Cough and dyspnea during bronchoconstriction: comparison of different stimuli.
BACKGROUND
Bronchial challenge tests are used to evaluate bronchial responsiveness in diagnosis and follow-up of asthmatic patients. Challenge induced cough has increasingly been recognized as a valuable diagnostic tool. Various stimuli and protocols have been employed. The aim of this study was to compare cough and dyspnea intensity induced by different stimuli.


METHODS
Twenty asthmatic patients underwent challenge tests with methacholine, bradykinin and exercise. Cough was counted during challenge tests. Dyspnea was assessed by modified Borg scale and visual analogue scale. Statistical comparisons were performed by linear mixed-effects model.


RESULTS
For cough evaluation, bradykinin was the most potent trigger (p < 0.01). In terms of dyspnea measured by Borg scale, there were no differences among stimuli (p > 0.05). By visual analogue scale, bradykinin induced more dyspnea than other stimuli (p < or = 0.04).


CONCLUSIONS
Bradykinin seems to be the most suitable stimulus for bronchial challenge tests intended for measuring cough in association with bronchoconstriction.
Suguikawa
Thais R
TR
Department of Medicine, Medical School of Ribeirão Preto, University of S, Paulo at Ribeirão Preto, Brazil. tha_ss@yahoo.com
Garcia
Clecia A
CA
Martinez
Edson Z
EZ
Vianna
Elcio O
EO