Impaired tracheobronchial clearance in bronchiectasis.

Abstract

Tracheobronchial clearance was measured by a radioaerosol technique in 12 patients with bronchiectasis, seven patients with chronic obstructive lung disease expectorating mucoid sputum daily (group X), eight patients with chronic obstructive lung disease but negligible sputum expectoration (group Y), and 10 healthy subjects. The patients with bronchiectasis all expectorated purulent sputum daily (mean wet weight 47 g/day), had reduced forced expiratory volume in one second (FEV1) (mean 47 5% predicted), and were unable to avoid coughing during the six hour observation period. None of the patients with bronchiectasis or the healthy subjects were current smokers. There were five current smokers in group X and six in group Y. The mean FEV1 in group X was 41% predicted and in group Y 52% predicted, both values similar to that of the patients with bronchiectasis.Tracheobronchial clearance in the first six hours after inhalation of radioaerosol was significantly (p < 0-01) slower in patients with bronchiectasis than in matched healthy subjects despite more proximal deposition of radioaerosol (p = 0 01) and more coughing (p < 001) in the former. Tracheobronchial clearance in patients with bronchiectasis was impaired to a similar degree to that in patients with chronic obstructive lung disease but no bronchiectasis.

Effect of increasing doses of mannitol on mucus clearance in patients with bronchiectasis

“…The majority of subjects had extensive bronchiectasis and poor baseline clearance (,10% over 60 min), consistent with previous findings [1][2][3][4][5]. However, the majority of subjects had improved clearance, which was dose dependent after mannitol.…”

“…ronchiectasis patients usually have increased and persistent mucus secretion along with impaired mucociliary transport, which results in mucus accumulation, cough and recurrent infections [1][2][3][4][5]. Most patients with bronchiectasis are troubled by the disease and have a poor quality of life [6,7].…”

Mucociliary Clearance in Bronchiectasis

“…The nasal mucociliary clearance in controls of this study was 7.84 ± 0.92) minutes, which was significantly longer in patients with bronchiectasis. Similar result was reported by Currie et al, 19 who measured tracheobronchial clearance by a radiosol technique in 12 patients with bronchiectasis and found that clearance in the first 6 hours after inhalation of radioaerosol was significantly slower in patients with bronchiectasis. …”

The biology of bacterial colonization and invasion of the respiratory mucosa

“…Whereas in chronic bronchitis [39], bronchiectasis [40] and cystic fibrosis [41], mucociliary clearance is delayed, giving bacteria that have adhered to mucus time to produce virulence factors (table 1) in sufficient quantities to establish the infection. Bacterial infection attracts leucocytes into the airways, many of which eventually degenerate releasing deoxyribonucleic acid (DNA) into the secretions making them more viscous and difficult to clear [42,43].…”