CAB vs ABC: Understanding the Difference in CPR Protocols

When it comes to cardiopulmonary resuscitation (CPR), two primary approaches are often discussed: CAB and ABC. CAB stands for Compressions, Airway, and Breathing, which means starting with chest compressions, followed by opening the airway, and then delivering rescue breaths. On the other hand, ABC refers to Airway, Breathing, and then Compressions, where the rescuer first opens the airway, provides two rescue breaths, and then proceeds with chest compressions.

Why the Shift from ABC to CAB?

The change from the traditional ABC method to CAB was introduced to reduce the critical time between cardiac arrest onset and the first chest compressions. In most cases, approximately 70% to 80% of cardiac arrests are caused by heart-related issues. Therefore, prioritizing chest compressions helps improve coronary perfusion, addressing the lack of blood flow and oxygen to the heart muscle. Delaying compressions to focus on airway management and breathing could reduce the chances of survival in such cases.

When is ABC Still Recommended?

Special Cases: Drowning and Asphyxiation

However, in specific scenarios such as drowning, suffocation, or other forms of asphyxial cardiac arrest, the ABC protocol may still be more effective. These situations are primarily caused by a lack of oxygen, meaning that providing rescue breaths before chest compressions can help restore oxygen levels in the blood and increase the likelihood of successful resuscitation.

Choosing the Right Approach

In conclusion, for the majority of adult cardiac arrest cases—especially those related to heart disease—the CAB method is generally recommended to ensure rapid circulation support. However, for victims of respiratory arrest or those whose cardiac arrest was triggered by oxygen deprivation, such as in drowning or choking incidents, the ABC method may be more appropriate, starting with rescue breathing before chest compressions.