Intraosseous versus intravenous access in adult out-of-hospital cardiac arrest: a Bayesian secondary analysis of the Paramedic-3 randomised controlled trial
In brief
Among 6,082 cardiac arrests, intraosseous-first had an 18% chance of improving survival
In a Bayesian secondary analysis of a randomized trial, an intraosseous-first strategy had an 18.4% probability of improving 30-day survival compared with intravenous-first access. Researchers estimated an 81.6% probability it was worse for survival and a 98% probability it reduced return of spontaneous circulation, though any overall disadvantage was likely modest.
- Journal
- Resuscitation (Q1)
- Published
- 25 September 2026
- Study design
- Randomized controlled trial
- Evidence level
- Level 1, High (CEBM 1b)
- Authors
- Keith Couper, Chen Ji, Charles D Deakin, Rachael T Fothergill, Rebecca Kandiyali, Jerry P Nolan, et al.
- PMID
- 42790855
- DOI
- 10.1016/j.resuscitation.2026.111335
Why clinicians should know about it
- Picked for Emergency Medicine (paper of the day, 26 September 2026): Sex differences following cardiac arrest: conceptual framework
Abstract
OBJECTIVE: To evaluate the clinical-effectiveness of an intraosseous-first strategy compared with an intravenous-first strategy in adult out-of-hospital cardiac arrest in a pre-planned Bayesian secondary analysis of the PARAMEDIC-3 trial. METHODS: In PARAMEDIC-3, adults with out-of-hospital cardiac arrest requiring vascular access were randomised to either an intraosseous-first strategy or an intravenous-first strategy. In this analysis, we describe the probability that an intraosseous-first strategy was superior or inferior to an intravenous-first strategy, and the probability that this exceeds specific odds ratio thresholds. Our outcomes were 30-day survival (primary), favourable neurological outcome at hospital discharge and return of spontaneous circulation at hospital handover. Our primary analysis used non-informative priors, adjusted for key baseline characteristics. RESULTS: In 6,082 randomised participants, the posterior probability that an intraosseous-first strategy improved 30-day survival (odds ratio (OR) > 1.0) was 18.4%. The probability that an intraosseous-first strategy was inferior to an intravenous-first strategy was 81.6% for any effect (OR<1.0), 55.0% for a small effect (OR<0.9), and 13.4% for a moderate effect (OR<0.75). For favourable neurological outcome, findings were comparable to 30-day survival. For return of spontaneous circulation, the posterior probability that an intraosseous-first strategy was inferior to an intravenous-first strategy (OR < 1.0) was 98.0%. CONCLUSION: Based on non-informative priors which represent minimal prior knowledge of the treatment effect, an intraosseous-first strategy in adult out-of-hospital cardiac arrest is more likely to be harmful, rather than beneficial. However, the low probability of a moderate or large treatment effect suggests that the overall treatment effect is likely to be modest. TRIAL REGISTRATION: ISRCTN14223494.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.