MODEL RELEASED. Resuscitation. Doctors performing cardiopulmonary resuscitation (CPR) on an unconscious man, following a cardiac arrest. The doctor on the right is giving heart massage (cardiac compression). Each downward compression on the chest squeezes blood out of the heart and around the body. The doctor on the left is inserting a tube into the patient's airway, a procedure known as endotracheal intubation. The tube will be connected to a ventilating machine to artificially inflate the patient's lungs, maintaining oxygenation of the blood and stimulating natural breathing.