Peyton Philip J, Kozub Monique
Department of Anaesthesia, Austin Health, Heidelberg, Melbourne, VIC, 3084, Australia.
Anaesthesia, Perioperative and Pain Medicine Unit (APPMU), Melbourne Medical School, University of Melbourne, Parkville, VIC, Australia.
J Clin Monit Comput. 2018 Dec;32(6):1057-1064. doi: 10.1007/s10877-018-0110-y. Epub 2018 Feb 8.
Technologies for minimally-invasive cardiac output measurement in patients during surgery remain little used in routine practice. We tested a redeveloped system based on CO elimination (VCO) by the lungs for use in ventilated patients, which can be seamlessly integrated into a modern anesthesia/monitoring platform, and provides automated, continuous breath-by-breath cardiac output monitoring. A prototype measurement system was constructed to measure VCO and end-tidal CO concentration with each breath. A baseline measurement of non-shunt cardiac output was made during a brief oscillating change in ventilator rate, according to the differential CO Fick approach and repeated at 5-10 min intervals. Continuous breath-by-breath monitoring of cardiac output was performed between these intervals from measurement of VCO, using a derivation of the Fick equation applied to pulmonary CO elimination and cardiac output displayed in real time. Measurements were compared with simultaneous measurements by thermodilution in 50 patients undergoing cardiac surgery or liver transplantation. Overall mean bias [sd] for agreement in cardiac output measurement was - 0.3 [1.1] L/min, percentage error ± 38.7%, intraclass correlation coefficient = 0.91. Concordance in measurement of changes of at least 15% in cardiac output was 81.4%, with a mean angular bias of - 1.7°, and radial limits of agreement of ± 76.2° on polar plot analysis. The accuracy and precision compared favourably to other clinical techniques. The method is relatively seamless and automated and has potential for continuous, cardiac output monitoring in ventilated patients during anesthesia and critical care.
手术患者微创心输出量测量技术在常规实践中的应用仍然很少。我们测试了一种基于肺二氧化碳清除（VCO）重新开发的系统，用于通气患者，该系统可无缝集成到现代麻醉/监测平台中，并提供自动、逐次呼吸的心输出量监测。构建了一个原型测量系统，以测量每次呼吸的VCO和呼气末二氧化碳浓度。根据差分CO菲克法，在呼吸机频率的短暂振荡变化期间进行非分流心输出量的基线测量，并以5-10分钟的间隔重复进行。在这些间隔之间，通过测量VCO，使用应用于肺二氧化碳清除的菲克方程推导并实时显示心输出量，进行逐次呼吸的心输出量连续监测。对50例接受心脏手术或肝移植的患者，将测量结果与同时进行的热稀释法测量结果进行比较。心输出量测量一致性的总体平均偏差[标准差]为-0.3[1.1]L/min，百分比误差±38.7%，组内相关系数=0.91。心输出量至少变化15%时测量的一致性为81.4%。在极坐标图分析中，平均角度偏差为-1.7°，一致性的径向极限为±76.2°。与其他临床技术相比，该方法的准确性和精密度良好。该方法相对无缝且自动化，在麻醉和重症监护期间对通气患者进行连续心输出量监测具有潜力。
