Mochizuki M, Tamura M, Shimasaki T, Niizeki K, Shimouchi A
Jpn J Physiol. 1984;34(2):295-306. doi: 10.2170/jjphysiol.34.295.
A new indirect method for measuring the arteriovenous O2 content difference (avDO2) was developed. The avDO2 was calculated by dividing the gradient of the CO2 dissociation curve by that of a gas exchange ratio against PCO2. The latter slope was obtained from O2 and CO2 concentrations in rebreathing air. The validity of the method was tested preliminarily in human subjects by comparing the cardiac output calculated from avDO2 and O2 uptake (VO2) with that measured hitherto by other authors, and then in dogs by comparing the calculated avDO2 with the measured value. In the dog experiments, the rebreathing was performed 7 times in each of 7 dogs. Immediately after the rebreathing arterial and mixed venous blood were sampled and analyzed for avDO2. For each rebreathing period the avDO2 was calculated by using the CO2 dissociation curve obtained in the individual dogs. The correlation coefficient between the measured and calculated avDO2 was 0.87, demonstrating reasonable validity of the method. The VO2 was further measured from the time interval during which a known amount of pure O2 was consumed. Then, the cardiac output was calculated by dividing the VO2 by the measured and calculated avDO2. The correlation coefficient between the respective cardiac output values was 0.88, indicating the reliability of using the calculated avDO2.
开发了一种测量动静脉氧含量差(avDO2)的新间接方法。avDO2通过将二氧化碳解离曲线的斜率除以气体交换率相对于PCO2的斜率来计算。后一斜率从重复呼吸空气中的氧气和二氧化碳浓度获得。通过将根据avDO2和氧气摄取量(VO2)计算出的心输出量与其他作者迄今测量的值进行比较,初步在人体受试者中测试了该方法的有效性,然后在狗身上通过将计算出的avDO2与测量值进行比较来测试。在狗的实验中,对7只狗中的每只狗进行了7次重复呼吸。重复呼吸后立即采集动脉血和混合静脉血样本,并分析avDO2。对于每个重复呼吸期,使用在个体狗中获得的二氧化碳解离曲线计算avDO2。测量的和计算的avDO2之间的相关系数为0.87,表明该方法具有合理的有效性。进一步从消耗已知量纯氧的时间间隔测量VO2。然后,通过将VO2除以测量的和计算的avDO2来计算心输出量。各自心输出量值之间的相关系数为0.88,表明使用计算的avDO2的可靠性。