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Addition of Intramuscular Epinephrine to Standard of Care by Paramedics to Decrease Time-to-Initial Epinephrine Dose
Jay Loosley1, Maysaa Assaf2,3, Katie McKenzie4
1Department of Education and Training, Middlesex-London Paramedic Service, London, Ontario, Canada.
Insights
Intramuscular (IM) epinephrine via autoinjector significantly speeds initial drug delivery in simulated pediatric out-of-hospital cardiac arrest (POHCA). This faster administration method offers a crucial advantage over traditional IV/IO routes, potentially improving outcomes for critically ill children.
Area of Science:
- Pediatric Emergency Medicine
- Cardiovascular Research
- Paramedic Practice
Background:
- Pediatric out-of-hospital cardiac arrest (POHCA) has low survival rates, emphasizing the need for rapid, effective interventions.
- Epinephrine administration is critical, but achieving intravenous (IV) or intraosseous (IO) access in emergencies is often difficult and time-consuming.
- Alternative epinephrine administration routes require evaluation for speed and accuracy in simulated POHCA scenarios.
Purpose of the Study:
- To evaluate the time to the first dose of epinephrine and dosing accuracy in a simulated pediatric out-of-hospital cardiac arrest (POHCA) event.
- To compare epinephrine administration via IV/IO, intramuscular (IM) autoinjector, and IM needle/syringe.
Main Methods:
- Paramedics were randomized to administer epinephrine via IV/IO, IM autoinjector, or IM needle/syringe to a pediatric mannequin in a simulated POHCA.
- Primary outcome: time to initial epinephrine dose.
- Secondary outcomes: time to definitive vascular access (IV/IO) and correct epinephrine dose administration (within 20% of target).
Main Results:
- Intramuscular (IM) epinephrine via autoinjector significantly reduced the time to the initial dose by 1.5 minutes compared to IV/IO (p < 0.001).
- IM epinephrine via needle/syringe showed no time advantage and resulted in more dosing errors for the definitive IV/IO dose.
- Time to secure vascular access was delayed by 1:07 minutes with IM autoinjector use compared to IV/IO (p = 0.002).
Conclusions:
- Intramuscular epinephrine delivered via autoinjector is a feasible and significantly faster method for initial epinephrine administration in simulated POHCA.
- This approach offers a critical time advantage over traditional IV/IO routes in pediatric emergency care.
- Findings support further investigation in human trials for IM epinephrine in POHCA management.
Objectives:
Survival rates for pediatric out-of-hospital cardiac arrest (POHCA) are low at around 10%. Paramedic services administer critical interventions including epinephrine. While typically administered via intravenous (IV) or intraosseous (IO) routes, obtaining these access points in out-of-hospital emergencies is challenging. We aimed to evaluate the time to first dose epinephrine and dosing accuracy in a simulated POHCA event.
Methods:
Paramedics were randomized to one of three epinephrine administration routes: 1) IV or IO; 2) intramuscular (IM) by autoinjector; or 3) IM by needle/syringe. Each participant was asked to provide resuscitation to a school-aged mannequin with asystole, including administration of epinephrine via their randomized route. Participants were not directly informed of the outcome variables. The primary outcome was time to initial epinephrine dose for each route. Our secondary outcomes were non-inferiority time to definitive dose epinephrine (i.e., by IV or IO), time to secure vascular access (either IO or IV), and administration of correct epinephrine dose (within 20% of correct dose).
Results:
Sixty six paramedics participated. We demonstrated a significant reduction in time to initial dose of epinephrine of 1.5 min (p < 0.001) by the IM route using epinephrine autoinjectors compared to standard of care by IV or IO. We also demonstrated that using a needle and syringe to administer epinephrine by the IM route offered no benefit in time to initial epinephrine dose and led to more dosing errors for the definitive dose of epinephrine (i.e., by IV or IO) (n = 4). We demonstrated that time to secure vascular access after IM injection with an auto-injector was delayed by 1:07 min (p = 0.002) compared to IV/IO.
Conclusions:
This is the first study to demonstrate that IM epinephrine by autoinjector is feasible in a simulated POHCA scenario and confers a significant advantage in time to initial dose of epinephrine. This study will inform future human trials of IM epinephrine for POHCA.
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