Man G C, Ahmed I H, Logus J W, Man S F
Department of Medicine, University of Alberta, Edmonton, Canada.
J Appl Physiol (1985). 1987 Nov;63(5):1871-6. doi: 10.1152/jappl.1987.63.5.1871.
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.
为研究高频振荡通气（HFOV）对肺上皮通透性的影响，我们在麻醉的杂种犬机械通气4小时前后，测量了雾化高锝酸钠（99mTcO4-）和二乙三胺五乙酸（99mTc-DTPA）的清除率。这些动物还进行了4小时自主呼吸（SB）以及有或无呼气末正压（PEEP）的间歇正压通气（IPPV）实验以作比较。IPPV和SB后，99mTcO4-或99mTc-DTPA的清除率均无变化。IPPV + PEEP和HPOV（8和16 Hz）后，99mTc-DTPA的清除率增加，但仅在IPPV + PEEP后观察到99mTcO4-清除率增加。在另一组犬中，IPPV + PEEP通气4小时后（但HFOV后未出现）呼气末肺容积增加，这可能解释了测得的99mTcO4-清除率增加的原因。我们得出结论，HFOV后99mTc-DTPA清除率增加表明肺上皮通透性增加，可能是通过HFOV期间细胞间连接受损的机制实现的。
