Pulmonary Function Testing
Pulmonary function tests traditionally show major airway irreversible obstruction with decreased FEV1 and FEV1:FVC ratio with no response to bronchodilator inhalation. However, as the large airways are not involved, a restrictive pattern may occur with decreased vital capacity and corresponding FEV1, resulting in no decrease in the FEV1:FVC ratio. In this setting, the small airways are often completely obliterated on a focal basis, resulting in a normal diffusing capacity because remaining lung is normally ventilated and perfused. Markopoulou and others found that among 19 patients with bronchiolar obliteration from both fibrotic and inflammatory lesions, 11 had airflow obstruction, one had restrictive pattern, one had mixed obstructive and restriction, two had air trapping, and four had normal spirometric values.
Expert Rev Resp Med. 2007;1(1):139-147. © 2007 Future Drugs Ltd.
Cite this: Constrictive Bronchiolitis Obliterans: The Fibrotic Airway Disorder - Medscape - Aug 01, 2007.