Papaioannou Theodore G, Xanthis Dimitrios, Argyris Antonis, Vernikos Pavlos, Mastakoura Georgia, Samara Stamatia, Floros Ioannis T, Protogerou Athanase D, Tousoulis Dimitrios
Biomedical Engineering Unit, First Department of Cardiology, Medical School, Hippokration Hospital, National and Kapodistrian University of Athens, Athens, Greece.
Intensive Care Unit, Laiko General Hospital, Athens, Greece.
Proc Inst Mech Eng H. 2020 Nov;234(11):1330-1336. doi: 10.1177/0954411919888321. Epub 2019 Nov 20.
Non-invasive monitoring of cardiac output is a technological and clinical challenge, especially for critically ill, surgically operated, or intensive care unit patients. A brachial cuff-based, automated, oscillometric device used for blood pressure and arterial stiffness ambulatory monitoring (Mobil-O-Graph) provides a non-invasive estimation of cardiac output values simultaneously with regular blood pressure measurement. The aim of the study was to evaluate the feasibility of this apparatus to estimate cardiac output in intensive care unit patients and to compare the non-invasive estimated cardiac output values with the respective gold standard method of thermodilution during pulmonary artery catheterization. Repeated sequential measurements of cardiac output were performed, in random order, by thermodilution (reference) and Mobil-O-Graph (test), in 24 patients hospitalized at intensive care unit. Reproducibility and accuracy of the test device were evaluated by Bland-Altman analysis, intraclass correlation coefficient, and percentage error. Mobil-O-Graph underestimated significantly the cardiac output by -1.12 ± 1.38 L/min ( < 0.01) compared to thermodilution. However, intraclass correlation coefficient was >0.7 indicating a fair agreement between the test and the reference methods, while percentage error was approximately 39% which is considered to be within the acceptable limits. Cardiac output measurements were reproducible by both Mobil-O-Graph (intraclass correlation coefficient = 0.73 and percentage error = 27.9%) and thermodilution (intraclass correlation coefficient = 0.91 and percentage error = 26.7%). We showed for the first time that cardiac output estimation in intensive care unit patients using a non-invasive, automated, oscillometric, cuff-based apparatus is reproducible (by analyzing two repeated cardiac output measurements), exhibiting similar precision to thermodilution. However, the accuracy of Mobil-O-Graph (error compared to thermodilution) could be considered fairly acceptable. Future studies remain to further examine the reliability of this technology in monitoring cardiac output or stroke volume acute changes which is a more clinically relevant objective.
心输出量的无创监测是一项技术和临床挑战，对于危重症、接受外科手术或入住重症监护病房的患者尤其如此。一种基于肱动脉袖带的自动示波装置（Mobil-O-Graph）用于血压和动脉僵硬度的动态监测，可在常规测量血压的同时无创估计心输出量值。本研究的目的是评估该仪器在重症监护病房患者中估计心输出量的可行性，并将无创估计的心输出量值与肺动脉导管插入术期间热稀释法这一相应的金标准方法进行比较。对24名入住重症监护病房的患者，以随机顺序通过热稀释法（参考方法）和Mobil-O-Graph（测试方法）重复连续测量心输出量。通过Bland-Altman分析、组内相关系数和百分比误差评估测试装置的可重复性和准确性。与热稀释法相比，Mobil-O-Graph显著低估心输出量，差值为-1.12±1.38L/min（P<0.01）。然而，组内相关系数>0.7，表明测试方法与参考方法之间有较好的一致性，而百分比误差约为39%，被认为在可接受范围内。Mobil-O-Graph（组内相关系数=0.73，百分比误差=27.9%）和热稀释法（组内相关系数=0.91，百分比误差=26.7%）测量的心输出量均具有可重复性。我们首次表明，使用基于无创、自动、示波、袖带的仪器对重症监护病房患者的心输出量进行估计具有可重复性（通过分析两次重复的心输出量测量），其精度与热稀释法相似。然而，Mobil-O-Graph的准确性（与热稀释法相比的误差）可被认为是相当可接受的。未来的研究仍需进一步检验该技术在监测心输出量或每搏输出量急性变化方面的可靠性，这是一个更具临床相关性的目标。
