Intravenous epinephrine has been part of the guidelines for cardiopulmonary resuscitation since the start. It improves outcome in animal studies, but has never been investigated in a controlled study in humans. Epidemiologic data indicate that it is an independent negative predictor for survival. If this is true in a controlled randomized study, it could be due to effects of the drug itself or more likely due to reduced quality of chest compressions and ventilations due to the time spent on placing an I.V. needle and injecting drugs.