Schuster K D, Heller H
Institute of Physiology I, University of Bonn, FRG.
Adv Exp Med Biol. 1990;277:637-45. doi: 10.1007/978-1-4684-8181-5_72.
Investigations were made as to whether or not there is a limitation of oxygen transport by stratified inhomogeneity in distal alveolar gas. Experiments were performed on 2 subjects. Single breath manoeuvres were carried out with similar phases of inspiration and expiration but varying breath-hold times. The inspiratory gas contained a small amount of oxygen labeled carbon dioxide, C18O2. End-expiratory gas was analysed on its residual C18O2 partial pressure by mass spectrometry. For evaluating a stratificational conductance, compartment model analysis was applied on the breath-hold data. Stratificational conductance has been found to be higher than 553 ml.mmHg-1. min-1. When transferred to oxygen transport, this means that stratificational conductance is more than 10 times higher than oxygen diffusing capacity. It can be concluded that (i) stratified inhomogeneity in distal alveolar space does not exhibit a limiting factor of oxygen uptake in lungs, (ii) a contribution of stratificational effects to sloping alveolar plateau is expected to be of minor importance.
针对远端肺泡气体分层不均匀是否存在氧输送限制进行了研究。对两名受试者进行了实验。进行了单次呼吸动作，吸气和呼气阶段相似，但屏气时间不同。吸入气体中含有少量氧标记的二氧化碳，即C18O2。通过质谱分析终末呼气气体中残余C18O2的分压。为了评估分层传导率，对屏气数据应用了隔室模型分析。已发现分层传导率高于553 ml·mmHg-1·min-1。当转换到氧输送时，这意味着分层传导率比氧扩散能力高10倍以上。可以得出结论：（i）远端肺泡空间的分层不均匀性并未表现为肺部氧摄取的限制因素；（ii）分层效应对倾斜肺泡平台的贡献预计较小。
