When should a first responder begin CPR?

A first responder should begin CPR when a patient is unconscious and has no pulse because these conditions indicate that the patient's heart is not effectively pumping blood to the body, leading to a life-threatening situation. In cases of cardiac arrest, where the heart has stopped beating, brain damage can begin within minutes due to lack of oxygenated blood. Therefore, immediate initiation of CPR is crucial to keep the blood flowing to vital organs and increase the chances of survival until further medical help arrives.

In circumstances where the patient is responsive but weak, or showing signs of shock, these indicate issues that may require medical attention but do not confirm cardiac arrest, which is the primary trigger for CPR. Similarly, when a patient mentions they have a heart condition, this alone does not provide sufficient indication that immediate CPR is needed—an assessment of consciousness and pulse is necessary to determine the need for resuscitation efforts.