Asthmatic subjects with tidal expiratory flow limitation have mucociliary clearance (MC)
impairment in central airways. Because tidal flow limitation develops in COPD, it is possible
that regional MC in these patients also may be affected. We tested this hypothesis by
measuring MC in the presence or absence of flow limitations. Patients with COPD and
chronic flow limitation were compared with non-flow-limited normal volunteers. Deposition
was normalized for regional lung volume and expressed as the specific central to peripheral …