In shockable rhythms, when should adrenaline be administered?

In the context of managing shockable rhythms during advanced life support, adrenaline is an important medication used to enhance the chances of successful resuscitation. The administration of adrenaline is recommended after the delivery of the first shock, which serves to reset the heart's rhythm. This timing is crucial because the primary goal after the shock is to check for a natural rhythm and begin high-quality cardiopulmonary resuscitation (CPR).

If there is still no return of spontaneous circulation (ROSC), adrenaline is then given to help enhance myocardial perfusion and systemic vascular resistance, thereby increasing the likelihood of converting the abnormal rhythm to a perfusing rhythm. By administering adrenaline after the second shock, the effects of the vasopressor can be maximized during the critical time post-defibrillation, especially as the heart may be more amenable to responding to this medication after it has been shocked.

In summary, the rationale for administering adrenaline after a specific number of shocks lies in the principles of advanced life support, which emphasize the importance of timing in medication administration to improve the likelihood of maintaining circulation and allowing heart interventions to be more effective.