A 65-year-old man presents to the ER with BP 220/130 mmHg and sudden onset severe tearing chest pain radiating to the back. CT angiography shows a type A aortic dissection (DeBakey Type I, involving ascending aorta). What is the MOST critical immediate pharmacological intervention before surgery?

• A IV sodium nitroprusside infusion alone for rapid BP reduction
• B IV hydralazine for afterload reduction
• C Sublingual nifedipine for immediate blood pressure control
• D IV labetalol to reduce BP and heart rate to target HR <60 and SBP 100–120 mmHg ✓

Explanation

In acute aortic dissection, the immediate goal is to reduce aortic wall stress by simultaneously decreasing blood pressure and heart rate (rate of rise of pressure, dP/dt). IV beta-blocker (esmolol or labetalol) is the preferred agent, targeting HR <60 bpm and SBP 100–120 mmHg. Nitroprusside can be added if BP remains elevated after beta-blockade, but must NEVER be used without prior beta-blocker (reflex tachycardia increases shear stress and extends dissection). Hydralazine causes reflex tachycardia. Sublingual nifedipine produces uncontrolled BP drops and is contraindicated.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

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Written and medically reviewed by the StethoPrep medical team.