Improving oxygenation in COPD reduces progression to pulmonary hypertension and cor pulmonale. Which intervention best achieves this?

• A. Bronchodilators
• B. Corticosteroids
• C. Antibiotics
• D. Oxygen therapy

Answer: (D)

The key idea is correcting chronic low blood oxygen (hypoxemia) to reduce the downstream effects on the lungs and heart. In COPD, long-standing hypoxemia triggers hypoxic pulmonary vasoconstriction, which over time causes remodeling of the pulmonary arteries and progressive pulmonary hypertension. This places increasing strain on the right ventricle, leading to cor pulmonale. Providing supplemental oxygen directly raises the amount of oxygen carried in the blood (increasing PaO2 and SaO2), which lessens hypoxic vasoconstriction, lowers pulmonary artery pressures, and reduces the workload on the right heart. When patients with COPD have resting hypoxemia (and sometimes exertional hypoxemia or signs like polycythemia), long-term oxygen therapy improves survival and slows the progression toward pulmonary hypertension and right-sided heart failure.

Bronchodilators, corticosteroids, and antibiotics can help with symptoms, inflammation, or infection, which may transiently improve oxygenation, but they do not address the chronic hypoxemia that drives the vascular and cardiac complications as effectively as oxygen therapy.