Persistent Dyspnea in a 74-Year-Old Man With Normal Spirometry and Lung Volumes

A 74-year-old man was referred to a pulmonologist for evaluation of a 1-year history of nonproductive cough and progressive exertional dyspnea. He was initially evaluated by his primary care physician, where he had spirometry that was negative for any obstructive or restrictive lung disease. An echocardiogram showed a normal left ventricular ejection fraction, with no wall motion abnormality or valvular heart disease. He had an outpatient chest radiograph performed (Fig 1), and he was subsequently treated empirically for a COPD exacerbation with 5 days of oral prednisone and azithromycin. He was eventually referred to a pulmonologist because of a lack of clinical improvement. On seeing his pulmonary physician, he described the same exertional dyspnea and a nonproductive cough. A review of systems was negative for fever, chills, wheezing, angina, arthralgia, myalgia, rash, or leg swelling. He denied any medical illness and was not taking any medications. He was currently retired and had worked as a cashier his entire adult life. He had no occupational exposure to asbestos, coal dust, beryllium, silica dust, or dust from hard metal objects, such as cobalt. However, he had smoked approximately 1 to 2 packs of cigarettes per day and had done so for the past 50 years. His vital signs were unremarkable, aside from an oxygen saturation of 94% on room air. His physical examination revealed bibasilar "velcro-like" inspiratory crackles on lung examination. There was no digital clubbing, nor was there peripheral edema in his lower extremities. He had no muscle tenderness and demonstrated normal muscle strength against resistance.