MEBT/MEBO阻止深Ⅱ度烧伤创面进行性加深机制的实验研究

目的:观察烧伤湿性医疗技术／美宝湿润烧伤膏(MEBT／MEBO)对大鼠深Ⅱ度烧伤创面的细胞、毛细血管形态结构的变化,探讨其改善深Ⅱ度烧伤创面进行性加深的作用机制。方法:SD大鼠20只,背部两侧造成40个对称性圆环形深Ⅱ度烧伤创面,每个创面中央留有一个同心圆岛状区(淤滞区),随机自身对照,治疗组侧使用MEBT／MEBO进行治疗,每6小时换药一次,对照组侧不用任何措施。动态观察烧伤大鼠于伤后2h、6h、8h、12h、24h、72h共6个时相点的创面的病理切片观察皮肤组织形态结构变化和淤滞区切片进行组织病理学评分。结果:①创面细胞形态学改变(病理检查):伤后8h毛细血管扩张、细胞水肿,炎性浸润最明显;治疗组中央淤滞区无进行性坏死,伤后24h后毛细血管扩张、细胞水肿、炎性浸润减轻;对照组2个创面呈进行性坏死(占10％),中央淤滞区细胞水肿、炎性浸润明显,毛细血管血栓形成,伤后72h水肿仍明显,真皮坏死加重;②淤滞区组织病理学评分:治疗组与对照组相比,治疗侧淤滞区的表皮结构相对完整、胶原纤维束相对正常,粒细胞浸润小于5个／400倍视野。结论:MEBT／MEBO能防止大鼠深Ⅱ度烧伤创面进行性加深,促进烧伤后的创面愈合,其作用机制为MEBT／MEBO能使创面局部毛细血管扩张、细胞水肿、炎性浸润减轻,防止微血栓生成,有效改善创面局部的微环境,挽救间生态组织。

Experimental study of the efficacy of MEBT/MEBO in preventing progressive necrosis of partial - thickness burn wound in rats and its mechanism

Objective: To observe the efficacy of MEBT/MEBO in preventing progressive necrosis of partial -thickness burn wounds. Method: 20 rats were burned in both sides of back symmetrically to form 2" degree burn wounds in ring shape. At the center of each wound, a concentric circle was preserved as stasis zone. Wounds in one side of the back were treated with MEBO every 6 hours. Wounds in the other side received no treatment ( as a control). The wounds were observed at2 h,6 h,8 h, 12 h,24 h and 72 h after injury. Skin tissue sections from the wounds and the stasis zones were observed under microscope and morphological structure changes were compared. Result: 1. Pathological examination of the wounds: At 8 h post injury, significant changes happened in the wounds, including capillary dilation, cell edema and inflammatory infiltration. In treatment group, there was no progressive necrosis in stasis zone, and at 24 h post injury, capillary dilation , cell edema and inflammatory infiltration were lessened significantly. In control group, 2 wounds had progressive necrosis ( accounted for 10% of the total). Cell edema, inflammatory infiltration and capillary thrombosis were serious, Until 72 hr post injury, cell edema did not subside and necrosis of the dermis worsened. 2. Pathological assessment of the stasis zone tissue: As compared with that in control group, in treatment group the dermis structure in stasis zone was intact and the col-lagenous fiber bundle was normal. Conclusion: MEBT/MEBO is efficacious in preventing progressive necrosis of deep burn wounds and promoting wound healing. Its mechanism may be that MEBO can lessen the injury such as local capillary dilation, cell edema and inflammatory infiltration, and prevent micro - thrombosis. So it can effectively improve local microcircu-lation in the wounds and save parabiotic tissue.