cardiopulmonary resuscitation (CPR), a basic emergency procedure for life support, consisting of artificial respiration and manual external cardiac massage. It is used in cases of cardiac arrest to establish effective circulation and ventilation in order to prevent irreversible cerebral damage resulting from anoxia. External cardiac massage compresses the heart between the lower sternum and the thoracic vertebral column. During compressions, blood is forced into systemic and pulmonary circulation, and venous blood refills the heart when the compression is released. Mouth-to-mask breathing or a mechanical form of ventilation is used concomitantly with CPR to oxygenate the blood being pumped through the circulatory system.
