title: Incorporation and analysis of ultrasonically nebulized distilled water challenges in an epidemiologic study of asthma and bronchial reactivity.
abstract: The usefulness of an ultrasonically nebulized distilled water (UNDW) challenge as a screening procedure was tested in an on-going epidemiologic study of asthma and bronchial reactivity. Sixty-six individuals underwent a methacholine challenge, an UNDW challenge, and were administered a standardized respiratory disease questionnaire. To perform the UNDW challenge, subjects inhaled increasing volumes of nebulized distilled water while breathing tidally. Thirty-eight asthmatics, two former asthmatics, 14 normal, and 12 allergic subjects, were included. Sixty-six percent of the asthmatics dropped 20% from their baseline FEV1 during the UNDW challenge. Only one allergic or normal subject had a similar drop. The Pearson's correlation coefficient between methacholine and UNDW challenges was 0.60. If positive, an UNDW seems to be highly specific in supporting a diagnosis of asthma, while methacholine challenges are more useful in verifying the presence of non-specific bronchial reactivity.
authors.affiliation: Allergic Disease Center, Creighton University, Omaha, NE 68178.
authors.forename: R J
authors.initials: RJ
authors.lastname: Hopp
authors.forename: J
authors.initials: J
authors.lastname: Christy
authors.forename: A K
authors.initials: AK
authors.lastname: Bewtra
authors.forename: N M
authors.initials: NM
authors.lastname: Nair
authors.forename: R G
authors.initials: RG
authors.lastname: Townley
mesh_terms: D001249:Asthma / Q000453:epidemiology*; D001980:Bronchi / Q000503:physiopathology*; D001985:Bronchial Provocation Tests; D004305:Dose-Response Relationship, Drug; D006801:Humans; D008688:Methacholine Compounds; D009330:Nebulizers and Vaporizers; D012129:Respiratory Function Tests; D014465:Ultrasonics; D014867:Water / Q000494:pharmacology*
chemical_list: D008688:Methacholine Compounds; D014867:Water