Disorders of the Great Vessels Flashcards
What is the most common cause of immediate death after an automobile accident or a fall from a great height?
Aortic rupture. Look for a widened mediastinum on a chest radiograph and an appropriate history of trauma. Order a CT scan or angiogram if a contained aortic rupture is suspected (of those who survive to be admitted to the hospital, 50% will die in the first 24 hours). Aortic laceration, traumatic aortic injury, and traumatic pseudoaneurysm all describe the phenomenon seen in initial survivors: an aortic rupture contained by a hematoma or an inadequate amount of surrounding tissue (e.g., adventitia only). Treat with immediate surgical repair.
What are the classic findings in a patient with an abdominal aortic aneurysm? How is this condition evaluated?
Abdominal aortic aneurysm classically involves a pulsatile abdominal mass that may cause abdominal pain. If pain is present, rupture or leakage of the aneurysm should be suspected, although an unruptured aneurysm may cause some degree of pain. Ultrasound or a CT scan is used for initial evaluation and diagnostic confirmation in stable patients, as well as for serial monitoring.
How is an abdominal aortic aneurysm managed? What clues indicate that the aneurysm has ruptured?
If the aneurysm is smaller than 5 cm, you can follow it with serial ultrasound examinations to ensure that it is not enlarging. These small aneurysms should be managed with risk factor reduction (smoking cessation and treatment of hypertension and dyslipidemia). If the aneurysm is larger than 5 cm, symptomatic, or rapidly enlarging, surgical correction should be advised if the patient can tolerate the surgery. Before surgery, the patient’s condition can be medically optimized by administration of a beta-blocker (esmolol) to a target heart rate of 60 beats/min and with nitroprusside or nicardipine to a target systolic blood pressure of 100 to 120 mm Hg. A pulsatile abdominal mass plus hypotension requires emergent laparotomy for a presumed ruptured aneurysm, which carries a mortality rate of roughly 90%. Management of an abdominal aortic aneurysm dissection depends on the location of the dissection. Patients who survive the initial tear typically have a severe sharp or tearing sensation in the back or chest. Acute dissections involving the ascending aorta are considered surgical emergencies. Dissections confined to the descending aorta are treated medically unless the dissection progresses or continues to bleed.
