van Herwaarden C L, Binkhorst R A, Fennis J F, van't Laar A
Pflugers Arch. 1980 May;385(1):21-3. doi: 10.1007/BF00583910.
Cardiac output measurements were performed during 50 exercise tests in 16 normal subjects employing the indirect Fick principle for CO2. During sub-maximal steady state exercise the plateau CO2 tension (PplatCO2) was estimated with a rebreathing procedure. The mixed venous CO2 tension (PvCO2) was calculated by subtracting the alveolocapillary CO2 tension difference from the PplatCO2. Compared with data from the literature the most valid calculation of the cardiac output was obtained by using the PvCO2. Cardiac output values, calculated via the PplatCO2 turned out to be too low. The reproducibility was tested by repitition of 18 exercise tests at least after 5 days. The relative standard error of a single observation was 4.1% for the cardiac output, which was found to be as good as that of invasive measurements.
在16名正常受试者的50次运动测试中，采用间接Fick原理测量二氧化碳来进行心输出量测定。在次最大稳态运动期间，通过重复呼吸程序估算平台期二氧化碳张力（PplatCO2）。混合静脉血二氧化碳张力（PvCO2）通过从PplatCO2中减去肺泡-毛细血管二氧化碳张力差来计算。与文献数据相比，使用PvCO2可获得最有效的心输出量计算结果。通过PplatCO2计算的心输出量值结果过低。通过至少在5天后重复18次运动测试来测试可重复性。单次观察的相对标准误差对于心输出量为4.1%，发现其与侵入性测量的结果一样好。
