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Difficulty: MediumPulmonary and Critical Care

A 71-year-old man is brought to the emergency department by his wife due to sudden-onset severe shortness of breath that awoke him from sleep. He reports feeling as though he is suffocating and has coughed up pink-tinged, frothy sputum. His past medical history is significant for a myocardial infarction 3 years ago, essential hypertension, and a 45-pack-year smoking history. Upon arrival, his temperature is 37.0°C (98.6°F), blood pressure is 180/105 mmHg, pulse is 118/min, and respirations are 32/min. Oxygen saturation is 84% on room air. He is diaphoretic and sitting upright, leaning forward. Lung auscultation reveals diffuse expiratory wheezing and bilateral crackles extending to the mid-lung fields. Cardiac auscultation demonstrates a regular tachycardia with a prominent S3 gallop. An arterial blood gas on room air shows:

pHpH: 7.22
PaCO2PaCO_2: 65 mmHg
PaO2PaO_2: 50 mmHg
HCO3−HCO_3^-: 26 mEq/L

Which of the following is the most appropriate initial pharmacologic intervention for this patient?

  1. A
    Inhaled albuterol and ipratropium
  2. B
    Intravenous piperacillin-tazobactam
  3. Intravenous furosemideAnswer
  4. D
    Intravenous methylprednisolone
  5. E
    Intravenous sodium bicarbonate

Answer

The most appropriate initial pharmacologic intervention is intravenous furosemide to treat acute decompensated heart failure.
Intravenous furosemide is the correct choice because the patient's presentation of paroxysmal nocturnal dyspnea, pink-tinged frothy sputum, bilateral crackles, and an S3 gallop are classic for acute decompensated heart failure (ADHF) leading to cardiogenic pulmonary edema. The prominent wheezing is a phenomenon known as 'cardiac asthma,' caused by peribronchial edema restricting the airways. In the acute setting, intravenous loop diuretics (along with oxygen support and potentially vasodilators like nitroglycerin, given his severe hypertension) are the primary pharmacologic therapy to reduce volume overload and left ventricular preload.

Step-by-Step Solution

1
Analyze the patient's history and presenting symptoms.
The patient has sudden-onset paroxysmal nocturnal dyspnea, frothy pink sputum, and a history of myocardial infarction.
To establish the primary clinical syndrome and identify risk factors.
2
Interpret the physical examination findings.
Severe hypertension, tachypnea, hypoxia, diffuse wheezing, bilateral crackles, and an S3 gallop are present.
To differentiate between respiratory (e.g., COPD exacerbation) and cardiac etiologies of the patient's dyspnea.
3
Evaluate the arterial blood gas results.
The ABG shows an acute, uncompensated respiratory acidosis (pHpH 7.22, PaCO2PaCO_2 65 mmHg, normal HCO3−HCO_3^-).
To assess the severity of respiratory failure and rule out primary metabolic derangements.
4
Formulate a diagnosis and select the appropriate initial pharmacologic therapy.
The diagnosis is acute decompensated heart failure (ADHF) presenting as 'cardiac asthma'. The most appropriate pharmacologic treatment is intravenous furosemide.
Loop diuretics reduce intravascular volume and preload, which rapidly relieves pulmonary congestion.

Key Concept

Acute decompensated heart failure can present with prominent wheezing ('cardiac asthma') due to peribronchial edema. It is distinguished from COPD exacerbations by signs of left ventricular failure, such as an S3 gallop, pink frothy sputum, and bilateral crackles, and is treated initially with loop diuretics, vasodilators, and noninvasive ventilation.
Estimated Time:1m 30s
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Topics

Pulmonary and Critical Care

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