Could Intramuscular Epinephrine Revolutionize Neonatal Resuscitation?

Dose-related pharmacokinetic and pharmacodynamic effects of intramuscular epinephrine in healthy neonatal piglets?

In the critical moments of neonatal cardiopulmonary resuscitation (CPR), time is everything. Epinephrine is currently the only vasopressor recommended during neonatal CPR, yet delivering it quickly and effectively poses a major clinical challenge. Traditional methods require intravascular (IV) access—a task that can take several minutes and demands significant training, especially in the high-stress delivery room environment.

What if there were a faster, simpler way?

Our team set out to explore whether intramuscular (IM) epinephrine could be a viable alternative to IV administration during neonatal resuscitation. The IM route has several advantages: it's fast, requires no specialized skills or equipment, and is already widely used in emergency medicine—for example, in the treatment of anaphylaxis.

In our study, we randomized fifteen healthy, post-transitional neonatal piglets (aged 1–3 days) to receive one of three treatments:

• 0.02 mg/kg IM epinephrine

• 0.1 mg/kg IM epinephrine

• 0.02 mg/kg IV epinephrine

The piglets were anesthetized and intubated via tracheostomy to allow continuous monitoring of heart rate, arterial blood pressure, and cardiac function. Blood samples were taken before and after drug administration for pharmacokinetic and pharmacodynamic analysis.

What did we find?

There was a clear, dose-dependent effect with IM epinephrine. The higher IM dose (0.1 mg/kg) produced significant improvements in hemodynamic and cardiac function—similar to the effects seen with IV epinephrine. In contrast, the lower IM dose (0.02 mg/kg) had little to no effect. Importantly, pharmacokinetic parameters (i.e., how the body absorbs and distributes the drug) were similar between the 0.1 mg/kg IM and 0.02 mg/kg IV doses.

Why does this matter?

These findings suggest that IM epinephrine, at the right dose, may offer a practical and effective alternative to IV administration during neonatal CPR—especially in situations where IV access is delayed or unavailable.

While this was a preclinical study in piglets, it lays the groundwork for future research in clinical settings. If validated in human studies, IM epinephrine could improve response times and outcomes during neonatal resuscitation—offering a faster, more accessible lifeline when every second counts.