【摘要】 目的探讨体外循环(CPB)中梯度控制动脉氧分压(PaO2)对紫绀型先天性心脏病心肌保护的影响。方法3岁以下经皮血氧饱和度<85%、行根治术的法洛四联症患儿90例,随机分为三组:实验1组(G1组,n=30)以接近患儿术前水平的低氧分压启动CPB并控制CPB中血流复温前的PaO2≤130mmHg,CPB血流复温后使PaO2逐渐升至250～300mmHg;实验2组(G2组,n=30)CPB中PaO2在250～300mmHg启动CPB,血流复温后使PaO2逐渐升至450～500mmHg;对照组(G3组,n=30)CPB中PO2始终控制在450～500mmHg。观察心肌生化改变:于CPB前、CPB10min、升主动脉开放(CCR)10min、术后6h、24h抽外周血检测心肌酶CKMB、LDH活性及cTnI浓度。结果①CKMB:CPB前及CPB10min三组间无差异;CCR10min、术后6h及24hG1组显著低于G3组(P<0.01);CCR10minG2组显著低于G3组(P<0.05)。②LDH:CPB前及CPB10min三组间无差异;CCR10min、术后6h和24hG1组显著低于G3组(P<0.01或P<0.05)。③cTnI:CPB前及CPB10min三组间无差异;CCR10min、术后6h、术后24hG1组显著低于G3组(P<0.01);术后6hG2组cTnI也显著低于G3组(P<0.05)。结论对于紫绀型先天性心脏病,CPB中PaO2控制在G1组的低水平能减少CKMB、LDH活性及cTnI的释放,改善心肌保护效果。更多还原

【Abstract】 OBJECTIVE To evaluate the effects of arterial oxygen partial pressure(PaO2)at the beginning and during cardiopulmonary bypass(CPB)on myocardial injury of cyanotic congenital heart diseas.METHODS90 Children diagnosed Tetrallogy of Fallot(TOF)under 3 years of age with SpO2<85% underwent one stage repairing operations were divided into 3 groups:G1(n=30),experimental group 1,PaO2 at the beginning and during CPB was maintained below 130 mmHg before CPB rewarming phase;G2(n=30),experimental group 2,PaO2 at the beginning and during CPB was controlled between 250-300 mmHg before CPB rewarming phase;G3(n=30),control group,PaO2 during CPB was maintained between 450-500 mmHg.Myocardial enzymes and cTnI were measured before CPB,10 min after CPB,10 min after cross clamp releasing(CCR),6 hrs and 24 hrs post operation with peripheral blood samples.RESULTSCKMB,LDH and cTnI had no significantly different between 3 groups preoperatively and 10 min after CPB among 3 group.At 10 min after CCR,6 hrs and 24 hrs post operation,KMB,LDH and cTnI in G1 were significantly lower than that in G3(P<0.01 or P<0.05).At 24 hrs post operation,also cTnI in G1 was significantly lower than that in G2(P<0.05).At 10min after CCR,CKMB in G2 was significantly lower than that in G3(P<0.05).At 6hrs post operation,cTnI in G2 was significantly lower than that in G3(P<0.05).CONCLUSIONDuring CPB controlling PaO2 to a preoperative low level would reduce releasing enzymes of myocardial and cTnI in cyanotic congenital heart disease.更多还原