Abstract
BACKGROUND: Early adrenaline administration is associated with return of spontaneous circulation (ROSC) and survival in out-of-hospital cardiac arrest (OHCA). Animal data demonstrate a similar rate of ROSC when early intramuscular (IM) adrenaline is given compared to early intravenous (IV) adrenaline. AIM: To evaluate the feasibility of protocolized first-dose IM adrenaline in OHCA and it's effect on time from Public Safety Access Point (PSAP) call receipt to adrenaline administration when compared to IO and IV administration. METHODS: This is a before-and-after feasibility study of adult OHCAs in a single EMS service following adoption of a protocol for first-dose IM adrenaline. Time from PSAP call to administration and outcomes were compared to 674 historical controls (from January 1, 2013-February 8, 2021) who received at least one dose of adrenaline by IV or IO routes. RESULTS: During the study period, first-dose IM adrenaline was administered to 99 patients (December 1, 2019-February 8, 2021). IM adrenaline was given a median of 12.2 min (95% CI 11.4-13.1 min) after the PSAP call receipt compared to 15.3 min for the IV route (95% CI 14.6-16.0 min) and 15.3 min for the IO route (95% CI 14.9-15.7 min) with a time savings of 3 min (95% CI 2-4 min). Rates of survival to hospital discharge appeared similar between groups: 10% for IM, 8% for IV and 7% for IO. However, results related to survival were underpowered for statistical comparison. CONCLUSIONS: Within the limitations of a small sample size and before-and-after design, first-dose IM adrenaline was feasible and reduced the time to adrenaline administration.