par Verbanck, Sylvia;Schuermans, Daniel;Van Muylem, Alain ;Paiva, Manuel ;Noppen, M.;Vincken, Walter
Référence Journal of applied physiology, 83, 6, page (1907-1916)
Publication Publié, 1997-12
Article révisé par les pairs
Résumé : We investigated ventilation inhomogeneity during provocation with inhaled histamine in 20 asymptomatic nonsmoking subjects. We used N2 multiple-breath washout (MBW) to derive parameters S(cond) and S(acin) as a measurement of veXation inhomogeneity in conductive and acinar zones of the lungs, respectively. A 20% decrease of forced expiratory volume in 1 s (FEV1) was used to distinguish responders from nonresponders. In the responder group, average FEV1 decreased by 26%, whereas S(cond) increased by 390% with no significant change in S(acin). In the nonresponder group, FEV1 decreased by 11%, whereas S(cond) increased by 198% with no significant S(acin) change. Despite the absence of change in Satin during provocation, baseline S(acin) was significantly larger in the responder vs. the nonresponder group. The main findings of our study are that during provocation large ventilation inhomogeneities occur, that the small airways affected by the provocation process are situated proximal to the acinar zone where the diffusion front stands, and that, in addition to overall decrease in airway caliber, there is inhomogeneous narrowing of parallel airways.