High-frequency oscillatory ventilation increases canine pulmonary epithelial permeability.
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.
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Department of Medicine, University of Alberta, Edmonton, Canada.
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D000818:Animals; D002245:Carbon Dioxide / Q000097:blood; D002463:Cell Membrane Permeability; D004285:Dogs; D004848:Epithelium / Q000378:metabolism; D006612:High-Frequency Ventilation; D008168:Lung / Q000378:metabolism*; D008176:Lung Volume Measurements; D009079:Mucociliary Clearance; D009942:Organometallic Compounds; D010100:Oxygen / Q000097:blood; D004369:Pentetic Acid; D011175:Positive-Pressure Respiration; D013670:Sodium Pertechnetate Tc 99m; D016284:Technetium Tc 99m Pentetate
D009942:Organometallic Compounds; D002245:Carbon Dioxide; D004369:Pentetic Acid; D013670:Sodium Pertechnetate Tc 99m; D010100:Oxygen; D016284:Technetium Tc 99m Pentetate