title: Airway responsiveness to hyperosmolar saline challenge in cystic fibrosis: a pilot study.
abstract: Hyperosmolar aerosols are used to assess airway responsiveness in subjects with asthma. Using a 10% NaCl aerosol, we investigated airway responsiveness in 23 cystic fibrosis (CF) subjects (12 females, 11 males; 19.1 +/- 3.3 years) who had asthma-like symptoms. The pre-challenge predicted forced expiratory volume in 1 second (FEV1) was 74.7 +/- 21.5. The aerosol was generated by a MistO2gen 143A ultrasonic nebulizer and inhaled for 0.5, 1, 2, 4, 8, 8, and 8 minutes or part thereof. Spirometry was performed before and 1 minute after each inhalation period. The challenge was stopped when a > or = 20% fall from the baseline FEV1 was recorded, after the last inhalation period, or when requested by the subject. We recorded different responses to 10% NaCl among subjects. In 7, the FEV1 fell progressively throughout the challenge in a manner similar to asthmatics. By contrast, in 15 subjects the FEV1 was higher at the completion of challenge compared to during challenge, i.e., the fall in FEV1 was transient. In 7 of these subjects, the final FEV1 at the end of the challenge was higher than the pre-challenge FEV1. We conclude that inhaled 10% hyperosmolar saline causes either progressive and sustained or transient airway narrowing during challenge in the majority of CF subjects. The cause of the transient airway narrowing requires further investigation.
authors.affiliation: Department of Respiratory Medicine, Royal Prince Alfred Hospital, Camperdown, New South Wales, Australia.
authors.forename: L T
authors.initials: LT
authors.lastname: Rodwell
authors.forename: S D
authors.initials: SD
authors.lastname: Anderson
mesh_terms: D000293:Adolescent; D000328:Adult; D000336:Aerosols; D000403:Airway Resistance / Q000502:physiology; D001249:Asthma / Q000503:physiopathology; D016535:Bronchial Hyperreactivity / Q000503:physiopathology*; D001985:Bronchial Provocation Tests; D003371:Cough / Q000503:physiopathology; D003550:Cystic Fibrosis / Q000503:physiopathology*; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008297:Male; D010865:Pilot Projects; D012462:Saline Solution, Hypertonic; D013147:Spirometry
chemical_list: D000336:Aerosols; D012462:Saline Solution, Hypertonic