Management of Neonates with Suspected Or Proven Early-Onset Bacterial Sepsis
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Guidance for the Clinician in Rendering Pediatric Care CLINICAL REPORT Management of Neonates With Suspected or Proven Early-Onset Bacterial Sepsis Richard A. Polin, MD and the COMMITTEE ON FETUS AND abstract NEWBORN With improved obstetrical management and evidence-based use of KEY WORDS intrapartum antimicrobial therapy, early-onset neonatal sepsis is be- early-onset sepsis, antimicrobial therapy, group B streptococcus, meningitis, gastric aspirate, tracheal aspirate, chorioamnionitis, coming less frequent. However, early-onset sepsis remains one of the sepsis screen, blood culture, lumbar puncture, urine culture, most common causes of neonatal morbidity and mortality in the pre- body surface cultures, white blood count, acute phase reactants, term population. The identification of neonates at risk for early-onset prevention strategies sepsis is frequently based on a constellation of perinatal risk factors ABBREVIATIONS fi CFU—colony-forming units that are neither sensitive nor speci c. Furthermore, diagnostic tests CRP—C-reactive protein for neonatal sepsis have a poor positive predictive accuracy. As a result, CSF—cerebrospinal fluid clinicians often treat well-appearing infants for extended periods of time, GBS—group B streptococci — even when bacterial cultures are negative. The optimal treatment of I/T immature to total neutrophil (ratio) PMN—polymorphonuclear leukocyte infants with suspected early-onset sepsis is broad-spectrum antimicro- PPROM—preterm premature rupture of membranes bial agents (ampicillin and an aminoglycoside). Once a pathogen is iden- This document is copyrighted and is property of the American tified, antimicrobial therapy should be narrowed (unless synergism is Academy of Pediatrics and its Board of Directors. All authors needed). Recent data suggest an association between prolonged empir- have filed conflict of interest statements with the American ≥ Academy of Pediatrics. Any conflicts have been resolved through ical treatment of preterm infants ( 5 days) with broad-spectrum anti- a process approved by the Board of Directors. The American biotics and higher risks of late onset sepsis, necrotizing enterocolitis, Academy of Pediatrics has neither solicited nor accepted any and mortality. To reduce these risks, antimicrobial therapy should be commercial involvement in the development of the content of discontinued at 48 hours in clinical situations in which the probability this publication. of sepsis is low. The purpose of this clinical report is to provide a The guidance in this report does not indicate an exclusive course of treatment or serve as a standard of medical care. practical and, when possible, evidence-based approach to the manage- Variations, taking into account individual circumstances, may be ment of infants with suspected or proven early-onset sepsis. Pediatrics appropriate. 2012;129:1006–1015 INTRODUCTION “Suspected sepsis” is one of the most common diagnoses made in the NICU.1 However, the signs of sepsis are nonspecific, and inflammatory syndromes of noninfectious origin mimic those of neonatal sepsis. Most infants with suspected sepsis recover with supportive care (with or without initiation of antimicrobial therapy). The challenges for clinicians www.pediatrics.org/cgi/doi/10.1542/peds.2012-0541 are threefold: (1) identifying neonates with a high likelihood of sepsis doi:10.1542/peds.2012-0541 promptly and initiating antimicrobial therapy; (2) distinguishing “high- All clinical reports from the American Academy of Pediatrics risk” healthy-appearing infants or infants with clinical signs who do not automatically expire 5 years after publication unless reaffirmed, require treatment; and (3) discontinuing antimicrobial therapy once revised, or retired at or before that time. sepsis is deemed unlikely. The purpose of this clinical report is to PEDIATRICS (ISSN Numbers: Print, 0031-4005; Online, 1098-4275). provide a practical and, when possible, evidence-based approach to the Copyright © 2012 by the American Academy of Pediatrics diagnosis and management of early-onset sepsis, defined by the Na- tional Institute of Child Health and Human Development and Vermont Oxford Networks as sepsis with onset at ≤3daysofage. 1006 FROM THE AMERICAN ACADEMY OF PEDIATRICS Downloaded from www.aappublications.org/news by guest on October 1, 2021 FROM THE AMERICAN ACADEMY OF PEDIATRICS PATHOGENESIS AND most of these women with histologic The major risk factors for early-onset EPIDEMIOLOGY OF EARLY-ONSET chorioamnionitis do not have a positive neonatal sepsis are preterm birth, SEPSIS placental culture.3 The incidence of clin- maternal colonization with GBS, rupture of membranes >18 hours, and mater- Before birth, the fetus optimally is ical chorioamnionitis varies inversely nal signs or symptoms of intra-amniotic maintained in a sterile environment. with gestational age. In the National infection.14–16 Other variables include Organisms causing early-onset sepsis Institute of Child Health and Human ethnicity (ie, black women are at higher ascend from the birth canal either Development Neonatal Research Net- risk of being colonized with GBS), low when the amniotic membranes rupture work, 14% to 28% of women delivering ’ socioeconomic status, male sex, and or leak before or during the course of preterm infants at 22 through 28 weeks low Apgar scores. Preterm birth/low labor, resulting in intra-amniotic infec- gestation exhibited signs compatible 4 birth weight is the risk factor most tion.2 Commonly referred to as “cho- with chorioamnionitis. The major risk closely associated with early-onset sep- rioamnionitis,” intra-amniotic infection factors for chorioamnionitis include sis.17 Infant birth weight is inversely indicates infection of the amniotic fluid, low parity, spontaneous labor, longer related to risk of early-onset sepsis. membranes, placenta, and/or decidua. length of labor and membrane rupture, multiple digital vaginal examinations The increased risk of early-onset sep- Group B streptococci (GBS) can also (especially with ruptured membranes), sis in preterm infants is also related to enter the amniotic fluid through occult meconium-stained amniotic fluid, internal complications of labor and delivery tears. Chorioamnionitis is a major risk fetal or uterine monitoring, and pres- and immaturity of innate and adaptive factor for neonatal sepsis. Sepsis can immunity.18 begin in utero when the fetus inhales ence of genital tract microorganisms 5 or swallows infected amniotic fluid. (eg, Mycoplasma hominis). The neonate can also develop sepsis in At term gestation, less than 1% of DIAGNOSTIC TESTING FOR SEPSIS the hours or days after birth when women with intact membranes will The clinical diagnosis of sepsis in the colonized skin or mucosal surfaces are have organisms cultured from amni- neonate is difficult, because many of compromised. The essential criterion otic fluid.6 The rate can be higher if the signs of sepsis are nonspecific and for the clinical diagnosis of chorio- the integrity of the amniotic cavity is are observed with other noninfectious amnionitis is maternal fever. Other compromised by procedures before conditions. Although a normal physical criteria are relatively insensitive. When birth (eg, placement of a cerclage or examination is evidence that sepsis is defining intra-amniotic infection (cho- amniocentesis).6 Inwomenwithpre- not present,19,20 bacteremia can occur rioamnionitis) for clinical research term labor and intact membranes, the in the absence of clinical signs.21 Avail- studies, the diagnosis is typically based rate of microbial invasion of the amni- able diagnostic testing is not helpful in on the presence of maternal fever of otic cavity is 32%, and if there is pre- deciding which neonate requires em- greater than 38°C (100.4°F) and at least term premature rupture of membranes pirical antimicrobial therapy but can two of the following criteria: maternal (PPROM), the rate may be as high as assist with the decision to discontinue leukocytosis (greater than 15 000 cells/ 75%.7 Many of the pathogens recovered treatment.22 mm3), maternal tachycardia (greater from amniotic fluidinwomenwithpre- than 100 beats/minute), fetal tachycar- term labor or PPROM (eg, Ureaplasma Blood Culture dia (greater than 160 beats/minute), species or Mycoplasma species) do A single blood culture in a sufficient uterine tenderness, and/or foul odor of not cause early-onset sepsis.8–10 How- volume is required for all neonates the amniotic fluid. These thresholds are ever, both Ureaplasma and Myco- with suspected sepsis. Data suggest associated with higher rates of neo- plasma organisms can be recovered that 1.0 mL of blood should be the natal and maternal morbidity. from the bloodstream of infants whose minimum volume drawn for culture Nonetheless, the diagnosis of cho- birth weight is less than 1500 g.11 When when a single pediatric blood culture rioamnionitis must be considered even a pathogen (eg, GBS) is recovered from bottle is used. Dividing the specimen in when maternal fever is the sole abnor- amniotic fluid, the attack rate of neo- half and inoculating aerobic and an- mal finding. Although fever is common natal sepsis can be as high as 20%.12 aerobic bottles is likely to decrease the in women who receive epidural anes- Infants born to women with PPROM sensitivity. Although 0.5 mL of blood thesia (15%–20%), histologic evidence who are colonized with GBS have an has previously been considered ac- of acute chorioamnionitis is very com- estimated attack rate of 33% to 50% ceptable, in vitro data from Schelonka