Cardiopulmonary Resuscitation - CPR - CPR or Cardiopulmonary Resuscitation is an emergency procedure for people in cardiac arrest or in some circumstances, respiratory arrest. It is performed both in hospitals and in pre-hospital settings. It involves physical interventions to create artificial circulation through rhythmic pressing on the patient's chest to manually pump blood through the heart, called chest compressions and usually also involves the recuer exhaling into the patient to ventilate the lungs and pass oxygen in to the blood, called artificial respiration.