This prevents oxygen from circulating throughout the body, rapidly killing cells and tissue. In essence, Cardio (heart) Pulmonary (lung) Resuscitation (revive, revitalize) serves as an artificial heartbeat and an artificial respirator.

CPR may not save the victim even when performed properly, but if started within 4 minutes of cardiac arrest and defibrillation is provided within 10 minutes, a person has a 40% chance of survival.

 
IMPORTANT AMERICAN HEART ASSOCIATION UPDATES

October 15, 2015: The recommended sequence for a single rescuer has been confirmed: the single rescuer is to initiate chest compressions before giving rescue breaths (C-A-B rather than A-B-C) to reduce delay to first compression. The single rescuer should begin CPR with 30 chest compressions followed by 2 breaths.

October 18, 2010: If a bystander is not trained in CPR, the bystander should provide compression-only CPR (see below) for the adult victim who suddenly collapses, with an emphasis to "push hard and fast" on the center of the chest, or follow the directions of the EMS dispatcher. The rescuer should continue compression-only CPR until an AED is available or first responders can assist the victim. If the trained lay rescuer is able to perform rescue breaths, compressions and breaths should be provided in a ratio of 30 compressions to 2 breaths.

March 2008: The American Heart Association published an advisory statement outlining "hands-only" or "compression-only" CPR which dictates that lay persons who are unable or unwilling to provide rescue breaths may perform hands-only CPR. This updated recommendation does not apply to first responders and/or medical personnel with access to CPR barrier or a mechanical respirator; unwitnessed cardiac arrest, cardiac arrest in children and infants, or cardiac arrest presumed to be of non-cardiac origin (drowning, trauma, airway obstruction, acute respiratory diseases, drug overdose, etc). AHA study concedes that when performed correctly, conventional CPR continues to prove a more effective rescue method for victims of cardiac arrest and as such we will continue to educate our students in ventilation as well as compressions.

Let's begin by emphasizing the very first step of Basic Life Support