What is the initial management of aortic dissection?

Initial Management of Aortic Dissection

Immediately initiate intravenous beta-blocker therapy targeting systolic blood pressure <120 mmHg and heart rate ≤60 beats per minute, with labetalol as the preferred agent due to its combined alpha- and beta-blocking properties that optimally reduce aortic wall stress. 1

Immediate Stabilization and Monitoring

Invasive Monitoring

• Place an arterial line immediately for continuous invasive blood pressure monitoring 1
• Establish continuous three-lead ECG recording 1
• Transfer to intensive care unit for appropriate hemodynamic monitoring 1
• Obtain intravenous access and blood samples 1

Pain Control

• Administer morphine sulfate for analgesia, which also reduces sympathetic surge that can propagate dissection 1, 2

Blood Pressure and Heart Rate Management

First-Line Therapy: Beta-Blockers

• Labetalol is the preferred first-line agent due to its dual alpha- and beta-blocking properties 1, 2
• Alternative beta-blockers include propranolol, esmolol, or metoprolol if labetalol is unavailable 1
• Target systolic blood pressure <120 mmHg 1, 2
• Target heart rate ≤60 beats per minute 1, 2

Second-Line Agents (Only After Beta-Blockade)

• Add sodium nitroprusside or nicardipine if blood pressure targets are not met despite adequate beta-blockade 1, 2
• Critical pitfall: Never administer vasodilators without prior beta-blockade, as reflex tachycardia increases aortic wall shear stress and propagates dissection 3, 2

Beta-Blocker Contraindications

• If beta-blockers are contraindicated, use intravenous non-dihydropyridine calcium channel blockers (e.g., diltiazem) for heart rate control 1, 2
• Never use dihydropyridine calcium channel blockers without beta-blockade due to reflex tachycardia risk 2

Special Consideration: Malperfusion

• In cases of visceral or limb malperfusion, tolerate higher blood pressure (potentially >120 mmHg systolic) to optimize perfusion to threatened organs 1, 2
• Measure blood pressure in both arms to rule out pseudo-hypotension from brachiocephalic trunk involvement 3

Urgent Diagnostic Imaging

Imaging Modality Selection

• Perform urgent definitive imaging with CT angiography, transesophageal echocardiography (TEE), or MRI 1
• All three modalities have comparable sensitivity and specificity >90% 1
• CT angiography is most commonly used due to speed and availability 1
• TEE allows rapid bedside assessment and is 86-100% sensitive 4

Chest X-Ray Considerations

• Perform chest X-ray in stable patients (abnormal in 60-90% of cases) 1
• Omit chest X-ray in unstable patients to avoid treatment delays 1

Type-Specific Management Pathways

Type A Dissection (Ascending Aorta)

• Obtain urgent surgical consultation immediately 1
• Emergency open surgical repair is mandatory given extremely high mortality (26-58%) 1, 4
• Surgery aims to prevent aortic rupture, pericardial tamponade, and relieve aortic regurgitation 1
• Surgical options include composite graft implantation in the ascending aorta with or without coronary artery reimplantation 1

Type B Dissection (Descending Aorta)

Complicated Type B (Emergency TEVAR Indications)

• Malperfusion syndrome (visceral, limb, or spinal cord ischemia) 1, 3
• Rupture signs (periaortic/mediastinal hematoma, hemothorax, contrast extravasation) 3
• Intractable pain despite medical therapy 1, 3
• Rapidly expanding aortic diameter 1, 3
• Dissection in pre-existing aneurysm 1, 3

Uncomplicated Type B (Medical Management)

• Continue aggressive anti-impulse therapy with intravenous beta-blockers 3
• Consider subacute TEVAR (14-90 days) if high-risk anatomical features present 3:
  • Maximum aortic diameter ≥40 mm 3
  • Patent false lumen with diameter >22 mm 3
  • Adverse entry tear location 3

Transition to Oral Therapy

• Switch from intravenous to oral beta-blockers after 24 hours of hemodynamic stability if gastrointestinal function is preserved 1, 2
• Target long-term blood pressure <135/80 mmHg with beta-blockers as preferred agents 1, 2

Surveillance Protocol

• Perform serial imaging at 1,3,6, and 12 months, then yearly if stable 3
• MRI is preferred for follow-up as it avoids radiation and nephrotoxic contrast 1, 3, 2
• CT is acceptable alternative, particularly in patients >60 years 1, 3
• Monitor for false lumen expansion, aneurysm formation, new tears, or malperfusion 3, 2

Special Populations

Hereditary Connective Tissue Disorders

• Lifelong beta-adrenergic blockade is mandatory for patients with Marfan syndrome or Ehlers-Danlos syndrome to prevent dissection 1, 2

Pregnant Patients

• Require multidisciplinary team management at specialized centers 1
• Use drugs with lowest teratogenic impact 1

Peripheral Malperfusion in Type A

• Consider percutaneous revascularization first before surgical repair to allow ischemic injury to resolve, as 30-day mortality correlates directly with severity and duration of ischemia 1