Intraosseous access achieved a higher first-attempt success rate than intravenous access (92% vs. 80%), yet it did not improve survival or neurologic outcomes in out-of-hospital cardiac arrest, according to a recent study. 

In the study, published in The New England Journal of Medicine, researchers conducted a randomized clinical trial to compare intraosseous vs intravenous (IV) vascular access in adult patients who experienced nontraumatic out-of-hospital cardiac arrests. They evaluated whether the choice of vascular access influenced the return of spontaneous circulation, 30-day survival, or neurologic outcomes. Given the increasing use of intraosseous access despite limited comparative evidence, the researchers sought to clarify its effectiveness relative to IV access.

The researchers enrolled 1,506 patients across Denmark, with 1,479 included in the primary analysis (731 in the intraosseous group, 748 in the IV group). The primary outcome of the trial, sustained return of spontaneous circulation, occurred in 30% (n = 221) of the patients in the intraosseous group and 29% (n = 214) of those in the IV group (risk ratio [RR] = 1.06, 95% confidence interval [CI] = 0.90–1.24, P = .49). Survival at 30 days was observed in 12% (n = 85) of the patients in the intraosseous group and 10% (n = 75) of those in the IV group (RR = 1.16, 95% CI = 0.87–1.56). A favorable neurologic outcome at 30 days, defined as a modified Rankin Scale score of 0 to 3, was achieved in 9% (n = 67) of the patients in the intraosseous group and 8% (n = 59) of those in the IV group (RR = 1.16, 95% CI = 0.83–1.62).

Procedural success was higher with intraosseous access, with successful establishment within two attempts in 92% (n = 669) of the patients compared with 80% (n = 595) of those in the IV group. However, there were no statistically significant differences in the time to vascular access and administration of epinephrine between the groups. Adverse events, including extravasation and transient arrhythmias, were infrequent and similar across both groups.

The researchers concluded that intraosseous and IV access yielded comparable outcomes in out-of-hospital cardiac arrest. Despite higher initial success rates with intraosseous access, it did not improve survival or neurologic outcomes. The findings aligned with current guideline recommendations favoring IV access as the preferred initial approach. Although, intraosseous access remains a viable alternative despite limited high-quality evidence.

Full disclosures can be found in the published study.