EM Weekly.Emergency medicine literature

Historical collection · First published Oct 31, 2024; added to EM Weekly Oct 27, 2026. This retrospective summary may be superseded by later evidence or guidance.

Randomized trialNew England Journal of Medicine

Intraosseous or Intravenous Vascular Access for Out-of-Hospital Cardiac Arrest

Mikael F Vallentin, Asger Granfeldt, Thomas L Klitgaard, Søren Mikkelsen, Fredrik Folke, Helle C Christensen, Amalie L Povlsen, Alberthe H Petersen, Sofie Winther, Lea W Frilund, Carsten Meilandt, Mathias J Holmberg, Kristian B Winther, Allan Bach, Thomas H Dissing, Christian J Terkelsen, Steffen Christensen, Line Kirkegaard Rasmussen, Lone R Mortensen, Mads L Loldrup, Thomas Elkmann, Anders G Nielsen, Charlotte Runge, Elise Klæstrup, Jimmy H Holm, Mikkel Bak, Lars-Gustav R Nielsen, Mette Pedersen, Gunhild Kjærgaard-Andersen, Peter M Hansen, Anne C Brøchner, Erika F Christensen, Frederik M Nielsen, Christian G Nissen, Jeppe W Bjørn, Peter Burholt, Laust E R Obling, Sarah L D Holle, Lene Russell, Henrik Alstrøm, Søren Hestad, Tanja H Fogtmann, Jens U H Buciek, Karina Jakobsen, Mette Krag, Michael Sandgaard, Birthe Sindberg, Lars W AndersenMikael F Vallentin, Asger Granfeldt, Thomas L Klitgaard et al.

First online Oct 31, 2024On EM Weekly Oct 27, 2026Discovered Oct 27, 2026AI-generated Not yet human-reviewed

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Summary

IVIO randomized 1,506 adults with nontraumatic OHCA; 1,479 entered the primary analysis. Sustained ROSC occurred in 30% with IO-first versus 29% with IV-first access (RR 1.06; 95% CI 0.90–1.24; P=.49), despite greater two-attempt access success with IO.

Why it matters

Supports separating technical access success from patient-centered benefit. The trial provides no basis for replacing feasible IV-first access routinely.

Study at a glance

Design: Randomized trial
Population: Adults with nontraumatic out-of-hospital cardiac arrest.
Sample size: 1506
Intervention: Initial IO access attempts.
Comparator: Initial IV access attempts.
Primary endpoint: Sustained return of spontaneous circulation.

Main findings

Access success within two attempts: 92% versus 80%.
Thirty-day survival: 12% versus 10%; RR 1.16 (95% CI 0.87–1.56).
Favorable neurologic survival: 9% versus 8%; RR 1.16 (95% CI 0.83–1.62); prespecified adverse events were uncommon.

Limitations

The primary endpoint was sustained ROSC; survival and neurologic estimates were less precise. Results concern initial access during nontraumatic adult OHCA.

Read the primary source

Full text: Abstract available; full text paywalled.

Original source

DOI: 10.1056/NEJMoa2407616

PMID: 39480221

Material reviewed: abstract.

Source retrieved Oct 27, 2026. Historical backfill: first-online date verified from the PubMed electronic publication record. Abstract reviewed; full text unavailable. This is historical evidence, not a new 2026 publication.

Resuscitation

Corrections & review history

No corrections recorded. Human review: not yet human-reviewed.