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Difficulty: MediumPulmonary and Critical Care

A 7272-year-old man is brought to the emergency department due to sudden-onset, severe shortness of breath that awoke him from sleep 22 hours ago. The patient has a history of hypertension, coronary artery disease, and a 4040-pack-year smoking history. He reports no recent fever, chills, or changes in sputum production. His blood pressure is 180/100180/100 mm Hg, pulse is 118118/min, respirations are 2828/min, and oxygen saturation is 86%86\% on room air. Physical examination reveals an upright, diaphoretic patient using accessory muscles of respiration. Jugular venous distention is present 99 cm above the sternal angle. Lung auscultation demonstrates a prolonged expiratory phase with loud, diffuse bilateral wheezes and no distinct crackles. A third heart sound (S 33) is heard at the apex. Bilateral 2+2+ pitting edema is noted in the lower extremities. The patient is placed on noninvasive positive pressure ventilation, which improves his oxygen saturation to 94%94\%. Arterial blood gas analysis before positive pressure ventilation showed:

pH: 7.257.25
PaCO 2_2: 6060 mm Hg
PaO 2_2: 5252 mm Hg
HCO 3−_3^-: 2626 mEq/L

Which of the following is the most appropriate next step in the management of this patient?

  1. Administer intravenous furosemideAnswer
  2. B
    Administer inhaled albuterol and ipratropium
  3. C
    Administer intravenous piperacillin-tazobactam
  4. D
    Administer intravenous sodium bicarbonate
  5. E
    Administer intravenous metoprolol

Answer

The most appropriate next step is to administer intravenous furosemide to treat the acute decompensated heart failure.
The correct answer is to administer intravenous furosemide. This patient is presenting with acute decompensated heart failure (ADHF), which can occasionally manifest with prominent wheezing known as 'cardiac asthma.' The wheezing occurs because elevated left-sided heart pressures lead to pulmonary venous congestion and peribronchial edema, which narrows the small airways. Although the patient has a significant smoking history making a COPD exacerbation a strong initial consideration, the sudden onset waking him from sleep (paroxysmal nocturnal dyspnea), severe hypertension, elevated jugular venous pressure, an S 33 gallop, and pitting edema are classic signs of ADHF. The primary medical treatment for ADHF with volume overload includes preload and afterload reduction, most commonly achieved with loop diuretics (e.g., intravenous furosemide) and vasodilators (e.g., nitroglycerin). Because he has already been placed on noninvasive positive pressure ventilation (NPPV) to support his acute respiratory acidosis and work of breathing, diuresis is the most appropriate next pharmacological step.

Step-by-Step Solution

1
Analyze the patient's presentation and vital signs.
The patient has sudden, severe dyspnea that awoke him from sleep (paroxysmal nocturnal dyspnea), marked hypertension (180/100180/100 mm Hg), and severe hypoxia.
To establish the acuity and potential etiologies of the respiratory distress.
2
Evaluate the physical examination findings.
The presence of jugular venous distention, an S 33 gallop, and bilateral pitting edema strongly indicate systemic and pulmonary venous congestion, despite the prominent wheezing (cardiac asthma).
To differentiate between acute decompensated heart failure and a primary COPD exacerbation.
3
Interpret the arterial blood gas (ABG).
The ABG shows an acute respiratory acidosis (pH 7.257.25, PaCO 2_2 6060 mm Hg) due to respiratory muscle fatigue from severe pulmonary edema.
To assess the severity of the respiratory failure, which justified the initiation of noninvasive positive pressure ventilation.
4
Select the most appropriate pharmacological intervention.
Intravenous loop diuretics (furosemide) are indicated to rapidly decrease intravascular volume and relieve the pulmonary venous congestion.
Preload reduction is the cornerstone of medical management for acute decompensated heart failure.

Key Concept

Cardiac asthma is a presentation of acute decompensated heart failure characterized by wheezing due to peribronchial edema. It must be differentiated from COPD exacerbation by identifying clinical signs of volume overload (e.g., JVD, S3 gallop) and is treated with preload reduction (e.g., loop diuretics).

Alternative Method

While point-of-care ultrasound (POCUS) is not listed as an option, performing a bedside lung ultrasound that demonstrates diffuse B-lines (comet tails) would rapidly confirm the diagnosis of pulmonary edema over a COPD exacerbation (which would typically show A-lines).
Estimated Time:1m 30s
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Topics

Pulmonary and Critical Care

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