Influence of hemodialysis blood flow rate on the thrombogenic potential in patients with central venous catheters

Abstract In this study we apply methods to determine the tendency for thrombus formation in different central venous catheters (CVC) models associated with flow rate variation. To calculate the thrombogenic potential, we proposed a new numerical model of the platelet lysis index (PLI) equation. To compare the results of PLI and flow rate in different models of catheters, numerical calculations were performed on three different tips of CVC. The results showed that the PLI increases as a power function of the flow rate independent of the type of CVC. This study evidenced that the higher the blood flow rate used in the catheter, the greater the potential for thrombus formation. The PLI computed at the catheter outlet presented higher values when compared to the values computed at the vein outlet indicating that the blood flow through the CVC arterial lumen presents a proportionally larger thrombogenic potential when compared to the blood flow that leaves the vein towards the atrium. This finding may have consequences for clinical practice, since there is no specific flow value recommended in the catheter when the hemodialysis machine is turned on, and with this equation it was possible to demonstrate the thrombogenic potential that the flow rate can possibly offer.摘要 本研究针对不同中心静脉导管（central venous catheters, CVC）模型，探究其伴随流速变化时的血栓形成倾向。为计算血栓形成潜能，本研究提出了一种全新的血小板溶解指数（platelet lysis index, PLI）方程数值模型。为对比不同导管模型下PLI与流速的结果，研究针对三款不同尖端的中心静脉导管开展了数值计算。结果显示，无论中心静脉导管类型如何，PLI均随流速呈幂函数形式增长。本研究证实：导管内血流流速越高，血栓形成潜能越大。相较于静脉出口处的计算值，导管出口处的PLI计算值更高，这表明相较于经静脉流向心房的血流，流经中心静脉导管动脉腔的血流具有比例更高的血栓形成潜能。鉴于目前血液透析机启动时未对导管设置特定流速推荐值，本研究提出的方程可用于量化流速可能带来的血栓形成潜能，该发现对临床实践具有参考意义。