Journal of Applied Physiology, Vol 63, Issue 5 1871-1876, Copyright © 1987 by American Physiological Society
High-frequency oscillatory ventilation increases canine pulmonary epithelial permeability
G. C. Man, I. H. Ahmed, J. W. Logus and S. F. Man
Department of Medicine, University of Alberta, Edmonton, Canada.
To investigate the effect of high-frequency oscillatory ventilation (HFOV)
on the pulmonary epithelial permeability, we measured the clearance rate of
nebulized sodium pertechnetate (99mTcO4-) and
diethylenetriaminepentaacetate (99mTc-DTPA) before and after a 4-h period
of mechanical ventilation in anesthetized mongrel dogs. The animals also
underwent experiments with 4 h of spontaneous breathing (SB) and
intermittent positive-pressure ventilation (IPPV) with and without addition
of positive end-expiratory pressure (PEEP) for comparison. After IPPV and
SB there was no change in the clearance rate of either 99mTcO4- or
99mTc-DTPA. After IPPV + PEEP and HPOV (8 and 16 Hz), there was an increase
in the clearance rate of 99mTc-DTPA, but an increase in clearance rate of
99mTcO4- was seen after IPPV + PEEP only. In a separate group of dogs an
increase in end-tidal lung volume was demonstrated after 4 h of ventilation
with IPPV + PEEP (but not after HFOV), and this may account for the
measured increase in 99mTcO4- clearance. We conclude that an increase in
99mTc-DTPA clearance rate after HFOV signifies an increase in pulmonary
epithelial permeability, possibly through the mechanism of damage to the
intercellular junctions during HFOV.
