Role of simulated repetitive coughing in mucus clearance.

The role of repetitive simulated coughing on the clearance of gel mucus simulant was investigated in vitro, by using a simulated cough machine. The repetition of cough induced a significant increase (p less than 0.01) in mucus simulant clearance (139.3 +/- 78.7 mm) in comparison to a single cough (24.9 +/- 27.5 mm). Moreover, the increase in frequency of the repetitive coughing induced a marked and significant increase in mucus simulant clearance (75.4 +/- 51.1 mm and 139.3 +/- 78.7 mm at 0.1 Hz and 1.6 Hz frequency, respectively). A significant (p less than 0.05) correlation was observed between the percentage increase of clearance and both shear-thinning index (r = 0.62) and the thixotropic index (r = 0.63). These results suggest that the shear-dependent properties of mucus, associated with a repetitive coughing, may increase the efficiency of mucus clearance by air flow mechanisms.

[1]  M. King,et al.  Effect of airway wall flexibility on clearance by simulated cough. , 1987, Journal of applied physiology.

[2]  C. Duvivier,et al.  Elasto-thixotropic properties of bronchial mucus and polymer analogs. I. Experimental results. , 1985, Biorheology.

[3]  Scherer Pw.  Mucus transport by cough. , 1981 .

[4]  J. Blake,et al.  On the movement of mucus in the lung. , 1975, Journal of biomechanics.

[5]  D. Quemada,et al.  Blood viscoelasticity and thixotropy from stress formation and relaxation measurements: a unified model. , 1983, Biorheology.

[6]  M. Huggins.  Viscoelastic Properties of Polymers. , 1961 .

[7]  M. Sackner,et al.  Mucus clearance by two-phase gas-liquid flow mechanism: asymmetric periodic flow model. , 1987, Journal of applied physiology.

[8]  K. Philipson,et al.  Elimination of test particles from the human tracheobronchial tract by voluntary coughing. , 1979, Scandinavian journal of respiratory diseases.

[9]  A new viscoelastometer for studying the rheological properties of bronchial mucus in clinical practice. , 1984, Biorheology. Supplement : the official journal of the International Society of Biorheology.

[10]  J. Zahm,et al.  The frog palate for studying mucus transport velocity and mucociliary frequency. , 1983, European journal of respiratory diseases. Supplement.

[11]  S W Clarke.  The role of two-phase flow in bronchial clearance. , 1973, Bulletin de physio-pathologie respiratoire.

[12]  J. Mead,et al.  Contribution of airway collapse to supramaximal expiratory flows. , 1974, Journal of applied physiology.

[13]  P. Scherer,et al.  Mucus transport by cough. , 1981, Chest.

[14]  J. Zahm,et al.  Mucociliary transport in vivo and in vitro. Relations to sputum properties in chronic bronchitis. , 1980, European journal of respiratory diseases.

[15]  M. King,et al.  The role of mucus sol phase in clearance by simulated cough. , 1989, Biorheology.

[16]  J M Zahm,et al.  The role of mucus gel viscosity, spinnability, and adhesive properties in clearance by simulated cough. , 1989, Biorheology.

[17]  M. King,et al.  Mucus transport by high-frequency nonsymmetrical oscillatory airflow. , 1988, Journal of applied physiology.

[18]  M King.  Rôle of mucus viscoelasticity in clearance by cough. , 1987, European journal of respiratory diseases. Supplement.