新生儿先天性心脏病术后早期心排血量评估及死亡原因分析

Early assessment of post-operative cardiac output and causes of early death in the neonates with congenital heart diseases

目的通过对先天性心脏病术后心排血量的评估，分析新生儿心脏术后早期较高病死率的原因，并探讨早期干预降低病死率的方法。方法2007年1～11月，体外循环复杂先心病手术后新生儿47例，平均年龄（21．98±8．15）天。死亡4例。分析心排血量的心指数（CI）与心肌肌钙蛋白Ⅰ（cTnI）、体外循环时间、混合静脉血氧饱和度（SvO2）的相关性，总结影响新生儿心脏术后心功能的高危因素，提出围术期治疗的优化方案。结果新生儿心脏术后早期CI值平均（2．0±0．3）L^-1·min^-1·m^-2，小于正常值（2．5±0．3）L^-1·min^-1·m^-2；CI值和体外循环时间负相关、与SvO2值正相关、与cTnI值相关性无统计学意义。cTnI值改变与手术操作有关。结论新生儿心脏术后心排血量稍低于正常值，但能满足全身脏器的氧需。新生儿心脏术后早期的较高病死率与术前存在严重酸中毒、本身疾病的复杂性、过长的体外循环时间及残留的解剖畸形有关。提高手术技术，消除残留的解剖畸形，减少体外循环时间，对危重病例尽早干预可降低病死率。

Objective To evaluate accurately the cardiac output, an early post-operative indicator for the cardiac function, after cardiac surgery in the neonates with congenital heart diseases and assess the risk factors for surgery, with an aim at exploring the early strategy for decreasing the mortality. Methods From January 2007 to November 2007, forty-seven consecutive neonates with complex congenital heart diseases underwent surgical correction at Shanghai Children＇s medical center, There were 38 boys and 9 girls with age from 3 days to 29 days [ mean age （21.98 ±8.15 ） days] and weight from 2.6 kg to 4.2 kg [ mean （ 3.49 ±0. 51 ） kg]. 15 patients had delayed sternal clousure. The operations were performed with hypothermia, deep hypothermia low flow, or deep hypothermia circulatory arrest techniques. Cardiac index （CI） was derived from pulse contour analysis and calculated with the PiCCO plus system. Meanwhile, serum cardiac troponin I （cTnl）, mixed venous oxygen saturation （ SvO2 ） and cardiopulmonary bypass （CPB） time were measured. Finally, the risk factors for surgical treatment in survivors and that associated with an increased mortality were analyzed. The association between post-operative cardiac output and the death after surgery was examined. Results Four neonates died after surgery, with a surgical mortality of 8.5%. CI value in the neonates [ （2.0 ± 0. 3 ） liters per minute per square meter of body surface was less than normal 2.5 ±0. 3. CI was associated inversely with CPB time but had a positive correlation with SvO2. No significant difference association between CI and cTnI was observed. The value of cTnl was associated with the type of surgical procedures. Cases for which DHCA and low flow cerebral perfusion technique were used were free from neurological complications, ischemia in the lower extremities and oliguria. The duration of cardiopulmonary bypass, urgent state of the operation and the abnormal coronary artery were associated with high mortality in the neonates after cardiac surgery. Conclusion The cardiac output of the neonates in whom cardiac procedures were performed is adequate for the the oxygen supply required by the whole body though it is slightly lower than normal after cardiac surgery. Higher mortality in the neonates during early postoperative period may be due to the complexity of the pri- mary diseases, prolonged cardiopulmonary bypass time, residual abnormalities and severe acidosis before operation. Various techniques for CPB and that for the myocardial protection are safe and can provide an appropriate operative field.