Epinephrine has been part of cardiac arrest resuscitation since the 1960s. For most of that time, the rationale was straightforward: alpha-adrenergic stimulation increases coronary and cerebral perfusion pressure during CPR. More perfusion, better outcomes.

The 2020 AHA guidelines refined the picture considerably. Here's what changed — and what didn't.

"For shockable rhythms, electricity comes first. The vasopressor waits its turn."

The key numbers

1 mg
Standard IV/IO dose in adult cardiac arrest