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.