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Difficulty: EasyPulmonary and Critical Care

During a routine outpatient follow-up, a 69-year-old retired carpenter complains of gradually increasing swelling in both ankles over the past month. He has a 45-pack-year smoking history and severe chronic obstructive pulmonary disease. The patient states his chronic daily cough and baseline exertional shortness of breath have not worsened. He denies waking up gasping for air at night and sleeps comfortably on a single pillow. He is afebrile. Vital signs show a blood pressure of 118/76 mm Hg, a pulse of 84/min, and a respiratory rate of 18/min. Pulse oximetry reveals an oxygen saturation of 87% on room air. Physical examination demonstrates an elevated jugular venous pressure, a prominent right ventricular heave, and 2+ bilateral pitting edema up to the shins. Auscultation of the lungs reveals distant breath sounds with prolonged expiration but no crackles. A basic metabolic panel reveals a serum bicarbonate of 32 mEq/L. Which of the following management steps is most likely to improve this patient's long-term survival?

  1. A
    Initiation of daily oral torsemide
  2. B
    Prescription of a broad-spectrum fluoroquinolone
  3. Provision of continuous supplemental oxygenAnswer
  4. D
    Administration of intravenous sodium bicarbonate
  5. E
    Initiation of daily carvedilol therapy

Answer

Provision of continuous supplemental oxygen
The correct answer provides continuous supplemental oxygen. This patient presents with classic signs of cor pulmonale (right-sided heart failure secondary to pulmonary disease), evidenced by his elevated jugular venous pressure, right ventricular heave, and peripheral edema in the setting of severe COPD. The underlying mechanism is chronic hypoxic pulmonary vasoconstriction leading to pulmonary hypertension and right ventricular hypertrophy. Long-term oxygen therapy (LTOT) is the most critical intervention because it reverses this hypoxic vasoconstriction, lowers pulmonary artery pressures, and is one of the only treatments definitively proven to improve survival in COPD patients. Criteria for LTOT include a resting PaO2≤55PaO_2 \leq 55 mm Hg or an SaO2≤88%SaO_2 \leq 88\% on room air. Since this patient's SaO2SaO_2 is 87%87\%, he meets the criteria.

Step-by-Step Solution

1
Analyze the clinical presentation.
The patient has signs of isolated right heart failure (JVD, right ventricular heave, pedal edema) without left heart failure signs (no orthopnea, no pulmonary crackles).
To identify the underlying pathophysiology as cor pulmonale secondary to severe COPD.
2
Evaluate the objective data.
The patient has severe resting hypoxemia (SpO2 is 87%).
To determine whether the patient meets the clinical criteria for specific evidence-based interventions.
3
Select the intervention proven to improve mortality.
Long-term supplemental oxygen therapy (LTOT).
LTOT is one of the few therapies demonstrated to improve long-term survival in patients with severe COPD and resting hypoxemia by reducing pulmonary vascular resistance.

Key Concept

Continuous long-term oxygen therapy (LTOT) improves survival in patients with COPD who have severe resting hypoxemia (PaO2≤55PaO_2 \leq 55 mm Hg or SaO2≤88%SaO_2 \leq 88\%) or moderate hypoxemia with evidence of cor pulmonale.
Estimated Time:1m 0s
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Topics

Pulmonary and Critical Care

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