Cardiopulmonary Resuscitation (CPR) is a life-saving technique used when someone’s heart has stopped beating effectively. Chest compressions are a part of CPR, manually circulating blood. Proper technique is important for effective CPR.
The Mechanics of Chest Compressions
When a person experiences cardiac arrest, their heart can no longer pump blood. Chest compressions manually assume this pumping function. By rhythmically pressing down on the center of the chest, rescuers squeeze the heart, pushing blood out into the arteries. This action creates an artificial circulation, moving oxygenated blood to essential organs like the brain and lungs.
The aim is to maintain a continuous, albeit reduced, blood flow throughout the body. Compressions help deliver oxygen and nutrients to tissues, preventing damage. Effective compressions are performed at a rate of 100 to 120 beats per minute and to a depth of at least 2 inches (5 centimeters) but no more than 2.4 inches (6 centimeters) for adults.
The Importance of Recoil
After each chest compression, full chest recoil is important. This recoil creates a negative pressure inside the chest cavity, similar to a vacuum. This negative pressure helps draw blood from the body’s veins back into the heart and allows the lungs to expand.
This refilling of the heart, known as venous return, is necessary. Without adequate blood returning to the heart, there is little blood to be pumped out during the next compression, making it less effective. Full recoil ensures the heart’s chambers fill completely, maximizing the amount of blood pumped with each subsequent compression. This also allows coronary arteries, which supply the heart muscle, to refill.
Consequences of Incomplete Recoil
Failing to allow full chest recoil can significantly diminish the effectiveness of CPR. If a rescuer leans on the chest, it prevents the chest cavity from fully expanding and the heart from refilling with blood. This restriction leads to a reduced amount of blood being pumped with each compression, lowering overall cardiac output.
Insufficient blood flow means less oxygen reaches the brain and other vital organs, increasing the risk of severe injury or organ failure. Studies show that even a small amount of leaning, such as 10-20% of body weight, can negatively impact blood flow and perfusion. Incomplete recoil also impedes coronary artery refilling, compromising heart muscle function. Continuous leaning can also increase rescuer fatigue, making it harder to maintain proper compression depth and rate over time.
Ensuring Proper Recoil During CPR
To ensure full chest recoil, rescuers should avoid leaning on the chest between compressions. After pressing down, hands should lift slightly to allow full chest re-expansion, while maintaining contact for proper hand placement. The goal is for the chest to return completely to its original, uncompressed position before the next compression.
Proper hand placement, with the heel of one hand in the center of the chest and the other hand stacked on top, helps facilitate effective compressions and recoil. Maintaining a consistent rhythm is also important, as it helps optimize chest recoil and prevents disruptions in blood flow. Real-time feedback devices can help monitor and improve recoil accuracy.