Cardiopulmonary Resuscitation (CPR) is an emergency procedure that maintains vital body functions when a person’s heart stops beating effectively. This life-saving intervention supports the body’s systems until professional medical help arrives. Understanding the science behind CPR highlights its importance in emergencies.
What Happens During Cardiac Arrest
Cardiac arrest occurs when the heart suddenly stops its effective pumping action. This abrupt halt in circulation means blood, carrying oxygen and essential nutrients, stops flowing throughout the body. Organs, particularly the brain, are immediately deprived. Brain cells are highly sensitive to oxygen deprivation and begin to die rapidly, often within minutes. This swift cellular death underscores the urgency of intervention, as without blood flow, the body’s entire system begins to fail, leading to irreversible damage.
How Chest Compressions Maintain Circulation
Chest compressions are the core mechanical action of CPR, mimicking the heart’s pumping function. A rescuer presses on the center of the chest, squeezing the heart between the sternum and spine. This displaces blood into major arteries, creating artificial blood flow to vital organs like the brain and heart muscle.
Allowing the chest to fully recoil between compressions is important, as this allows heart chambers to refill with blood. Effective compressions require a specific depth and rate. For adults, guidelines recommend compressing the chest 2 to 2.4 inches (5-6 cm) deep, at 100 to 120 compressions per minute. Consistent, high-quality compressions are crucial for maintaining even minimal circulation.
The Role of Rescue Breaths in Oxygen Delivery
While chest compressions circulate blood, rescue breaths introduce oxygen into the victim’s lungs. After opening the airway, the rescuer delivers breaths, typically mouth-to-mouth or using a barrier device, allowing air to enter. This oxygen is absorbed by the circulated blood, which then delivers oxygen-rich blood to the brain and other vital organs.
Although chest compressions are the primary component of CPR, rescue breaths provide the necessary oxygen for effective circulation. For trained rescuers, the standard is 30 chest compressions followed by two rescue breaths. This combination addresses both circulation and oxygenation, supporting body functions until advanced medical care takes over.
Why Immediate and Quality CPR is Crucial
The time-sensitive nature of cardiac arrest makes immediate and high-quality CPR important. Every minute without effective CPR reduces survival chances and increases long-term brain damage. Brain cells die rapidly without oxygen, leading to irreversible neurological injury. Immediate CPR helps mitigate this damage by providing some blood flow and oxygen to the brain.
Quality CPR involves minimizing interruptions and ensuring effective artificial circulation and oxygen delivery. By performing high-quality CPR, rescuers buy time, maintaining life until advanced medical support, such as paramedics or a defibrillator, becomes available.