家兔烧伤后血浆内毒素和丙二醛水平及早期切痂对其影响

通过复制创面绿脓杆菌感染、背部Ⅱ度30％体表面积烧伤的家兔动物模型，动态检测了烧伤动物血浆内毒素及MDA含量的变化。结果表明：烧伤创面及感染是血中内毒素和氧自由基的重要来源；早期切痂能降低血内毒素和MDA水平。对内毒素影响氧自由基形成及早期切痂影响血中内毒素和MDA水平的机理作了初步探讨。

Study of the level of plasma endotoxin and MDA in burned rabbits and the effect of early escharectomy

One of the fatal outcomes in patients with extensive burn is infection,which is commonly causedby Pseudomonas aeruginosa,the endotoxin of which may induce serious clinical signs. Using experimentalburn models of rabbits with the wound infected with P. aeruginosa,the changes of plasma endotoxin andMDA levels were studied. The results showed that the level of plasma endotoxin was obviously increased,reaching peak value in 2 days postburn,which was 0. 88Eu/ml higher than that of normal control,and re-turned to normal at the 7th day postburn. The plasma content of MDA was also greatly increased postburnand arrived peak value at the 4th day,which was 286. 18 percent higher than that of the normal control.We also observed that early escharectomy could decrease the level of plasma endotoxin and MDA,but withless effect on animal's body temperature. However,early excision of heavily contaminated eshar did not in-crease the chance of germs entering the blood flow.The above results suggested that:1. The mechanisms of bacterial invasion and toxin absorption are different.2. Burn wound and infection were the major origin of the endotoxin and oxygen free radical in blood.3. There is close relationship between endotoxin absorption and oxygen free radical formation.4. Early escharectomy decreased the level of endotoxin and MDA in blood,but did not show increasedchance of germs invading the blood flow from the wound.The paper also prelimnarily investigated the mechanisms of the effect of endotoxin on oxygen freeradical formation and,of early escharectomy on the levels of endotoxin and MDA in blood plasma.