Effect Of Ketamine On Preinflammatory Cytokines And Oxygen Free Radical In Tourniquet-induced Limb Ischemia-reperfusion Injury

Objective:Limb ischemia-reperfusion injury (I/R) induces a whole-body inflammatory response in which cytokines and oxygen free radicals play important roles.In this study we examined the efficacy of ketamine (KET) on proinflammatory cytokines and oxygen free radicals in tourniquet-induced limb ischemia-reperfiision injury.Methods: Thirty ASA Ⅰ -Ⅱ scheduled patients undergoing elective surgery of the knee with tourniquet were selected and divided randomly into two groups. Patients in group K (n=15) received ketamine 0.5mg/kg intravenously 10min before the tourniquet inflation . Patients in group C (n=15) received the same volume of normal saline with the same method as group K. Blood samples were taken from the ischemia femoral veins and tumor necrosis factor-α(TNF-α), interleukm-8 (IL-8), malondialdehyde (MDA) and superoxide dismutase (SOD) activity were measured before ketamine administration (T1) and 5min(T2), 20min(T3), 30min (T4) after the tourniquet deflation.Results: There was no significant difference between the two groups in age,weight,sex ratio and the time of the tourniquet. TNF-α: Levels at T2~T4 were higher than that of the baseline in both groups, while levels at T3,T4 were lower in group K than in group C (P<0.01). IL-8: Levels at T3 and T4 increased significantly compared to the baseline in both groups, and there were significant difference at T3,T4 between two groups(P< 0.01). MDA: Levels at T2-T4 in group C and levels at T3,T4 in group K were higher than the baseline,but levels were lower at T2-T4 in group K than in group C(P<0.01). SOD activity: Levels at T2,T3 were lower than the baseline in both groups. Level at T4 was also lower than the baseline in group C, however in group K it increased to the baseline value, and there was significant difference between two groups at T4 (P<0.05).Conclusion: Ketamine can reduce the levels of TNF-α,IL-8 and MDA,and reserve...