Cardiopulmonary resuscitation (CPR) is a life-saving technique used when someone’s breathing or heartbeat has stopped, such as during a cardiac arrest. The “ABCs” of CPR represent fundamental principles for emergency response, guiding rescuers through a sequence of actions. These steps are designed to keep oxygenated blood flowing to the brain and other essential organs when the heart cannot effectively pump on its own, until professional medical help arrives.
Understanding the “A” for Airway
The “A” in CPR stands for Airway, the passage for air to and from the lungs. An open airway is essential for oxygen to reach the lungs and bloodstream. When a person is unconscious, throat muscles can relax, causing the tongue to block the airway. This prevents oxygen from entering the body.
To open an obstructed airway, rescuers use the head-tilt/chin-lift maneuver. This involves gently tilting the head back while lifting the chin, moving the tongue away from the throat. This creates a clear path for air, allowing for spontaneous breathing or rescue breaths. In cases of suspected neck or spinal injury, a jaw-thrust maneuver may be used instead.
Understanding the “B” for Breathing
The “B” in CPR signifies Breathing, the process of moving air in and out of the lungs to deliver oxygen to tissues. Once the airway is clear, assessing for normal breathing determines if rescue breaths are needed. Normal breathing involves regular chest rise and fall, and quiet, consistent airflow.
Rescuers assess breathing by looking for chest movement, listening for breath sounds, and feeling for exhaled air. This assessment should take no more than 10 seconds. If the person is not breathing normally or is only gasping, rescue breaths may be provided. These breaths, often given mouth-to-mouth or using a barrier device, deliver oxygen directly into the person’s lungs.
Understanding the “C” for Circulation
The “C” in CPR represents Circulation, focusing on maintaining blood flow through chest compressions. When the heart stops beating effectively, blood stops circulating, depriving vital organs like the brain and heart of oxygen. Chest compressions manually pump blood to these organs, sustaining them until medical care arrives.
These compressions involve rhythmic pressure applied to the center of the chest, mimicking the heart’s natural pumping action. The goal is to generate enough pressure to move oxygen-rich blood throughout the body. Continuous and effective compressions are important because interruptions reduce blood flow to the brain and decrease survival chances.
Putting the ABCs into Action
Before initiating CPR, ensure scene safety to protect both the rescuer and the person in need. Once safe, assess responsiveness by tapping the person’s shoulder and shouting. If there is no response and the person is not breathing normally, call emergency services immediately.
Modern CPR guidelines prioritize chest compressions, shifting the sequence from A-B-C to C-A-B (Compressions, Airway, Breathing). This change was implemented because resuming blood flow with chest compressions is the most immediate need in cardiac arrest. Delaying compressions to first clear the airway and give breaths can reduce survival chances, as the blood already contains some oxygen.
Following the C-A-B sequence, rescuers begin with high-quality chest compressions. For adults, this involves pushing hard and fast in the center of the chest, at a rate of 100 to 120 compressions per minute. After 30 compressions, the rescuer opens the airway and delivers two rescue breaths, ensuring the chest visibly rises. This cycle continues until emergency medical help arrives or signs of movement appear. For untrained bystanders, hands-only CPR, involving continuous chest compressions without rescue breaths, is also recommended for adults.