Bronchial challenge testing in occupational epidemiology: is the diluent step really necessary?
| Autor: | J.-P. Michaely, Abraham Bohadana, Dan B. Teculescu |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Adult
Male Pulmonary and Respiratory Medicine Spirometry medicine.medical_specialty medicine.medical_treatment Immunology Provocation test Bronchi medicine.disease_cause Diluent Occupational epidemiology Forced Expiratory Volume Occupational Exposure medicine Humans Immunology and Allergy Saline Methacholine Chloride medicine.diagnostic_test business.industry Aeroallergen medicine.disease respiratory tract diseases Bronchial hyperresponsiveness Anesthesia Physical therapy Female Methacholine business medicine.drug |
| Zdroj: | Annals of Allergy, Asthma & Immunology. 89:24-28 |
| ISSN: | 1081-1206 |
| Popis: | Background There is no unanimous agreement on the use of a diluent step to preface methacholine challenge testing. The "pros" for this step are that it allows a better training of the patient; the "cons" are that it requires additional time and effort. Objective We examined if there were any systematic effects when either the baseline or postdiluent (saline) forced expiratory volume in 1 second (FEV 1 ) was used to define the reactivity status. Methods All methacholine challenge tests performed during a 1-year period by a group of occupationally exposed workers (n = 183) were examined. Results The mean percentage change in FEV 1 from baseline to postsaline was −1.44 (± 3.47)% and the mean absolute change was −0.043 (± 0.11) L ( P 1 from baseline were −12.7% and +10.9%, respectively. Three subjects had a fall in FEV 1 after saline of 10% or more and were not given methacholine. From the remaining 180 subjects, 172 were equally classified as reactors (n = 67) or nonreactors (n = 105), both by baseline FEV 1 and postsaline FEV 1 . Eight subjects were classified as reactors by baseline FEV 1 but as nonreactors by saline FEV 1 . In these subjects, the average FEV 1 dropped 4.9% from baseline to saline and 17.3% from saline to end-test; thus, the total FEV 1 drop (22.5%) exceeded the 20% required for the test to be positive. Among reactors, no relationship was found between the response to saline and the subsequent response to methacholine ( r = 0.13). Conclusions Our data did not provide evidence to support the compulsory use of a diluent step when measuring bronchial responsiveness in populations. In general, the diluent step added time and expense to the test and, on occasion, forced a greater absolute drop in FEV 1 than is needed to demonstrate bronchial hyperresponsiveness. |
| Databáze: | OpenAIRE |
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