A 56-year-old man comes to the office due to worsening cough for the past several months. He initially had a morning cough productive of minimal sputum, but now the cough occurs throughout the day with large amounts of yellowish sputum. The patient also has breathlessness on moderate exertion. He has had 3 hospitalizations over the past year for respiratory infections. The patient has smoked a pack of cigarettes daily for the past 30 years and has failed multiple attempts to quit. Oxygen saturation is 90% at rest and decreases to 84% with moderate exertion. Which of the following additional findings is most likely to be seen in this patient?

Question

A 56-year-old man comes to the office due to worsening cough for the past several months.  He initially had a morning cough productive of minimal sputum, but now the cough occurs throughout the day with large amounts of yellowish sputum.  The patient also has breathlessness on moderate exertion.  He has had 3 hospitalizations over the past year for respiratory infections.  The patient has smoked a pack of cigarettes daily for the past 30 years and has failed multiple attempts to quit.  Oxygen saturation is 90% at rest and decreases to 84% with moderate exertion.  Which of the following additional findings is most likely to be seen in this patient?

Quizplus · Accepted Answer

This patient with progressive dyspnea and productive cough in the setting of significant smoking history likely has chronic obstructive pulmonary disease (COPD). His recent hospitalizations for respiratory infections likely represent COPD exacerbations. Hypoxemia (O₂ saturation <92%) is common in advanced COPD and occurs via 2 major mechanisms: Hypoxemia leads to hypoxia throughout the tissues of the body, which is sensed by specialized interstitial cells in the renal cortex and medulla. In response, these cells release erythropoietin, which stimulates the bone marrow to increase production of red blood cells and bolster the oxygen-carrying capacity of the blood. The resulting increase in hematocrit, known as secondary polycythemia, is an expected finding in diseases or conditions that cause significant chronic hypoxemia (eg, COPD, interstitial lung disease, obesity hypoventilation syndrome, residing at high altitude). (Choice A) Air-trapping leads to an increase in the functional residual capacity in patients with COPD. (Choice B) Hypoxic vasoconstriction in advanced COPD increases pulmonary vascular resistance and leads to increased right ventricular afterload. (Choice D) Airway obstruction in COPD leads to decreased expiratory flow rates. This is apparent as a reduction in forced expiratory volume in 1 second (FEV1). (Choice E) Left ventricular compliance is increased in conditions that lead to eccentric left ventricular hypertrophy (eg, dilated cardiomyopathy, ischemic heart disease, severe aortic or mitral valve regurgitation). It is not significantly affected in COPD. Educational objective: In response to tissue hypoxia, specialized interstitial cells in the renal medulla and cortex release erythropoietin to stimulate the bone marrow to increase red blood cell production and improve the oxygen-carrying capacity of the blood. This response, known as secondary polycythemia, is an expected finding in diseases or conditions that cause significant chronic hypoxemia (eg, chronic obstructive pulmonary disease).

A 56-Year-Old Man Comes to the Office Due to Worsening