Kheirabadi Bijan S, Terrazas Irasema B, Miranda Nahir, Estep J Scot, Corona Benjamin T, Kragh John F, Dubick Michael A
From the US Army Institute of Surgical Research, JBSA Fort Sam Houston, San Antonio, Texas.
J Trauma Acute Care Surg. 2014 Sep;77(3 Suppl 2):S101-8. doi: 10.1097/TA.0000000000000350.
Groin application of Combat Ready Clamp (CRoC) in pigs elicits an acute inflammation in underlying ischemic tissues. This study examined functional recovery of pigs' hind leg(s) following 2 hours of CRoC application.
Left femoral arteries were isolated and injured in anesthetized pigs. Following 25% hemorrhage, CRoC was applied on the inguen for 2 hours (n = 6), and wounds were covered with combat gauze (CG). Bleeding was treated in the control animals (n = 5) with CG only. Next, CRoC and CG were removed, arteries were repaired and reflowed, and animals were recovered. The legs' mobility was scored daily, and their neuromuscular functions were measured on Days 7 and 14. Computed tomographic angiography and blood analysis were performed on Days 0, 2, 7, and 14. Pigs were then euthanized, and tissues were collected for histology. Umbilicus application of CRoC was also tested in four pilot experiments.
Inguinal application of CRoC with 524 ± 12 mm Hg pressure occluded iliac arteries and collateral circulation. Following surgical repair, blood flow to the arteries was restored, and five of six CRoC-applied legs recovered full mobility within 9 days. Control-treated legs recovered full function in 3 days (p = 0.001). At 2 weeks, muscle strength of CRoC-applied legs was diminished (p < 0.05 vs. baselines or controls). Injury biomarkers in the CRoC group increased severalfold compared with the controls on Day 2 but returned to baseline afterward. Histologic changes were mostly mild and indicative of ischemia in the CRoC group. Umbilical application of CRoC required higher pressure (625 ± 8 mm Hg) and caused gross ischemic necrosis of lumbar muscles with significant disabilities.
Two-hour inguinal application of CRoC caused mild and reversible ischemic injuries, which delayed full recovery of the limb function by a few days. In contrast, 2-hour umbilicus application of CRoC resulted in extensive muscle necrosis with functional disabilities. While CRoC seems safe and effective for inguinal application, other tourniquets should be evaluated for treating bilateral junctional bleeding.
在猪身上腹股沟处应用战斗止血夹（CRoC）会引发其下方缺血组织的急性炎症。本研究检测了应用CRoC 2小时后猪后腿的功能恢复情况。
在麻醉的猪身上分离并损伤左股动脉。在失血25%后，将CRoC应用于腹股沟2小时（n = 6），伤口用战斗纱布（CG）覆盖。对照组动物（n = 5）仅用CG处理出血情况。接下来，移除CRoC和CG，修复动脉并恢复血流，让动物恢复。每天对腿部的活动能力进行评分，并在第7天和第14天测量其神经肌肉功能。在第0、2、7和14天进行计算机断层血管造影和血液分析。然后对猪实施安乐死，收集组织进行组织学检查。还在四项试点实验中测试了在脐部应用CRoC。
以524±12毫米汞柱的压力在腹股沟处应用CRoC可阻断髂动脉和侧支循环。手术修复后，动脉血流得以恢复，应用CRoC的六条腿中有五条在9天内恢复了完全活动能力。对照组处理的腿在3天内恢复了全部功能（p = 0.001）。在2周时，应用CRoC的腿的肌肉力量减弱（与基线或对照组相比，p < 0.05）。与对照组相比，CRoC组的损伤生物标志物在第2天增加了几倍，但随后恢复到基线水平。CRoC组的组织学变化大多轻微，提示存在缺血。在脐部应用CRoC需要更高的压力（625±8毫米汞柱），并导致腰肌严重缺血性坏死，伴有明显的功能障碍。
在腹股沟处应用CRoC 2小时会导致轻度且可逆的缺血性损伤，这使肢体功能的完全恢复延迟了几天。相比之下，在脐部应用CRoC 2小时会导致广泛的肌肉坏死和功能障碍。虽然CRoC在腹股沟应用似乎安全有效，但对于治疗双侧交界性出血，应评估其他止血带。
