Hegelmaier T, Kumowski N, Mainka T, Vollert J, Goertz O, Lehnhardt M, Zahn P K, Maier C, Kolbenschlag J
Department of Pain Medicine, BG University Hospital Bergmannsheil, Ruhr University, Bochum, Germany.
Department of Neurology, University Medical Center Hamburg Eppendorf, Germany.
Eur J Pain. 2017 Sep;21(8):1346-1354. doi: 10.1002/ejp.1033. Epub 2017 Mar 24.
Remote ischaemic conditioning (RIC) is the cyclic application of non-damaging ischaemia leading to an increased tissue perfusion, among others triggered by NO (monoxide). Complex regional pain syndrome (CRPS) is known to have vascular alterations such as increased blood shunting and decreased NO blood-levels, which in turn lead to decreased tissue perfusion. We therefore hypothesized that RIC could improve tissue perfusion in CRPS.
In this proof-of-concept study, RIC was applied in the following groups: in 21 patients with early CRPS with a clinical history less than a year, in 20 age/sex-matched controls and in 12 patients with unilateral nerve lesions via a tourniquet on the unaffected/non-dominant upper limb. Blood flow and tissue oxygen saturation (StO ) were assessed before, during and after RIC via laser Doppler and tissue spectroscopy on the affected extremity. The oxygen extraction fraction was calculated.
After RIC, blood flow declined in CRPS (p < 0.01). StO decreased in CRPS and healthy controls (p < 0.01). Only in CRPS, the oxygen extraction fraction correlated negatively with the decreasing blood flow (p < 0.05).
Contrary to our expectations, RIC induced a decrease of blood flow in CRPS, which led to a revised hypothesis: the decrease of blood flow might be due to an anti-inflammatory effect that attenuates vascular disturbances and reduces blood shunting, thus improving oxygen extraction. Further studies could determine whether a repeated application of RIC leads to a reduced hypoxia in chronic CRPS.
Remote ischaemic conditioning leads to a decrease of blood flow. This decrease inversely correlates with the oxygen extraction in patients with CRPS.
远程缺血预处理（RIC）是指循环应用非损伤性缺血，可导致组织灌注增加，其中一氧化氮（NO）起触发作用。已知复杂性区域疼痛综合征（CRPS）存在血管改变，如血液分流增加和血液中NO水平降低，进而导致组织灌注减少。因此，我们推测RIC可改善CRPS患者的组织灌注。
在这项概念验证研究中，对以下几组患者应用了RIC：21例病程小于1年的早期CRPS患者、20例年龄和性别匹配的对照者以及12例通过在未受影响/非优势上肢使用止血带造成单侧神经损伤的患者。通过激光多普勒和组织光谱技术，在RIC治疗前、治疗期间和治疗后，对患侧肢体的血流和组织氧饱和度（StO）进行评估。计算氧摄取分数。
RIC治疗后，CRPS患者的血流下降（p < 0.01）。CRPS患者和健康对照者的StO均降低（p < 0.0）。仅在CRPS患者中，氧摄取分数与血流减少呈负相关（p < 0.05）。
与我们的预期相反，RIC导致CRPS患者血流减少，这引发了一个修正后的假设：血流减少可能是由于抗炎作用减弱了血管紊乱并减少了血液分流，从而改善了氧摄取。进一步的研究可以确定重复应用RIC是否会减轻慢性CRPS患者的缺氧情况。
远程缺血预处理导致血流减少。这种减少与CRPS患者的氧摄取呈负相关。
