Pulmonary function tests carbon monoxide diffusing capacity

IV. Diagnosis is based on a history of exposure to asbestos (usually at least 15-20 years before onset of symptoms) and clinical presentation of one or more of the syndromes described above. Chest x-ray typically shows small, irregular, round opacities distributed primarily in the lower lung fields. Pleural plaques, diffuse thickening, or calcification may be present. Pulmonary function tests reveal decreased vital capacity and total lung capacity and impairment of carbon monoxide diffusion. 

Pulmonary function tests reveal a restrictive pattern in early disease. In the acute phase, a reduction in lung volume, carbon monoxide diffusing capacity, and static lung compliance are common. Some patients also show evidence of small airway obstruction. 

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