A 68-year-old man is brought to the emergency department by emergency medical services due… — USMLE Step 2 CK

A 68-year-old man is brought to the emergency department by emergency medical services due to severe, progressively worsening shortness of breath that began 4 hours ago. He has a history of essential hypertension, type 2 diabetes mellitus, and a 40-pack-year smoking history. He has not seen a physician in three years and does not take any medications currently. Upon arrival, the patient is agitated, diaphoretic, and unable to speak in full sentences. He is sitting upright and leaning forward. Vital signs show a temperature of $37.0^\circ\text{C}$ ( $98.6^\circ\text{F}$ ), blood pressure of $215/115\text{ mmHg}$ , heart rate of $122/\text{min}$ , and respiratory rate of $32/\text{min}$ . Oxygen saturation is $85\%$ on room air. Jugular venous pulsation is visible $10\text{ cm}$ above the sternal angle. Pulmonary auscultation reveals prolonged expiration with diffuse, loud, bilateral wheezing; no crackles are heard. Cardiac auscultation reveals a regular tachycardia and an extra low-frequency diastolic heart sound heard immediately after S2. The point of maximal impulse is displaced laterally. Bedside electrocardiogram demonstrates sinus tachycardia with voltage criteria for left ventricular hypertrophy. Which of the following is the most appropriate initial pharmacotherapy for this patient?

Intravenous nitroglycerinAnswer
B
Inhaled albuterol and intravenous methylprednisolone
C
Intravenous metoprolol tartrate
D
Intravenous diltiazem
E
Oral azithromycin and inhaled ipratropium

Answer

Intravenous nitroglycerin

The correct answer is intravenous nitroglycerin. This patient is presenting with acute decompensated heart failure (ADHF) presenting as flash pulmonary edema, triggered by a hypertensive emergency. The key findings pointing to a cardiac etiology over a primary pulmonary process are the extremely elevated blood pressure, jugular venous distention, laterally displaced point of maximal impulse, and an S3 gallop. The diffuse wheezing represents 'cardiac asthma'—bronchospasm induced by peribronchial edema—rather than a true COPD exacerbation. Intravenous nitroglycerin acts as a potent venodilator (decreasing preload) and, at higher doses, an arterial vasodilator (decreasing afterload). This rapidly reduces left ventricular filling pressures and relieves pulmonary edema in the setting of severe hypertension.

Step-by-Step Solution

Analyze the physical examination and vital signs.

The patient has severe dyspnea, wheezing, extreme hypertension (

215/115\text{ mmHg}

), elevated JVP, and an S3 gallop.

Identifying the constellation of symptoms is necessary to differentiate the underlying etiology of the acute respiratory distress.

Differentiate between a primary pulmonary event and a cardiovascular event.

The presence of an S3 gallop, elevated JVP, and laterally displaced PMI confirms acute decompensated heart failure (ADHF) with flash pulmonary edema, despite the wheezing ('cardiac asthma').

Patients with a heavy smoking history who present with wheezing are often misdiagnosed with a COPD exacerbation, but the cardiac exam findings rule this out.

Determine the most appropriate initial pharmacotherapy for this specific presentation of ADHF.

Intravenous nitroglycerin is selected to rapidly reduce preload and afterload.

In ADHF driven by severe hypertension (sympathetic crashing acute pulmonary edema), rapid vasodilation is the primary and most immediate lifesaving intervention.

Key Concept

Acute decompensated heart failure can present with severe wheezing ('cardiac asthma') that mimics a COPD exacerbation. In patients with ADHF and severe hypertension, intravenous nitroglycerin is the initial pharmacotherapy of choice to rapidly decrease preload and afterload.

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