Background

The underlying mechanism of pulsatile flushing technique has not been fully elucidated, and the partial understanding of the mechanism has been confined to hydrodynamic simulation, ignoring the dynamic interaction among the catheter, blood vessel, blood stream, and saline.

Methods

The peripheral intravenous catheter and vein models and their internal flow fields were assessed using a commercial software. The parameters of both fluid and structural mechanics were calculated and compared in the push and pause phase. The effect of different flushing volumes per bolus before each pause (0.5, 1.0, 1.5, and 2.0 mL) were compared, respectively corresponding to group (A, B, C and D).

Findings

In groups C and D, the wall shear stress value (≥2 Pa) and enhanced shear rates (peaks up to 10,000 s⁻¹) were higher in the vessel wall near the catheter tip, which may be at risk of vascular endothelial injury. Furthermore, extraluminal flushing might be attributed to the recirculation of jet from the catheter outlet. The vortices of all groups faded away in an extremely short period (≤0.1 s) if the push was suddenly discontinued. Finally, overlarge displacement of the catheter tip in groups C and D (0.91 and 1.1 mm, respectively) caused the peripheral intravenous catheters to angle with the venous wall.

Interpretation

The pulsatile flushing technique can facilitate intra- and extraluminal flushing of peripheral intravenous catheters. Furthermore, an insufficient volume per bolus can lead to inefficient flushing, and an overdose of single push may cause mechanical endothelial injury.

中文翻译：

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通过外围静脉导管注射盐水的脉冲冲洗技术的机理。

背景

尚未完全阐明脉动冲洗技术的潜在机理，并且对该机理的部分理解仅限于流体动力学模拟，而忽略了导管，血管，血流和盐水之间的动态相互作用。

方法

使用商业软件评估外周静脉导管和静脉模型及其内部流场。在推动和暂停阶段计算并比较了流体力学和结构力学的参数。比较每次暂停之前每个推注的不同冲洗量（0.5、1.0、1.5和2.0 mL）的效果，分别对应于组（A，B，C和D）。

发现

在C组和D组中，导管尖端附近的血管壁中的壁切应力值（≥2Pa）和增强的切变速率（峰值高达10,000 s ^-1）更高，这可能具有血管内皮损伤的风险。此外，腔外冲洗可归因于来自导管出口的射流的再循环。如果突然停止推动，所有组的涡旋会在极短的时间内（≤0.1s）消失。最后，C和D组（分别为0.91和1.1 mm）中导管尖端的过大位移导致外围静脉内导管与静脉壁倾斜。

解释

搏动冲洗技术可以促进外周静脉导管的腔内和腔外冲洗。此外，每次推注的体积不足会导致冲洗效率低下，单次推入剂量过大可能会导致机械性内皮损伤。