Rehabilitation Research Laboratory, Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Champaign, IL, USA.
Physiol Meas. 2012 Oct;33(10):1733-45. doi: 10.1088/0967-3334/33/10/1733. Epub 2012 Sep 26.
The objectives of this study were to investigate the effects of local cooling on skin blood flow response to prolonged surface pressure and to identify associated physiological controls mediating these responses using the wavelet analysis of blood flow oscillations in rats. Twelve Sprague-Dawley rats were randomly assigned to three protocols, including pressure with local cooling (Δt = -10 °C), pressure with local heating (Δt = 10 °C) and pressure without temperature changes. Pressure of 700 mmHg was applied to the right trochanter area of rats for 3 h. Skin blood flow was measured using laser Doppler flowmetry. The 3 h loading period was divided into non-overlapping 30 min epochs for the analysis of the changes of skin blood flow oscillations using wavelet spectral analysis. The wavelet amplitudes and powers of three frequencies (metabolic, neurogenic and myogenic) of skin blood flow oscillations were calculated. The results showed that after an initial loading period of 30 min, skin blood flow continually decreased under the conditions of pressure with heating and of pressure without temperature changes, but maintained stable under the condition of pressure with cooling. Wavelet analysis revealed that stable skin blood flow under pressure with cooling was attributed to changes in the metabolic and myogenic frequencies. This study demonstrates that local cooling may be useful for reducing ischemia of weight-bearing soft tissues that prevents pressure ulcers.
本研究的目的是探讨局部冷却对皮肤血流对长时间表面压力的反应的影响，并使用大鼠血流振荡的小波分析来确定介导这些反应的相关生理控制。12 只 Sprague-Dawley 大鼠被随机分配到三个方案中，包括局部冷却（Δt = -10°C）、局部加热（Δt = 10°C）和无温度变化的压力。将 700mmHg 的压力施加到大鼠右侧转子区域 3 小时。使用激光多普勒血流仪测量皮肤血流。3 小时加载期分为不重叠的 30 分钟时段，用于使用小波谱分析分析皮肤血流振荡的变化。计算了皮肤血流振荡的三个频率（代谢、神经和肌源性）的小波幅度和功率。结果表明，在初始加载 30 分钟后，在加热压力和无温度变化的压力条件下，皮肤血流持续下降，但在冷却压力下保持稳定。小波分析表明，冷却压力下稳定的皮肤血流归因于代谢和肌源性频率的变化。本研究表明，局部冷却可能有助于减少承重软组织的缺血，从而预防压疮。
