Cardiopulmonary Resuscitation CAB: What Does It Mean?

Cardiopulmonary Resuscitation, commonly known as CPR, follows a sequence referred to as CAB. In this acronym, C stands for Chest Compressions, A for Airway, and B for Breathing. These steps form the foundation of basic life support during cardiac emergencies.

Understanding the CAB Sequence

C – Chest Compressions

Chest compressions are the first and most critical step in the CAB sequence. The reason this step comes first is due to the primary cause of cardiac arrest, which is often linked to heart-related issues in about 70-80% of cases. When the heart stops beating, blood flow to vital organs, including the heart muscle itself, ceases. To restore circulation and ensure adequate coronary perfusion, effective chest compressions are essential. Experts recommend a compression depth of at least 5 cm and a rate of 100 to 120 compressions per minute for optimal results.

A – Airway

After performing chest compressions, the next step is to ensure the victim's airway is open. This is typically done using the head-tilt chin-lift maneuver, where the rescuer gently tilts the patient's head back and lifts the chin. This action helps to prevent the tongue from blocking the air passage and allows for easier breathing or artificial ventilation.

B – Breathing

Once the airway is open, rescue breathing follows. This can be administered through mouth-to-mouth resuscitation or with the help of a bag-mask device. Proper ventilation ensures that oxygen reaches the lungs and subsequently the bloodstream, supporting vital organs until normal heart function can be restored.

Why Chest Compressions Come First

The prioritization of chest compressions in the CAB protocol is based on the urgency of restoring blood circulation. In most cardiac arrest cases, the heart stops due to underlying cardiovascular issues. Without immediate intervention, the lack of blood flow leads to tissue ischemia and organ dysfunction. High-quality chest compressions are therefore vital to maintain coronary perfusion pressure and increase the chances of successful resuscitation. Speed must be balanced with precision—compressions that are too fast can reduce effectiveness, so maintaining the recommended rhythm is crucial.