Schöps Malte, Groß-Hardt Sascha H, Schmitz-Rode Thomas, Steinseifer Ulrich, Brodie Daniel, Clauser Johanna C, Karagiannidis Christian
Department of Cardiovascular Engineering, Institute of Applied Medical Engineering, Medical Faculty, RWTH Aachen University, Pauwelstrasse 20, 52074, Aachen, Germany.
Center for Acute Respiratory Failure, Columbia University College of Physicians and Surgeons/NewYork-Presbyterian Hospital, New York, NY, USA.
J Transl Med. 2021 Jan 5;19(1):2. doi: 10.1186/s12967-020-02599-z.
Treating severe forms of the acute respiratory distress syndrome and cardiac failure, extracorporeal membrane oxygenation (ECMO) has become an established therapeutic option. Neonatal or pediatric patients receiving ECMO, and patients undergoing extracorporeal CO removal (ECCOR) represent low-flow applications of the technology, requiring lower blood flow than conventional ECMO. Centrifugal blood pumps as a core element of modern ECMO therapy present favorable operating characteristics in the high blood flow range (4 L/min-8 L/min). However, during low-flow applications in the range of 0.5 L/min-2 L/min, adverse events such as increased hemolysis, platelet activation and bleeding complications are reported frequently.
In this study, the hemolysis of the centrifugal pump DP3 is evaluated both in vitro and in silico, comparing the low-flow operation at 1 L/min to the high-flow operation at 4 L/min.
Increased hemolysis occurs at low-flow, both in vitro and in silico. The in-vitro experiments present a sixfold higher relative increased hemolysis at low-flow. Compared to high-flow operation, a more than 3.5-fold increase in blood recirculation within the pump head can be observed in the low-flow range in silico.
This study highlights the underappreciated hemolysis in centrifugal pumps within the low-flow range, i.e. during pediatric ECMO or ECCOR treatment. The in-vitro results of hemolysis and the in-silico computational fluid dynamic simulations of flow paths within the pumps raise awareness about blood damage that occurs when using centrifugal pumps at low-flow operating points. These findings underline the urgent need for a specific pump optimized for low-flow treatment. Due to the inherent problems of available centrifugal pumps in the low-flow range, clinicians should use the current centrifugal pumps with caution, alternatively other pumping principles such as positive displacement pumps may be discussed in the future.
体外膜肺氧合（ECMO）已成为治疗严重急性呼吸窘迫综合征和心力衰竭的既定治疗选择。接受ECMO治疗的新生儿或儿科患者以及接受体外二氧化碳清除（ECCOR）的患者代表了该技术的低流量应用，与传统ECMO相比，所需血流量更低。离心血泵作为现代ECMO治疗的核心元件，在高血流量范围（4升/分钟 - 8升/分钟）具有良好的运行特性。然而，在0.5升/分钟 - 2升/分钟的低流量应用期间，经常报告出现诸如溶血增加、血小板活化和出血并发症等不良事件。
在本研究中，对离心血泵DP3在体外和计算机模拟中进行溶血评估，将1升/分钟的低流量操作与4升/分钟的高流量操作进行比较。
在体外和计算机模拟中，低流量时均出现溶血增加。体外实验显示低流量时相对溶血增加高出六倍。与高流量操作相比，在计算机模拟中低流量范围内可观察到泵头内血液再循环增加超过3.5倍。
本研究强调了在低流量范围内（即儿科ECMO或ECCOR治疗期间）离心血泵中未得到充分重视的溶血问题。溶血的体外结果以及泵内流动路径的计算机计算流体动力学模拟提高了人们对在低流量工作点使用离心血泵时发生血液损伤的认识。这些发现强调了迫切需要针对低流量治疗优化的特定血泵。由于现有离心血泵在低流量范围内存在固有问题，临床医生应谨慎使用当前的离心血泵，未来可考虑讨论其他泵送原理，如容积泵。
