Respiratory system reactance is an independent determinant of asthma control

摘要: The mechanisms underlying not well-controlled (NWC) asthma remain poorly understood, but accumulating evidence points to peripheral airway dysfunction as a key contributor. present study tests whether our recently described respiratory system reactance (Xrs) assessment of reveals insight into poor control. aim this was investigate the contribution Xrs In 22 subjects with asthma, we measured (forced oscillation technique), spirometry, lung volumes, and ventilation heterogeneity (inert-gas washout), before after bronchodilator administration. relationship between volume during deflation maneuver yielded two parameters: at which abruptly decreased (closing volume) (Xrscrit). Lowered (more negative) Xrscrit reflects reduced apparent compliance high volumes due, for example, heterogeneous narrowing unresolved closure or near above critical volume. Asthma control assessed via 6-point Control Questionnaire (ACQ6). NWC defined ACQ6 > 1.0. 10 12 subjects, strongly associated postbronchodilator (post-BD) (R(2) = 0.43, P < 0.001), independent all variables, strong predictor (receiver operator characteristic area 0.94, 0.001). By contrast, measures lower were ACQ6. itself significantly gas trapping heterogeneity, thus confirming link heterogeneity. Residual is an contributor