A 56-year-old man comes to the physician with progressive shortness of breath over the past 4 months. He gets significantly short of breath after walking 2-3 blocks. He does not use tobacco.
On examination, blood pressure is 144/90 mm Hg, heart rate is 84/min, respirations are 16/min, and pulse oximetry is 91% on room air. Neck veins are flat in the sitting position. The skin of the fingers and hands appears thickened with a few ulcerations at the fingertips. Fine bibasilar crackles are heard on chest examination. There is no peripheral edema.
Chest x-ray reveals bilateral interstitial markings, most prominent at the bases.
Which of the following is most likely to be seen on pulmonary function testing?
FEV₁ = Forced expiratory volume in 1 second; FVC = Forced vital capacity; DLCO = Diffusing capacity for carbon monoxide

Question

Quizplus · Accepted Answer

11ec193a_98e7_ac90_853d_ef70e53be1a4_MD0002_00 Skin thickening over the hands and fingers and digital ulceration is one of the earliest signs of systemic sclerosis (SSc). About 70% of patients with SSC have pulmonary involvement (interstitial lung disease [ILD] or pulmonary hypertension). Lung involvement is the major cause of mortality associated with SSc; pulmonary function tests (PFTs) are routinely performed in these patients upon diagnosis, even in the absence of respiratory symptoms. This patient has fine basilar crackles and interstitial markings on chest x-ray suggesting ILD. Restrictive pattern PFTs will be seen, (including reduced FEV₁, FVC, and total lung capacity [TLC]), with preserved FEV₁/FVC ratio. Diffusion capacity of carbon monoxide (DLCO) is also reduced. ₁ ₁ (Choice A) Obstructive pattern spirometry with high TLC and normal DLCO is usually seen in asthma. (Choice B) Preserved lung volumes with reduced DLCO is more typical of pulmonary hypertension. (Choice C) Completely normal spirometry would not be expected in this patient with symptomatic ILD. (Choice D) Low DLCO can also be seen in COPD but the FEV₁/FVC ratio is not preserved (<0.7) and TLC will be high. ₁ Educational objective: Systemic sclerosis (SSc) is associated with pulmonary hypertension and interstitial lung disease. Restrictive lung diseases such as SSc-associated pulmonary fibrosis show reduced FEV₁, FVC, TLC, and DLCO with a normal FEV₁/FVC ratio. ₁ ₁ __________ References: Scleroderma lung disease. (http://www.ncbi.nlm.nih.gov/pubmed/23457159) Pulmonary function tests. (http://www.ncbi.nlm.nih.gov/pubmed/18784151)

A 56-Year-Old Man Comes to the Physician with Progressive Shortness