A 69-year-old man is brought to the emergency department at 3:00 AM due to severe shortnes… — USMLE Step 2 CK

A 69-year-old man is brought to the emergency department at 3:00 AM due to severe shortness of breath that awoke him from sleep. The patient states he has been feeling increasingly fatigued over the past 3 days and has noticed swelling in both of his lower legs. His past medical history includes hypertension, hyperlipidemia, and a 45-pack-year smoking history. He admits to poor adherence to his prescribed daily medications. On arrival, his temperature is $37.1^\circ\text{C}$ ( $98.8^\circ\text{F}$ ), blood pressure is $172/96\text{ mmHg}$ , pulse is $115/\text{min}$ , and respiratory rate is $26/\text{min}$ . Pulse oximetry shows $89\%$ on room air. Physical examination reveals a patient in moderate respiratory distress, sitting upright on the edge of the stretcher. The jugular venous pressure is visibly elevated to $11\text{ cm H}_2\text{O}$ . Lung auscultation demonstrates diffuse expiratory wheezes and prominent bibasilar crackles. Cardiac examination reveals a tachycardic, regular rhythm with a third heart sound ( $S_3$ ). There is 2+ pitting edema extending up to the knees bilaterally. Which of the following is the most appropriate initial pharmacologic therapy for this patient?

Intravenous furosemideAnswer
B
Inhaled albuterol and ipratropium
C
Intravenous methylprednisolone
D
Oral azithromycin
E
Intravenous piperacillin-tazobactam

Answer

Intravenous furosemide

The patient's presentation of paroxysmal nocturnal dyspnea, elevated jugular venous pressure, bibasilar crackles, an

S_3

gallop, and bilateral lower extremity edema is diagnostic of acute decompensated heart failure (ADHF) with significant volume overload. In patients with severe ADHF, fluid transudation into the peribronchial spaces can lead to airway narrowing, causing a characteristic wheeze commonly referred to as 'cardiac asthma.' Intravenous loop diuretics, such as furosemide, are the first-line pharmacologic therapy. They rapidly reduce intravascular volume and decrease cardiac preload, which lowers pulmonary capillary hydrostatic pressure and relieves pulmonary edema.

Step-by-Step Solution

Identify the primary clinical syndrome based on the patient's symptoms and vital signs.

The patient presents with paroxysmal nocturnal dyspnea, orthopnea, tachycardia, tachypnea, and hypoxia in the setting of long-standing hypertension.

Establishing the overarching clinical picture is required to direct physical examination interpretation.

Analyze the physical examination findings to differentiate between pulmonary and cardiac etiologies of dyspnea.

The presence of elevated jugular venous pressure, bibasilar crackles, an

S_3

gallop, and bilateral pitting edema points definitively to volume overload and acute decompensated heart failure.

Although wheezing is present and the patient is a heavy smoker, the wheezing in this context represents 'cardiac asthma' (peribronchial edema) rather than primary bronchospasm.

Determine the most appropriate initial pharmacologic management.

Intravenous loop diuretics (e.g., furosemide) are the most appropriate initial therapy to induce diuresis and venodilation, thereby reducing cardiac preload.

Rapid preload reduction alleviates pulmonary capillary hydrostatic pressure, resolving the pulmonary edema and improving oxygenation.

Key Concept

Differentiation of acute decompensated heart failure ('cardiac asthma') from COPD exacerbation based on volume status markers, and appropriate initial management with intravenous loop diuretics.

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