Effects Of Lidocaine On Oxygen Free Radical After Hemorrhagic Shock In Rabbits

Reperfusion at fist time is the radical measure to releive tissue injury after hemorrhagic shock . But many animal experiment and clinical observation indicated that after regain blood flow some animals and patients occurrence serious function disorder and dysbolism and disorganization .This is called ischemia-reperfusion injury.It is not completely clear about the mechanism of ischemia-reperfusion.At present it is consider concerned with oxygen free radical, calcium overload and white cell-stimulating.When hemorrhagic shock,there are many humoral factor which retain homeostatic by regulate organal function under physiological condition while have important significance during shock happening, developing,tumover and prognosis under pathological contion.Many oxygen free radical be produced while hemorrhagic shock . Oxygen free radical are production of neutrophil which have tissue venenous .They can induce lipid peroxidation ,hurt cell membrane and mitochondria membrane and kill cell.They can cross link protein thus inactivate protein,change protein's structure.They also can change basic radical of nucleic acid or break DNA then cause whole cell lossing function.During resuscitation,many oxygen free radical produced by tissue were released into blood then entered recycle.They hurt cell permanent by lipid peroxidation.In recent years,many studies hint local anesthetic lidocaine might stabilize cell membrane, play an important role in inflammation reaction by effecting to heterophil granulocyte,inhibit heterophil granulocyte's tendency and sticky, decrease the release of oxygen free radicals, neutrality hydratase, lysomal enzyme, soften inflammation reaction . Malonaldehyde is the final production of lipid peroxidation, which react the intension of lipid peroxidation in organism. hepatocuprein is the enzyme relating to cell oxygen metabolism, which clean oxygen free radicals and conservancy cell. To detecting MDA and SOD together,might reflect the ability of oxygen free radicals producted and cleaned. Our goal were to deserve the influence of lidocaine to MDA and SOD during hemorrhagic shock anabiosis in rabbit, approach to effects of lidocaine on oxygen free radical after hemorrhagic Shock in rabbits.Materials and MethodsEighteen white rabbits weighing 2.0-2.6kg were used in this study and randomly divided into three group(n=6 for each group):lidocaine group(group L), hemorrhagic shock group(group H)and control group(group C).hemorrhagic shock model was set up by bloodletting in rabbits.lidocaine (2.5mg/kg) was intravenously given before bloodletting, and then lidocaine 1 mg/kg once per hour for three times.Rabbits were anesthetized by ketamine. Anesthesia was maintained with continuous infusion of ketamine by 4mg/kg/hr.Via femoral artery and vein cutdown,a catheter was placed in the distal aorta to monitor arterial pressure and to take samples for measurement of plasma MDA and SOD. Bloodletting was executed by right femoral artery after 15 minutes in group H and group L to achieve the goal of mean arterial pressure 40±5mmHg and maintain 60 minutes. Autoblood and Lactated Ringer'S Solution were infused 2 hour later.Mean arterial pressure, central venous pressure, heart rate , respiration femoral vein pressure were recorded at experimentation process. Blood samples of femoral vein were collected for measurement of plasma MDA and SOD before hemorrhage ,2 hour after hemorrhagic shock and 2 hour after reperfusion.Data analysis: measurement data are expressed as mean±standard deviation.All data were computed with SPSS 13.0 for windows.Differences were consider statistically significant when P was less than 0.05.Repeated measurement data were analyzed by using repeated measures analysis of variance.We used the AVON to test for differences for measurement data.Results1. There were no significant differences in three groups in basic condition, including quantity of bloodletting, quantity of infuse autoblood and Lactated Ringer'S Solution, how long bloodletting and how long infusion(p>0.05).2. There were no significant differences in three groups at TO in vital signs,including MAP(mean arterial pressure), FVP(femoral venous pressure), HR(heart rate)and RR(respiratory rate)(p>0.05).While MAP and FVP decrease while HR,RR increase in group H and group L compare with group C at T1 and T2.In group H or group L such signs were significant different at T0,T1andT2.But there were no significant differences between group H and group L.3. The MDA ratio of the group L was significantly lower than those of the group H (p<0.05),while SOD of group L was significantly higher than that of the group H(P<0.05).ConclusionLidocaine can remarkably decrease the release of MDA occurred and increase plasma SOD in rabbit during hemorrhagic shock. Lidocaine can decreasing lipid peroxidation reaction caused by oxygen free radical.