早期血乳酸清除率判断危重新生儿预后的初步观察

Primary study on prognostic value of early arterial blood lactate clearance rate in the neonatal critical illness

目的初步探讨早期血乳酸清除率在危重新生儿预后判断中的作用。方法选择东南大学附属中大医院NICU2008年6月至2009年12月收治的、胎龄>28周或出生体重>1000g,且存活时间>6h的危重新生儿。以患儿入住NICU为研究起点(0h),进行新生儿危重病例评分(NCIS),行动脉血气分析并测定血乳酸水平;在治疗6h再次观测上述指标,计算6h乳酸清除率。以痊愈出院或死亡为研究终点,将患儿分为存活组和死亡组,以6h动脉血乳酸清除率分为高乳酸清除率(乳酸清除率≥10%)组和低乳酸清除率(乳酸清除率<10%)组。分别比较各组间的病死率、NCIS评分、6h血乳酸清除率、血乳酸水平和pH差异。组内均数比较采用配对t检验,组间均数比较采用独立样本t检验,分类资料采用χ2检验。结果 126例危重新生儿进入分析,其中男74例,女52例。进入研究时平均日龄(2.54±2.9)d,平均胎龄(33.5±3.9)周;出生体重(2281±816)g。存活组102例,死亡组24例;高乳酸清除率组96例,低乳酸清除率组30例。存活组6h血乳酸清除率(32.3%±12.2%)显著高于死亡组(18.3%±1.9%),t=3.41,P<0.05;高乳酸清除率组病死率(9.4%,9/96例)显著低于低乳酸清除率组(50%,15/30例),χ2=22.5,P<0.05。存活组和死亡组、高乳酸清除率组和低乳酸清除率组0hNCIS评分、动脉血乳酸水平和pH值差异均无统计学意义;各组间6h血乳酸水平差异均有统计学意义(P<0.05),NCIS评分差异无统计学意义。结论 6h血乳酸清除率可以作为危重新生儿预后判断的一个良好指标,为进一步深入研究血乳酸清除率与预后的相关性提供了线索。

Objective To investigate the prognostic significance of early arterial blood lactate clearance rate in neonates with critical illness.Methods Infants with critical illness,gestational age over 28 weeks or birth weight more than 1 000 g and survival time more than 6 h were admitted into the newborn intensive care unit（NICU）in affiliated Zhong Da Hospital of Southeast University from June 2008 to December 2009.The neonatal critical illness score（NCIS）,arterial blood lactate and arterial blood gas analysis were measured before treatment and 6 hours after the treatment respectively,and then the 6 h arterial blood lactate acid clearance rate was calculated in all infants.The infants were divided into survival group and death group from hospital admission to the end of study,discharging or death of the patients.According to 6h arterial blood lactate clearance rate 10% limit,the infants were also divided into high lactic acid clearance（≥10%）group and low lactic acid clearance（〈10%）group.Arterial blood lactate level,NCIS,pH,lactate clearance rate were compared between survival group and death group,high lactate clearance rate group and low lactate clearance rate group.Paired t-tests and group t-tests were performed for within-group and between-group comparisons.Chi-square tests were performed for proportion comparisions.Results One hundred twenty-six infants including 74 males and 52 females,with the average age（2.5±2.9）days,average gestational age（33.5±3.9）weeks and average birth weight（2 281±816）g,including 102 infants for survival group and 24 for dealth group;96 in high lactate clearance rate group and 30 in low lactate clearance rate group.The 6 h lactate clearance rate of survival group（32.3%±12.2%）was significantly higher than that of death group（18.3%±1.9%）（P〈0.05）.Mortality of the high lactate clearance rate group（9.4%）was significantly lower than that of the low lactate clearance rate group（50.0%）（P〈0.05）.There were no statistical differences（P〉0.05）in NCIS scoring,arterial blood lactate and pH before treatment between survival and death groups,high lactate clearance rate and low lactate clearance rate groups.After 6 h treatment,there was no statistical difference（P〉0.05）in NCIS scoring but there was statistic difference（P〈0.05）in the arterial blood lactate level between survival and death groups,high lactic acid clearance rate and low lactic acid clearance rate groups.Conclusions Early arterial blood lactate clearance rate could be a good index for predicting the prognosis of infants with critical illness.