Pulmonary function in relapsing polychondritis.

The pulmonary mechanics and bronchoscopic findings in 5 patients with relapsing polychondritis were studied to evaluate the mechanism of obstruction. Two of the patients did not have clinical symptoms referable to the respiratory tract: pulmonary function was normal in 1 patient and was suggestive of mild restriction in the other. Three patients had dyspnea; pulmonary function studies revealed expiratory and inspiratory obstruction in all 3. The maximal flow-static recoil curves demonstrated that the expiratory obstruction was due predominantly to airway abnormality and not to loss of elastic recoil forces of the lung. The bronchoscopic appearance of the extrathoracic airway during quiet breathing did not accurately reflect pulmonary function results. One patient had a visually normal upper airway but greatly reduced maximal inspiratory flow rates, whereas another patient had pronounced narrowing of the upper airway but only a modest reduction of maximal inspiratory flow rates. The bronchoscopic appearance of the intrathoracic airway during quiet breathing did relate well to maximal expiratory flow rates. We conclude that in our group of patients the predominant mechanism of expiratory obstruction in relapsing polychondritis is due to airway abnormality. Although the bronchoscopic and radiographic findings are useful, spirometry is more important in determining functional abnormality.