Daily Literature Update
Early intramuscular adrenaline administration is associated with improved survival from out-of-hospital cardiac arrest
Palatinus HN, Johnson MA, Wang HE, Hoareau GL, Youngquist ST. Early intramuscular adrenaline administration is associated with improved survival from out-of-hospital cardiac arrest. Resuscitation. 2024 Aug;201:110266. doi: 10.1016/j.resuscitation.2024.110266. Epub 2024 Jun 9. PMID: 38857847.
Study Type: Before-and-after EMS protocol implementation study
Population: Adult, nontraumatic out-of-hospital cardiac arrest (OHCA) patients meeting adrenaline criteria
Intervention: Single initial 5 mg intramuscular (IM) adrenaline dose followed by standard intravenous/intraosseous (IV/IO) adrenaline
Outcomes: Primary: survival to hospital discharge; Secondary: time to adrenaline administration, survival to hospital admission, favorable neurologic function at discharge
- IM adrenaline group received first dose faster (median 4.3 min vs. 7.8 min)
- Improved survival to hospital admission (37.1% vs. 31.6%; aOR 1.37, 95% CI 1.06-1.77)
- Higher survival to hospital discharge (11.0% vs. 7.0%; aOR 1.73, 95% CI 1.10-2.71)
- Increased favorable neurologic function at discharge (9.8% vs. 6.2%; aOR 1.72, 95% CI 1.07-2.76)
Context & Related Research
- Ran et al., 2020: Early pre-hospital adrenaline linked with increased survival to discharge and favorable neurological outcomes. (PMID: 32441184)
- PARAMEDIC2 RCT: Adrenaline improved OHCA survival rates but neuro outcomes not significantly enhanced. (PMID: 27639950)
- Studies demonstrating IM adrenaline reduces time to drug delivery and may improve survival outcomes. (PMCID: PMC8244431)
- Concerns about immortal time bias in before-and-after designs highlight need for randomized controlled trials. (Resuscitation Journal)
Strengths & Limitations
| Strengths | Limitations |
|---|---|
| Large cohort (N=1405) with real-world EMS implementation | Before-and-after design susceptible to confounding and bias |
| Rapid IM adrenaline administration reduced time to first dose | Imbalance in age and bystander CPR between groups |
| Multiple relevant outcomes including neurological function | Single-center EMS limits generalizability |
Clinical Implications & Impact
Pharmacists should support protocols enabling earlier adrenaline administration via intramuscular injection in OHCA to improve survival outcomes, particularly where IV/IO access may be delayed. Advocacy for EMS training in IM adrenaline delivery and awareness of updated resuscitation guidelines is recommended.
Conclusion
In this study, initial intramuscular adrenaline administration as an adjunct to standard care was associated with significantly improved survival to hospital admission, survival to discharge, and favorable neurological function in OHCA, supporting further investigation through randomized controlled trials.
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Citations
- Palatinus HN et al. Resuscitation. 2024;201:110266. PMID:38857847
- Ran et al. Resuscitation. 2020;152:152-160. PMID:32441184
- Nichol et al. Lancet. 2015;386(9998):711-720. PMID:27639950
- Aukland et al. Resuscitation. 2021;162:127-133. PMCID:PMC8244431
- Semple et al. Resuscitation. 2024;175:1-7.
