Importance of CPR Before and After Shock Delivery

Importance of CPR before and after shock delivery

When ventricular fibrillation is visualised on a cardiac monitor in an intensive care unit, immediate defibrillation would be the treatment of choice even prior to any attempts at cardiopulmonary resuscitation. But this is not the situation in most of the cardiac arrests. In such cases, CPR performed immediately after collapse can double or triple the chance of survival in cardiac arrest due to ventricular fibrillation and most victims of cardiac arrest do have ventricular fibrillation at some point in their cardiac arrest.

There is role for CPR before and after direct current cardioversion. CPR should be provided till defibrillation with an automated external defibrillator (AED) or manual defibrillator is available. If the arrest has lasted longer than five minutes, the outcome may be better if defibrillation is preceded by effective CPR which delivers some blood into the coronary and cerebral circulation. CPR is also important immediately after a shock as most victims have a variable period of asystole or pulseless electrical activity after defibrillation. These rhythms can be converted to a perfusing rhythm with CPR. Defibrillation is most successful when performed within five minutes of onset of ventricular fibrillation in the absence of CPR. CPR increases this time window for defibrillation.