Cardiopulmonary Resuscitation (CPR) is a life-saving medical procedure designed to manually circulate blood and oxygen when a person’s heart has stopped beating effectively (cardiac arrest). This intervention involves rhythmic, forceful chest compressions that mimic the heart’s pumping action to keep the brain and other vital organs perfused. Applying these powerful compressions to a person with a beating heart is a potentially dangerous assault on a functioning system. When CPR is misapplied, it transforms from a bridge to survival into a source of severe, immediate trauma, highlighting why careful assessment is necessary before initiating compressions.
Structural Damage from Unnecessary Compressions
The force required for effective chest compressions is substantial, involving pushing down at least two inches (five to six centimeters) on the center of an adult’s chest. When this force is exerted on a body not in cardiac arrest, the musculoskeletal system absorbs the full impact. This action frequently results in sternal and rib fractures, even in true emergencies. However, when the heart is still circulating blood, the resulting pain and physical damage are immediate and severe.
Fractures most commonly occur in the anterior part of the ribs, where they join the sternum or costal cartilage. The displacement of fractured ribs or the sternum itself poses a significant threat to underlying thoracic and abdominal organs. Organs at risk include the lungs, which can suffer contusions or lacerations, and the liver or spleen, which can be injured by misplaced pressure. This trauma requires immediate medical attention, shifting the focus from the initial ailment to the complications caused by the compressions.
Physiological Impact on a Functioning Heart
Applying forceful chest compressions to a heart that is already contracting normally introduces a dangerous mechanical disruption to the cardiovascular system. The heart’s electrical system, which maintains a stable, rhythmic beat, is sensitive to external pressure. This mechanical interference can induce iatrogenic arrhythmias—abnormal heart rhythms caused by the treatment itself. The external force risks destabilizing electrical signaling, potentially triggering life-threatening rhythms such as ventricular tachycardia or ventricular fibrillation.
Compressing a heart that is actively pumping blood also causes a sharp spike in systemic blood pressure. During a normal heartbeat, the ventricles contract to push blood into the arteries, and external compression hyper-pressurizes the circulatory system. This acute hypertension can be dangerously high, potentially leading to catastrophic vascular events. The extreme pressure can cause an aortic dissection, where the inner layers of the aorta tear, or rupture a blood vessel in the brain, resulting in a hemorrhagic stroke.
Ensuring Appropriate CPR Application
The risk of unnecessary compressions is mitigated by adhering to established safety protocols for determining the need for CPR. Cardiopulmonary resuscitation is only indicated if the person is unresponsive and not breathing normally. The rescuer must first check for a response by gently tapping the person and shouting a question like, “Are you okay?”
If there is no response, the next step is to quickly observe for normal breathing, looking for the chest to rise and fall rhythmically for no more than ten seconds. Only gasping or the complete absence of breathing signals the need for intervention. Emergency services should be called immediately before starting compressions. For lay rescuers, the lack of responsiveness and normal breathing is the primary trigger to start compressions.
The risk of causing injury with unnecessary CPR is small compared to the near-certainty of death if needed CPR is withheld. This reality is the foundation of current guidelines, which prioritize acting quickly in a clear emergency. When a person is breathing normally, even if unconscious, the decision to withhold compressions is based on the certainty that their heart is still beating and the risks of severe trauma outweigh the benefits.