新生儿血培养阳性报警时间的临床意义

The clinical value of time to positive of blood culture as indicator for neonatal sepsis

目的分析血培养阳性报警时间(time to positive,TTP)对新生儿败血症的临床意义。方法选取2016年8月至2019年6月深圳市宝安区妇幼保健院新生儿科收治的血培养阳性患儿进行回顾性研究,分析患儿临床资料,根据病原菌、早发/晚发型败血症、污染/非污染进行分组,比较不同组别的TTP,分析TTP的临床意义。结果共10035例进行血培养,阳性307例,排除污染菌162例,确诊败血症145例(1.4%)。145例败血症血培养TTP中,<24 h 131例(90.3%),24~<48 h 11例(7.6%),48~<72 h 2例(1.4%),≥72 h 1例(0.7%)。其中早发型败血症TTP中位数为9.0 h,晚发型败血症TTP中位数为11.5 h。污染菌TTP[24.5(19.9,30.5)h]长于非污染菌TTP[11.1(8.1,16.2)h];革兰阳性菌TTP[14.0(9.4,18.8)h]长于革兰阴性菌TTP[9.6(7.5,11.3)h];真菌TTP[32.5(25.5,39.0)h]较细菌TTP[10.6(8.1,15.5)h]长,差异均有统计学意义(P<0.05)。结论不同病原菌的TTP不同,对于怀疑败血症的新生儿,若血培养72 h仍未报阳,结合临床表现及血液非特异性检查,可考虑停用经验性抗生素。

Objectives To study the clinical significance of time to positive(TTP)of blood culture for neonatal sepsis.Methods From August 2016 to June 2019,a retrospective study was conducted in patients with positive blood cultures admitted to the Neonatology Department of our hospital.The patients were assigned into different groups according to the species of pathogen,types of neonatal sepsis and the samples contaminated or not.TTP of different groups were analyzed.Results A total of 307 cases with positive blood cultures were identified from 10035 cases with blood culture specimens.Among the 307 cases,162 were contaminated(the contaminated group)and 145(1.4%)were diagnosed of neonatal sepsis(the pathogenic group).The proportion of TTP<24 h,24~<48 h,48~<72 h and≥72 h in the 145 sepsis cases were 90.3%(131/145),7.6%(11/145),1.4%(2/145)and 0.7%(1/145),respectively.The median TTP was 9.0 h in early-onset sepsis(EOS)group and 11.5 h in late-onset sepsis(LOS)group.The median TTP of the contaminated group was 24.5(19.9,30.5)h,which was longer than 11.1(8.1,16.2)h of the pathogenic group(P<0.05).The median TTP of Gram(+)group was 14.0(9.4,18.8)h,which was longer than 9.6(7.5,11.3)h of Gram(-)group(P<0.05).The median TTP of fungi group was 32.5(25.5,39.0)h,which was longer than 10.6(8.1,15.5)h of bacteria group(P<0.05).Conclusions Different pathogens has different TTP for neonatal sepsis.If blood culture maintains negative for more than 72 h,empiric use of antibiotics may be discontinued for patients of suspected sepsis without specific clinical manifestations or other lab results.