Haller M, Zöllner C, Manert W, Briegel J, Kilger E, Polasek J, Hummel T, Forst H, Peter K
Department of Anesthesiology, Ludwig-Maximilians-University of Munich, Germany.
Am J Respir Crit Care Med. 1995 Dec;152(6 Pt 1):1812-7. doi: 10.1164/ajrccm.152.6.8520741.
Cardiac output measurement is part of routine monitoring in critically ill patients. In patients on extracorporeal lung assist, thermodilution cardiac output measurement may lead to erroneous results caused by indicator loss into the extracorporeal circuit. Seven patients on venovenous extracorporeal lung assist were studied using different extracorporeal blood flows. We compared conventional thermodilution cardiac output determinations with dye dilution cardiac output measurement, with dye injection into the pulmonary artery. The latter method is not affected by the extracorporeal circuit. The conventional thermodilution method overestimated cardiac output up to a maximum of 300%, providing results up to 10 L/min higher than true cardiac output. The mean difference between thermodilution and true cardiac output as determined by dye dilution with pulmonary artery indicator injection was 3.0 +/- 2.41 L/min. There was no correlation between thermodilution cardiac output values and true cardiac output (r = 0.06). We conclude that conventional thermodilution is not a suitable method for cardiac output measurement in patients on extracorporeal lung assist, especially if high extracorporeal blood flows are applied.
心输出量测量是重症患者常规监测的一部分。在接受体外肺辅助的患者中，热稀释法测量心输出量可能会因指示剂流失到体外循环中而导致错误结果。我们对7例接受静脉-静脉体外肺辅助的患者使用不同的体外血流量进行了研究。我们将传统热稀释法测定的心输出量与通过向肺动脉注射染料进行染料稀释法测量的心输出量进行了比较。后一种方法不受体外循环的影响。传统热稀释法高估心输出量最多可达300%，所提供的结果比真实心输出量高出多达10 L/min。通过肺动脉指示剂注射染料稀释法测定的热稀释法与真实心输出量之间的平均差值为3.0±2.41 L/min。热稀释法心输出量值与真实心输出量之间无相关性（r = 0.06）。我们得出结论，传统热稀释法不适用于接受体外肺辅助患者的心输出量测量，尤其是在应用高体外血流量时。
