The Clinical Effect Of Superoxide Dismutase On The Protection Of Child Lung During The Cardiopulmonary Bypass

OBJECTIVE To study the clinical effect of superoxide dismutase (SOD) on the protection of child lung during the Cardiopulmonary Bypass (CPB).METHODS 40 children of CPB were randomly divided into two groups, 20 (experimental group) were given SOD during CPB . 20(control group) were not given SOD during CPB. The levels of airway peak pressure, dynamic pulmonary compliance, plasma MDA and IL-8 were detected, and the levels of P_A-aO₂ and PaO₂/FiO₂ were calculated at 5 minutes before CPB, 20minutes CPB , 30 and 60 minutes after heart resuscitation in both groups .RESULTS (1) Peak Pressure of Airway There were no statistical difference between peak pressure of Experimental Group and that of Control Group before 60min after heart resuscitation(p>0.05). But there were statistical significance when 60 minutes after heart resuscitation (p<0.05). There was statistical significance in the Control Group at the same time vs. before CPB (p<0.05). The pressure of airway of the group, which applied SOD, did not increase severely.(2)Dynamic Pulmonary Compliance The levels of average ofdynamic pulmonary compliance of the Control Group were less than that of the Experimental Group after CPB .And there were no statistical significance at 20 minutes CPB and 30 minutes after heart resuscitation (p>0.05). But there were statistical significance at 60 minutes after heart resuscitation (p<0.05). So SOD had protection for lung.(3) Alveolar-arterial Oxygen Tension Difference (P_A-aO₂) The PA-aO2 of two group had no significance difference before 60 minutes after heart resuscitation (p>0.05). The PA-aO2 of the Experimental Group was less than that of the Control Group at 60 minutes after heart resuscitation, with statistical significance (p<0.05).(4) Oxygenate Index ( PaO₂/FiO₂ ) The oxygenate index of the Experimental Group was higher than that of the Control Group at 30 minutes after heart resuscitation, with statistical significance(p<0.05).So SOD can inhibit oxygenate index from descending.(5) Levels of MDA of Plasma The levels of the MDA of plasma in the Experimental Group were less than those of the Control Group at 30 minutes after heart resuscitation, with statistical significance(p<0.05). At the same time, comparing with before CPB, there was statistical significance in the Control Group (p<0.05).(6) Levels of Interleukin-8 of Plasma Comparing with the levels of IL-8 of plasma between two group, the Experimental Group' s were less than the Control Group's at 30 minutes after heart resuscitation and 60 minutes after heart resuscitation (p<0.05). Comparing with before CPB, the levels of plasma interleukin-8 (IL-8) of the Control Group were rise at 30 minutes, 60 minutes after heart resuscitation, with very significance difference (p<0.01). So we canconclude that CPB can produce lots of IL-8 and SOD can reduce the levels of plasma IL-8 and pulmonary damage.CONCLUSION SOD treatment can protect lung during CPB. It maybe obtains that by decreasing the lung early ischemia-reperfusion injury, and inhibiting the free radical injury caused by CPB.