Secher N J, Arnsbo P, Andersen L H, Thomsen A
Scand J Clin Lab Invest. 1979 Oct;39(6):569-76. doi: 10.3109/00365517909108835.
A total of 220 simultaneous pairs of measurements of cardiac stroke volume were made in twelve women before and during Caesarean section in order to compare impedance cardiography with the thermodilution method. A significantly higher coefficient of correlation was found before (r = 0.77) than during anaesthesia (r = 0.55). Further, there was a significant difference in the slope of the regression lines: before anaesthesia the slope was 1.07 and during anaesthesia with thiopentone, nitrous oxide, oxygen and suxamethonium it was 0.45. Significant changes in the intercept on the Y-axis were found before (-13.9 ml) and during anaesthesia (33.4 ml). When the uterus was displaced upwards and to the left from the 15 degrees tilt position the stroke volume and the cardiac output were increased when measured by both methods to nearly the same values as in the left lateral position. It is concluded that the impedance method is reliable for measuring cardiac stroke volume in late pregnancy under physiological conditions in the conscious patient, but that it cannot replace the thermodilution method in pharmacological studies.
为了比较阻抗心动描记法与热稀释法，在12名女性剖宫产手术前及手术过程中总共进行了220对同时测量心搏量的操作。结果发现，术前（r = 0.77）的相关性系数显著高于麻醉期间（r = 0.55）。此外，回归线的斜率也存在显著差异：麻醉前斜率为1.07，而在使用硫喷妥钠、一氧化二氮、氧气和琥珀酰胆碱进行麻醉期间斜率为0.45。Y轴截距在术前（-13.9 ml）和麻醉期间（33.4 ml）有显著变化。当子宫从15度倾斜位置向上向左移位时，两种方法测得的心搏量和心输出量均增加，且几乎与左侧卧位时的值相同。结论是，阻抗法在清醒患者的生理条件下测量晚期妊娠的心搏量是可靠的，但在药理学研究中它不能替代热稀释法。
