Mithoefer J C, Keighley J F, Cook W R
Crit Care Med. 1978 May-Jun;6(3):131-5. doi: 10.1097/00003246-197805000-00001.
The alveolar to arterial oxygen pressure difference (AaDO2) and pulmonary venous admixture (Qs/Qt) were measured in 32 patients with chronic obstructive pulmonary disease during right heart catheterization at inspired oxygen concentrations (FIO2) of 21, 24, 28, 35, and 40%. Patients without chronic hypercapnia (PaCO2 is less than 45 torr, group A) had Qs/Qt less than 25% while breathing room air; their AaDO2 rose at a rate of 3 torr for each percent increase in FIO2. In those with chronic hypercapnia (PaCO2 greater than 44 torr., (group B), THE Qs/Qt was always greater than 24% during air breathing and the AaDO2 rose at a rate of 5 torr for each percentage increase in FIO2. These changes should be considered in the interpretation of the AaDO2 in patients with COPD in whom the FIO2 is changed during the course of therapy. The Qs/Qt fell curvilinearly with increasing FIO2 but the rates of fall were quantitatively different in groups A and B. A physiological explanation for the changes in Qs/Qt and ADO2 which result from changes in FIO2 is presented.
在32例慢性阻塞性肺疾病患者进行右心导管检查期间，于吸入氧浓度（FIO2）分别为21%、24%、28%、35%和40%时，测定了肺泡 - 动脉氧分压差（AaDO2）和肺静脉混合血（Qs/Qt）。无慢性高碳酸血症（动脉血二氧化碳分压[PaCO2]小于45托，A组）的患者在呼吸空气时Qs/Qt小于25%；随着FIO2每升高1%，其AaDO2以3托的速率上升。对于有慢性高碳酸血症（PaCO2大于44托，B组）的患者，在呼吸空气时Qs/Qt始终大于24%，且随着FIO2每升高1%，AaDO2以5托的速率上升。在解释慢性阻塞性肺疾病患者治疗过程中FIO2发生变化时的AaDO2时，应考虑这些变化。随着FIO2升高，Qs/Qt呈曲线下降，但A组和B组的下降速率在数量上有所不同。本文给出了因FIO2变化导致的Qs/Qt和AaDO2变化的生理学解释。
