Final answer:
To respond to a cardiac arrest, activate the emergency response system first and begin CPR immediately. If available, use an AED, which can diagnose and treat abnormal heart rhythms, but maintain chest compressions until professional assistance arrives or the patient recovers.
Step-by-step explanation:
When someone experiences a cardiac arrest, it is crucial to act quickly to increase the chances of survival. A cardiac arrest occurs when the heart stops beating effectively, cutting off blood flow to vital organs and requiring immediate intervention. The emergency response system should be activated immediately to ensure professional medical help is on the way. Once the emergency response has been activated, CPR (cardiopulmonary resuscitation) should be started without delay. CPR involves manual chest compressions to maintain blood flow, particularly to the brain, to minimize damage until further medical treatment can be provided.
In the meantime, if an automated external defibrillator (AED) is available, it can be used even by laypersons thanks to the verbal instructions provided. AEDs are designed to diagnose the heart's rhythm automatically and apply a shock with the appropriate energy and waveform to potentially restore normal heartbeat patterns. However, high-quality chest compressions should be maintained until the patient regains spontaneous contraction or professional healthcare providers take over the care of the patient.