Resuscitation of children and adults differs in a number of ways, including the appropriate time to activate the emergency response system, initiate rescue breathing, and use defibrillation. Children who collapse suddenly are likely experiencing ventricular fibrillation (VF) or pulseless ventricular tachycardia (PVT), which requires immediate CPR. The ability to use a defibrillator safely and effectively on a pediatric patient experiencing cardiac arrest is essential to providing quality care.