCA). Therefore, this study aimed to evaluate the effect of the ALS protocol of NFA on prehospital return of spontaneous circulation (PROSC) in patients with OHCA. Methods:This study was conducted on patients with adult-presumed cardiac arrest between January and December 2020. The main factor of interest was ambulance type according to the ALS protocol, which was divided into dedicated ALS(DA), smartphone-based ALS(SALS), and non-dedicated ALS(Non-DA), and the main analysis factor was PROSC. Multivariate logistic regression analysis was performed. Results:During the study period, a total of 18,031 adult patients with OHCA were treated by the emergency medical service (EMS), including 7,520 (41.71 %) DA, 2,622 (14.54 %) SALS, and 7,889 (43.75 %) Non-DA. The prehospital ROSC ratio was 13.19% for the DA, 11.17% for the SALS, and 7.91% for the Non-DA ambulance (P < 0.01). Compared with that of the DA group, the odds ratio (95% confidence interval [CI]) for PROSC ratio in the SALS and Non-DA groups were 0.97 (0.82-1.15) and 0.57 (0.50-0.65), respectively. It was shown that the PROSC ratio of the DA group was higher than that of the Non-DA group and was not lower than that of the SALS group. Conclusion:ALS protocol intervention was associated with difference in PROSC rates. Therefore, continuous efforts on the systemic implementation of the ALS protocol to improve OHCA outcomes are necessary.