High frequency oscillations and mucociliary transport

The effect of high-frequency ventilation on non-Newtonian properties of bronchial mucus

We have investigated the changes in the non-Newtonian properties of human bronchial mucus brought about by in vitro high frequency ventilation. This type of ventilation brought about changes in viscous properties, measured during creep and oscillation of the mucus, which would be expected to reduce mucus clearance in vivo. We suggest that any beneficial effects of clinical high-frequency ventilation on respiratory mucus clearance in patients are not brought about by long-term (more than a few seconds) changes in the viscous properties of the mucus itself.

Effect of low frequency air oscillations on nasal mucociliary transport

Air oscillations of 16 Hz and pressure differences of 200 mmHg were applied to the nose of 30 volunteers. The mucociliary transport was measured by the saccharin test. Tests under the same circumstances were performed with and without oscillations on the same person within the same day. There was a significantly faster mucociliary transport during air oscillations. The possible mechanisms for this effect are discussed.