heart surgery, any surgical procedure involving the heart, performed to correct acquired or congenital defects, replace diseased valves, open or bypass blocked vessels, or graft a prosthesis or a transplant. Two major types of heart surgery are performed: closed and open. The closed technique is done through a small incision, without use of the heart-lung machine. In the open technique the heart chambers are open and fully visible, and blood is detoured around the surgical field by the heart-lung machine. Preoperative care focuses on correcting metabolic imbalances and cardiac and pulmonary ailments and on performing diagnostic and laboratory tests. General anesthesia is used, the chest cavity is opened, and the heart-lung machine is connected. Hypothermia also is used to decrease the metabolic rate and the need of the tissues for oxygen. After surgery, constant observation is required in an intensive care unit for signs of hemorrhage and shock, cardiac arrhythmias, sudden chest pain, organ failure, and pulmonary edema. The blood pressure and all pulses, respirations, and venous and pulmonary artery pressures and cardiac rhythm (ECG) are monitored. If the blood pressure is high enough to ensure cerebral profusion, the head of the patient’s bed is elevated to a semi-Fowler’s position to encourage chest drainage and lung expansion. The patient is quickly extubated. Oxygen is provided. Chest tube drainage, urinary output, and temperature are noted hourly; IV infusions and sometimes blood transfusions are given. Narcotics help control pain so the patient can effectively cough, deep breathe, and become quickly mobile. Antibiotics are given to prevent infection. Mortality rate is highest during the first 48 hours after surgery. Kinds include coronary bypass, endarterectomy. See also arrhythmia, fibrillation, heart-lung machine, hypothermia, pulmonary edema.
