Inspiratory flow-volume curve evaluation for detecting upper airway disease.

Abstract

An abnormal inspiratory curve in the presence of otherwise normal spirometry should prompt an evaluation for the etiology. If one of the flow-volume inspiratory curves shows an abnormality, all the inspiratory curves from that PFT session should be reviewed, and if more than one inspiratory curves is abnormal, both anatomical and functional evaluation should be undertaken for intrathoracic and extrathoracic upper airway obstruction.