A simple method of bronchoprovocation using a valved holding chamber.

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 amoun…