Stewart R I, Lewis C M
Respiration. 1986;49(3):161-9. doi: 10.1159/000194875.
Twenty patients with chronic obstructive pulmonary disease (COPD) walked on the treadmill until symptoms limited further exercise. Ventilation, pulmonary gas exchange, arterial and mixed venous blood gas and haemodynamic variables were measured during steady state. It was not possible to predict from any resting cardiopulmonary variables (including static lung function tests) which patients would develop a decline in arterial PO2. In spite of variable PvO2 values at symptom-limited exercise, a good correlation was obtained between arterial haemoglobin saturation with oxygen and the venous admixture fraction. The directional change in PaO2, however, did not always follow that of the total oxygen transport to the tissues as gauged by either the PvO2 or the efficiency of oxygen delivery (oxygen flux/oxygen consumption) when expressed as a percentage of the value predicted for the level of exertion. This was due to the variable and unpredictable response of the cardiac output on exercise. It is concluded that there is a need to assess each patient individually both at rest and on exercise when evaluating arterial oxygenation and oxygen transport. The pattern of exercise-induced change in these oxygen indices is not predictable from resting data and they may even follow opposite directional trends.
20例慢性阻塞性肺疾病（COPD）患者在跑步机上行走，直至症状限制进一步运动。在稳定状态下测量通气、肺气体交换、动脉和混合静脉血气及血流动力学变量。无法从任何静息心肺变量（包括静态肺功能测试）预测哪些患者会出现动脉血氧分压下降。尽管在症状限制运动时混合静脉血氧分压值存在差异，但动脉血氧血红蛋白饱和度与静脉混合血分数之间仍存在良好的相关性。然而，当以运动水平预测值的百分比表示时，动脉血氧分压的变化方向并不总是与通过混合静脉血氧分压或氧输送效率（氧通量/氧消耗）衡量的组织总氧输送的变化方向一致。这是由于运动时心输出量的反应可变且不可预测。得出的结论是，在评估动脉氧合和氧输送时，需要在静息和运动时分别对每位患者进行评估。这些氧指标运动诱发的变化模式无法从静息数据预测，甚至可能呈现相反的变化趋势。
