coronary artery bypass
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cor·o·nar·y artery by·pass
cor·o·nar·y ar·te·ry by·pass(kōr'ŏ-nār-ē ahr'tĕr-ē bī'pas)
coronary artery bypass
Traditional surgery requires opening the chest and sternum, spreading the ribs, and use of external heart/lung oxygenation. Less invasive techniques use several small incisions (keyhole surgery), smaller surgical instruments, and fiber-optic cameras. Recovery time is reduced and there are fewer postoperative complications. See: illustration
Preoperative: The surgical procedure and the equipment and procedures used in the postanesthesia and intensive care units are explained. If possible, a tour of the facilities is arranged for the patient. The nurse assists with insertion of arterial and central lines and initiates cardiac monitoring when the patient enters the operating room.
Postoperative: Initially the postoperative patient will be intubated, mechanically ventilated, and will undergo cardiac monitoring. He will also have a nasogastric tube, a chest tube and drainage system, an indwelling urinary catheter, arterial and venous lines, epicardial pacing wires, and, often, a pulmonary artery catheter.
Signs of hemodynamic compromise, e.g., severe hypotension, decreased cardiac output, and shock, are monitored; vital signs are obtained and documented according to protocol until the patient's condition stabilizes. Disturbances in heart rate or rhythm are monitored; any abnormalities are documented and reported. Preparations are made to initiate or assist with epicardial pacing, cardioversion, or defibrillation as necessary. Pulmonary artery, central venous, and left atrial pressures are monitored, and arterial pressure is maintained within prescribed guidelines (usually between 110 and 70 mm Hg). Peripheral pulses, capillary refill time, and skin temperature and color are assessed frequently; the chest is auscultated for changes in heart sounds or pulmonary congestion. Any abnormalities are documented and reported to the surgeon. Tissue oxygenation is monitored by assessing breath sounds, chest excursion, symmetry of chest expansion, pulse oximeter, and arterial blood gas (ABG) values. Ventilator settings are adjusted as needed. Fluid intake and output and electrolyte levels are assessed for imbalances. Chest tube drainage is maintained at the prescribed negative pressure (usually -10 to -40 cm H2O); chest tubes are inspected for patency. The patient is assessed for hemorrhage, excessive drainage (> 200 ml/hr), and sudden decrease or cessation of drainage. Prescribed analgesics and other medications are administered.
Throughout recovery the patient is evaluated for changes in oxygenation, ventilation, neurological status, and urinary output. After the patient is weaned from the ventilator and extubated, chest physiotherapy and incentive spirometry are used, and the patient is encouraged to breathe deeply and to cough to prevent atelectasis of the lung and to clear mucus from the airway. The patient is helped to change position frequently. Help is also given with range-of-motion exercises and with active leg movement and gluteal and quadriceps setting exercises.
Before discharge the patient is instructed to report any signs of infection (fever, sore throat, redness, swelling, or drainage from the leg or chest incisions) or cardiac complications (angina, dizziness, rapid or irregular pulse, or increasing fatigue or prolonged recovery time after activity or exercise). Postpericardiotomy syndrome often develops after open heart surgery. Postoperative depression may also develop weeks after discharge; both patient and family are reassured that this is normal and usually passes quickly. The patient is advised to observe any tobacco, sodium, cholesterol, fat, and calorie restrictions, which may help reduce the risk of recurrent arterial occlusion. The patient needs to maintain a balance between activity and rest and should schedule a short afternoon rest period and plan to get 8 hr of sleep nightly. Frequent rest should also follow any tiring activity. Participation in the prescribed cardiac rehabilitative exercise program is recommended, and any activity restrictions (avoiding lifting heavy objects, driving a car, or doing strenuous work until specific permission is granted) are reinforced. Appropriate reassurance is offered that the patient can climb stairs, engage in sexual activity, take baths or showers, and do light chores. The patient is referred to local information and support groups or organizations, such as the American Heart Association. Synonym: aortocoronary bypass