Cardiopulmonary resuscitation (CPR) is an emergency procedure performed when a person’s heart stops beating. Its effectiveness is directly tied to the quality of the techniques used, as performing high-quality CPR significantly increases the chances of survival from cardiac arrest. The difference between basic and high-quality CPR lies in the precision of these actions, which work together to circulate oxygenated blood to the brain and other organs.
Core Components of High-Quality Compressions
The foundation of high-quality CPR rests on the mechanics of chest compressions. To be effective, compressions must be delivered at a rate of 100 to 120 per minute. Many find it helpful to time their compressions to the beat of songs like “Stayin’ Alive,” which falls within this recommended tempo range. This rate is designed to maximize blood flow, as rates that are too slow or too fast are less effective.
The depth of each compression is as important as the rate. For adults, the chest should be compressed at least 2 inches (5 cm), but no more than 2.4 inches (6 cm). Compressions that are too shallow fail to adequately circulate blood, while those that are too deep can cause injury without adding benefit. Proper hand placement on the lower half of the breastbone helps ensure this force is applied correctly.
After each compression, the chest must be allowed to fully recoil to its normal position. This action allows the heart’s chambers to refill with blood before the next compression. Leaning on the chest between compressions prevents this refilling and significantly reduces the effectiveness of CPR.
Minimizing Interruptions and Effective Ventilation
Minimizing pauses in chest compressions is a priority. Interruptions reduce the blood pressure that has been built up, and it takes several compressions to restore it once they resume. Any pause, such as for giving breaths, should be limited to less than 10 seconds. The goal is to achieve a chest compression fraction—the proportion of time compressions are performed—of at least 60%.
When rescue breaths are provided, they are integrated with compressions. For a single rescuer on an adult, the standard is 30 compressions followed by 2 breaths. This ratio balances circulating blood with providing new oxygen. Each breath should be delivered over one second, just enough to make the chest visibly rise.
For rescuers who are untrained, unable, or unwilling to perform rescue breaths, hands-only CPR is a recognized alternative. This approach focuses on delivering continuous, high-quality chest compressions without pauses for ventilation. During the first few minutes of a typical adult cardiac arrest, circulation is the most immediate need, so prioritizing uninterrupted compressions can still provide a significant benefit.
Integrating Automated External Defibrillators
An automated external defibrillator (AED) is a portable device that analyzes the heart’s rhythm and can deliver an electrical shock to restore a normal heartbeat. When an AED is available, it should be used immediately as part of the resuscitation effort, working in concert with chest compressions.
The process involves continuing CPR while a second rescuer prepares and applies the AED pads to the person’s bare chest. Rescuers should follow the device’s audio and visual prompts, continuing compressions until the AED advises standing clear for analysis or shock delivery.
Immediately after a shock is delivered, or if the device determines no shock is needed, rescuers should resume chest compressions without delay. The AED is a specific intervention for certain types of cardiac arrest that is most effective when supported by ongoing, high-quality compressions.
Adapting Techniques for Children and Infants
While the principles of CPR are consistent, techniques must be adapted for children and infants. For a child (from age 1 to puberty), rescuers may use one or two hands for compressions, depending on size. The goal is to compress the chest to a depth of about 2 inches (5 cm), or approximately one-third the diameter of the chest.
For infants (under 1 year of age), a lone rescuer should use two fingers in the center of the chest, just below the nipple line. If two rescuers are present, the preferred method is the two-thumb-encircling hands technique. The compression depth for infants is about 1.5 inches (4 cm), representing about one-third the diameter of the chest.
In pediatric cases, rescue breaths are particularly important, as cardiac arrest in children is more often caused by respiratory issues. If a child’s collapse was not witnessed, guidelines suggest performing two minutes of CPR before leaving to call for help. For two rescuers, the compression-to-ventilation ratio is adjusted to 15:2 to provide more frequent breathing support.