Arbabi S, Brundage S I, Gentilello L M
Department of Surgery, Harborview Medical Center, University of Washington School of Medicine, Seattle, USA.
J Trauma. 1999 Nov;47(5):829-33. doi: 10.1097/00005373-199911000-00002.
Near-infrared spectroscopy (NIRS) noninvasively measures tissue O2 saturation (StO2), and has been proposed as a means of monitoring for compartmental syndrome (CS). However, its specificity in hypoxemic, hypotensive patients with severely reduced systemic oxygen delivery has not been tested. We hypothesized that NIRS can differentiate muscle ischemia caused by shock from ischemia caused by CS.
Nine swine were anesthetized and an NIRS probe placed over the anterolateral compartment of the hind leg. Compartment pressure was also measured. A nerve stimulator was placed over the peroneal nerve, and CS was defined as loss of dorsiflexion twitch. At 30-minute sequential intervals, mean arterial blood pressure was reduced to 60% of baseline (phlebotomy), fraction of inspired oxygen was reduced to 0.15, and compartment pressure was increased in one limb by interstitial albumin infusion until CS occurred.
Hypotension combined with hypoxemia reduced StO2 from 82+/-4% to 66+/-10%. CS further reduced StO2 to 16+/-12% (p<0.0001). During hypotension + hypoxemia + CS, control limb StO2 was 70+/-15% (p = 0.0002 vs. experimental limb).
NIRS detects muscle ischemia caused by CS despite severe hypotension and hypoxemia, making it potentially useful in critically injured, unstable patients.
近红外光谱（NIRS）可无创测量组织氧饱和度（StO2），并已被提议作为监测骨筋膜室综合征（CS）的一种手段。然而，其在全身氧输送严重降低的低氧血症、低血压患者中的特异性尚未得到测试。我们假设NIRS能够区分休克引起的肌肉缺血和CS引起的缺血。
对9头猪进行麻醉，将NIRS探头置于后腿外侧骨筋膜室上方。同时测量骨筋膜室内压力。将神经刺激器置于腓总神经上方，将背屈抽搐消失定义为CS。每隔30分钟依次进行以下操作：将平均动脉血压降至基线的60%（放血），将吸入氧分数降至0.15，并通过间质输注白蛋白使一侧肢体的骨筋膜室内压力升高，直至发生CS。
低血压合并低氧血症使StO2从82±4%降至66±10%。CS进一步将StO2降至16±12%（p<0.0001）。在低血压+低氧血症+CS期间，对照肢体的StO2为70±15%（与实验肢体相比，p = 0.0002）。
尽管存在严重的低血压和低氧血症，NIRS仍能检测到CS引起的肌肉缺血，这使其在严重受伤、病情不稳定的患者中具有潜在的应用价值。
