新生儿先天性心脏病术后血液动力学的临床研究

目的 通过测定心指数(CI)、血清乳酸浓度(Lac)、混合静脉血氧饱和度(SvO2)等指标,评估新生儿在经过体外循环术后的早期血液动力学状况.方法 2007年1月至11月,80例患儿作心脏术后48 h的血液动力学评估,包括新生儿组47例,年龄3～29 d,体重2.6～4.2 kg;婴儿组33例,年龄30～180 d,体重3.1～6 kg.并初步讨论新生儿心脏术后较高死亡率原因.结果 术后存活患儿两组比较中,新生儿组CI值[(2.01±0.35)L/(min·m~2)]<婴儿组[(2.26±0.39)L/(min·m~2)],术后2、6 h两组CI均值差异有统计学意义(P<0.05);新生儿组脉压<婴儿组,CI与新生儿组脉压的相关性有统计学意义;心率155次/min是心输出量的适宜心率;新生儿组血清Lac婴儿组,术后12 h两组差异有统计学意义;新生儿存活患儿的术后SvO_2均60%,SvO_2两组间均值差异无统计学意义;CI与SvO_2相关性有统计学意义(P<0.05),与血清Lac相关性无统计学意义.新生儿4例死亡(死亡率8.5%),与术前心跳骤停,严重酸中毒,冠状动脉畸形,体外循环时间过长有关,术后6～12 h血清Lac值10 mmol/L,SvO_2<50%;婴儿组1例死亡(死亡率3.0%),与手术方法增加了心脏前后负荷有关.结论 新生儿心脏术后的心输出量能满足全身脏器的氧需,血清Lac水平和变化趋势可以评估疗效和预后,SvO_2能及时反映心输出量对组织器官的供氧状况.新生儿心脏术后的较高死亡率可能同本身病种的复杂性、危重性有关.

Evaluation on the early hemodynamic changes after cardiac surgery for congenital heart diseases in neonates

Objective To accurately evaluate the early hemodynamic status of neonates who undergo complex neonatal cardiac surgery, through monitoring the cardiac index (CI), serum lactate (Lac), mixed venous oxygen saturation (SvO_2). Methods From January to November 2007, haemodynamic data of 80 patients who had open heart surgery for congenital heart disease were analyzed within 48 hours after operation. Of the 80 patients, 47 were neonates, their age ranged from 3 days to 29 days [mean (21.98±8.15) days]and weight ranged from 2. 6 kg to 4. 2 kg [mean (3.51±0.39) kg]. As the control group, 33 young infants at the age of 30 days to 180 days [mean (76. 36±24.79) days]with body weight ranged from 3. 1 kg to 6.0 kg [mean (4. 59±0. 59) kg]were also enrolled. The value of CI derived from pulse contour and was calculated by using the PiCCO system. Meanwhile, measurements of serum lactate level and SvO_2 were recorded. Serial measurements of the cardiac output were performed for the neonates.Results CI in survivors of neonates(2.01±0.35)L/(min·m~2)was lower than that of the infants(2.26±0.39)L/(min·m~2)after cardiac surgery(P<0.05)at 2h,6h postoperatively.However, urine output remained normal. The value of pulse pressure in neonates was less than that in young infants. Serum lactate level in neonates was significantly higher than that of young infants during cardiac surgical procedures (P<0.01) at 12 h postoperatively; the SvO_2 was more than 60% postoperatively in survived neonates, there was no significant difference (P0.05) in SvO_2 between neonates and young infants during preoperative and postoperative periods. There was a positive correlation between CI and SvO_2. Four neonates and 1 young infant died after surgical treatment, surgical mortality was 8.5% and 3.0%, respectively. The deaths of the neonates were related to the cardiocirculatory function decompensation, unrelieved severe acidosis preoperatively, and the transposition of great artery with coronary artery malformation and longer cardiopulmonary bypass. The patients with significantly high arterial blood lactate levels during the first 6-12 hours postoperatively had poor outcome, lactate levels were higher than 10 mmol/L and SvO_2 less than 50% in neonates who developed multiple organ system failure. One young infant died of sudden arrhythmia after surgical treatment, whose death may be related the surgical procedure itself with pulmonary artery banding and blalock-taussig shunt leading to increased preload and afterload of the heart.Conclusions Elevated serum lactate level postoperatively may reflect intraoperative tissue hypoperfusion.Serial blood lactate level measurements may be an accurate predictor of clinical outcomes in children after podiatric open heart surgery. Mixed venous oxygen saturation changes more rapidly than other standard hemedynamic variables. The highter mortality of neonates with congenital heart disease is related to the malformation complexity itself and illness severity.