Mucociliary clearance in early simple chronic bronchitis.

Tracheobronchial mucociliary clearance was measured in 37 patients with early simple chronic bronchitis. A non-invasive radio-aerosol technique with inhalation of 99Tcm labelled 5-microns polystyrene particles followed by assessment of radio-nuclide distribution by posterior gamma-camera scans was employed. The mucociliary clearance of the bronchitics was significantly lower than clearance of a non-smoker control group. An interim analysis of the effect of treatment with a surfactant stimulating drug, ambroxol, suggested a dosage-dependent tendency to a faster mucociliary clearance than seen in placebo-treated bronchitics.