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Sponsors and Collaborators: |
University of Florida GlaxoSmithKline |
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Information provided by: | University of Florida |
ClinicalTrials.gov Identifier: | NCT00145990 |
To determine whether there is a difference in two different breathing tests used to detect asthma. Hypothesis: The Digidoser delivers less methacholine to the airways and will result in a higher PC20 than the value determined by the Rosenthal Dosimeter.
Condition | Intervention |
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Asthma |
Drug: methacholine Device: KoKo Digidoser Device: Rosethal Dosimeter |
Study Type: | Interventional |
Study Design: | Diagnostic, Randomized, Open Label, Uncontrolled, Crossover Assignment |
Estimated Enrollment: | 12 |
Study Start Date: | September 2005 |
Estimated Study Completion Date: | December 2005 |
Bronchoprovocation with methacholine is used to confirm the diagnosis of asthma. The procedure involves inhaling methacholine through a nebulizer attached to a dosimeter that delivers a precise volume of methacholine. The endpoint of the test is the provocational concentration that produces a 20% decrease in FEV1 (PC20). To standardize the procedure, the American Thoracic Society (ATS) recommends that the nebulizer output be calibrated to deliver an output of 0.9 ± 0.09 mL/min.
The Rosenthal Dosimeter and the KoKo Digidoser are two commonly used dosimeters. In an attempt to follow the ATS guideline we discovered that the nebulizer output was lower with the KoKo Digidoser and could not be calibrated. However, it is unclear whether the apparent lower output is a result of the Digidoser delivering less solution or that the ATS method of determining output is not applicable to this dosimeter. To answer this question, we propose to determine the methacholine PC20 in subjects with asthma using the two dosimeters. It is our hypothesis that the Digidoser delivers less methacholine and thus will produce a higher PC20 than the Rosenthal Dosimeter.
Twelve nonsmoking subjects with mild asthma will be selected on the basis of > 18 years of age, a baseline FEV1 of > 60% predicted and a screening PC20 of < 8mg/ml. Subjects will be randomized to perform a methacholine challenge with the Digidoser and the Rosenthal Dosimeter on two different days in an unblinded, crossover manner. The geometric mean PC20 with each dosimeter will be compared with a paired t test. The results of this study will indicate whether the Digidoser has the potential of causing false negative test results or whether the ATS method of determining output should not be used with this dosimeter.
Ages Eligible for Study: | 18 Years to 60 Years |
Genders Eligible for Study: | Both |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
Exclusion Criteria:
United States, Florida | |
University of Florida Asthma Research Lab | |
Gainesville, Florida, United States, 32610 |
Principal Investigator: | Yasmeen Khan, MD | University of Florida |
Study ID Numbers: | 257-2005 |
Study First Received: | September 1, 2005 |
Last Updated: | September 28, 2006 |
ClinicalTrials.gov Identifier: | NCT00145990 |
Health Authority: | United States: Institutional Review Board |
methacholine PC20 dosimeter asthma |
Hypersensitivity Lung Diseases, Obstructive Respiratory Tract Diseases Lung Diseases |
Methacholine Chloride Hypersensitivity, Immediate Asthma Respiratory Hypersensitivity |
Parasympathomimetics Respiratory System Agents Neurotransmitter Agents Molecular Mechanisms of Pharmacological Action Bronchial Diseases Immune System Diseases Cholinergic Agonists Bronchoconstrictor Agents |
Miotics Physiological Effects of Drugs Cholinergic Agents Pharmacologic Actions Autonomic Agents Therapeutic Uses Muscarinic Agonists Peripheral Nervous System Agents |