Mucociliary transport time was determined ex vivo as an indicator of mucociliary function [ 19].
Consequently, when the upper airways are bypassed (as in a patient with an endotracheal tube) medical gases, which are drier than ambient air [ 2], must be heated and humidified by heated humidifiers or heat-moisture exchangers [ 1] in order to avoid bronchial inflammation, cell damage, impairment of mucociliary clearance and loss of pulmonary function [ 3- 6].
The initial response of the nasal mucosa to the presence of a pathogen is an inflammatory reaction accompanied with mucus hypersecretion [1, 2], resulting in increased mucus viscosity and eventually an impairment of mucociliary clearance.
This increase in ceramide results in chronic inflammation, increased death of epithelial cells, release of DNA into the bronchial lumen and thereby an impairment of mucociliary clearance; while the lack of sphingosine in airway epithelial cells causes high infection susceptibility in CF mice and possibly patients.
In addition, diuresis might lead to systemic dehydration and impairment of mucociliary clearance [ 30, 31].
Disruption of these processes can lead to altered composition of nasal secretions and impairment of mucociliary clearance, common features of various nasal and paranasal diseases (Tos & Mogensen 1984).
Moreover, areas of post-stenotic pneumonia and impairment of mucociliary clearance are accompanied by some degree of inflammation, which may again affect lymph node perfusion.
Signs and symptoms of respiratory tract infection also occur commonly in visitors to altitude [ 61, 62] in whom there is also evidence of impairment of mucociliary transport - a crucial respiratory defence mechanism [ 56].
Dynlrb2 is differentially expressed in patients with primary ciliary dyskinesia, a condition that can lead to the development of bronchiectasis due to impairment of mucociliary clearance (Geremek et al. 2011).
52 Structural changes in the respiratory tract that have been attributed to tobacco smoke include peribronchiolar inflammation and fibrosis, increased mucosal permeability, impairment of mucociliary clearance, changes in pathogen adherence and disruption of the respiratory epithelium, 52 53 which are thought to predispose individuals to the development of respiratory tract infections.
