持续缓慢放松止血带对肢体缺血再灌注损伤的保护作用

Protective effect of continuous slow relaxation of tourniquet for patients with limb ischemia reperfusion injury

[目的]探讨持续缓慢放松止血带对肢体缺血再灌注损伤的保护作用。[方法]采用实验研究方法,将18只比格犬随机分为假手术组(S组)、快速放松组(RR组)、持续缓慢放松组(SR组)3组,RR组和SR组持续缚扎止血带3h后分别采取快速放松和持续缓慢放松的方法松解止血带,观察再灌注后动脉/组织血流量、平均动脉压、心率、组织骨骼肌丙二醛(MDA)、超氧化物歧化酶(SOD)、血清乳酸脱氢酶(LDH)、内皮素-1(ET-1)的改变及骨骼肌病理形态的变化情况。[结果]放松止血带后,与S组相比,RR组和SR组动脉血流量及组织血流量迅速增加,平均动脉压显著下降,心率增快,且SR组的变化程度显著小于RR组(P<0.05或P<0.01);阻断3h组织MDA、血清LDH和ET-1开始升高,SOD含量下降,且SR组的变化程度明显低于RR组(P<0.05或P<0.01)。组织切片及电镜显示,放松止血带后肌细胞水肿明显,间质血管扩张充血,炎性细胞浸润,线粒体肿胀、溶解,RR组炎性反应较SR组明显加重。[结论]采用持续缓慢放松止血带的方法有助于维持血液循环稳定,减轻脂质过氧化反应及血管内皮的损伤程度,对肢体缺血再灌注损伤具有一定的保护作用。

Objective：To probe into the protective effect of continuous slow relaxation of tourniquet for patients with limbs ischemic reperfusion inj ury.Methods：With the experimental research method,a total of 1 8 beagle dogs were randomly divided into sham operation group （group S）,the fast relaxation group （group RR）,contin-uous slow relaxation group（SR group）.In RR group and SR group after continuing to tie a tourniquet for 3 h, the patients in both groups respectively took fast relaxation and slow relaxation method to release tourniquet, then to observe the changes of reperfusion artery/tissue blood flow,mean arterial pressure,heart rate,skeletal muscle tissue malondialdehyde（MDA）,changes in superoxide dismutase（SOD）and serum lactate dehydrogen-ase（LDH）,endothelin 1 （ET 1 ）and pathological skeletal muscle.Results：After relaxing tourniquet,compa-ring with S group,the arterial blood flow and tissue blood flow of RR group and SR group increased rapidly,and the mean arterial pressure decreased significantly;heart rate increased,and its extent of change in SR group was smaller than that of RR group（P〈0.05 or P〈0.01）;after block for 3 h,tissue MDA,serum LDH and ET 1 began to rise,the content of SOD decreased,and its change in SR group was significantly lower than that in RR group（P〈0.05 or P〈0.01）.Tissue sections and electron microscopy showed that after relaxing tourniquet the muscle cell edema was obvious and with interstitial vascular dilatation and congestion,inflammatory cell infiltra-tion,mitochondrial swelling and dissolution,inflammatory reaction in RR group was obviously aggravated com-pared with that in group SR.Conclusion：By continuous slow relaxing tourniquet method is helpful to maintain the stability of blood circulation,reduce lipid peroxidation and the degree of inj ury of vascular endothelium, which has a protective effect for limb ischemia reperfusion inj ury.