RESUMEN
BACKGROUND: A single dose epinephrine protocol (SDEP) for out-of-hospital cardiac arrest (OHCA) achieves similar survival to hospital discharge (SHD) rates as a multidose epinephrine protocol (MDEP). However, it is unknown if a SDEP improves SHD rates among patients with a shockable rhythm or those receiving bystander cardiopulmonary resuscitation (CPR). METHODS: This pre-post study, spanning 11/01/2016-10/29/2019 at 5 North Carolina EMS systems, compared pre-implementation MDEP and post-implementation SDEP in patients ≥18 years old with non-traumatic OHCA. Data on initial rhythm type, performance of bystander CPR, and the primary outcome of SHD were sourced from the Cardiac Arrest Registry to Enhance Survival. We compared SDEP vs MDEP performance in each rhythm (shockable and non-shockable) and CPR (bystander CPR or no bystander CPR) subgroup using Generalized Estimating Equations to account for clustering among EMS systems and to adjust for age, sex, race, witnessed arrest, arrest location, AED availability, EMS response interval, and presence of a shockable rhythm or receiving bystander CPR. The interaction of SDEP implementation with rhythm type and bystander CPR was evaluated. RESULTS: Of 1690 patients accrued (899 MDEP, 791 SDEP), 19.2% (324/1690) had shockable rhythms and 38.9% (658/1690) received bystander CPR. After adjusting for confounders, SHD was increased after SDEP implementation among patients with bystander CPR (aOR 1.61, 95%CI 1.03-2.53). However, SHD was similar in the SDEP cohort vs MDEP cohort among patients without bystander CPR (aOR 0.81, 95%CI 0.60-1.09), with a shockable rhythm (aOR 0.96, 95%CI 0.48-1.91), and with a non-shockable rhythm (aOR 1.26, 95%CI 0.89-1.77). In the adjusted model, the interaction between SDEP implementation and bystander CPR was significant for SHD (p = 0.002). CONCLUSION: Adjusting for confounders, the SDEP increased SHD in patients who received bystander CPR and there was a significant interaction between SDEP and bystander CPR. Single dose epinephrine protocol and MDEP had similar SHD rates regardless of rhythm type.
RESUMEN
BACKGROUND: Cardiac arrest guidelines recommend epinephrine every 3-5 minutes during cardiac arrest resuscitation. However, it is unclear if multiple epinephrine doses are associated with improved outcomes. The objective of this study was to determine if a single-dose epinephrine protocol was associated with improved survival compared to traditional multidose protocols. METHODS: We conducted a pre-post study across five North Carolina EMS agencies from 11/1/2016 to 10/29/2019. Patients ≥18 years old with attempted resuscitation for non-traumatic prehospital cardiac arrest were included. Data were collected 1 year before and after implementation of the single-dose epinephrine protocol. Prior to implementation, all agencies used a multidose epinephrine protocol. The Cardiac Arrest Registry to Enhance Survival (CARES) was used to obtain patient outcomes. Study outcomes were survival to hospital discharge (primary) and return of spontaneous circulation (ROSC). Analysis was by intention to treat. Outcomes were compared pre- vs. post-implementation using generalized estimating equations to account for clustering within EMS agencies. Adjusted analyses included age, sex, race, shockable vs. non-shockable rhythm, witnessed arrest, automatic external defibrillator availability, EMS response interval, and bystander cardiopulmonary resuscitation. RESULTS: During the study period there were 1,690 encounters (899 pre- and 791 post-implementation). The population was 74.7% white, 61.1% male, and had a median age of 65 (IQR 53-76) years. Survival to hospital discharge was similar pre- vs. post-implementation [13.6% (122/899) vs. 15.4% (122/791); OR 1.19, 95%CI 0.89-1.59]. However, ROSC was more common post-implementation [42.3% (380/899) vs. 32.5% (257/791); OR 0.66, 95%CI 0.54-0.81]. After adjusting for covariates, the single-dose protocol was associated with similar survival to discharge rates (aOR 0.88, 95%CI 0.77-1.29), but with decreased ROSC rates (aOR 0.58, 95%CI 0.47-0.72). CONCLUSION: A prehospital single-dose epinephrine protocol was associated with similar survival to hospital discharge, but decreased ROSC rates compared to the traditional multidose epinephrine protocol.