July 20, 2018

Background: Epinephrine(adrenaline) has been used in advanced life support in cardiac arrest since the early 1960s. Despite the routine recommendation for its use, evidence to support administration is less than ideal.  Although it is clear from multiple observational studies that epinephrine improves return of spontaneous circulation (ROSC) and short-term survival, most evidence suggests an absence of improvements in survival with good neurologic outcomes.  In cardiac arrest we want to take advantage of the alpha effects of epinephrine, including peripheral vasoconstriction, and therefore increasing aortic diastolic pressure, which in turn helps augment coronary and cerebral blood flow.  On the other hand, we want to avoid the potentially detrimental beta effects including dysrhythmias, decreased microcirculation, and increased myocardial oxygen demand all of which increase the chances of recurrent cardiac arrest and decreased neurologic recovery.  The only two interventions in cardiac arrest that have shown improve survival with good neurologic outcomes continue to be high-quality CPR and early defibrillation. The debate over the utility of epinephrine in OHCA has been ongoing for several years now and many providers have been awaiting the results of the PARAMEDIC-2 trial that was just published in the NEJM 2018.