辅助循环在婴幼儿难治性心力衰竭治疗中的应用

Mechanical circulatory support in treatment of children with refractory heart failure

目的总结应用体外膜肺氧合(ECMO)和左心室辅助泵(LVAD)监护治疗婴幼儿难治性心力衰竭的经验。方法 13例复杂先天性心脏病(CHD)术后患儿和1例爆发性心肌炎患儿因发生难治性心力衰竭接受辅助循环;其中ECMO组8例,LVAD组6例。辅助循环期间监测动脉、中心静脉、左心房、右心房压力,以及血清乳酸浓度、混合静脉血氧饱和度,调整正性肌力药物剂量,激活凝血时间(ACT)维持在150～180 s,红细胞压积为30%～35%,血小板数量>80 000/mm3。当血压稳定、脉压差≥20mmHg、左心室射血分数达50%时,撤离辅助循环。结果 ECMO组和LVAD组平均辅助循环时间为(147±152)h;辅助循环后,平均动脉压由(48.1±5.2)mmHg上升至(60.2±7.8)mmHg(P<0.05);血清乳酸浓度由(5.1±0.8)mmol/L下降至(3.6±0.5)mmol/L(P<0.05)。患儿脱机生存率为57.1%(8/14),出院生存率为42.9%(6/14)。主要并发症为严重胸、腹腔出血(63.7%)。神志淡漠4例(28.6%);多脏器功能受损8例(57.1%)。随访4～26个月,左心室射血分数≥50%,心功能Ⅱ级,遗留轻、中度大脑萎缩及神经系统后遗症2例,患儿生长发育明显改善。结论辅助循环是CHD术后难治性心力衰竭较好的治疗方法;ECMO更适合用于小年龄的复杂CHD患儿;出血是辅助循环中的严重并发症。

Objective To summarize the intensive care experience of extracorporeal membrane oxygenation(ECMO) and left ventricular assist device(LVAD) in children with refractory heart failure.Methods Thirteen children having undergone operation for complicated congenital heart disease and 1 child with fulminant myocarditis received mechanical circulatory support due to refractory heart failure.There were 8 children in ECMO group and 6 children in LVAD group.The mean arterial pressure,central venous pressure,pressure of right atrium,pressure of left atrium,serum lactate concentration and oxygen saturation of mixed venous blood were monitored during mechanical circulatory support.The dosage of inotropic medicine was adjusted,the activated coagulation time was maintained between 150 s and 180 s,hematocrit between 30% and 35%,and platelet count >80 000/mm3.The mechanical circulatory support was weaned off when blood pressure was stable,pulse pressure was no lower than 20 mmHg,and left ventricular ejection fraction reached 50%.Results The mean time of mechanical circulatory support was(147±152) h in ECMO group and LVAD group.During the mechanical circulatory support,the blood pressure increased from(48.1±5.2) mmHg to(60.2±7.8) mmHg(P<0.05),while the serum lactate concentration decreased from(5.1±0.8) mmol/L to(3.6±0.5) mmol/L(P<0.05).The survival rate of weaning off was 57.1%(8/14),and the survival rate of hospital discharge was 42.9%(6/14).The major complication was severe bleeding in thoracic and abdominal cavity(63.7%).Four children had indifferent mind(28.6%),and 8 had multiple organ dysfunction(57.1%).During the follow up of 4 to 26 months,the left ventricular ejection fraction was no less than 50%,the cardiac function was class Ⅱ,the growth of children was significantly improved,and mild to moderate neural sequela was found in 2 children.Conclusion Mechanical circulatory support plays an effective role in the treatment of children having undergone operation for refractory heart failure.ECMO is more appropriate for neonates,infant and those with complicated congenital heart disease.Bleeding is the severe complication in mechanical circulatory support.