Préfaut C, Ramonatxo M, Mouliade B, Chardon G
Pathol Biol (Paris). 1977 Jun;25(6):375-82.
We measured blood gases, steady state diffusing lung capacity, global and partial lung ductances in 16 subjects aged from 20 to 63 in supine and seated position. We obtained three types of response. In group I, (n = 6) blood gases and TLCO increased probably chiefly due to an increase of perfusion of lung apices and a more even distribution of regional VA/Q (all these subjects are young and thin). In group II, (n = 4) blood gases and TLCO decreased probably due to a ventilation at closing volume level with a decrease of ventilation in the dependent parts of the lung (2 subjects with abdominal obesity and a third who is the oldest one). In group III (n = 7), PaO2 decreased but DLCO increased. Probably ventilation took a slight place in closing volume. The increase of the exchange surface area is likely to be unable to compensate the arterial hypoxemia induced by the low VA/Q in the dependent parts of the lung. Influence of body position seems to be a function of age which increases closing volume.
我们对16名年龄在20至63岁之间的受试者，在仰卧位和坐位时测量了血气、稳态肺扩散容量、全肺和部分肺导纳。我们获得了三种类型的反应。在第一组（n = 6）中，血气和肺一氧化碳弥散量（TLCO）增加，可能主要是由于肺尖部灌注增加以及区域通气/血流比值（VA/Q）分布更加均匀（所有这些受试者都年轻且消瘦）。在第二组（n = 4）中，血气和TLCO下降，可能是由于在闭合容量水平通气，且肺下垂部位通气减少（2名腹部肥胖受试者和第三名年龄最大的受试者）。在第三组（n = 7）中，动脉血氧分压（PaO2）下降，但肺一氧化碳弥散量（DLCO）增加。可能通气在闭合容量时稍有增加。交换表面积的增加似乎无法补偿肺下垂部位低VA/Q所导致的动脉低氧血症。体位的影响似乎是年龄的一个函数，年龄增加会使闭合容量增加。
