McEvoy R D, Davies N J, Mannino F L, Prutow R J, Schumacker P T, Wagner P D, West J B
J Appl Physiol Respir Environ Exerc Physiol. 1982 May;52(5):1278-87. doi: 10.1152/jappl.1982.52.5.1278.
Gas exchange was investigated in normal anesthetized dogs during high-frequency, low-tidal volume ventilation (HFV) using the multiple inert gas elimination method. The pattern of inert gas elimination was initially normal during conventional mechanical ventilation. During HFV there was an increase in the difference between the excretion values of acetone and its less soluble neighboring gases, enflurane and ether, but elimination was independent of molecular weight. This pattern was consistent with a major degree of parallel ventilation-perfusion inequality with 49.4 +/- 1.7% of alveolar ventilation being distributed to lung units with VA/Q ratios greater than 20. Additional experiments, however, showed insufficient change in pulmonary blood flow distribution during HFV to account for these apparently poorly perfused lung units. Instead, it was found that the flux from the lung of the most soluble gas, acetone, per unit concentration difference along the airways was approximately twice that for other gases. Experiments using a simple airway model suggested that this enhanced transport of high-solubility gases during HFV is dependent on the wet luminal surface of conducting airways. A reciprocating exchange of gas between the lumen and airway lining layer is proposed as the most likely explanation for these results.
使用多惰性气体排除法，在高频低潮气量通气（HFV）期间，对正常麻醉犬的气体交换进行了研究。在传统机械通气期间，惰性气体的排除模式最初是正常的。在HFV期间，丙酮与其溶解度较低的相邻气体安氟醚和乙醚的排泄值之间的差异增加，但排除与分子量无关。这种模式与主要程度的平行通气-灌注不均一性一致，其中49.4±1.7%的肺泡通气分布到VA/Q比值大于20的肺单位。然而，额外的实验表明，HFV期间肺血流分布的变化不足以解释这些明显灌注不良的肺单位。相反，发现最易溶气体丙酮沿气道每单位浓度差从肺中的通量约为其他气体的两倍。使用简单气道模型的实验表明，HFV期间高溶解度气体的这种增强传输取决于传导气道的湿腔表面。提出管腔与气道衬里层之间的往复气体交换是这些结果最可能的解释。
