Anthonisen N R
Am Rev Respir Dis. 1977 May;115(5):873-6. doi: 10.1164/arrd.1977.115.5.873.
Using xenon-133, we measured regional lung volumes in three seated young men with 25 to 40 per cent pneumothorax. There was no gravitational gradient of regional lung expansion in the lung affected by the pneumothorax. There was no gravitational gradient of regional lung expansion in the lung affected by the pneumothorax, whereas an apex-to-base gradient of regional volume was apparent on the contralateral, normal side. When over-all lung volume increased from residual volume to 20 per cent of vital capacity, there was little volume change in the lungs with pneumothoraces. These lungs received relatively small fractions of boluses inhaled at residual volume and bolus distributuion was even from apex to base on the sides with the pneumothoraces. Regional washout half-times were not prolonged in lungs with pneumothoraces and did not differ from apex to base, whereas in unaffected lungs, half-times at the apex exceeded those at the base. The results indicated that regional volume and half-time gradients were absent when gravitational gradients of pleural surface pressure were abolished by pneumothorax. Lungs with pneumothorax demonstrated uniform airway closure at low lung volumes, and it is suggested that this is the chief cause of ventilation maldistribution in spontaneous pneumothorax.
我们使用氙 - 133对三名患有25%至40%气胸的年轻男性在坐位时的局部肺容积进行了测量。在受气胸影响的肺中，局部肺扩张不存在重力梯度。在受气胸影响的肺中，局部肺扩张不存在重力梯度，而在对侧正常肺侧，局部容积存在从肺尖到肺底的梯度。当总肺容积从残气量增加到肺活量的20%时，有气胸的肺容积变化很小。这些肺在残气量时吸入的团注中所占比例相对较小，并且在有气胸的一侧，团注从肺尖到肺底分布均匀。有气胸的肺的局部洗脱半衰期没有延长，且从肺尖到肺底没有差异，而在未受影响的肺中，肺尖的半衰期超过肺底的半衰期。结果表明，气胸消除了胸膜表面压力的重力梯度时，局部容积和半衰期梯度也不存在。有气胸的肺在低肺容积时表现出均匀的气道关闭，提示这是自发性气胸通气分布不均的主要原因。
