Airway mucus clearance

Breathing control techniques include autonomous breathing exercises like forced and deep expirations, and diaphragmatic breathing to optimize airway mucus clearance. 

Rubin BK. Physiology of airway mucus clearance. Respir Care 2002 47(7) 761-768. 

Konstan MW, Stern RC, Doershuk CF. Efficacy of the Flutter device for airway mucus clearance in patients with cystic fibrosis. J Pediatr 1994 124(5 pt l) 689-693. 

Disruption of these defense mechanisms can lead to bacterial colonization or viral infection. Mucus temperature is important in controlling respiratory infections because decreasing below central body core temperature not only impairs ciliary movement,hut also enhances viral replication,- greatly increasing the likelihood of respiratory infection. Drying of airway mucus also increases the possibility of respiratory infection by reducing mucus thickness and impairing mucociliary clearance, i- i--... 

Knowles MR, Boucher RC (2002) Mucus clearance as a primary innate defense mechanism for mammalian airways. J Clin Invest 109 571—577... 

Pulmonary disease is characterized by thick mucus secretions, impaired mucus clearance, chronic airway infection and colonization, obstruction, and an exaggerated neutrophil-dominated inflammatory response. 

The rate of removal of mucus from the airways is determined by such factors as mucus viscosity, the amount of mucus produced, and the degree of ciliary activity. These processes may be influenced by a variety of diseases, including asthma, cystic fibrosis, and chronic bronchitis [82,83], In patients suffering from cystic fibrosis or chronic bronchitis, mucus hypersecretion is evident and mucociliary function is impaired. The failure to clear mucus from the airways leads to airway obstruction and to chronic colonization of the airways with bacterial organisms (which leads to lung infections and airway inflammation and damage). In asthmatic subjects, airway mucus is more viscous and ciliary transport mechanisms are inhibited [82,83]. In these diseases, the therapeutic objective is to improve mucus clearance from the airways. For example, aerosols of water or saline (especially hypertonic saline) promote clearance of mucus by... 

It is believed that the lung infection results from impaired mucus clearance followed by colonization of bacteria in the mucus. The bacteria elaborate a number of toxins, polysaccharides, and enzymes including proteases, elastases, and exotoxin A, which may stimulate the production of additional mucus and further contribute to airway obstruction (Sam et al., 1980 Adler et al., 1983). Pseudomonas aeruginosa and Staphylococcus aureus are the most commonly found bacteria in the lungs of patients with CF, but Klebsiella, Esherichia coli, streptococci, and Haemophilus influenza can also be found. Of particular interest is the observation that mucoid strains of infectious bacteria, which are more pathogenic than nonmucoid strains, are most commonly found in patients with CF (Reynolds et al., 1975, 1976). The mucoid strains are also more resistant to phagocytosis by alveolar macrophages and are impermeable to antibiotics because of their mucoid coats. Thus treatment of pulmonary infections in patients with CF can be unusually difRcult. 

The effective elimination of airway mucus and other debris is one of the most important factor that permits successful use of chronic and acute ventilation support (noninvasive and invasive) for patients with either ventilatory or oxygenation impairment. In ventilatory dependent patients, the goals of intervention are to maintain lung compliance and normal alveolar ventilation at all times and to maximize cough flows for adequate bronchopulmonary secretion clearance (6). 

When there is extensive ciliary damage and mucus hypersecretion, airflow-dependent mucus clearance such as cough becomes critically important for airway hygiene. As a result of mucus production increase and poor ciliary response related to inflammation, ciliary... 

Mucus clearance and bronchial hygiene are often decreased in patients with airways diseases, such as asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF), as well as in patients with neuromuscular disorders and consequent dysfunctional cough or glottic control. 

King M, Rubin BK. Rheology of airway mucus relationship with clearance function. In Takashima T, Shimura S, eds. Airway Secretion Physiological Bases for the Control of Mucous Hypersecretion. New York Marcel Dekker, 1994 283-314. 

The particle size is the most important factor that contributes to the clearance of particles. For particles deposited in the anterior parts of the nose, wiping and blowing are important mechanisms whereas particles on the other areas of the nose are removed with mucus. The cilia move the mucus toward the glottis where the mucus and the particles are swallowed. In the tracheobronchial area, the mucus covering the tracheobronchial tree is moved upward by the cilia beating under the mucus. This mucociliary escalator transports deposited particles and particle-filled macrophages to the pharynx, where they are also swallowed. Mucociliary clearance is rapid in healthy adults and is complete within one to two days for particles in the lower airways. Infection and inflammation due to irritation or allergic reaction can markedly impair this form of clearance. 

Q Ineffective Airway Clearance related to narrowed airway passages, thick or excessive mucus... 

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