Department of Rehabilitation Science and Technology, University of Pittsburgh, Pittsburgh, PA 15206, USA.
J Tissue Viability. 2010 Aug;19(3):86-97. doi: 10.1016/j.jtv.2009.12.003. Epub 2010 Feb 11.
People with spinal cord injuries are at high risk for developing pressure ulcers. Increased skin temperature is one of the extrinsic causative factors for this multi-factorial disease. Previous animal studies revealed that local skin cooling reduced the severity of ulceration, and cooling is widely used in plastic surgery and organ transplants for tissue preservation. The objectives of this pilot study were to develop test protocols and instrumentation and to investigate the effect of local cooling on skin perfusion response to pressure on young healthy human subjects. Reactive hyperemia was quantified in this study to compare the effects of pressure with and without cooling. Reactive hyperemia is a normal physiological response occurring after vessel occlusion. Laser Doppler flowmetry was used to measure skin blood flow. Time-dependent spectral analysis was used to analyze and decompose the blood flow data into frequency ranges associated with specific blood flow control mechanisms. The study used a repeated measures design with two test conditions: 8 kPa of pressure with and without cooling to 25 degrees C. We hypothesized that local cooling would reduce the post-ischemic reactive hyperemic response induced by the rigid indenter. Time series results showed that normalized peak perfusion response was significantly lower with cooling (p=0.019). Time-dependent spectral analysis results suggested that both metabolic and myogenic responses contribute to this protective effect. Findings from our study on humans were consistent with previous animal studies. Additional studies on individuals with spinal cord injury are planned to further evaluate the cooling effect in a high-risk population.
脊髓损伤患者发生压疮的风险很高。皮肤温度升高是这种多因素疾病的外在致病因素之一。先前的动物研究表明，局部皮肤冷却可降低溃疡的严重程度，并且冷却在整形手术和器官移植中广泛用于组织保存。本初步研究的目的是开发测试方案和仪器，并研究局部冷却对年轻健康人体皮肤对压力的灌注反应的影响。在这项研究中量化了反应性充血，以比较有和没有冷却时的压力影响。反应性充血是血管闭塞后发生的正常生理反应。激光多普勒流量仪用于测量皮肤血流量。时变谱分析用于分析和分解血流数据，将其分解为与特定血流控制机制相关的频率范围。该研究采用重复测量设计，有两种测试条件：压力为 8 kPa，有和没有冷却至 25°C。我们假设局部冷却会降低刚性压头引起的缺血后反应性充血反应。时间序列结果表明，冷却时归一化峰值灌注反应明显降低（p=0.019）。时变谱分析结果表明，代谢和肌源性反应都有助于这种保护作用。我们对人类的研究结果与先前的动物研究一致。计划对脊髓损伤患者进行进一步研究，以进一步评估高危人群的冷却效果。
