Cough and dyspnea during bronchoconstriction: comparison of different stimuli

Abstract 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 ≤ 0.04). Conclusion Bradykinin seems to be the most suitable stimulus for bronchial challenge tests intended for measuring cough in association with bronchoconstriction.

This work was supported by grants from S. Paulo State Government (FAPESP – grants: 98/10382-6 and 03/09865-2). The authors would like to thank Elizabet Sobrani for her technical assistance and Eliza Omai for her assistance with the statistical analysis.

This work was supported by grants from S. Paulo State Government (FAPESP – grants: 98/103826 and 03/098652). The authors would like to thank Elizabet Sobrani for her technical assistance and Eliza Omai for her assistance with the statistical analysis.