title: A simple method of bronchoprovocation using a valved holding chamber.
abstract: This study was undertaken to ascertain whether the use of a valved holding chamber (VHC) during bronchial provocation testing might increase lung deposition and repeatability of the test relative to the tidal breathing method. The 2-min tidal breathing results were compared to five inhalations from a VHC device in patients using the Pari-provoII nebulizer (MMD = 2.1mkm). Lung and mouth deposition, losses though the exhaled air and losses before aerosol delivery to the patient's mouth were measured in patients using a radiolabeled 99Tc-DTPA solution and gamma camera. The study revealed that lung deposition was 67% with the VHC method, and losses with exhaled air were 29% of the inhaled amount. The tidal breathing method resulted in lung deposition of 20.9 +/- 3.4%, and losses with exhaled air were 77.5 +/-3.5%. Mouth deposition did not differ significantly between methods. Variability in lung deposition was 15.3% for the VHC and 32.0% for the tidal breathing method. In addition to greater lung deposition and reproducibility, the VHC method allows easier calculation of the inhaled dose.
authors.affiliation: Department of Pathology, University of Latvia, Faculty of Medicine, Riga. taivans@latnet.lv
authors.forename: I
authors.initials: I
authors.lastname: Taivans
authors.forename: N
authors.initials: N
authors.lastname: Jurka
authors.forename: G
authors.initials: G
authors.lastname: Strazda
authors.forename: G
authors.initials: G
authors.lastname: Brezinskis
mesh_terms: D000336:Aerosols / Q000008:administration & dosage*; D001985:Bronchial Provocation Tests / Q000379:methods*; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D009330:Nebulizers and Vaporizers; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D016284:Technetium Tc 99m Pentetate; D013990:Tidal Volume
chemical_list: D000336:Aerosols; D019275:Radiopharmaceuticals; D016284:Technetium Tc 99m Pentetate