What does the acronym ABC stand for in basic life support?

The acronym ABC stands for Airway, Breathing, and Circulation in the context of basic life support. This foundational sequence emphasizes the critical steps to take when assessing and stabilizing a patient in an emergency situation.

First, ensuring the airway is clear is paramount because a blocked airway can prevent oxygen from reaching the lungs and, subsequently, the brain. Without a clear airway, a patient's ability to breathe and maintain life is severely compromised.

Next, promoting effective breathing is essential. After securing the airway, the responder must assess whether the patient is breathing adequately. If not, appropriate interventions such as rescue breaths or artificial ventilation may be necessary to ensure oxygenation.

Finally, evaluating circulation involves checking for a pulse and assessing the heart's function. If there is no pulse, initiating chest compressions and automated external defibrillator (AED) use, if available, is critical for restoring blood flow and oxygen delivery to vital organs.

This sequence—Airway, Breathing, and Circulation—serves as a systematic method to prioritize life-saving measures, making it a fundamental principle in basic life support training. The other options do not represent the recognized steps in basic life support and therefore do not align with established emergency response protocols.