The emergency first aid protocol for an unconscious person on whom both breathing and pulse cannot be detected is called cardiopulmonary resuscitation (CPR). It is a combination of mouth-to-mouth resuscitation and chest compressions. This kind of mouth-to-mouth resuscitation was first described in the Bible, but it fell out of practice. Drs. James Elam and Peter Safar rediscovered it in the 1950s. In the early 1960s, the advantages of chest compression to help artificial circulation was discovered by Drs. Kouwenhoven, Knickerbocker and Jude. Both mouth-to-mouth resuscitation and chest compression were then combined to form modern CPR.

CPR is usually taught to people who may be the only ones present in the crucial few minutes before emergency personnel arrive. Lack of oxygen can cause permanent damage to the brain or lead to death in less than eight minutes. Effective CPR helps enough oxygen reach the brain and delay brain death. It allows the heart to remain responsive to defibrillation attempts.

CPR has three basic rules: (a) the victim's airway must be open for breathing to be restored. (b) Rescue breathing -- when the rescuer forces air into the lungs of the victim by mouth-to-mouth resuscitation and (c) when rescue breathing alone is not enough and chest compressions are needed to start circulation.

CPR acts as a substitute pumping to circulate blood when the heart cannot. All it does is provide some amount of air and circulation to a victim, allowing more time for help to arrive. The goal is only to maintain the circulation of oxygenated blood to the brain until more advanced medical help arrives to provide advanced cardiac life support . It is not the way restart the heart, a myth inaccurately portrayed by the media. Nor is it the definitive treatment of cardiac arrest, as only 5% of victims regain regular heatbeat solely by CPR . CPR is never guaranteed to save someone's life and should only be performed when a person isn't breathing or circulating blood adequately. Whenever CPR is needed, remember to first call for emergency medical assistance.