Chronic obstructive pulmonary disease following idiopathic pulmonary fibrosis.

The rapid development of irreversible airflow obstruction in two nonsmoking women who recovered from acute idiopathic pulmonary fibrosis is discussed. Pulmonary fibrosis was diagnosed clinically and by lung biopsy. Recovery both clinically and radiologically was complete. Several pulmonary function studies in both patients showed a typical restrictive pattern (reduced lung volumes and carbon dioxide diffusing capacity, normal FEV1/FVC ratio). Within one year both patients exhibited an obstructive pattern of dysfunction (hyperinflation, gas trapping, reduced airflow measurements). These patients illustrated irreversible airway obstruction following recovery from the restrictive stage of pulmonary fibrosis.