Pulmonary Mucociliary Clearance in Cystic Fibrosis

Pulmonary clearance was examined by measurement of the rate of removal of a 99mTc-albumin aerosol (aerodynamic mass median diameter 3 μ) in 13 children with cystic fibrosis. Lung retention of radioactive label was monitored with a scintillation camera interfaced to a data-storage and retrieval system. The results were compared to those of nine normal adults. Overall lung retention was at all times greater in the normal subjects than in the patients (83.9 per cent at six hours after initial deposition vs. 59.6 per cent). The clearance curves of the patients had two exponentials with clearance half-times of 0.7 and 11.5 hours respectively. The mean curve for the normal subjects had a single exponential with half-times of 23.0 hours. In clinically stable patients with cystic fibrosis, clearance of inhaled aerosol from ciliated airways takes place at rapid rates, similar to those previously reported for mucociliary transport in normal adults.