Written by Joshua Dodge and Ketan Patel
Spoon Feed
In adult out-of-hospital cardiac arrest (OHCA), initial intraosseous (IO) versus intravenous (IV) access showed no significant difference in long-term survival, favorable neurological outcomes, or quality of life.
Different routes, same destination
Rapid vascular access is a core component of advanced life support in OHCA, and prior trials have shown neutral results on outcomes at 30 and 90 days but not past these windows.
This is the longterm follow-up from the original IVIO randomized clinical trial, which evaluated adult patients with non-traumatic OHCA randomized to initial IO versus IV access, with up to two attempts allowed for the assigned strategy. A total of 1,479 patients were included, with follow-up at 6 months and 1 year. At 1 year, survival was 11% in the IO group versus 9% in the IV group (RR 1.24; 95%CI 0.91–1.67). Favorable neurological outcomes (mRS 0–3) occurred in 10% versus 8%, respectively (RR 1.28; 95%CI 0.93–1.77). Among survivors, quality-of-life scores were slightly higher in the IO group (mean difference +7 points, 95%CI 1-13); however, authors warn quality-of-life confidence intervals have not been adjusted for multiplicity, increasing the risk of a type 1 error.
Despite the randomized design, relatively low long‑term survival yielded wide confidence intervals and potential type II error, and the exclusively Danish EMS system limits generalizability to different prehospital settings and practice patterns.
How does this change my practice?
This study reinforces that the priority in cardiac arrest is rapid, reliable access, not the specific route. If IV access is not immediately obtainable, early IO placement is a reasonable first-line strategy without concern for worse long-term outcomes. Practically, this supports minimizing delays in medication delivery and avoiding prolonged attempts at IV access during active resuscitation. The decision should be driven by speed and success probability rather than theoretical superiority of one route.
Source
Effect of vascular access strategy on long-term outcomes in patients with out-of-hospital cardiac arrest: a randomised clinical trial. Resuscitation. 2026 Apr 10;223:111087. doi: 10.1016/j.resuscitation.2026.111087. Epub ahead of print. PMID: 41967754.
