[Anesthesia for the surgery of the thoracic and thoraco-abdominal aorta]

Haemodynamic monitoring, anaesthetic technique and perioperative management were reported for a series of 317 consecutive patients who underwent graft replacement of descending thoracic or thoracoabdominal aortic aneurysms at the Baylor College of Medicine, Houston (Texas) between january 1979 and june 1982. The surgical technique used was aortic clamping without shunt. The anaesthetic technique combined high dose fentanyl (50-100 micrograms X kg-1), oxygen ventilation, pancuronium bromide and vascular filing. The patients were monitored by Swan-Ganz catheters. The systemic blood pressure increased by 8% during the clamping of the aorta in spite of the use of sodium nitroprussiate, whereas the systemic vascular resistances did not increase significantly. The cardiac output increased by 19%, whereas the heart rate remained stable. After unclamping, the systemic blood pressure did not decrease significantly, whereas the systemic vascular resistances fell by 20%; the cardiac output increased by 64%, whereas the heart rate remained stable. The 30-day mortality was 10% (32 patients). Four of them died during surgery. The postoperative morbidity included 33 cases of paraplegia and paraparesis, 31 cases of renal insufficiency and 28 cases of postoperative pulmonary complications. The prevention of the consequences of aortic clamping and the management of the hypoxaemia occurring during one lung anaesthesia are discussed.