0000000000353020
AUTHOR
Trisevgeni Kapsali
Deep inspiration-induced bronchoprotection is stronger than bronchodilation
We have previously shown that in healthy subjects, deep inspiration (DI) has not only a bronchodilatory but also a bronchoprotective effect that is absent in asthmatic subjects. We conducted the study reported here to test the hypothesis that the bronchoprotective effect is stronger than the bronchodilatory effect, and to determine the extent to which these two effects are related. Ten healthy subjects underwent provocations in which single doses of methacholine, previously shown to reduce FEV(1) by 10% to 20% (Dose 1) and by 20% to 40% (Dose 2) were administered after a 20-min period devoid of DI. To measure the bronchodilator effect, DIs were performed immediately after the first spiromet…
Potent bronchoprotective effect of deep inspiration and its absence in asthma
In the absence of deep inspirations, healthy individuals develop bronchoconstriction with methacholine inhalation. One hypothesis is that deep inspiration results in bronchodilation. In this study, we tested an alternative hypothesis, that deep inspiration acts as a bronchoprotector. Single-dose methacholine bronchoprovocations were performed after 20 min of deep breath inhibition, in nine healthy subjects and in eight asthmatics, to establish the dose that reduces forced expiratory volume in 1 s by >15%. The provocation was repeated with two and five deep inspirations preceding methacholine. Additional studies were carried out to assess optimization and reproducibility of the protocol …