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Difficulty: MediumPulmonary and Critical Care

A 72-year-old man is brought to the emergency department by emergency medical services due to severe, progressive shortness of breath over the past 48 hours. He also reports a cough productive of clear sputum and difficulty sleeping unless propped up on three pillows. His medical history is significant for severe chronic obstructive pulmonary disease (COPD), ischemic cardiomyopathy with a left ventricular ejection fraction of 35%, and hypothyroidism. He admits to missing his medications for the past two weeks.

Vital signs are temperature 37.1 °C (98.8 °F), blood pressure 162/94 mm Hg, pulse 115/min, and respirations 28/min. Oxygen saturation is 85% on room air.

Physical examination shows a patient in acute respiratory distress, using accessory muscles of respiration. Jugular venous distention is present up to 10 cm H2O. Lung auscultation reveals diffuse, bilateral expiratory wheezing and scattered crackles at the lung bases. Cardiovascular examination demonstrates a regular tachycardia with a prominent S3 gallop. There is 2+ bilateral lower extremity pitting edema.

Laboratory and diagnostic studies show:
Leukocyte count: 8,200/mm³
Thyroid-stimulating hormone (TSH): 0.3 µU/mL (Normal: 0.5–5.0 µU/mL)
Free T4: 0.8 ng/dL (Normal: 0.9–1.7 ng/dL)
Sputum culture (obtained 3 days ago at an outpatient clinic for a mild cough): heavy growth of *Streptococcus pneumoniae*, susceptible to amoxicillin.

Arterial blood gas analysis on room air:
pHpH: 7.297.29
pCO2pCO_2: 5656 mm Hg
pO2pO_2: 5252 mm Hg
HCO3−HCO_3^-: 2626 mEq/L

A portable chest radiograph shows cardiomegaly, bilateral perihilar alveolar opacities, and prominent interlobular septa.

Which of the following is the most appropriate initial step in the management of this patient's respiratory distress?

  1. Intravenous furosemide and noninvasive positive-pressure ventilationAnswer
  2. B
    Intravenous methylprednisolone and nebulized albuterol-ipratropium
  3. C
    Intravenous piperacillin-tazobactam and vancomycin
  4. D
    Intravenous sodium bicarbonate infusion
  5. E
    Intravenous levothyroxine and hydrocortisone

Answer

The most appropriate initial step is the administration of intravenous furosemide and noninvasive positive-pressure ventilation.
The correct approach involves administering intravenous loop diuretics (furosemide) and initiating noninvasive positive-pressure ventilation (NPPV). This patient presents with classic signs of acute decompensated heart failure (ADHF), including an S3 gallop, jugular venous distention, orthopnea, and peripheral edema. The chest radiograph confirms cardiogenic pulmonary edema with cardiomegaly, perihilar opacities, and prominent interlobular septa (Kerley B lines). The diffuse wheezing heard on auscultation represents 'cardiac asthma,' which occurs when fluid accumulates in the peribronchial spaces, causing airway narrowing. Furthermore, the patient's arterial blood gas reveals an acute respiratory acidosis (pH7.29pH 7.29, pCO256pCO_2 56 mm Hg) due to impending respiratory failure from the increased work of breathing. NPPV (such as CPAP or BiPAP) is the ideal respiratory support for ADHF because it not only improves oxygenation but also increases intrathoracic pressure, thereby decreasing both cardiac preload and afterload. Concurrently, intravenous furosemide provides rapid diuresis and venodilation, further reducing preload.

Step-by-Step Solution

1
Analyze the patient's presentation and physical exam findings.
The patient presents with orthopnea, JVD, an S3 gallop, bilateral crackles, wheezing, and peripheral edema.
These signs collectively and strongly suggest acute decompensated heart failure (ADHF) with fluid overload, despite the history of COPD.
2
Evaluate the diagnostic data.
The chest radiograph shows cardiomegaly, perihilar alveolar opacities, and prominent interlobular septa (Kerley B lines). The ABG demonstrates acute respiratory acidosis with hypoxemia.
The imaging confirms cardiogenic pulmonary edema. The respiratory acidosis is driven by increased work of breathing and V/Q mismatch stemming from the pulmonary edema.
3
Determine the best immediate management.
Intravenous furosemide and noninvasive positive-pressure ventilation (NPPV) are indicated.
Furosemide provides rapid preload reduction through diuresis and venodilation, while NPPV improves oxygenation, decreases the work of breathing, and further reduces cardiac preload and afterload.

Key Concept

Differentiating acute decompensated heart failure from COPD exacerbation and managing cardiogenic pulmonary edema with preload reduction and noninvasive ventilation.
Estimated Time:1m 30s
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Topics

Pulmonary and Critical Care

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