Upper airway stenosis: a physiologic study.

Upper airways stenosis and other forms of obstructive ventilatory disturbances were easily distinguished by the analysis of flow volume curves. This was not true for stenosis of the main bronchi. More than an increase in airway resistance, the characteristic pattern was the limitation of maximal inspiratory and expiratory flows at high lung volume. In the present work, 14 cases of laryngeal or tracheal obstruction were studied by conventional spirometry, flow volume curves, and body plethysmography.