In an emergency, what should be the first life function a responder addresses?

In an emergency situation, ventilation is often the first life function that a responder addresses because it is critical for ensuring that the patient is receiving adequate oxygen. When a person is in respiratory distress or has stopped breathing, the immediate priority is to restore airflow to the lungs, which is essential for sustaining life. Without ventilation, oxygen cannot enter the bloodstream, leading to a rapid decline in the patient's condition due to hypoxia.

Addressing ventilation first also sets a foundation for the other vital functions. For example, once a patent airway is established and effective ventilation is occurring, the responder can then focus on ensuring adequate circulation and perfusion. If oxygenation is compromised due to inadequate ventilation, then perfusion and circulation will also be affected. Therefore, initiating ventilation is key to stabilizing the patient's overall condition in an emergency.