Dissection of the aorta: a clinical update

Aortic dissection is a catastrophic condition that occurs precipitously and is most commonly associated with a history of hypertension or cystic medial necrosis. Although the clinical presentation is quite variable, the heralding symptom is almost always severe chest or back pain. Aortic dissection is categorized as Type A if it involves the ascending thoracic aorta and Type B if it involves only the aorta distal to the left subclavian artery. During the first 48 hours, acute Type A dissection has a mortality of greater than 1% per hour; it is treated as a surgical emergency. Surgical repair for Type B dissection is generally reserved for patients who have persistent pain, intractable hypertension, or evidence of dissection progression. In all patients with aortic dissection, pharmacologic antihypertensive and negative inotropic therapy is essential to control extension of the dissection process. Vigilant monitoring of blood pressure and serial assessment to detect dissection progression are the key components of nursing management.