Single Dose Epinephrine Protocol Is Associated With Improved Survival of Older Adults With Out-Of-Hospital Cardiac Arrest.

BACKGROUND

A single-dose epinephrine protocol (SDEP) for out-of-hospital cardiac arrest (OHCA) was recently found to have similar survival to hospital discharge (survival) rates compared to a multidose epinephrine protocol (MDEP). It remains unknown if survival rates vary for SDEP vs. MDEP by age. This study aims to determine if an SDEP protocol improves survival in distinct age groups.

METHODS

We conducted a pre-post implementation study (MDEP vs. SDEP) in 5 North Carolina EMS systems from 11/01/2016-10/29/2019 among adult OHCA patients. Demographics and the outcome of survival were sourced from the Cardiac Arrest Registry to Enhance Survival. Patients were categorized as older (≥ 65 years), middle-aged (46-64 years), and young (18-45 years). Survival rates were compared pre vs. post SDEP implementation within age groups using Generalized Estimating Equations to account for clustering within EMS systems and adjust for sex, race, witnessed arrest, AED application, rhythm type, bystander CPR, arrest location, and EMS response time. The interaction of SDEP implementation with age group was evaluated.

RESULTS

Among 1690 patients (899 MDEP, 791 SDEP), 864 were older, 538 were middle-aged, and 288 were young. Survival occurred in 13.6% (122/899) in the MDEP group and 15.4% (122/791) in the SDEP group. SDEP was associated with improved survival in older patients (12.2% [50/409] vs. 6.6% [30/455]; OR: 1.95, 95% CI 1.58-2.41) and similar survival in middle-aged (17.5% [47/268] vs. 18.2% [49/270]; OR: 0.96, 95% CI 0.53-1.25) and young (21.9% [25/114] vs. 24.7% [43/174]; OR: 0.88, 95% CI 0.41-1.90) patients. After adjusting, SDEP remained associated with improved survival among older adults (aOR: 1.87, 95% CI 1.36-2.56) and similar survival rates among middle-aged (aOR: 0.85, 95% CI 0.63-1.15) and young (aOR: 0.82, 95% CI 0.41-1.64) patients. The interactions of SDEP implementation between older and middle-aged (p = 0.001) and older and young (p = 0.05) patients indicate a differential effect.

CONCLUSION

SDEP was associated with improved survival rates among older adults.