From the Guidelines
Epinephrine is indicated in cardiac arrest because it significantly increases survival to hospital discharge and 30-day survival, as evidenced by the 2019 American Heart Association guidelines update 1, 2. The standard dose is 1 mg IV/IO every 3-5 minutes during resuscitation efforts. Epinephrine works through its alpha-adrenergic effects, causing peripheral vasoconstriction which redirects blood flow to vital organs like the heart and brain. This vasoconstriction increases diastolic pressure and coronary perfusion pressure, which is critical for myocardial blood flow during chest compressions. While epinephrine also has beta-adrenergic effects that increase heart rate and contractility, these are less beneficial during cardiac arrest. The medication should be administered as soon as possible after cardiac arrest is confirmed, particularly in non-shockable rhythms (asystole and PEA), and after initial defibrillation attempts in shockable rhythms (VF/VT). Key benefits of epinephrine administration include:
- Increased survival to hospital discharge (RR, 1.44 [95% CI, 1.11–1.86]) 1
- Increased 30-day survival (RR, 1.40 [95% CI, 1.07–1.84]) 1
- Increased return of spontaneous circulation (ROSC) (RR, 3.09 [95% CI, 2.82–3.39]) 1 Healthcare providers should ensure proper CPR technique with minimal interruptions when administering epinephrine, as the medication's effectiveness depends on adequate chest compressions to circulate it throughout the body. It is essential to note that the evidence supporting epinephrine use is based on out-of-hospital cardiac arrest (OHCA) studies, and its application to in-hospital cardiac arrest (IHCA) is unclear 2. However, given the potential benefits and the current guidelines, epinephrine should be administered to patients in cardiac arrest as soon as possible, following the standard dosing protocol of 1 mg every 3 to 5 minutes 2.
From the Research
Indications for Epinephrine in Cardiac Arrest
- Epinephrine is indicated in cardiac arrest as it increases arterial blood pressure and coronary perfusion during CPR via alpha-1-adrenoceptor agonist effects 3
- The American Heart Association recommends epinephrine as part of Advanced Cardiac Life Support for patients with cardiac arrest, although the literature behind its use is not strong 4
- Epinephrine may improve return of spontaneous circulation, but does not improve survival to discharge or neurologic outcome 5, 3, 4, 6, 7
Dosage and Administration
- The standard dose of epinephrine is 1 mg, which is recommended to be administered intravenously, although intraosseous access can be used if IV access is unsuccessful 5
- Higher doses of epinephrine may not have better outcomes and can potentially be harmful 7
- Research suggests that earlier administration of epinephrine in cardiac arrest is more likely to have improved outcomes compared to later administration and longer intervals 7
Benefits and Limitations
- Epinephrine improves rates of return of spontaneous circulation, but evidence indicates potential harms with routine use of standard dose epinephrine, with no improvement in neurologic or long-term outcomes 5, 3, 6
- The combination of vasopressin, steroids, and epinephrine may improve return of spontaneous circulation among those with in-hospital cardiac arrest, but there is no improvement in survival to discharge and survival with a favorable neurologic outcome 5
- Basic Life Support measures, including adequate chest compressions and early defibrillation, provide the greatest benefit in cardiac arrest resuscitation 4