Abstract: Background　Hand，foot and mouth disease（HFMD）is a acute infectious disease in children.Severe HFMD is mostly caused by Enterovirus 71 （EV71）．Some patients with severe HFMD face short-term cardiopulmonary failure or even death.It is not clear whether levocarnitine，as the cardioprotection therapy，can improve the prognosis of patients with abnormal cardiac function and myocardial enzymes before cardiopulmonary failure.Objective　To evaluate cardiac function and the levels of myocardial enzyme before and after treatment in critically ill children at the early stage of cardiopulmonary failure with HFMD infected by EV71，and to explore the efficacy of adjuvant therapy with levocarnitine on myocardial injury and cardiac dysfunction and improvement of clinical prognosis and outcomes.Methods　A total of 120 critically ill HFMD patients infected by EV71 admitted to Children's Hospital Affiliated of Zhengzhou University from April 2016 to September 2017 were enrolled and randomly divided into conventional group （n=60） and levocarnitine group （n=60）．All patients were given the conventional therapy as the basic treatment，and subjects in levocarnitine group were treated with additional levocarnitine injection as adjuvant therapy.The levels of blood creatine kinase （CK），creatine kinase isoenzyme （CK-MB） and troponin T （cTnT），brain natriuretic peptide （BNP），N-terminal pro-brain natriuretic peptide （NT-proBNP）were measured before and 24 hours after treatment in two groups.Left ventricular ejection fraction （LVEF），left ventricular fractional shortening （FS） and cardiac index （CI） were measured by three-dimensional echocardiography.The curative effect was determined on the seventh day of treatment，and the occurrence of complications was recorded．Results　Of the 120 cases，57 （47.5%） had abnormal CK，70 （58.3%） had abnormal CK-MB，40 （33.3%） had abnormal cTnT，75 （62.5%） had abnormal BNP，81 （67.5%） had abnormal NT-proBNP，61 （50.8%） had abnormal LVEF，and 53 （44.2%） had abnormal FS.There was no significant difference in the abnormal rates of CK，CK-MB，cTnT，BNP，NT-proBNP，LVEF and FS between the two groups （P>0.05）．After the treatment，the levels of blood CK，CK-MB，cTnT，BNP and NT-proBNP in levocarnitine group were significantly lower than those in conventional group；CK level in conventional group was lower than that before treatment （P<0.05）；levels of CK，CK-MB，cTnT，BNP，NT-proBNP in levocarnitine group were lower than those before treatment （P<0.05）；LVEF，FS and CI in levocarnitine group were higher than those in conventional group （P<0.05）．LVEF，FS and CI after the treatment in two groups were all higher than those before treatment （P<0.05）．After the treatment，the clinical efficacy of levocarnitine group was better than that of conventional group （Z=-2.317，P=0.013）．The incidence of pulmonary edema and pulmonary hemorrhage in levocarnitine group was lower than that in conventional group （P<0.05）．Conclusion　Abnormal heart function and abnormal levels of myocardial enzyme are found in critically ill children at the early stage of cardiopulmonary failure with HFMD infected by EV71.Levocarnitine can improve clinical efficacy，prognosis and outcome by effectively improving myocardial cells and cardiac function in short-term.

Key words: Hand, foot and mouth disease；Cardiopulmonary failure；Levocarnitine；Abnormal myocardial enzymes；Abnormal cardiac function；Treatment outcome

摘要： 背景　手足口病（HFMD）是常见的儿童急性传染病，重症病例多由肠道病毒71型（EV71）感染引起，部分重症HFMD短期可发生心肺功能衰竭，甚至死亡。心肺功能衰竭前期心肌酶及心功能异常的病例可采用左卡尼汀心肌营养保护性治疗策略，但是否可改善其预后尚不明确。目的　观察EV71感染心肺功能衰竭前期的重症HFMD患儿心肌酶和心功能的异常情况，探讨左卡尼汀辅助治疗对心肌酶和心功能异常的影响以及临床预后及转归的改善情况。方法　选取2016年4月—2017年9月在郑州大学附属儿童医院治疗的EV71感染心肺功能衰竭前期的重症HFMD患儿120例为研究对象，采用随机数字表法将其分为常规组和左卡尼汀组，每组各60例。常规组给予常规治疗，左卡尼汀组在常规治疗基础上给予左卡尼汀治疗，两组患儿于治疗前及治疗24 h后检测肌酸激酶（CK）、肌酸激酶同工酶（CK-MB）、肌钙蛋白T（cTnT）、脑钠肽（BNP）、N末端脑钠肽前体（NT-proBNP），并行床旁三维心脏超声检查，检测左心室射血分数（LVEF）、左心室短轴缩短率（FS）、心脏指数（CI），于治疗第7天进行疗效判定，并记录合并症发生情况。结果　120例患儿中，CK异常57例（47.5%）、CK-MB异常70例（58.3%）、cTnT异常40例（33.3%）、BNP异常75例（62.5%）、NT-proBNP异常81例（67.5%）、LVEF异常61例（50.8%）、FS异常53例（44.2%）。两组CK、CK-MB、cTnT、BNP、NT-proBNP、LVEF、FS异常率比较，差异均无统计学意义（P>0.05）。治疗后左卡尼汀组CK、CK-MB、cTnT、BNP、NT-proBNP水平均低于常规组（P<0.05）。常规组治疗后CK水平低于治疗前（P<0.05）；左卡尼汀组治疗后CK、CK-MB、cTnT、BNP、NT-proBNP水平均低于治疗前（P<0.05）。治疗后左卡尼汀组LVEF、FS、CI均高于常规组（P<0.05）。两组治疗后LVEF、FS、CI均高于治疗前（P<0.05）。治疗后左卡尼汀组临床疗效优于常规组（Z=-2.317，P=0.013）。左卡尼汀组肺水肿、肺出血发生率均低于常规组（P<0.05）。结论　EV71感染心肺功能衰竭前期的重症HFMD患儿存在心肌细胞及心脏收缩功能异常；左卡尼汀可短期有效改善心肌细胞和心功能异常，提高临床疗效，改善临床预后和转归。

关键词: 手足口病, 心肺功能衰竭, 左卡尼汀, 心肌酶异常, 心功能异常, 治疗结果