What is CPR and how does CPR work?
CPR is an emergency technique used to revive a person whose heart or breathing has stopped. When the heart and lungs stop, nourishing oxygenated blood is not pumped through the body. Using mouth-to-mouth resuscitation or an airbag, along with cardiac massage (chest compressions), the rescuer may be able to revive the victim. CPR is most effective when it’s performed within the first four minutes after cardiac arrest.