Laboratory of Vascular Investigations, University Hospital of Angers, and L'UNAM University, University of Angers, Biologie Neurovasculaire et Mitochondriale Intégrée (BNMI)-Unité mixte UMR CNRS 6214/INSERM U 1083, Medicine Faculty, Angers, France.
Microvasc Res. 2013 Jul;88:56-60. doi: 10.1016/j.mvr.2013.04.005. Epub 2013 Apr 27.
Microcirculatory dysfunction plays a key role in the development of sepsis during which core temperature is often disturbed. Skin microvascular assessment using laser techniques has been suggested to evaluate microvascular dysfunction during sepsis, but skin microcirculation is also a major effector of human thermoregulation. Therefore we aimed to study the effect of skin temperature on endothelial- and non-endothelial microvascular responses.
Fifteen healthy participants were studied at different randomized ambient temperatures leading to low (28.0+/-2.0 °C), intermediate (31.6+/-2.1 °C), and high (34.1+/-1.3 °C) skin temperatures. We measured skin blood flow using laser speckle contrast imaging on the forearm in response to vasodilator microvascular tests: acetylcholine (ACh) iontophoresis, sodium nitroprussiate (SNP) iontophoresis, and post-occlusive reactive hyperemia (PORH). The results are expressed as absolute (laser speckle perfusion units, LSPU) or normalized values (cutaneous vascular conductance, CVC in LSPU/mmHg and multiple of baseline).
Maximal vasodilation induced by these tests is modified by skin temperature. A low skin temperature induced a significant lower vasodilation for all microvascular tests when results are expressed either in absolute values or in CVC. For example, ACh peak was 57.6+/-19.6 LSPU, 66.8+/-22.2 LSPU and 88.5+/-13.0 LSPU for low, intermediate and high skin temperature respectively (p<0.05). When results are expressed in multiple of baseline, statistical difference disappeared.
These results suggest that skin temperature has to be well controlled when performing microvascular assessments in order to avoid any bias. The effect of skin temperature can be corrected by expressing the results in multiple of baseline.
微循环功能障碍在脓毒症的发展中起着关键作用，在此期间核心体温常常受到干扰。使用激光技术评估皮肤微血管已被建议用于评估脓毒症期间的微血管功能障碍，但皮肤微循环也是人体体温调节的主要效应器。因此，我们旨在研究皮肤温度对内皮和非内皮微血管反应的影响。
在不同随机环境温度下，15 名健康参与者被随机分为三组，导致皮肤温度分别处于低（28.0±2.0°C）、中（31.6±2.1°C）和高（34.1±1.3°C）。我们使用激光散斑对比成像在前臂上测量皮肤血流，以响应血管扩张剂微血管测试：乙酰胆碱（ACh）离子电渗、硝普钠（SNP）离子电渗和闭塞后反应性充血（PORH）。结果以绝对值（激光散斑灌注单位，LSPU）或归一化值（皮肤血管传导性，CVC 以 LSPU/mmHg 和基线倍数表示）表示。
这些测试引起的最大血管扩张受皮肤温度的影响。皮肤温度低时，所有微血管测试的血管扩张均明显降低，无论是以绝对值还是 CVC 表示。例如，ACh 峰值在低、中、高皮肤温度下分别为 57.6±19.6 LSPU、66.8±22.2 LSPU 和 88.5±13.0 LSPU（p<0.05）。当结果以基线倍数表示时，统计学差异消失。
这些结果表明，在进行微血管评估时，必须很好地控制皮肤温度，以避免任何偏差。可以通过将结果表示为基线倍数来纠正皮肤温度的影响。
