Why is it 30 chest compressions to two breaths?

The 30:2 ratio of chest compressions to rescue breaths is based on physiological principles and aims to provide effective cardiopulmonary resuscitation (CPR). Here's the reasoning behind this ratio:

1. Maximizing Blood Circulation: Chest compressions are the primary means of maintaining blood circulation during CPR. By pushing down on the chest, the heart is compressed, helping to expel blood out of the heart and into the body. The goal is to generate enough pressure and depth to produce an effective circulation of oxygenated blood to vital organs such as the brain and heart.

2. Minimizing Interruptions: Each rescue breath temporarily pauses chest compressions, which can interrupt blood flow and reduce the overall effectiveness of CPR. Limiting the number of breaths allows for more continuous chest compressions and, thus, a more consistent supply of oxygenated blood to the brain and other organs.

3. Optimizing Oxygen Delivery: While rescue breaths provide oxygen, they are not the main focus of CPR during cardiac arrest. The primary objective is to maintain blood circulation, as it is the continuous flow of oxygen-rich blood that nourishes the body's tissues. Chest compressions help circulate both the available oxygen in the bloodstream and the oxygen provided through rescue breaths.

4. Efficiency for Single Rescuer: Performing 30 chest compressions followed by 2 rescue breaths allows a single rescuer to provide continuous and uninterrupted CPR. This ratio reduces the physical strain on the rescuer while still providing adequate ventilation to the patient.

5. Following Guidelines and Standards: The 30:2 ratio is recommended by international resuscitation guidelines, including those published by the American Heart Association (AHA) and the European Resuscitation Council (ERC). These guidelines are based on extensive research and evidence supporting the effectiveness of this ratio in improving survival rates and outcomes in cardiac arrest cases.

Overall, the 30:2 ratio of chest compressions to rescue breaths is designed to maintain adequate blood circulation, minimize interruptions, optimize oxygen delivery, and provide an efficient approach for single rescuers during CPR.