Which of the following is a sign of cardiac arrest in a child or adult?

In a child or adult experiencing cardiac arrest, an irregular gasping or snorting sound, known as agonal breathing, can occur. This type of breathing is not a reliable sign of adequate respiration and often indicates that the person's heart is no longer functioning effectively. Agonal breathing may happen in the absence of normal breathing and is a critical indicator that emergency medical assistance is needed immediately.

This sign is an important part of the assessment process when determining if someone is in cardiac arrest. Recognizing agonal breathing can help lifeguards and first responders take appropriate action, such as starting cardiopulmonary resuscitation (CPR) or using an automated external defibrillator (AED).

In contrast, the presence of a strong pulse, regular breathing, and clear speech with alertness denote states of health and function that are incompatible with cardiac arrest. A strong pulse and regular breathing indicate effective cardiac and respiratory function, while clear speech and alertness reflect a person who is conscious and responsive. These factors highlight why agonal breathing is a key sign of an emergency situation such as cardiac arrest.