Journal of Applied Physiology, Vol 55, Issue 6 1854-1861, Copyright © 1983 by American Physiological Society
Effects of high-frequency breathing on pulmonary ventilation and gas exchange
C. Frostell, J. N. Pande and G. Hedenstierna
The effects of spontaneous high-frequency breathing (HFB) on lung function
were evaluated in three subjects highly trained in the practice of yoga.
Transpulmonary pressure was measured by an esophageal balloon catheter and
gas flow by pneumotachography. The abdominal and rib cage contributions to
tidal breathing were measured separately by respiratory inductive
plethysmography. Gas exchange was studied by the conventional technique and
by multiple inert gas elimination. During HFB, respiratory rate increased
to 232 cycles/min with a tidal volume of 0.35 liter. This resulted in a
more than 10-fold increase in expired minute ventilation to approximately
90 1/min. The transpulmonary pressure varied by 20 cmH2O, with the
calculated elastic, resistive, and accelerative components varying by 2,
20, and 8 cmH2O, respectively. Respiratory work increased more than
200-fold in comparison with resting ventilation. A phase shift between
thoracic and abdominal breathing was observed and was interpreted as a
volume displacement of approximately 30 1/min between the two parts of the
respiratory system. Arterial oxygen and carbon dioxide tension remained
normal. Bohr dead space increased, while acetone dead space remained
unaltered. A bimodal distribution of ventilation-perfusion ratios (VA/Q)
was observed, with one mode in normal and another in "high" VA/Q regions.
