PDF(Pubmed)
Abstract：
Background: Negative pressure wound therapy (NPWT) is an intensely investigated topic, but its mechanism of action accounts for one of the least understood ones in the area of wound healing. Apart from a misleading nomenclature, by far the most used diagnostic tool to investigate NPWT, the laser Doppler, also has its weaknesses regarding the detection of changes in blood flow and velocity. The aim of the present study is to explain laser Doppler readings within the context of NPWT influence. Methods: The cutaneous microcirculation beneath an NPWT system of 10 healthy volunteers was assessed using two different laser Dopplers (O2C/Rad-97®). This was combined with an in vitro experiment simulating the compressing and displacing forces of NPWT on the arterial and venous system. Results: Using the O2C, a baseline value of 194 and 70 arbitrary units was measured for the flow and relative hemoglobin, respectively. There was an increase in flow to 230 arbitrary units (p = 0.09) when the NPWT device was switched on. No change was seen in the relative hemoglobin (p = 0.77). With the Rad-97®, a baseline of 92.91% and 0.17% was measured for the saturation and perfusion index, respectively. No significant change in saturation was noted during the NPWT treatment phase, but the perfusion index increased to 0.32% (p = 0.04). Applying NPWT compared to the arteriovenous-vessel model resulted in a 28 mm and 10 mm increase in the venous and arterial water column, respectively. Conclusions: We suspect the vacuum-mediated positive pressure of the NPWT results in a differential displacement of the venous and arterial blood column, with stronger displacement of the venous side. This ratio may explain the increased perfusion index of the laser Doppler. Our in vitro setup supports this finding as compressive forces on the bottom of two water columns within a manometer with different resistances results in unequal displacement.
摘要：
背景：负压伤口治疗（NPWT）是一个备受关注的话题，但它的作用机制是伤口愈合领域最不了解的机制之一。除了误导性的命名法，迄今为止最常用的NPWT诊断工具，激光多普勒,在检测血流和速度的变化方面也有其弱点。本研究的目的是在NPWT影响的背景下解释激光多普勒读数。方法：使用两种不同的激光多普勒（O2C/Rad-97®）评估了10名健康志愿者的NPWT系统下的皮肤微循环。这与模拟NPWT对动脉和静脉系统的压缩力和位移力的体外实验相结合。结果：使用O2C，测量流量和相对血红蛋白的基线值为194和70任意单位，分别。当NPWT器件接通时,流量增加到230个任意单位(p=0.09)。相对血红蛋白没有变化(p=0.77)。有了Rad-97®,饱和度和灌注指数的基线为92.91%和0.17%，分别。在NPWT治疗阶段，饱和度没有显著变化，但灌注指数增加到0.32%(p=0.04)。与动静脉血管模型相比，应用NPWT可导致静脉和动脉水柱增加28毫米和10毫米，分别。结论：我们怀疑NPWT的真空介导正压会导致静脉和动脉血柱的不同位移，静脉侧位移更强。该比率可以解释激光多普勒的灌注指数增加。我们的体外设置支持这一发现，因为具有不同阻力的压力计内两个水柱底部的压缩力导致位移不相等。
