Cardiac Arrest Recognition, CPR and AED Priorities

Recognition of Cardiac Arrest and Primary Assessment

The management of any patient in suspected cardiac arrest begins before making direct patient contact. Scene safety must be assessed and confirmed before initiating care. Once the scene is determined to be safe, the emergency medical technician immediately begins the primary assessment by checking responsiveness. This is done by tapping the patient and shouting. Cardiac arrest should be strongly suspected in any unresponsive individual who presents with absent or abnormal breathing.

Accurately evaluating respiration requires recognizing abnormal breathing patterns that can mimic true ventilation. In the early stages of cardiac arrest, patients frequently exhibit agonal gasps. These are sporadic, ineffective gasps that provide no meaningful air exchange. The emergency medical technician must never interpret agonal gasps as normal breathing. Confusing these gasps with effective respirations delays life-saving interventions when immediate action is required.

While evaluating the patient for breathing, the emergency medical technician must simultaneously assess for a pulse. For an adult patient, the carotid pulse is palpated. In an infant, the pulse is assessed at the brachial artery. In a pediatric child, the rescuer checks either the carotid artery or the femoral artery. This combined assessment of breathing and circulation must take at least 5 seconds but no more than 10 seconds. Conducting these checks at the same time prevents valuable seconds from being lost during the initial encounter.

Begin chest compressions if no pulse is felt within 10 seconds; for a child or infant, also begin compressions if the heart rate is less than 60/min with signs of poor perfusion despite effective oxygenation and ventilation. Furthermore, if the provider is uncertain whether a pulse is present within those 10 seconds, chest compressions must also be started immediately without hesitation. At the same time, the emergency medical technician must activate the emergency response system and request advanced life support backup if available, following local protocol, while ensuring that neither CPR nor automated external defibrillator use is delayed.