Validation of an Exposure System to Particles for the Diagnosis of Occupational Asthma
Autor: | Yves Cloutier, Françoise Lagier, André Cartier, Jean-Luc Malo |
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Rok vydání: | 1992 |
Předmět: |
Pulmonary and Respiratory Medicine
medicine.medical_specialty Time Factors Dose-Response Relationship Immunologic Occupational disease Bronchial provocation tests Critical Care and Intensive Care Medicine Bronchial Provocation Tests Forced Expiratory Volume medicine Humans Lung function Aerosolization Bronchial hyperreactivity Asthma Aerosols business.industry Dust Equipment Design Allergens medicine.disease Surgery Occupational Diseases Evaluation Studies as Topic Anesthesia Exposure chamber Bronchial Hyperreactivity Cardiology and Cardiovascular Medicine business Occupational asthma |
Zdroj: | Chest. 102:402-407 |
ISSN: | 0012-3692 |
Popis: | Study Objective : We previously described a closed-circuit system for exposure to particles in humans. This system has three components: a particle generator, an exposure chamber connected to an orofacial mask, and monitors. We describe results of challenges in 56 subjects who underwent challenges with the apparatus using occupational sensitizers in particles. Subjects : Fifty-six consecutive subjects referred for the investigation of occupational asthma to occupational sensitizers in particles were included. The agents were the following: flour and grains (n = 19), cedar (n = 10), psyllium (n = 9), guar gum (n = 9), drugs (n = 3), persulfate (n = 2), and miscellaneous (n = 4). Intervention : The duration of exposure was progressive and varied from one breath to a maximum of 180 min depending on the reaction. When no significant fall in FEV 1 occurred after exposure with the aerosolization device, the standard approach of tipping particles from one tray to another was used. Results : Twenty-nine subjects (52 percent) had a significant (≥20 percent) fall in FEV 1 after exposure. This includes 18 subjects with isolated immediate reactions, four with dual asthmatic reactions, and two with atypical reactions. In 20/24 instances (83 percent), the percentage of fall in FEV 1 did not exceed 30 percent, thus showing that dose-response curves can generally be obtained in a safe way. In all instances except one (26/27 cases), subsequent exposures using the traditional method did not result in significant falls in FEV 1 . Conclusion : This new procedure results in safe tests in terms of the percentage of changes in FEV 1 during the immediate reactions and very rare false-negative challenges. |
Databáze: | OpenAIRE |
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