Mucus clearance at rest and during exercise in patients with bronchial hypersecretion.

The purpose of this study was to measure the effects on mucus clearance after physical exercise. We measured mucociliary clearance at rest and during exercise in eleven patients with mild or moderate bronchial hypersecretion. The subjects inhaled an aerosol containing 99mTc-labelled albumin millimicrospheres. Four sets of scintigraphic images were obtained with 15 minute intervals. The lung retention of radioactivity was quantified using a gamma camera and the clearance of particles from the lungs were calculated for each 15 min period. The first image was obtained directly after inhalation, the second after a period of 15 min rest, the third after a period of exercise on a bicycle ergometer and the final fourth image after another period of rest. We found no differences in the clearance rate at rest and after exercise.