激光多普勒血流仪测定兔后肢电损伤局部血流变化

Determination of local blood flow in rabbit extremities following electrical injury with Laser Doppler flowmeter

目的:应用激光多谱勒血流仪监测局部血流变化以判断高压电损伤程度。方法:实验于2003-10/2005-01在深圳市第二人民医院烧伤整形科实验室完成。选择健康新西兰兔32只,采用自制电击设备建立电损伤重度损伤模型,将电击区域均分为A,B,C,D,E5个区,依次为肢体远端到近端。在A,B,E区于伤前、伤后0,2,4,24,48,72h,4,5,6,7d测定局部皮肤表面及肌肉中血流值变化情况。结果:①损伤前A、B、E区皮肤表面平均血流值分别为75.74,78.86,84.21PU,表明肢体近端至远端血流值逐渐减少,各点之间血流值差异无显著性意义(P>0.05)。②A区皮肤表面伤后2h血流值明显低于伤后0,4,24,48h,差异有显著性意义[分别为(27.22±22.80),(91.60±74.37),(63.97±44.41),(58.80±52.50),(58.72±39.02)PU,t=2.357,2.856,2.364,2.998,P<0.05],此时组织学表现为细胞水肿明显,有少量中性粒细胞浸润。A区皮肤表面伤后4h血流值增加,但至伤后4d才逐渐恢复到伤前水平。A区肌肉伤后2h血流值低于伤后24h,4d,差异有显著性意义[分别为(83.70±73.30),(135.10±63.07),(160.26±71.32)PU,t=2.383,2.367,P<0.05]。此时组织学表现为肌纤维肿胀,部分横纹消失,肌纤维的胞浆呈红染的疏松水波状和网状结构。③B区皮肤表面伤后4,24h血流值低于损伤前和伤后0h,差异有显著性意义[分别为(50.75±41.69),(47.23±35.36),(78.86±26.47),(83.89±32.77)PU;t=2.324,2.732,2.826,3.189,P<0.05,0.01],组织学表现同A区。B区局部肌肉伤后4h血流值低于伤后0,48,72h,差异有显著性意义[分别为(64.65±34.08),(107.11±36.50),(130.30±75.04),(180.56±72.59)PU,t=2.545,2.712,2.963,P<0.05]。此时组织学表现基本上同A区伤后2h。④E区皮肤表面各时相点之间血流值差异无显著性意义(P>0.05)。组织学表现同A区。E区局部肌肉伤后2h血流值低于伤后0,24,72h,差异有显著性意义[分别为(129.11±65.08),(175.02±71.67),(169.14±71.05),(196.64±67.34)PU,t=2.776,2.521,2.895,P<0.05]。此时组织学表现为肌纤维溶解断裂及中性粒细胞浸润。结论:用激光多谱勒血流仪监测损伤局部血流变化可以判断高压电损伤程度。

AIM： To evaluate the extent of high voltage electrical injuries by using laser Doppler flowmeter （LDF）. METHODS： The experiment was conducted in the laboratory of Plastic Surgery and Burns. Second People＇s Hospital of Shenzhen between October 2003 and January 2005. Thirty-two healthy Zelanian rabbits were selected and established into models of electrical injury with self-designed equipment. There were five parts （A, B, C, D and E） between small and big electrodes, which were respectively from the distal part to the proximal part of limbs. The blood flow on local skin surface and the muscle was determined before electrical injury and 0, 2, 4, 24, 48. and 72 hours as well as 4, 5, 6, and 7 days post-injury respectively. RESULTS： （1） The average value of blood flow in A, B and E area before the injury was 75.74, 78.86 and 84.21 PU respectively, which suggested that the blood flow decreased gradually from the proximal end to the distal end of the limbs, while there was no significant difference in the value of blood flow among each point （P 〉 0.05）. （2） The value of blood flow on the surface of skin in A area at 2 hours after the injury was obviously lower than that at 0, 4, 24 and 48 hours after the injury, and the differences were remarkable [（27.22±22.80）. （91.60±74.37）, （63.97±44.41）, （58.80±52.50）, （58.72±39.02） PU,t =2.357, 2.856, 2.364, 2.998, P 〈 0.05]. Besides, there was remarkable cellular edema and neutrophil infiltration was found. The value of blood flow on skin-surface of A area increased at 4 hours after the injury, while it didn＇t recover to the level before injury until the 4th day post injury. The value of blood flow in muscle of A area at 2 hours after injury was lower than that at 24 hours and 4 days after the injury, and the differences were significant [（83.70±73.30）, （135.10±63.07）, （160.26±71.32） PU, t =2.383, 2.367, P 〈 0.05]. Besides, muscle fibers engorged with some transverse striation disappeared. The cytoplasm of muscle fibers was in red ripple and net structures. （3） The values of blood flow on the surface of B-area skin at 4 and 24 hours after the injury were significantly lower than that before injury and that immediate after the injury [（50.75±41.69）, （47.23±35.36）, （78.86±26.47）, （83.89±32.77） PU; t =2.324, 2.732, 2.826, 3.189, P〈 0.05, 0.01], and the histological manifestations were the same as those in A area. The value of blood value in local muscle of B area at 4 hours after the injury was remarkably lower than that at 0, 48 and 72 hours after the injury [（64.65±34.08）, （107.11±36.50）, （130.30±75.04）, （180.56±72.59） PU, t =2.545, 2.712, 2.963, P 〈 0.05]. Meanwhile, the histological representations were generally the same as those of A area at 2 hours post injury. （4） There was no obvious difference in the value of blood flow on the surface of skin in E area among all time-points （P 〉 0.05）, and the histological manifestations were the same as those in A area. The value of blood flow in Iocal muscle of E area at 2 hours post injury was lower than that at o, 24 and 72 hours after the injury, and the difference was remarkable [（129.11 ±65.08）, （175.02±71.67）, （169.14 ±71.05）, （196.64±67.34） PU, t =2.776, 2.521, 2.895, P 〈 0.05]. Meanwhile, muscular fibrolysis and breakage as well as neutrophil infiltration were found. CONCLUSION： LDF is a convenient and useful method in evaluating the extent of high-voltage electrical injury.