Johnson C E, Whitwell J K, Pethe K, Saxena K, Super D M
Department of Pediatrics, Case Western Reserve University at MetroHealth Medical Center, Cleveland, Ohio, USA.
Pediatrics. 1997 Apr;99(4):E10. doi: 10.1542/peds.99.4.e10.
To determine: (1) whether a lumbar puncture (LP) is indicated in asymptomatic full-term newborns delivered by mothers at risk of intrapartum sepsis; and (2) whether gentamicin improves bacterial coverage for such newborns when used with ampicillin.
A retrospective chart review from 1987 through 1993 of all newborns with positive blood and/or cerebrospinal fluid cultures in the first 7 days of life.
Pregnant women were screened in the second trimester for group B streptococci and given ampicillin during labor if two or more risk factors were present: group B streptococci colonization, maternal fever or leukocytosis, rupture of membranes at more than 18 hours, foul-smelling amniotic fluid, and fetal tachycardia. After sepsis evaluation (LP, blood culture, white blood cell count, and differential), asymptomatic infants received ampicillin and gentamicin for 48 to 72 hours unless cultures grew pathogens.
Of approximately 24 452 full-term births in 7 years, 7% (1712) had evaluations for symptoms of sepsis, and 14% (3423) were asymptomatic but had evaluations for maternal risk factors. There were 11 cases of meningitis, all involving symptomatic newborns; 10 of these 11 had positive blood cultures for the same organism. In asymptomatic infants, none of the 3423 had meningitis (95% confidence interval, 0 to 0.0008), although 35 grew contaminants. Of 73 pathogens isolated from blood or cerebrospinal fluid, 7 (9.5%) were resistant to ampicillin. Addition of gentamicin provided coverage for only 2 of these 7 pathogens. Of 5135 infants who received ampicillin and gentamicin, only 2 required gentamicin for improved coverage.
(1) LP is unnecessary in asymptomatic full-term newborns. (2) Empiric coverage for asymptomatic newborns with maternal risk factors need not include gentamicin at all hospitals, because it only improved the coverage of ampicillin alone from 90% to 93% of pathogens, but it exposed more than 5000 infants to the side effects of gentamicin. (3) The presence of leukopenia (<5000 white blood cells/mm) is highly predictive of bacteremia.
确定：(1)对于由有产时败血症风险的母亲分娩的无症状足月儿是否需要进行腰椎穿刺(LP)；(2)庆大霉素与氨苄西林联合使用时是否能改善对此类新生儿的细菌覆盖范围。
对1987年至1993年所有出生后7天内血培养和/或脑脊液培养呈阳性的新生儿进行回顾性病历审查。
在孕中期对孕妇进行B族链球菌筛查，若存在两个或更多风险因素则在分娩时给予氨苄西林：B族链球菌定植、母亲发热或白细胞增多、胎膜破裂超过18小时、羊水有异味以及胎儿心动过速。在进行败血症评估(LP、血培养、白细胞计数及分类)后，无症状婴儿接受氨苄西林和庆大霉素治疗48至72小时，除非培养出病原体。
7年中约24452例足月儿出生，7%(1712例)因败血症症状接受评估，14%(3423例)无症状但因母亲风险因素接受评估。有11例脑膜炎病例，均涉及有症状的新生儿；这11例中有10例血培养对同一病原体呈阳性。在无症状婴儿中，3423例均无脑膜炎(95%置信区间，0至0.0008)，尽管有35例培养出污染物。从血液或脑脊液中分离出的73种病原体中，7种(9.5%)对氨苄西林耐药。添加庆大霉素仅能覆盖这7种病原体中的2种。在5135例接受氨苄西林和庆大霉素治疗的婴儿中，仅2例需要庆大霉素以改善覆盖范围。
(1)无症状足月儿无需进行LP。(2)对于有母亲风险因素的无症状新生儿，并非所有医院经验性用药都需包括庆大霉素，因为它仅将氨苄西林单独的病原体覆盖范围从90%提高到93%，但使5000多名婴儿暴露于庆大霉素的副作用之下。(3)白细胞减少症(白细胞<5000/mm)的存在高度预示菌血症。
