Lemaire F, Harf A, Harari A, Teisseire B, Régnier B, Atlan G, Rapin M
Bull Physiopathol Respir (Nancy). 1975 Sep-Oct;11(5):659-81.
Acutely ill patients often show rapid and sometimes concomitant changes in haemodynamics, pulmonary exchange and O2-uptake. PaO2 reflects the interrelationships between these three factors. The Qs/Qt shunt is computed by taking two simultaneous blood samples, one systemic arterial, the other mixed venous, with the patient inhaling pure O2 for twenty minutes. In estimating the fraction of total cardiac output unsaturated in pulmonary transit, Qs/Qt is practically used as a selective test for pulmonary gas exchange. We propose a nomogram, showing in terms of Qs/Qt shunt the variations of PaO2, of haemoglobin O2 saturation and of arterial-venous difference of O2 concentrations. Blood gas changes during treatment of shock or of acute respiratory insufficiency are explained by use of this nomogram.
危重病患者常常表现出血流动力学、肺换气和氧摄取的快速且有时是同时发生的变化。动脉血氧分压（PaO2）反映了这三个因素之间的相互关系。分流率（Qs/Qt）通过同时采集两份血样来计算，一份是体循环动脉血样，另一份是混合静脉血样，患者吸入纯氧20分钟。在评估肺循环中未饱和的心输出量占总心输出量的比例时，分流率（Qs/Qt）实际上被用作肺气体交换的选择性检测指标。我们提出了一种列线图，以分流率（Qs/Qt）表示动脉血氧分压（PaO2）、血红蛋白氧饱和度以及氧浓度动静脉差值的变化。利用该列线图可以解释休克或急性呼吸功能不全治疗期间的血气变化。
