| OBJECTIVES:Both anesthetic preconditioning and postconditioning are promising therapeutic strategies of attaining protection against myocardial ischemia-reperfusion injury(MIRI). Clinically,anesthetic postconditioning administered right at the onset of reperfusion is more attractive than anesthetic preconditioning,in that interventions could be done at the time of reperfusion and do not have to predict an ischemic episode. Sevoflurane, a commonly used volatile anesthetic, has been demonstrated in clinical and experimental studies, to have protective profiles against MIRI. However, the underlying mechanism responsible for such cardioprotection induced by sevoflurane,particularly sevoflurane postconditioning, remains poorly understood. Therefore, this study was undertaken to probe into the effect of sevoflurane postconditioning on myocardial ischemia-reperfusion injury of children undergoing repair of interventricular septal defect through detecting the levels of CK-MB, cTnl, MDA and activity of SOD in human blood.METHODS: Thirty-two (18 male,14 female) children scheduled for elective repair of interventricular septal defect surgery with cardiopulmonary bypass were randomly divided into two groups of 16 children:sevoflurane postconditioning group and control group.In sevoflurane postconditioning group, low tidal volume ventilation was started at 3 min before declamping aorta and at the same time 2.0vol% sevoflurane was inhaled,which lasted to 10 min after declamping aorta. But during this period sevoflurane was not inhaled in control group. The central venous blood samples were collected for the measurements of creatine kinase(CK-MB), cTnI, superoxide dismutase(SOD) and malondialdehyde(MDA) before anesthesia (T1), immediately before clamping aorta(T2), immediately before declamping aorta(T3),5min after declamping aorta (T4), 10min after declamping aorta (T5) and 30min after declamping aorta(T6). HR, MAP and CVP were recorded at T1-T6 also.RESULTS:Hemodynamic parameters were kept stable throughout in both groups.At each period of time after reperfussion, compared with T1, the contents of CK-MB in both groups increased significantly (p<0.05 or 0.01). But compared with control group,the content of CK-MB was significantly lower in SPC group(p<0.05). At each period of time after reperfussion,compared with Tl,the content of cTnl in both groups increased significantly (p<0.01). But compared with control group, the content of cTnl was significantly lower in SPC group(p<0.05).The MDA in SPC group increased significantly (p<0.05 or 0.01)at T2-T6,compared with that at T1, but at T4-T6, the content of MDA in SPC group was significantly lower than that in control group(p<0.01). At T4-T6, the activity of SOD decreased(p<0.05 or 0.01) in both groups, and SOD in SPC group was higher than that in control group(p<0.01). It is suggested that sevoflurane postconditioning can inhibit increasing of MDA levels to attenuate myocardial ischemia/reperfusion injuries mediated by reactive oxygen series (ROS) during open-heart surgery.CONCLUSION:Sevoflurane postconditioning can attenuate myocardial ischeamia-reperfusion injury in children undergoing repair of interventricular septal defect surgery, and.the mechanisms are possiblely related to the antioxidant function of sevoflurane postconditioning. |
