Orthogonal polarization spectroscopy to detect mesenteric hypoperfusion
Orthogonal polarization spectroscopy to detect mesenteric hypoperfusion
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DOI：
10.1007/s00134-008-1130-8
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发表时间：
2008-10-01
影响因子：
38.9
通讯作者：
Jakob, Stephan M.
中科院分区：
文献类型：
--
作者：
Bracht, Hendrik;Krejci, Vladimir;Jakob, Stephan M.
目的：应用正交偏振光谱（OPS）成像技术评价口腔黏膜微循环。我们测试了OPS在评估肠系膜血流量（Q(sma)）减少时的敏感性和可变性。单位：大学动物实验室。干预措施：在8头猪中，Q（sma）从基线逐步降低15%；5只动物作为对照。应用OPS和激光多普勒血流仪记录各步骤空肠黏膜微循环血流。收集每个时期的项目事务处数据并随机排序。每个时期的样本由两名盲法调查人员单独选择，并在对方法达成一致后量化[毛细血管密度（越过预定线的血管数量），灌注绒毛数量]。测量和结果：代表相同流动条件的样品的毛细管密度的观察者间变异系数（CV）为0.34(0.04-1.41)，观察者内CV为0.10（0.02-0.61）。只有一名研究者观察到，在45% Q（sma）降低时，毛细血管密度下降至基线值的62% (48-82%)；P = 0.011]，但与对照组比较未发现显著差异。相比之下，两位研究者在肠系膜血流减少75%时检测到灌注绒毛减少。激光多普勒血流显示非均匀微循环灌注。结论：评估毛细血管密度并没有显示Q（sma）减少和未减少动物之间的差异，而评估灌注绒毛仅在Q（sma）非常低时才显示血流量减少。可能的解释是血流重新分布和异质性，以及OPS图像对比度不理想。尽管分析方法是一致的，但观察者之间在使用OPS定量肠粘膜血管密度方面的差异很大。
Objective: Orthogonal polarization spectral (OPS) imaging is used to assess mucosal microcirculation. We tested sensitivity and variability of OPS in the assessment of mesenteric blood flow (Q(sma)) reduction. Setting: University Animal Laboratory. Interventions: In eight pigs, Q(sma) was reduced in steps of 15% from baseline; five animals served as controls. Jejunal mucosal microcirculatory blood flow was recorded with OPS and laser Doppler flowmetry at each step. OPS data from each period were collected and randomly ordered. Samples from each period were individually chosen by two blinded investigators and quantified [capillary density (number of vessels crossing predefined lines), number of perfused villi] after agreement on the methodology. Measurement and results: Interobserver coefficient of variation (CV) for capillary density from samples representing the same flow condition was 0.34 (0.04-1.41) and intraobserver CV was 0.10 (0.02-0.61). Only one investigator observed a decrease in capillary density [to 62% (48-82%) of baseline values at 45% Q(sma) reduction; P = 0.011], but comparisons with controls never revealed significant differences. In contrast, reduction in perfused villi was detected by both investigators at 75% of mesenteric blood flow reduction. Laser Doppler flow revealed heterogeneous microcirculatory perfusion. Conclusions: Assessment of capillary density did not reveal differences between animals with and without Q(sma) reduction, and evaluation of perfused villi revealed blood flow reduction only when Q(sma) was very low. Potential explanations are blood flow redistribution and heterogeneity, and suboptimal contrast of OPS images. Despite agreement on the method of analysis, interobserver differences in the quantification of vessel density on gut mucosa using OPS are high.