Epinephrine in cardiac arrest: how strongly is it supported by the evidence?

From a recent review:

Background

Sudden cardiac arrest accounts for approximately 15% of deaths in developed nations, with poor survival rate. The American Heart Association states that epinephrine is reasonable for patients with cardiac arrest, though the literature behind its use is not strong.

Objective

To review the evidence behind epinephrine for cardiac arrest.

Discussion

Sudden cardiac arrest causes over 450,000 deaths annually in the United States. The American Heart Association recommends epinephrine may be reasonable in patients with cardiac arrest, as part of Advanced Cardiac Life Support. This recommendation is partly based on studies conducted on dogs in the 1960s. High-dose epinephrine is harmful and is not recommended. Epinephrine may improve return of spontaneous circulation, but does not improve survival to discharge or neurologic outcome. Literature suggests that three phases of resuscitation are present: electrical, circulatory, and metabolic. Epinephrine may improve outcomes in the circulatory phase prior to 10 min post arrest, though further study is needed. Basic Life Support measures including adequate chest compressions and early defibrillation provide the greatest benefit.

Conclusions

Epinephrine may improve return of spontaneous circulation, but it does not improve survival to discharge or neurologic outcome. Timing of epinephrine may affect patient outcome, but Basic Life Support measures are the most important aspect of resuscitation and patient survival.