American Board of Internal Medicine (ABIM) Certification Practice Exam

What combination is part of the indication for long-term oxygen therapy in the presence of pulmonary hypertension and COPD?

1. Increased exercise capacity

2. Evidence of liver failure

3. Peripheral edema suggesting right-sided heart failure

4. Chronic bronchitis without hypoxia

The correct answer is: Peripheral edema suggesting right-sided heart failure

Long-term oxygen therapy is indicated for patients with chronic obstructive pulmonary disease (COPD) who also exhibit pulmonary hypertension, particularly when there are signs of right-sided heart failure. The presence of peripheral edema is a significant clinical marker in these cases, indicating potential right-sided heart strain. When the heart struggles to pump effectively due to increased pressure in the pulmonary circulation, fluid can accumulate in the body, leading to peripheral edema. This combination occurs because chronic hypoxia, common in COPD, can lead to vasoconstriction in the pulmonary arteries, causing sustained elevations in pulmonary artery pressure. Over time, this can result in cor pulmonale, which is characterized by right ventricular hypertrophy and subsequent heart failure. Therefore, monitoring for peripheral edema in these patients becomes crucial, as it may signal worsening right heart function necessitating immediate interventions, including the use of long-term oxygen therapy to help alleviate hypoxemia and improve hemodynamics. In contrast, increased exercise capacity, evidence of liver failure, and chronic bronchitis without hypoxia do not provide the necessary clinical context for initiating long-term oxygen therapy related to pulmonary hypertension in COPD. Increased exercise capacity typically indicates better overall health and usually would not prompt long-term oxygen use. Liver failure, while a serious condition,