Background: Airway function, as assessed by standard
spirometry, and the intensity of dyspnea reported by asthmatic patients
Objective: This study tests the
following two hypotheses: (1) that measures of the tendency of a
patient to somatize will reduce the variation in the report of dyspnea
not explained by airway function; and (2) that plethysmography is a
better tool with which to estimate the degree of dyspnea associated
Design: A prospective laboratory study
carried out over one study session.
Forty asthmatic subjects who had withheld bronchodilator (BD) therapy
Interventions: We performed spirometry,
plethysmography, and an assessment of dyspnea (ie,
modified Borg scale) on all subjects before and after they received BD
therapy. Standard questionnaires pertaining to psychological state and
trait were administered as well.
Results: The change
in specific airway conductance with BD therapy correlated with a
decline in the Borg score (r = 0.47; p = 0.007). By
contrast, neither spirographic measures nor measures of static lung
volumes correlated. Correlation with the Borg scale score was not
improved by adding indexes of either somatization or psychological
state or trait.
Conclusion: The relief of dyspnea
reported by patients with mild asthma after BD therapy is related to
dilatation of the central airways.