Nelson Ashley D, Rossman Matthew J, Witman Melissa A, Barrett-O'Keefe Zachary, Groot H Jonathan, Garten Ryan S, Richardson Russell S
Department of Internal Medicine, University of Utah, Salt Lake City, Utah; Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah;
Geriatric Research, Education, and Clinical Center, Veterans Affairs Medical Center, Salt Lake City, Utah; Department of Exercise & Sport Science, University of Utah, Salt Lake City, Utah; and.
J Appl Physiol (1985). 2016 May 1;120(9):991-9. doi: 10.1152/japplphysiol.00961.2015. Epub 2016 Feb 11.
Post-cuff occlusion flow-mediated dilation (FMD) is a proposed indicator of nitric oxide (NO) bioavailability and vascular function. FMD is reduced in patients with sepsis and may be a marker of end organ damage and mortality. However, FMD likely does not solely reflect NO-mediated vasodilation, is technically challenging, and often demonstrates poor reproducibility. In contrast, passive leg movement (PLM), a novel methodology to assess vascular function, yields a hyperemic response that is predominately NO-dependent, reproducible, and easily measured. This study evaluated PLM as an approach to assess NO-mediated vascular function in patients with sepsis. We hypothesized that PLM-induced hyperemia, quantified by the increase in leg blood flow (LBF), would be attenuated in sepsis. In a cross-sectional study, 17 subjects in severe sepsis or septic shock were compared with 16 matched healthy controls. Doppler ultrasound was used to assess brachial artery FMD and the hyperemic response to PLM in the femoral artery. FMD was attenuated in septic compared with control subjects (1.1 ± 1.7% vs. 6.8 ± 1.3%; values are means ± SD). In terms of PLM, baseline LBF (196 ± 33 ml/min vs. 328 ± 20 ml/min), peak change in LBF from baseline (133 ± 28 ml/min vs. 483 ± 86 ml/min), and the LBF area under the curve (16 ± 8.3 vs. 143 ± 33) were all significantly attenuated in septic subjects. Vascular function, as assessed by both FMD and PLM, is attenuated in septic subjects compared with controls. These data support the concept that NO bioavailability is attenuated in septic subjects, and PLM appears to be a novel and feasible approach to assess NO-mediated vascular function in sepsis.
袖带阻断后血流介导的血管舒张（FMD）是一种一氧化氮（NO）生物利用度和血管功能的潜在指标。脓毒症患者的FMD降低，可能是终末器官损伤和死亡率的标志物。然而，FMD可能不仅仅反映NO介导的血管舒张，在技术上具有挑战性，并且常常显示出较差的可重复性。相比之下，被动腿部运动（PLM）是一种评估血管功能的新方法，可产生主要依赖于NO的充血反应，具有可重复性且易于测量。本研究评估了PLM作为评估脓毒症患者NO介导的血管功能的一种方法。我们假设，通过腿部血流（LBF）增加来量化的PLM诱导的充血在脓毒症中会减弱。在一项横断面研究中，将17名严重脓毒症或感染性休克患者与16名匹配的健康对照进行比较。使用多普勒超声评估肱动脉FMD和股动脉对PLM的充血反应。与对照受试者相比，脓毒症患者的FMD减弱（1.1±1.7%对6.8±1.3%；数值为平均值±标准差）。就PLM而言，脓毒症受试者的基线LBF（196±33 ml/min对328±20 ml/min）、LBF相对于基线的峰值变化（133±28 ml/min对483±86 ml/min）以及曲线下LBF面积（16±8.3对143±33）均显著减弱。与对照组相比，脓毒症受试者通过FMD和PLM评估的血管功能均减弱。这些数据支持脓毒症受试者中NO生物利用度降低的概念，并且PLM似乎是评估脓毒症中NO介导的血管功能的一种新的可行方法。
