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Comparison of FEV 1 and specific airway conductance in assessing airway response to occupational agents
Author(s) -
Larbanois A.,
Delwiche J.P.,
Jamart J.,
Vandenplas O.
Publication year - 2003
Publication title -
allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.363
H-Index - 173
eISSN - 1398-9995
pISSN - 0105-4538
DOI - 10.1046/j.1398-9995.2003.00313.x
Subject(s) - medicine , asthma , cardiology , inhalation , airway , physical therapy , anesthesia
Background: There is theoretical evidence that specific airway conductance (SGaw) could be more reliable than forced expiratory volume in 1 s (FEV 1 ) for assessing changes in airway calibre. We investigated the changes in FEV 1 and SGaw when assessing bronchial responses to occupational agents. Methods: SGaw and FEV 1 were measured during inhalation challenges with various occupational agents in 174 consecutive subjects investigated for possible occupational asthma. Results: A decline in SGaw of 50% or greater was documented in 77 of 90 subjects (86%) who showed a ≥20% fall in FEV 1 and in 11 of 84 subjects (13%) who failed to demonstrate such a fall in FEV 1 . Among subjects who developed a ≥20% fall in FEV 1 , those who failed to develop a ≥50% decline in SGaw had a lower baseline SGaw than those who did. Among the group without a ≥20% fall in FEV 1 , a ≥50% decrease in SGaw was associated with either an ‘intermediate’ fall in FEV 1 (between 15 and 17% from baseline value) ( n = 4), a significant postchallenge increase in nonspecific bronchial hyper‐responsiveness to histamine ( n = 2), or both features ( n = 3). Conclusions: A decline in SGaw of 50% or greater may provide useful complementary evidence of a bronchial response during challenges that produce equivocal results in FEV 1 .