Suzuki H, Papazoglou K, Bryan A C
Department of Pediatrics, Saitama Medical School, Japan.
Acta Paediatr Jpn. 1992 Oct;34(5):494-500. doi: 10.1111/j.1442-200x.1992.tb00995.x.
The relationship between oxygenation and lung volume during high frequency oscillatory ventilation (HFOV) was studied. We ventilated anesthetized, tracheostomized adult rabbits that were rendered surfactant-deficient by lung lavage. Lung volume was measured by the 'disconnection technique'. In the first experiment, HFOV was commenced after conventional mechanical ventilation (CMV) for 1 hr. In the absence of sustained inflation (SI), oxygenation improved with time during HFOV. In the second experiment, HFOV was instituted after CMV for 4 hr. In the absence of SI, all animals expired during the experimental period. In the third experiment we ventilated rabbits for 4 hr and then switched to HFOV. We applied SI first and increased mean airway pressure (MAP) by increments of 2 cmH2O every 15 min. However, there was little improvement in PaO2 despite the use of repeated SI and the increase in MAP. We conclude that oxygenation has a linear relationship to lung volume during HFOV, and that secondary lung injury due to long-term CMV impairs the response to HFOV. Therefore, it is important to minimize the risk of such secondary injuries before instituting HFOV.
研究了高频振荡通气（HFOV）期间氧合与肺容积之间的关系。我们对经气管切开的成年麻醉兔进行通气，这些兔子通过肺灌洗造成表面活性物质缺乏。肺容积通过“断开技术”测量。在第一个实验中，在传统机械通气（CMV）1小时后开始HFOV。在没有持续充气（SI）的情况下，HFOV期间氧合随时间改善。在第二个实验中，在CMV 4小时后开始HFOV。在没有SI的情况下，所有动物在实验期间死亡。在第三个实验中，我们对兔子通气4小时，然后切换到HFOV。我们首先应用SI，并每隔15分钟将平均气道压（MAP）增加2 cmH₂O。然而，尽管使用了重复的SI和MAP增加，PaO₂几乎没有改善。我们得出结论，HFOV期间氧合与肺容积呈线性关系，并且长期CMV引起的继发性肺损伤会损害对HFOV的反应。因此，在开始HFOV之前尽量减少此类继发性损伤的风险很重要。
