Robinson Gavin J B, Peyton Philip J, Vartuli Giuseppe M, Burfoot Rodney B, Junor Paul A
Department of Anaesthesia and Pain Management, Bayside Health, The Alfred, Bayside Health, Melbourne, Australia.
J Cardiothorac Vasc Anesth. 2003 Apr;17(2):204-10. doi: 10.1053/jcan.2003.48.
The throughflow method is a new technique for continuous and minimally invasive measurement of cardiac output by the Fick principle, which uses ventilation of the 2 lungs with unequal inspired gas concentrations by means of a double-lumen endobronchial tube. It exploits steady-state gas exchange and thus permits rapid repetition of measurement.
Comparison of paired measurements by the throughflow method using N(2)O exchange with bolus thermodilution.
Departments of anesthesiology in 2 university teaching hospitals.
Nine patients undergoing cardiac surgery in the precardiopulmonary bypass period.
Patients intubated with a double-lumen endobronchial tube were ventilated with 45% nitrous oxide (N(2)O) to the left lung (zero to the right lung). Arterial blood gas samples were taken to measure alveolar deadspace to allow correction for the alveolar-arterial N(2)O difference and to correct for the presence of unmeasured shunt perfusion.
Throughflow measurements correlated with thermodilution (r = 0.719, p < 0.05) with a mean bias of -0.208 L/min (-5.2%). The standard error of the bias was 0.060 L/min, with 95% confidence limits for the bias of -0.088 L/min and -0.328 L/min. The limits of agreement between the 2 methods were +0.960 L/min and -1.376 L/min.
The throughflow method showed good agreement with thermodilution. It permits continuous cardiac output measurement without the need for sampling of mixed venous blood, using techniques of lung isolation, which are readily available in clinical anesthetic practice.
通流法是一种基于菲克原理的连续、微创测量心输出量的新技术，该技术通过双腔支气管内导管对双肺进行不等吸入气体浓度的通气。它利用稳态气体交换，因此允许快速重复测量。
使用氧化亚氮交换的通流法与团注热稀释法进行配对测量的比较。
两所大学教学医院的麻醉科。
9例心脏手术患者，处于心肺转流术前阶段。
使用双腔支气管内导管插管的患者，左肺用45%氧化亚氮（N₂O）通气（右肺为零）。采集动脉血气样本以测量肺泡死腔，以便校正肺泡 - 动脉N₂O差值，并校正未测量的分流灌注的存在。
通流测量值与热稀释法相关（r = 0.719，p < 0.05），平均偏差为 -0.208 L/min（-5.2%）。偏差的标准误差为0.060 L/min，偏差的95%置信限为 -0.088 L/min和 -0.328 L/min。两种方法之间的一致性界限为 +0.960 L/min和 -1.376 L/min。
通流法与热稀释法显示出良好的一致性。它允许连续测量心输出量，无需采集混合静脉血样本，采用肺隔离技术，这在临床麻醉实践中很容易获得。
