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Difficulty: Very hardCardiovascular System

Emergency medical services bring a 58-year-old male to the emergency department due to the abrupt onset of excruciating, tearing chest pain radiating to his interscapular region. He has a history of poorly controlled hypertension. Vital signs show a blood pressure of 215/115215/115 mm Hg in his right arm and 180/95180/95 mm Hg in his left arm. His heart rate is 112112/min. Physical examination reveals a faint early diastolic decrescendo murmur at the right upper sternal border. An initial portable chest radiograph demonstrates a widened mediastinum.

Arrange the following management steps in the optimal chronological sequence to minimize the risk of catastrophic complications and ensure appropriate definitive care.

  1. 1Initiate an intravenous, short-acting beta-blocker (e.g., esmolol)
  2. 2Initiate an intravenous vasodilator (e.g., nitroprusside)
  3. 3Obtain urgent computed tomography angiography (CTA) of the aorta
  4. 4Transfer the patient to the operating room for emergent surgical repair

Answer

The correct sequence is: 1) Initiate an intravenous beta-blocker, 2) Initiate an intravenous vasodilator, 3) Obtain urgent CTA of the aorta, and 4) Transfer to the operating room for emergent surgical repair.
The management of an acute aortic dissection prioritizes hemodynamic stabilization to prevent propagation of the intimal tear, followed by definitive diagnosis and surgical intervention. Intravenous beta-blockers must be administered first to lower the heart rate to approximately 6060/min and decrease the rate of rise of left ventricular pressure (dP/dt), which reduces aortic wall shear stress. Only after adequate beta-blockade is achieved should an intravenous vasodilator be administered to lower the systolic blood pressure to a target of 100−120100-120 mm Hg. Once the patient is medically stabilized, urgent CTA is performed to confirm the diagnosis and delineate the anatomy. Because this patient has signs of a Stanford Type A dissection (aortic regurgitation murmur, right arm blood pressure discrepancy), emergent surgical repair is the final, definitive step.

Step-by-Step Solution

1
Identify the suspected diagnosis
Acute Stanford Type A aortic dissection
The patient presents with tearing chest pain, asymmetric blood pressures, a murmur of aortic regurgitation, and a widened mediastinum.
2
Determine the first pharmacological intervention
Administer an intravenous beta-blocker (e.g., esmolol)
Reduces heart rate and left ventricular dP/dt, minimizing shear stress on the aortic wall and preventing propagation of the dissection flap.
3
Determine the second pharmacological intervention
Administer an intravenous vasodilator (e.g., nitroprusside)
Given strictly after beta-blockade to reduce systolic blood pressure to 100−120100-120 mm Hg. Giving it beforehand would cause reflex tachycardia and increase shear stress.
4
Determine the appropriate diagnostic imaging
Perform computed tomography angiography (CTA) of the aorta
Once the patient is hemodynamically stabilized, noninvasive imaging is required to define the exact anatomy and extent of the dissection for surgical planning.
5
Determine the definitive treatment
Transfer to the operating room for surgical repair
Type A dissections have a high mortality rate due to rupture and tamponade, requiring emergent surgical intervention.

Key Concept

Chronological management of acute aortic dissection (anti-impulse therapy followed by imaging and surgery)
Estimated Time:1m 30s
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Topics

Cardiovascular System

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