The symptoms of cardiac arrest are as follows: 1) the patient loses consciousness, does not respond to calls, and appears delirious; 2) the patient stops breathing or breathes irregularly and very slowly, and may appear cyanotic and hypoxic; 3) the large arterial pulsations disappear, commonly by touching the carotid, femoral, and dorsalis pedis arteries; 4) the patient’s pupils are dilated. In summary, before implementing the resuscitation of cardiac arrest, the above symptoms and signs are judged before the next step of active resuscitation.