What is the initial workup and management for a suspected aortic dissection?

Initial Workup and Management of Suspected Aortic Dissection

For suspected aortic dissection, urgent definitive imaging with CT angiography, transesophageal echocardiography, or MRI is required, along with immediate blood pressure and heart rate control using intravenous beta-blockers as first-line therapy. 1

Clinical Presentation and Risk Assessment

High-Risk Features

• Sudden onset of severe chest, back, or abdominal pain described as tearing or ripping
• Pulse differentials or blood pressure differences >20 mmHg between arms
• Mediastinal widening on chest X-ray
• Unexplained hypotension or syncope
• Focal neurological deficits
• Aortic regurgitation murmur
• Pericardial effusion or tamponade

Risk Stratification

• Use the Aortic Dissection Detection (ADD) score 1:
  • High-risk conditions (Marfan syndrome, family history, known aortic disease)
  • High-risk pain features (sudden onset, severe, tearing/ripping quality)
  • High-risk examination features (pulse deficit, BP differential, neurologic deficit)
• ADD score ≥1 indicates high risk and warrants immediate advanced imaging 1

Initial Management Algorithm

1. Immediate Stabilization

• Establish IV access with two large-bore IVs
• Continuous cardiac monitoring
• Obtain ECG to rule out myocardial infarction
• Pain control with IV morphine sulfate 1
• Transfer to intensive care unit 1

2. Blood Pressure and Heart Rate Control

• First step: IV beta-blockers to target heart rate ≤60 bpm 1

  • Options: propranolol (0.05-0.15 mg/kg every 4-6h), esmolol (loading dose 0.5 mg/kg over 2-5 min, then 0.1-0.2 mg/kg/min), metoprolol, or labetalol 1
  • Target systolic BP: 100-120 mmHg 1

• If systolic BP remains >120 mmHg after adequate heart rate control:

  • Add vasodilators (IV sodium nitroprusside) 1
  • Important: Never start vasodilators before beta-blockers to avoid reflex tachycardia 1

• For patients with contraindications to beta-blockers:

  • Use non-dihydropyridine calcium channel blockers 1

3. Diagnostic Imaging

• First-line imaging: CT angiography of chest with IV contrast 2

  • Sensitivity >95%, specificity >95% 2
  • Consider extending to abdomen/pelvis for complete evaluation 2

• For hemodynamically unstable patients:

  • Bedside TTE to assess for obvious dissection, pericardial effusion, or aortic regurgitation 2
  • If available quickly, proceed to TEE (sensitivity 99%, specificity 89%) 2, 3

• If initial imaging is negative but clinical suspicion remains high:

  • Obtain a second imaging study 1

4. Laboratory Testing

• Complete blood count
• Basic metabolic panel
• Coagulation profile
• Blood type and screen
• Consider D-dimer (high negative predictive value) 1

Management Based on Classification

Type A Dissection (Involving Ascending Aorta)

• Immediate surgical consultation 1
• Emergent surgical repair 1, 4
• Direct admission to operating room for confirmed or highly suspected Type A dissection 4

Type B Dissection (Limited to Descending Aorta)

• Continue medical management with beta-blockers and blood pressure control 1
• Surgical or endovascular intervention only for complications:
  • Malperfusion syndrome
  • Progression of dissection
  • Enlarging aneurysm
  • Uncontrollable pain or blood pressure 1

Common Pitfalls and Caveats

• Do not delay definitive imaging in high-risk patients even with a negative chest X-ray 1
• Do not rely solely on bedside TTE to rule out aortic dissection (sensitivity only 59-80%) 1, 2
• Do not administer thrombolytics without ruling out aortic dissection in patients with chest pain and ST-elevation 1
• Do not perform pericardiocentesis as initial therapy for cardiac tamponade in aortic dissection as it may cause recurrent bleeding 1
• Do not use vasodilators before beta-blockers as this can increase aortic wall stress through reflex tachycardia 1
• Use beta-blockers cautiously in patients with acute aortic regurgitation as they block compensatory tachycardia 1

Rapid diagnosis and appropriate management are critical, as mortality increases by 1-2% per hour in untreated patients with acute aortic dissection 5.