Anesthesia and monitoring for aortic aneurysm surgery

Cardiopulmonary bypass is employed in the treatment of aneurysms of the ascending aorta and transverse aortic arch. Anesthesia in these cases is similar to that used in the treatment of cardiac lesions requiring cardiopulmonary bypass. Most surgeons use some form of bypass or shunt for aneurysms in the distal arch, descending thoracic aorta, and the thoracoabdominal aortic segment. My surgical associate replaces these lesions with grafts without bypass or shunt, using simple cross-clamping technique. This paper is concerned with anesthetic technique and general supportive measures that provide safety for this method of treatment. Anesthesia and muscle relaxation is obtained by drugs that do not depress the myocardium. Surgical exposure and lung protection are facilitated by one lung ventilation, collapsing the left lung with a double lumen endobronchial tube. Blood pressure and cardiac hemodynamics are extensively monitored and controlled by administration of intravenous fluids and nitroprusside, as indicated. Serum electrolytes, blood gases, plasma osmolarity, acid-base balance, and body temperature are frequently monitored and maintained in safe range. Blood coagulability is assessed and normal ranges achieved by appropriate therapy.