Cardiopulmonary Resuscitation (CPR) is a life-saving technique used when a person’s heart stops beating. While any attempt is better than none, survival rates depend on the quality of the intervention. High-Quality CPR (HQC) is the gold standard, defined by precise, measurable parameters that maximize the chance of a successful outcome. These standards, established by organizations like the American Heart Association (AHA) and the International Liaison Committee on Resuscitation (ILCOR), focus on optimizing blood flow to the brain and heart until professional help arrives.
Mastering Compression Rate and Depth
Effective chest compressions are the core of HQC, pushing oxygenated blood through the body to keep vital organs alive. Two measurable metrics govern this action: the rate (speed) and the depth (how far the chest is pushed down). The required speed for compressions is 100 to 120 pushes per minute.
Maintaining this rate is necessary because pushing slower does not generate enough blood flow, and pushing too fast reduces the time the heart has to refill. The recommended depth for an adult is at least 2 inches (5 centimeters), but should not exceed 2.4 inches (6 centimeters).
This specific depth range is designed to compress the heart effectively enough to circulate blood without causing injury. Compressing less than 2 inches does not move enough blood to sustain life. Pushing deeper than 2.4 inches is not associated with improved outcomes and increases the risk of complications.
Minimizing Pauses and Ensuring Recoil
The efficiency of chest compressions is compromised if they are interrupted. A major focus of HQC is minimizing “hands-off” time, or the period when compressions are paused. The goal is to keep interruptions to less than 10 seconds. This relates to the chest compression fraction, which should be greater than 80%.
Every pause causes a near-immediate drop in blood pressure and reduces blood flow to the brain and heart. Another component is ensuring full chest recoil after every compression. Full recoil means allowing the chest to return completely to its normal, uncompressed position.
This recoil creates negative pressure inside the chest, allowing the heart to adequately refill with blood before the next compression. Leaning on the chest prevents this refilling action and significantly reduces effectiveness. Proper technique requires the rescuer to lift their weight entirely off the chest after each push.
Standards for Rescue Breathing
While compressions circulate the blood, rescue breathing introduces oxygen into the lungs. For a single rescuer performing CPR on an adult, the standard compression-to-ventilation ratio is 30 compressions followed by two breaths. This ratio prioritizes continuous circulation while still providing necessary oxygen.
Each breath must be delivered over approximately one second, with just enough volume to cause a visible rise of the chest. It is important to avoid aggressive or excessive ventilation, which can be detrimental. Too forceful breaths increase pressure within the chest, impeding blood flow back to the heart and counteracting the benefit of compressions.