Impact of adrenaline dose and timing on out-of-hospital cardiac arrest survival and neurological outcomes.

STUDY

OBJECTIVE

The 2015 ILCOR Advanced Cardiovascular Life Support Guidelines recommend intravenous adrenaline (epinephrine) as a crucial pharmacologic treatment during cardiac arrest resuscitation. Some recent observational studies and clinical trials have questioned the efficacy of its use and suggested possible deleterious effects on overall survival and long-term outcomes. This study aimed to describe the association between time and dose of adrenaline on return of spontaneous circulation (ROSC) and neurologic function.

METHODS

We performed a retrospective analysis of the Penn Alliance for Therapeutic Hypothermia (PATH) data registry. The timing of the first dose of adrenaline and the total dose of adrenaline during cardiac arrests was compared between survivors to discharge and non-survivors for arrests lasting greater than 10 min.

RESULTS

The registry contained 5594 patients. After excluding patients with an in-hospital cardiac arrest, a non-shockable rhythm, or no adrenaline administration, 1826 were included in the final analysis. Survivors to discharge received adrenaline sooner (median 5.0 vs. 7.0 min, p = 0.022) and required a lower total dose than non-survivors (2.0 vs. 3.0 mg, p < 0.001). For survivors, there was no significant association between the time to first adrenaline dose and favorable neurological outcome as measured by Cerebral Performance Category (CPC). Among survivors, those that received less than 2 mg of adrenaline had a more favorable neurologic outcome than those administered > 3 mg. (CPC 1-2 16.6% vs. 12.5%, p = 0.004).

CONCLUSION

Early adrenaline administration is associated with a higher percentage of survival to discharge but not associated with favorable neurological outcome. Those patients with a favorable neurologic outcome received a lower total adrenaline dose prior to ROSC.