Vinitskaia R S
Biull Eksp Biol Med. 1980 Jul;89(7):3-6.
The phases of the nitrogen washout curve (NWC): dead space phase (DSP), mixed phase (MP), alveolar phase (AP) and lung closing volume (LCV) were studied in 7 healthy subjects and 47 patients with diverse disorders of gas mixing in the lungs. Under conditions of a diffuse decrease in the elasticity induced by blood congestion consequent on mitral heart disease, the gas in uniformly mixed in the lungs so that the magnitudes of NWC phases (in % of ZCV) almost do not differ from normal. When ZCV was drastically decreased, DSP showed a relative augmentation, while AP fell down. In local ventilation disorders induced by pulmonary diseases (bronchoectasis, abscesses, etc.), NWC patterns demonstrated significant changes indicating a non-uniform gas mixing in the lungs. LCV was well identifiable in healthy subjects whereas in patients with heart diseases, it was more poorly and less frequently identifiable, especially in subjects with pulmonary diseases. An increase in the time of diffuse gas mixing, which was attained as a result of breath holding at the height of inspiration, leads to the reduced DSP magnitude and gas supply to the alveoli. This does not improve, however, gas exchange in the most poorly ventilated zones.
对7名健康受试者和47名患有各种肺部气体混合障碍的患者的氮洗脱曲线（NWC）的各个阶段：死腔期（DSP）、混合期（MP）、肺泡期（AP）和肺闭合容积（LCV）进行了研究。在二尖瓣心脏病导致血液淤滞引起弹性普遍降低的情况下，气体在肺内均匀混合，因此NWC各阶段的幅度（占闭合气量的百分比）与正常情况几乎没有差异。当闭合气量急剧下降时，DSP相对增加，而AP下降。在由肺部疾病（支气管扩张、脓肿等）引起的局部通气障碍中，NWC模式显示出显著变化，表明肺内气体混合不均匀。LCV在健康受试者中很容易识别，而在心脏病患者中，它更难识别且识别频率更低，尤其是在患有肺部疾病的受试者中。在吸气末屏气导致弥漫性气体混合时间增加，这会导致DSP幅度降低以及肺泡气体供应减少。然而，这并不能改善通气最差区域的气体交换。
