Observational study of laryngoscopy plus flow-volume loops during exercise.

Laryngoscopy is the gold standard to diagnose exercise-induced laryngeal obstruction, though inspiratory flow-volume loop may provide a clue. We combined tidal flow-volume loop analysis plus laryngoscopy during exercise and found that cigar-shaped - not flattened - inspiratory loops are associated with obstruction. Pursed-lip breathing slows inhalation thereby reducing vocal fold adduction.