aortic dissection

  1. Define
    • not an aneurysm
    • most common in thoracic aorta
    • result from a tear in the intimal lining
    • more often men
    • acute
    • 90% mortality rate
  2. pathophysiology
    • a tear in the inimal lining allows blood to "track" between the layersand creates a false lumen of blood flow
    • systolic pulsationcauses increased pressure in damaged areas => increases dissection
    • - extends proximal and distal
    • - may occlude major branches of the aorta, cutting off blood supply to areas (brain, organs, kidneys, spinal cord extremities)
    • - idiopathic- may be due to destruction of lmedial layer elastic fibers; usually pts with chronic hypertension; Marfan's
    • - pregnancy- increases vascular stress due to increased total blood volume, decreased peripheral vvascular resistance and increased aortic compliance
    • -blunt trauma-
    • most common- ascending aorta, aortic arch, and descending aorta beyond left subclavian artery
  3. clinical manifestations
    • depend on location and extent
    • ACUTE
    • -sudden, severe pain the anterior part of the chest or intrascapula pain radiating down the spine into the abd. or legs. pain "tearing, rippin" "MI like pain"
    • -pregnant- epigastric discomfort or heart burn like symptoms; cardio, neuro, and resp signs
    • -aortic arch- neurologic deficiencis- LOC, dizziness, weakened or absent carotid and temporal pulses
    • angina, MI high-pitched,diastolic cardiac murmur
    • if severe=> L ventricular failure w. dyspnea
    • if subclavian artery is involved, radial ulnal and brachial pulse quality and BP readings may be different b/w left and right arms
    • if progresses down the aorta the abdominal organs and lwr ext. have altered tissue perfusion
  4. Complications
    • cardiac tamponade (blood into the pericardial sac)
    • -hypotension, narrowed pulse pressure, distended neck veins, muffled heart sounds, pulsus paradoxus
    • death
    • occulsion of arterial blood supply to organs and spinal cord - weakness and decreased pain sensation to complete paralysis of the lwr ext. ,renal failure, decreased bowel sounds and altered elmination patterns.
  5. Diagnosticstudies
    • Left ventricular hypertrophy on an echocardiogram r/t systemic hypertension
    • cxr shw a widening of the mediastianl silhouette and left pleural effusion
    • transesophageal echo TEE - identify dissections that are close to the arotic root
    • MRI or MDRCT scan - a emergency diagnostics of choice
    • angiography - to assess the extent of dissection
  6. collaborative care
    • lower BP and contractility - diminish pulsatile forces w/ in the aorta
    • IV Beta blockers, esmolol (decrease BP and contractility)
    • antihypertensive agents - nipride
    • ca+ ch blockers
    • ACE
  7. conservative therapy
    • pain relief
    • blood transfusion
    • management heart failure
  8. surgical therapy
    (when drug therapy ineffective or complications (heart failure, leaking dissection,occlusion of an artery)
    surgery is delayed as long as possible to allow time for edema inthe area of the dissecrtion to decrease and to permit clotin gof the blood in the falsw lumen

    resectin of the aortic segment containing
Card Set
aortic dissection
nursing med surge IV