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 fl ow 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 fl ow 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 fl ow rate independent of the type of CVC. This study evidenced that the higher the blood fl ow rate used in th e 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 fl ow through the CVC arterial lumen presents a proportionally larger thrombogenic potential when compared to the blood fl ow that leaves the vein towards the atrium. This fi nding may have consequences for clinical practice, since there is no specifi c fl ow 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 fl ow rate can possibly offer.

Dialysis flow rate in central venous catheters – A numerical analisys with experimental validation.

“…The values used were μ 0 = 0.056 Pa.s, μ ∞ = 0.0035 Pa.s, a = 2, λ = 3.313 s and n = 0.0357 [13,23]. It was adopted the value of 1060 kg/m 3 for the blood density [13,21]. The fluid used in the experimental bench was a solution of water and glycerin, 40% by mass of glycerin, with density value of 1099.5 kg/m 3 , and viscosity value of 3.820 mPa.s, at 25 °C, as commonly used to reproduce blood flow in vitro [30].…”

“…Haniel, Lucas and Huebner (2019) developed a Eulerian model for calculating the thrombogenic potential of cardiovascular devices, with a methodology similar to the study of Lacasse, Garon and Pelletier (2007) [31]. The Equation 3 shows the Eulerian model for the linear platelet lysis index inearized with respect to residence time [21,31].…”

“…To achieve adequate effectiveness during an average dialysis treatment of 4 hours, a minimum CVC blood pump flow rate of 100 to 300 mL/min is necessary [19,20]. The variation in the minimum flow values, however, depends on the type of CVC, place of insertion and degree of chronic renal disease [20][21].…”