DISTRIBUTION OF BLOOD FLOW AND VENTILATION-PERFUSION RATIO IN THE LUNG, MEASURED WITH RADIOACTIVE CO2
DISTRIBUTION OF BLOOD FLOW AND VENTILATION-PERFUSION RATIO IN THE LUNG, MEASURED WITH RADIOACTIVE CO2
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DOI：
10.1152/jappl.1960.15.3.405
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发表时间：
1960-01-01
影响因子：
3.3
通讯作者：
DOLLERY, CT
中科院分区：
文献类型：
--
作者：
WEST, JB;DOLLERY, CT
吸入的放射性CO2迅速被肺血吸收。通过在屏气期间对胸部进行外部计数，可以记录来自计数野的放射性CO2的清除率，并且与区域灌注成比例。在正常受试者中，清除率从约20%/秒变化。在肺的底部几乎为零，并且这种变化与胸部向上的距离近似线性。上区和下区之间的差异在适度运动时减小，当受试者仰卧时消除。通过将吸气结束时的计数率与计数场中的肺体积相关联，测量了上区和下区之间的通气差异，发现差异很小。由此确定通气-灌注比的变化。根据该通气-灌注比不等性计算出的肺泡-动脉O2梯度约为4 mm Hg。这表明直立人肺上下部血流量的变化是正常肺通气灌注比不平衡的全部原因。
Inhaled radioactive CO2 is rapidly taken up by pulmonary blood. By external counting over the chest during breath holding, the clearance rate of radioactive CO2 from the counting field can be recorded, and is proportional to the regional perfusion. In normal subjects, the clearance rate varied from about 20%/sec. at the base of the lung to virtually nil at the apex, and the change was approximately linear with distance up the chest. The difference between upper and lower zones was reduced on moderate exercise and eliminated when the subject lay on his back. By relating the counting rate at the end of inspiration to the volume of lung in the counting field, the difference in ventilation between upper and lower zones was measured and found to be small. Variation in ventilation-perfusion ratio was thus determined. Alveolar-arterial O2 gradient expected from this ventilation-perfusion ratio inequality was calculated to be about 4 mm Hg. This suggests that the variation in blood flow between upper and lower parts of the lung in erect man accounts for the whole of the ventilation-perfusion ratio inequality in the normal lung.