不同剂量谷胱甘肽对体外循环下心内直视手术患儿心肌损伤的影响

Effects of cardioplegic solution enriched with different doses of glutathione on myocardial injury in children undergoing cardiac surgery under cardiopulmonary bypass

目的评价不同剂量谷胱甘肽（GSH）对体外循环（CPB）下心内直视手术患儿心肌损伤的影响。方法择期CPB下行室间隔缺损修补术患儿48例，年龄2～5岁，ASA分级Ⅱ或Ⅲ级，采用随机数字表法，将患儿随机分为4组（n=12）：对照组（C组）和不同剂量GSH组（G1-3组）。G1-3组分别于含血停搏液中加入GSH50、75、100mg／kg，C组单用含血停搏液。分别于切皮前即刻（T0）、主动脉开放后30min（T1）、停CPB后6、12、24h（T2-4）时取颈内静脉血样，测定血浆心肌肌钙蛋白I（cTnI）浓度。于主动脉阻断前即刻及主动脉开放后15min取心肌组织，观察心肌超微结构，对心肌细胞行线粒体量化评分。结果与C组比较，G1,2组L3,4时、G3组，T1-4时血浆cTnI浓度降低（P〈0．05）；与G1组和G2组比较，G3组T1-4时血浆cTnI浓度降低（P〈0．05）；与C组和G1,2组比较，G3组主动脉开放后15min时心肌细胞线粒体量化评分降低（P〈0．05）。G组心肌损伤程度较C组明显减轻。结论GSH可呈剂量依赖性地减轻CPB下心内直视手术患儿心肌损伤，剂量100mg／kg时效果较好。

Objective To investigate the effects of cardioplegic solution enriched with different doses of glutathione on myocardial injury in children undergoing cardiac surgery under eardiopulmonary bypass （CPB）. Methods Forty-eight ASA Ⅱ or Ⅲ patients aged 2-5 yr undergoing repair of ventrieular septal defect under CPB were randomly divided into 4 groups （n = 12 each） ： control group （group C） and cardioplegic solution containing 3 different-dose of glutathione groups （group G1-3 ）. Glutathione 50,75,100 mg/kg were added to cardioplegic solution in group G1-3 respectively. Blood samples were collected before operation （TO ）, at 30 min after release of aort- ic cross-clamp （T1 ）, at 6, 12, 24 h after termination of CPB （T2-4） for determination of plasma cTnI concentration. Myocardial specimens were obtained from right auricle before aortic cress-clamp and 15 min after release of aortic cross-clamp. The ultrastructure of myocardium was examined with scanning electron microscope. A mitochondrial FlaMeng semiquantitative analysis was done. Results The plasma concentration of cTnl at T3,4 were significantly lower in groups G1,2 than in group C. The plasma concentration of cTnl at T1-4 were significantly lower in group G3 than in group C and group G1,2 . The quantization score of myocardial mitochondria at 15 min after release of aortic cross-clamp were significantly lower in group G3 than in group C and group G1,2 . Mieorseopic examination showed that the injury to myocardial ultrastructure was attenuated in group G3 compared with group C. Conclusion Cardioplegic solution enriched with glutathione can reduce myocardial injury induced by CPB in a dose dependent manner. Glutathione 100 mg/kg can exert a visibly protective effect on myocardium.