In vitro and in vivo assessment of oxygenator blood volume for the prediction of clot formation in an ECMO circuit (theory and validation)
In vitro and in vivo assessment of oxygenator blood volume for the prediction of clot formation in an ECMO circuit (theory and validation)
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DOI：
10.1177/0267659118765883
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发表时间：
2018-05-01
期刊：
影响因子：
1.2
通讯作者：
Rais-Bahrami, Khodayar
中科院分区：
文献类型：
--
作者：
Krivitski, Nikolai;Galyanov, Gregory;Rais-Bahrami, Khodayar
简介：凝血是体外膜氧合（ECMO）中死亡和发病的主要原因之一。一项大型荟萃分析研究表明，29%的患者在ECMO期间需要更换氧合器。由于凝块通常在氧合器中形成，氧合器血容量（OXBV）随着时间的推移而减少。目前使用的压力梯度作为血块形成的预测指标是不可靠的。目的：本研究的目的是开发和验证超声稀释技术在血液凝血定量评估中的应用。方法：使用ELSA监测器（Transonic Systems Inc., Ithaca， NY， USA）从盐水丸通过氧合器的传递时间开始测量OXBV，并由放置在氧合器后的传感器记录。在体外羔羊和临床数据档案中评估了OXBV测量的准确性和可重复性（变异系数[CV]）及其与ECMO流量的独立性。结果：在流速为300-700 ml/min时，OXBV 22-134 ml的体外准确度与容积法相比为-0.86.6%。当OXBV为355 ml，流量为1020-7000 ml/min时，精度为-0.4 +/- 1.6%。在88例动物OXBV检测中，CV为1.49±1.12%。对于OXBV为153（范围42-387 ml），临床测量流量范围为210-5960 ml/min， CV为3.20 +/- 2.44%。结论：稀释技术能够准确、重复性地评价氧合器内的凝血过程。需要更大规模的研究来建立预测即将发生凝血的指导方针，并可能有助于避免不必要的电路改变。
Introduction: Clotting is one of the major causes of mortality and morbidity during extracorporeal membrane oxygenation (ECMO). A large meta-analysis study suggests that 29% of patients require the oxygenator to be replaced during ECMO. As clots usually form in the oxygenator, the oxygenator blood volume (OXBV) decreases over time. The currently used pressure gradient as a predicator of clot formation is unreliable.Objective: The aim of this study was to develop and validate ultrasound dilution technology in a quantitative assessment of clotting, using measurements of OXBV.Methods: OXBV was measured using the ELSA monitor (Transonic Systems Inc., Ithaca, NY, USA) from the transit time of a saline bolus passing through the oxygenator as recorded by a sensor placed after the oxygenator. The accuracy and reproducibility (coefficient of variation [CV]) of OXBV measurement and its independence from ECMO flow was assessed in vitro in lambs and from a clinical data archive.Results: The in vitro accuracy compared with volumetric measurements of OXBV of 22-134 ml at flows of 300-700 ml/min was -0.86.6%. For an OXBV of 355 ml at flows of 1020-7000 ml/min, accuracy was -0.4 +/- 1.6%. In 88 animal OXBV measurements, the CV was 1.49 +/- 1.12%. For an OXBV of 153 (range 42-387 ml), clinical measurements at flow ranged from 210-5960 ml/min, with a CV of 3.20 +/- 2.44 %.Conclusion: Dilution technology has the ability to accurately and reproducibly assess the clotting process in the oxygenator. Larger studies are needed to establish guidelines for the prediction of imminent clotting and may help to avoid unnecessary circuit changes.