Study On Protective Effects Of Iscfemic Preconditioning On Endothelial Injury And Inflammatory Reaction In Lower Extremity Tourniquets

Objective: This study examined the use of von Willebrand factor(vWF),interleukin-6(IL-6),and D-dimer before and after tourniquet surgery for patients with tibial fractures.Follow-up results of short-term thrombosis were used to investigate the extent of vascular endothelial damage associated with reperfusion injury induced by lower extremity tourniquets,the effects of inflammatory reactions,and the intervention of ischemic preconditioning.Methods: Selected from June 2016 to February 2018,40 patients undergoing surgical treatment for humerus fractures at the First People's Hospital of Huaihua City,including 27 male patients and 13 female patients.All were performed by the same surgeon using tension band wire fixation.Randomly divided into ischemic preconditioning group(experimental group)20 cases and conventional tourniquet group(control group)20 cases.In the ischemic preconditioning group,after the induction of anesthesia,an auto-pneumatic tourniquet was affixed to the roots of the affected limbs for 3 cycles of 5 min ischemia(pressure maintained at 60 kPa)/5 min reperfusion followed by routine use of a tourniquet.In the control group,no ischemic preconditioning intervention was performed,and the tourniquet was used as usual.The levels of plasma vWF,IL-6,and D-dimer before induction of anesthesia and 2h,6h,24 h after release of the tourniquet were measured and statistically analyzed.The wound infection and limb ischemia were observed.The vascular venous thrombosis of the lower extremities was determined by vascular ultrasonography of the lower extremities 1 week after the follow-up and 1 month after the operation.The functional recovery of the knee joint was assessed by the Bostman tibial fracture clinical treatment score 3 months after operation.Result: 1.Compared with the conventional tourniquet group,the ischemic preconditioning group had no statistical difference(P>0.05)in terms of body weight,height,age,sex,tourniquet use time,and operation time before surgery.2.The levels of plasma vWF,IL-6 and D-dimer before induction of anesthesia in the two groups were not statistically different(P>0.05).The plasma levels of vWF,IL-6 and D-dimer at the 2h,6h and 24 h after release of the tourniquet were significantly higher than those before induction of anesthesia,and the differences were statistically significant(P < 0.05).Compared with the conventional tourniquet group,the ischemic preconditioning group can reduce plasma v WF levels and IL-6 levels at 2h,6h and 24 h after release of tourniquet(P<0.05).3.There was no significant difference in the clinical treatment scores of Bostman tibial fractures in the ischemic preconditioning group compared with the conventional tourniquet group at 3 months postoperatively(P>0.05).4.There was no wound infection in the experimental group.In the control group,there was 1 case of wound infection.No venous thrombosis of the lower extremities was found in all the patients 1 week postoperatively and 1 month postoperatively.No changes of limb ischemia were found in both groups.Conclusion: 1.Lower extremity tourniquet surgery can induce vascular endothelial injury and inflammation associated with ischemia-reperfusion injury.2.Limb ischemic preconditioning has a protective effect on vascular endothelial injury after tourniquet surgery and can reduce the level of inflammation.3.The use of classic ischemic preconditioning(3 5-min ischemia-5min reperfusion)did not produce significant adverse complications and did not affect the recovery of knee function.