Epinephrine administration in adults with out-of-hospital cardiac arrest: A comparison between intraosseous and intravenous route

Abstract

Introduction: The benefits and risks of the intraosseous (IO) route for vascular access in patients with out-of-hospital cardiac arrest (OHCA) remain controversial. This study compares the success rates of establishing the access route, epinephrine administration rates, and time-to-epinephrine between adult patients with OHCA with IO access and those with intravenous (IV) access established by paramedics in the prehospital setting.

Methods: This was a retrospective study conducted by the San-Min station of Taoyuan Fire Department. Data for IV access were collected between January 1, 2020, and December 31, 2020. Data for IO access were collected between January 1, 2021, and March 10, 2021. Inclusion criteria were adult patients with OHCA who received on-scene resuscitation attempts and in whom either IV or IO route access was established by paramedics. Exclusion criteria were missing data, return of spontaneous circulation before establishing vascular access, cardiac arrest en route to hospital, patients not resuscitated, and OHCA unidentified by the dispatcher. Exposure was defined as IV route vs. IO route (EZ-IO®). The outcome measurements were per-patient based success rates of route establishment (successes/attempts), administration rates of epinephrine (epinephrine administered per case/enrolled OHCAs), and odds ratios of IV versus IO on epinephrine administration. We used nonparametric Mann-Whitney rank sum tests for the analysis in continuous variables and Fisher's exact tests for the analysis of categorical variables and the outcomes. Firth logistic regression method was used for sparse data. Factors associated with epinephrine administration other than vascular access were also analyzed. Time-to-epinephrine (defined as time from paramedic arrival to epinephrine injection) was reviewed and calculated by two independent observers and the Kaplan-Meier method was used to compare the two access routes.

Results: A total of 112 adult patients were enrolled in the analysis, including 71 men and 41 women, with an average age of 67 years. There were 90 IV access cases and 22 IO access cases. The groups were compared for median success rates of route establishment (33% vs. 100%, P < 0.001) and administration rates of epinephrine (52% vs. 100%, P < 0.001). The adjusted odds ratio of IO versus IV was 32.445, 95% confidence interval (CI) of 1.844-570.861. Time-to-epinephrine was significantly shorter in the cumulative time-event analysis by the Kaplan-Meier method (P < 0.001).

Conclusion: The IO route was significantly associated with higher success rates of route establishment, epinephrine administration, and shorter time-to-epinephrine in the prehospital resuscitation of adult patients with OHCA.

Keywords: Advanced life support (ALS); Epinephrine; Intraosseous (IO); Intravenous (IV); Out-of-hospital cardiac arrest (OHCA).