title: The flow-volume loop in bilateral vocal cord paralysis.
abstract: A 38-year-old man with posttraumatic bilateral vocal cord paralysis and a surgically repaired avulsion of the extrathoracic trachea presented with a slight increase of exertional dyspnea (grade 2). Spirometry showed high normal FEV1 for FVC variables, but the F-V loop was characteristic for highly variable UAO with an increased FEV1/PEF ratio of 11 ml/L/min as well as a MEF50/MIF50 of 4.55. Endoscopy during forced respiration showed near total inspiratory obstruction of the larynx due to paradoxical behavior of the vocal cords. In extrathoracic airway obstruction a FEV1/PEF ratio > 10 ml/L/min combined with a MEF50/MIF50 ratio > 4 is suggestive of variable UAO caused by bilateral vocal cord paralysis rather than by a tracheal lesion.
authors.affiliation: Department of Internal Medicine, University Hospital, Basel, Switzerland.
authors.forename: C T
authors.initials: CT
authors.lastname: Bolliger
authors.forename: J
authors.initials: J
authors.lastname: Sopko
authors.forename: P
authors.initials: P
authors.lastname: Maurer
authors.forename: M
authors.initials: M
authors.lastname: Soler
authors.forename: A P
authors.initials: AP
authors.lastname: Perruchoud
mesh_terms: D000328:Adult; D004417:Dyspnea / Q000209:etiology*; D006801:Humans; D007829:Laryngostenosis / Q000175:diagnosis / Q000209:etiology*; D008297:Male; D008449:Maximal Expiratory Flow-Volume Curves / Q000502:physiology; D013147:Spirometry; D013997:Time Factors; D014132:Trachea / Q000293:injuries; D014826:Vocal Cord Paralysis / Q000150:complications / Q000503:physiopathology*