CPR

CPR
Name	Cardiopulmonary Resuscitation
Caption	A training manikin used for instruction.
Specialty	Emergency medicine, Cardiology
MeshID	D016887
MedlinePlus	000010

CPR. Cardiopulmonary resuscitation is an emergency procedure performed to manually preserve brain function until further measures are taken to restore spontaneous blood circulation and breathing in a person who is in cardiac arrest. It involves chest compressions, often combined with artificial ventilation, and is a critical component of basic life support. Immediate initiation by a bystander can double or triple a victim's chance of survival, making widespread public knowledge a key public health goal.

Overview

The primary goal is to maintain a flow of oxygenated blood to the brain and heart, thereby delaying tissue death and extending the brief window for successful defibrillation with an automated external defibrillator. The procedure is a cornerstone of the Chain of Survival outlined by the American Heart Association and the European Resuscitation Council. Key physiological concepts underpinning its effectiveness include generating cardiac output via external chest compressions and providing minimal essential oxygenation through rescue breaths.

Indications and contraindications

The primary indication is the absence of normal breathing and unresponsiveness in a victim, suggesting sudden cardiac arrest. It is indicated for victims of drowning, electrocution, drug overdose, and trauma. Relative contraindications are rare in the emergency context but may include obvious signs of irreversible death, such as rigor mortis or dependent lividity. A valid Do Not Resuscitate order or a legally recognized advance directive would also preclude its initiation.

Procedure

For lay rescuers, current guidelines from the International Liaison Committee on Resuscitation emphasize high-quality chest compressions at a rate of 100 to 120 per minute, with a depth of at least two inches for adults. The traditional A-B-C sequence has been largely supplanted by C-A-B for adults to minimize delay in starting circulations. For healthcare providers, the procedure integrates compressions with advanced interventions like securing an endotracheal tube and administering medications such as epinephrine. The use of mechanical CPR devices like the LUCAS device can provide consistent compressions during transport.

Effectiveness and outcomes

Survival rates vary dramatically based on factors like the initial heart rhythm, with ventricular fibrillation having a better prognosis than asystole. Bystander intervention before the arrival of Emergency Medical Services significantly improves outcomes, as documented in registries like the CARES program. Neurologically intact survival remains a key metric, influenced by the duration of cerebral hypoxia. Research from institutions like the Resuscitation Outcomes Consortium continues to refine protocols to improve these rates.

Training and certification

Widespread training is conducted by organizations such as the American Red Cross, the American Heart Association, and the National Safety Council. Courses range from basic Heartsaver classes for the public to advanced Advanced Cardiac Life Support for healthcare professionals. Certification typically requires demonstration of proficiency on a manikin and passing a written exam, with renewal every two years. Initiatives like the World Restart a Heart Day aim to increase global public training rates.

History and development

The modern technique was pioneered in the 1960s, combining earlier work on chest compressions by William Kouwenhoven with the mouth-to-mouth ventilation method promoted by James Elam and Peter Safar. Its formal codification is often credited to a landmark conference in Bethesda, Maryland sponsored by the National Academy of Sciences. The development of the automated external defibrillator and the standardization of guidelines through the Utstein style for reporting data have been major subsequent advancements.

Special considerations

Protocols differ for specific populations; for infants, rescuers use two-finger compressions and cover the nose and mouth for breaths. For victims of hypothermia, resuscitation efforts are prolonged due to the protective effects of cold on the brain. In settings like operating rooms or catheterization labs, the cause of arrest may be immediately reversible, such as from anaphylaxis or cardiac tamponade. The use of Extracorporeal Membrane Oxygenation during resuscitation is an emerging area of study in major medical centers.

Category:Emergency medicine Category:First aid Category:Cardiology