Ganushchak Yuri M, Körver Erik Pj, Maessen Jos G
Department of Cardiothoracic Surgery, Maastricht University Medical Center, Maastricht, The Netherlands.
Cardiovascular Research Institute Maastricht (CARIM), Maastricht University Medical Center, Maastricht, The Netherlands.
Perfusion. 2020 Sep;35(6):521-528. doi: 10.1177/0267659120936453. Epub 2020 Jul 4.
Successes of extracorporeal life support increased the use of centrifugal pumps. However, reports of hemolysis call for caution in using these pumps, especially in neonatology and in pediatric intensive care. Cavitation can be a cause of blood damage. The aim of our study was to obtain information about the cavitation conditions and to provide the safest operating range of centrifugal pumps. A series of tests were undertaken to determine the points at which pump performance decreases 3% and gas bubbles start to appear downstream of the pump. Two pumps were tested; pump R with a closed impeller and pump S with a semiopen impeller. The performance tests demonstrated that pump S has an optimal region narrower than pump R and it is shifted to the higher flows. When the pump performance started to decrease, the inlet pressure varies but close to -150 mmHg in the test with low gas content and higher than -100 mmHg in the tests with increased gas content. The same trend was observed at the points of development of massive gas emboli. Importantly, small packages of bubbles downstream of the pump were registered at relatively high inlet pressures. The gaseous cavitation in centrifugal pumps is a phenomenon that appears with decreasing inlet pump pressures. There are a few ways to increase inlet pump pressures: (1) positioning the pump as low as possible in relation to the patient; (2) selecting appropriate sized venous cannulas and their careful positioning; and (3) controlling patient's volume status.
体外生命支持技术的成功应用增加了离心泵的使用。然而，有关溶血的报告提醒人们在使用这些泵时要谨慎，尤其是在新生儿科和儿科重症监护中。气穴现象可能是血液受损的一个原因。我们研究的目的是获取有关气穴现象的情况信息，并提供离心泵的最安全工作范围。进行了一系列测试，以确定泵性能下降3%且泵下游开始出现气泡的点。测试了两台泵：R泵为闭式叶轮泵，S泵为半开式叶轮泵。性能测试表明，S泵的最佳区域比R泵窄，且向更高流量偏移。当泵性能开始下降时，入口压力会发生变化，在气体含量低的测试中接近-150 mmHg，在气体含量增加的测试中高于-100 mmHg。在大量气体栓塞形成的点也观察到了相同的趋势。重要的是，在相对较高的入口压力下记录到了泵下游有小气泡群。离心泵中的气体空化是一种随着泵入口压力降低而出现的现象。有几种方法可以提高泵入口压力：（1）将泵相对于患者尽可能放置得低一些；（2）选择合适尺寸的静脉插管并小心放置；（3）控制患者的容量状态。
