Routine antibiotic use in preterm neonates: a randomised controlled trial

Maternal and peripartum risk factors for acute funisitis among term deliveries complicated by intraamniotic infection

BACKGROUND

Acute funisitis-the histologic diagnosis of inflammation within the umbilical cord-represents a fetal inflammatory response and has been associated with adverse neonatal outcomes. Little is known regarding the maternal and intrapartum risk factors associated with the development of acute funisitis among term deliveries complicated by intraamniotic infection.

OBJECTIVE

This study aimed to identify the maternal and intrapartum risk factors associated with developing acute funisitis among term deliveries complicated by intraamniotic infection.

STUDY DESIGN

After institutional review board approval, we conducted a retrospective cohort study of term deliveries affected by clinical intraamniotic infection at a single tertiary center between 2013 and 2017, with placental pathology consistent with histologic chorioamnionitis. The exclusion criteria included intrauterine fetal demise, missing delivery information or placental pathology, and documented congenital fetal abnormalities. Maternal sociodemographic, antepartum, and intrapartum factors were compared among patients with acute funisitis on pathology to those without acute funisitis using bivariate statistics. Regression models were developed to estimate the adjusted odds ratios.

RESULTS

Of 123 patients meeting the inclusion criteria, 75 (61%) had acute funisitis on placental pathology. Compared with placental specimens without acute funisitis, acute funisitis was observed more frequently among patients with maternal BMI ≥30 kg/m2 (58.7% vs 39.6%, P=.04) and labor courses with increased rupture of membrane duration (17.3 vs 9.6 hours, P=.001). Use of fetal scalp electrode was observed less frequently in acute funisitis (5.3% vs 16.7%, P=.04) than cases without acute funisitis. In regression models, maternal BMI ≥30 kg/m2 (adjusted odds ratio, 2.67; 95% confidence interval, 1.21-5.90) and rupture of membrane >18 hours (adjusted odds ratio, 2.48; 95% confidence interval, 1.07-5.75) were significantly associated with acute funisitis. Fetal scalp electrode use (adjusted odds ratio, 0.18; 95% confidence interval, 0.04-0.71) was negatively associated with acute funisitis.

CONCLUSION

In term deliveries with intraamniotic infection and histologic chorioamnionitis, maternal BMI ≥30 kg/m2, and rupture of membrane>18 hours were associated with acute funisitis on placental pathology. As insight into the clinical impact of acute funisitis grows, the ability to predict which pregnancies are at the greatest risk for its development may allow for a tailored approach to predicting neonatal risk for sepsis and related comorbidity.

Neonatal sepsis definitions from randomised clinical trials

INTRODUCTION

Neonatal sepsis is a leading cause of infant mortality worldwide with non-specific and varied presentation. We aimed to catalogue the current definitions of neonatal sepsis in published randomised controlled trials (RCTs).

METHOD

A systematic search of the Embase and Cochrane databases was performed for RCTs which explicitly stated a definition for neonatal sepsis. Definitions were sub-divided into five primary criteria for infection (culture, laboratory findings, clinical signs, radiological evidence and risk factors) and stratified by qualifiers (early/late-onset and likelihood of sepsis).

RESULTS

Of 668 papers screened, 80 RCTs were included and 128 individual definitions identified. The single most common definition was neonatal sepsis defined by blood culture alone (n = 35), followed by culture and clinical signs (n = 29), and then laboratory tests/clinical signs (n = 25). Blood culture featured in 83 definitions, laboratory testing featured in 48 definitions while clinical signs and radiology featured in 80 and 8 definitions, respectively.

DISCUSSION

A diverse range of definitions of neonatal sepsis are used and based on microbiological culture, laboratory tests and clinical signs in contrast to adult and paediatric sepsis which use organ dysfunction. An international consensus-based definition of neonatal sepsis could allow meta-analysis and translate results to improve outcomes.

Early antibiotics and risk for necrotizing enterocolitis in premature infants: A narrative review

While prompt initiation of antibiotics at birth due to concerns for early onset sepsis is common, it often leads to many preterm infants being exposed to treatment despite negative blood cultures. Such exposure to early antibiotics can impact the developing gut microbiome putting infants at increased risk of several diseases. Necrotizing enterocolitis (NEC), a devastating inflammatory bowel disease that affects preterm infants, is among the most widely studied neonatal disease that has been linked to early antibiotics. While some studies have demonstrated an increased risk of NEC, other studies have demonstrated seemingly contrary findings of decreased NEC with early antibiotics. Studies using animal models have also yielded differing findings of benefit vs. harm of early antibiotic exposure on subsequent NEC susceptibility. We thus sought to conduct this narrative review to help clarify the relationship between early antibiotics exposure and future risk of NEC in preterm infants. Our objectives are to: (1) summarize findings from human and animal studies that investigated the relationship between early antibiotics and NEC, (2) highlight important limitations of these studies, (3) explore potential mechanisms that can explain why early antibiotics may increase or decrease NEC risk, and (4) identify future directions for research.

Reduction of unnecessary antibiotic days in a level IV neonatal intensive care unit

OBJECTIVE

Antibiotics are widely prescribed in the neonatal intensive care unit (NICU) and duration of prescription is varied. We sought to decrease unnecessary antibiotic days for the most common indications in our outborn level IV NICU by 20% within 1 year.

DESIGN AND INTERVENTIONS

A retrospective chart review was completed to determine the most common indications and treatment duration for antibiotic therapy in our 39-bed level IV NICU. A multidisciplinary team was convened to develop an antibiotic stewardship quality improvement initiative with new consensus guidelines for antibiotic duration for these common indications. To optimize compliance, prospective audit was completed to ensure antibiotic stop dates were utilized and provider justification for treatment duration was documented. Multiple rounds of educational sessions were conducted with neonatology providers.

RESULTS

In total, 262 patients were prescribed antibiotics (139 in baseline period and 123 after the intervention). The percentage of unnecessary antibiotic days (UAD) was defined as days beyond the consensus guidelines. As a balancing measure, reinitiation of antibiotics within 2 weeks was tracked. After sequential interventions, the percentage of UAD decreased from 42% to 12%, which exceeded our goal of a 20% decrease. Compliance with antibiotic stop dates increased from 32% to 76%, and no antibiotics were reinitiated within 2 weeks.

CONCLUSIONS

A multidisciplinary antibiotic stewardship team coupled with a consensus for antibiotic therapy duration, prescriber justification of antibiotic necessity and use of antibiotic stop dates can effectively reduce unnecessary antibiotic exposure in the NICU.

Fetal-neonatal exposure to antibiotics and NEC development: A systematic review and meta-analysis

BACKGROUND

Fetal and neonatal exposure to antibiotics may contribute to the development of necrotizing enterocolitis (NEC) in preterm infants. This systematic review and meta-analysis investigate whether exposure to third trimester maternal antibiotics (MAB) and/or prolongation of empirical antibiotics (PEAB) are associated with NEC development in preterms.

METHOD

We included observational and randomized controlled studies, including those on preterm or very low birth weight (VLBW) infants, from MEDLINE and EMBASE, published between 1990 and June 2021. Exposure was defined as third trimester MAB and/or PEAB. The two reviewers independently performed study selection, data extraction, and quality assessment.

RESULTS

Three cohort studies compared third trimester MAB with no antibiotics. MAB was associated with lower NEC incidence, unadjusted pooled odds ratio (OR) is 0.57 (95% CI: 0.35-0.93). Twelve cohort studies showed that PEAB was associated with an increased risk of NEC. Ten observational cohort studies show an unadjusted OR of 2.72 (1.65-4.47), and two case-control studies show an unadjusted mean difference of 2.31 (0.94-3.68). Moderate to substantial heterogeneity was observed but decreased in studies with low risk of bias and large sample size.

CONCLUSION

Evidence suggests an association between MAB and decreased risk of NEC and an association between PEAB and increased risk of NEC. Further studies should confirm these associations and explore causality.

SYSTEMATIC REVIEW REGISTRATION

identifier [CRD42022304937].

Pathogenesis of necrotising enterocolitis: The impact of the altered gut microbiota and antibiotic exposure in preterm infants

Necrotising enterocolitis (NEC) is a devastating condition with high morbidity and mortality seen predominately in preterm infants. Multiple factors are associated with the pathogenesis of NEC. The widespread use of antibiotics in the neonatal intensive care unit might play a role in the pathogenesis of NEC in preterm infants. This review provides a summary on the intestinal microbiota in preterm infants with a focus on how antibiotic exposure may reduce the biodiversity of the intestinal microbiota and may predispose preterm infants to NEC. CONCLUSION: Prolonged antibiotic therapy has been suggested as a risk factor for the development of NEC in preterm infants.

Association of initial empirical antibiotic therapy with increased risk of necrotizing enterocolitis

Whether the prophylactic use of antibiotics increase the risk of necrotizing enterocolitis (NEC) remains controversial. This review aims to investigate initial empirical antibiotic therapy (IEAT) and is associated with the risk of NEC. PubMed, EMBASE, Cochrane Library, and Web of Science databases were searched through March 1, 2020. All studies on the impacts of antibiotic exposure on NEC development were included. Thirteen studies including 7901 participants were selected. Two reviewers independently examined the extracted data and assessed the quality of the included studies. Random-effects model was used to pool the effect estimates. We found that IEAT (≥ 5 days) was associated with an increased risk of NEC in adjusted (Odds risk [OR] 1.51, 95% confidence interval [CI] 1.22-1.87) and unadjusted (OR 2.35, 95% CI 1.54-3.57) analyses. Sensitivity analysis also supported these findings.Conclusion: The evidence suggests an association between IEAT (≥ 5 days) and the risk of NEC. Further studies are needed to address whether the association with IEAT is causal.What is Known:•Necrotizing enterocolitis (NEC) is acute inflammatory necrosis of the intestinal tractin the newborn infant.•Some observational studies have associated initial empirical antibiotics with an increased risk of subsequent NEC.What is New:•Initial empirical antibiotic therapy (IEAT) (≥ 5 days) appear to increase the risk of NEC.

Antibiotic Stewardship in Premature Infants: A Systematic Review

INTRODUCTION

Antibiotic treatment in premature infants is often empirically prescribed, and practice varies widely among otherwise comparable neonatal intensive care units. Unnecessary and prolonged antibiotic treatment is documented in numerous studies. Recent research shows serious side effects and suggests long-term adverse health effects in prematurely born infants exposed to antibiotics in early life. One preventive measure to reduce unnecessary antibiotic exposure is implementation of antibiotic stewardship programs. Our objective was to review the literature on implemented antibiotic stewardship programs including premature infants with gestational age ≤34 weeks.

METHODS

Six academic databases (PubMed [Medline], McMaster PLUS, Cochrane Database of Systematic Reviews, UpToDate, Cochrane Central Register of Controlled Trials, and National Institute for Health and Care Excellence) were systematically searched. PRISMA guidelines were applied.

RESULTS

The search retrieved 1,212 titles of which 12 fitted inclusion criteria (11 observational studies and 1 randomized clinical trial). Included articles were critically appraised. We grouped the articles according to common area of implemented stewardship actions: (1) focus on reducing initiation of antibiotic therapy, (2) focus on shortening duration of antibiotic therapy, (3) various organizational stewardship implementations. The heterogeneity of cohort composition, of implemented actions and of outcome measures made meta-analysis inappropriate. We provide an overview of the reduction in antibiotic use achieved.

CONCLUSION

Antibiotic stewardship programs can be effective for premature newborns especially when multifactorial and tailored to this population, focusing on reducing initiation or on shortening the duration of antibiotic therapy. Programs without specific measures were less effective.

Prevention of necrotizing enterocolitis in premature infants – an updated review

Necrotizing enterocolitis (NEC) is among the most common and devastating diseases encountered in premature infants, yet the true etiology continues to be poorly understood despite decades of research. Recently, gut bacterial dysbiosis has been proposed as a risk factor for the development of NEC. Based on this theory, several best clinical practices designed to reduce the risk of NEC have been proposed and/or implemented. This review summarizes the results of recent clinical trials and meta-analyses that support some of the existing clinical practices for reducing the risk of NEC in premature infants. It is evident that human milk feeding can reduce the incidence of NEC. While most of the studies demonstrated that probiotic supplementation can significantly reduce the incidence of NEC in premature infants, there are still some concerns regarding the quality, safety, optimal dosage, and treatment duration of probiotic preparations. Antibiotic prophylaxis does not reduce the incidence of NEC, and prolonged initial empirical use of antibiotics might in fact increase the risk of NEC for high-risk premature infants. Lastly, standardized feeding protocols are strongly recommended, both for prevention of postnatal growth restriction and NEC.

Necrotizing Enterocolitis Pathophysiology: How Microbiome Data Alter Our Understanding

Necrotizing enterocolitis is a major cause of mortality and morbidity in the preterm infant population. The gut microbiome is of particular interest in research surrounding necrotizing enterocolitis, because variations in the intestinal microbiota seem to correlate with the risk of inflammation and disease. Recent advances in non-culture-based genomic sequencing have also allowed for more intricate analyses of the intestinal microbiome. Its evolution seems to be influenced by intrauterine and extrauterine factors, ranging from antenatal antibiotic exposure to type of enteral feeds. Ultimately, these alterations in the gut microbiome have the potential to result in devastating diseases like necrotizing enterocolitis.

Does antibiotic choice for the treatment of suspected late-onset sepsis in premature infants determine the risk of developing necrotising enterocolitis? A systematic review

BACKGROUND

Necrotising enterocolitis (NEC) is a significant cause of infant morbidity and mortality, disproportionately affecting those of extreme prematurity and/or very low birth weight. A number of risk factors have been identified, including an association between the use of antibiotics, and the subsequent development of NEC.

AIM

This review sought to address whether the choice of antibiotic(s) used to treat infants with suspected late-onset sepsis (LOS) influences the risk of developing NEC.

METHODS

A systematic review was performed across Web of Knowledge, Cochrane Library, Ovid Medline, EMBASE and CINAHL databases, up to February 2018, assessing the primary outcome of NEC occurrence, as extracted directly from the published articles. Studies were included if they were randomised control trials (or featured adequate adjustment for confounders); included clear criteria for defining LOS/NEC; and assessed occurrence of NEC in premature infants treated for LOS with intravenous antibiotics. Studies were excluded if non-original, not exclusively featuring premature infants, or where treatment was given for early-onset sepsis only.

FINDINGS

2291 titles and abstracts were identified, of which one study (81 subjects) was suitable for analysis, following screening against eligibility criteria. This suggested a decreased risk of developing definite NEC following treatment with a vancomycin/aztreonam combination, versus a vancomycin/gentamicin regimen (OR = 0·08, 95%CI = 0·00-1·45).

CONCLUSION

This systematic review identified one study where the occurrence of NEC was reported in the context of comparing different antibiotic regimens for late onset sepsis and highlights that the type of antibiotic used to treat LOS in preterm infants might be a determinant of the risk of developing NEC. Although it is known that different antibiotic combinations impact the enteric microbiome and that antibiotic exposure is a risk factor for NEC, there is a paucity of well-designed studies that look at the relationship between NEC risk and specific antibiotic exposures.

Antibiotic exposure in neonates and early adverse outcomes: a systematic review and meta-analysis

Objectives

To systematically review and meta-analyse the relationship between antibiotic exposure in neonates and the following early adverse outcomes: necrotizing enterocolitis (NEC), invasive fungal infections (IFIs) and/or death.

Methods

Data sources were PubMed, Embase, Medline and the Cochrane Database (to December 2016), supplemented by manual searches of reference lists. Randomized controlled trials (RCTs) and observational studies were included if they provided data on different categories of antibiotic exposures (yes versus no, long versus short duration, and/or broad- versus narrow-spectrum regimens) and the risk of developing NEC, IFI and/or death in the neonatal period. Two reviewers extracted data and evaluated the risk of bias using the Cochrane Handbook, adapted to include observational studies. When appropriate, meta-analyses were conducted using the random-effect model.

Results

We identified 9 RCTs and 38 observational studies. The quality of the majority of studies was poor to moderate. There was a significant association between prolonged antibiotic exposure and an increased risk of NEC in five observational studies (5003 participants) and/or risk of death in five observational studies (13 534 participants). Eleven of 15 studies with data on broad- versus narrow-spectrum regimens reported an increased risk of IFI after broad-spectrum antibiotic exposure, in particular with third-generation cephalosporins and carbapenems. Meta-analysis was limited by few and old RCTs, insufficient sample sizes and diversity of antibiotic exposure and outcomes reported.

Conclusions

Prolonged antibiotic exposure in uninfected preterm infants is associated with an increased risk of NEC and/or death, and broad-spectrum antibiotic exposure is associated with an increased risk of IFI.

Multiple brain abscesses caused by Serratia marcescens in preterm newborn

Background

Brain abscesses are possible but very uncommon complications of bacterial sepsis and meningitis in neonates. We report a case of multiple brain abscesses in a preterm neonate as a complication of Serratia marcescens sepsis.

Case

The female preterm weighing 1990 g was delivered by cesarean section at 32 weeks of gestation. Apart from moderate respiratory distress syndrome (RDS), the baby was in a good condition with no indicators of perinatal infection. On the 3rd day of life, the clinical status deteriorated and the sepsis screen was positive. The baby was intubated and, along with other intensive measures, treated with high doses of vancomycin and imipenem. Serattia marcescens was isolated in hemoculture. The baby clinicaly improved in the following days, but the cranial ultrasound revealed multiple hypoechoic lesions in parietal lobes bilaterally. Magnetic resonance imaging (MRI) of the brain showed multiple (five) hypodense lesions with the peripheral enhancement suggestive of intra-parenchymal abscesses. The neurosurgical consilium suggested conservative treatment with antibiotics and weekly neuroimiging follow-up. The antibiotic treatment was conducted for a total of 8 weeks. The final MRI showed a total regresion of previous abscesses with the formation of small cavitations. The clinical and neurological examination of the baby was normal as was the EEG. The baby was discharged with a recommendation of neurological follow-up.

Conclusion

A multidisciplinary team approach, including neurosurgeons, neonatologists and infectious disease specialists, is needed for a decision on treatment of brain abscesses in neonates. Serial imaging is important in the assessment of the efficacy of treatment.

The initial prophylactic antibiotic usage and subsequent necrotizing enterocolitis in high-risk premature infants: a systematic review and meta-analysis

OBJECTIVE

To investigate the correlation between the initial prophylactic antibiotic use and the subsequent NEC in high-risk premature infants.

METHODS

We performed a literature search of PubMed, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), and the Web of Science, and nine studies with a total of 5207 infants were selected for inclusion in this study.

RESULTS

The pooled estimate for the seven studies combined indicating that prophylactic antibiotic usage was associated with a non-significant trend toward increased incidence of NEC [odds ratio (OR) 0.75; 95% confidence interval (CI) 0.26-2.17], and prolonged exposure to prophylactic antibiotics, compared with limited prophylactic antibiotic use, was associated with a significant trend toward the risk of increasing incidence of NEC (OR 1.31; 95% CI 1.08-1.59).

CONCLUSION

Current evidence does not support the use of prophylactic antibiotics to reduce the incidence of NEC for high-risk premature infants.

NEC-zero recommendations from scoping review of evidence to prevent and foster timely recognition of necrotizing enterocolitis

BACKGROUND

Although decades have focused on unraveling its etiology, necrotizing enterocolitis (NEC) remains a chief threat to the health of premature infants. Both modifiable and non-modifiable risk factors contribute to varying rates of disease across neonatal intensive care units (NICUs).

PURPOSE

The purpose of this paper is to present a scoping review with two new meta-analyses, clinical recommendations, and implementation strategies to prevent and foster timely recognition of NEC.

METHODS

Using the Translating Research into Practice (TRIP) framework, we conducted a stakeholder-engaged scoping review to classify strength of evidence and form implementation recommendations using GRADE criteria across subgroup areas: 1) promoting human milk, 2) feeding protocols and transfusion, 3) timely recognition strategies, and 4) medication stewardship. Sub-groups answered 5 key questions, reviewed 11 position statements and 71 research reports. Meta-analyses with random effects were conducted on effects of standardized feeding protocols and donor human milk derived fortifiers on NEC.

RESULTS

Quality of evidence ranged from very low (timely recognition) to moderate (feeding protocols, prioritize human milk, limiting antibiotics and antacids). Prioritizing human milk, feeding protocols and avoiding antacids were strongly recommended. Weak recommendations (i.e. "probably do it") for limiting antibiotics and use of a standard timely recognition approach are presented. Meta-analysis of data from infants weighing <1250 g fed donor human milk based fortifier had reduced odds of NEC compared to those fed cow's milk based fortifier (OR = 0.36, 95% CI 0.13, 1.00; p = 0.05; 4 studies, N = 1164). Use of standardized feeding protocols for infants <1500 g reduced odds of NEC by 67% (OR = 0.33, 95% CI 0.17, 0.65, p = 0.001; 9 studies; N = 4755 infants). Parents recommended that NEC information be shared early in the NICU stay, when feedings were adjusted, or feeding intolerance occurred via print and video materials to supplement verbal instruction.

DISCUSSION

Evidence for NEC prevention is of sufficient quality to implement. Implementation that addresses system-level interventions that engage the whole team, including parents, will yield the best impact to prevent NEC and foster its timely recognition.

Effectiveness of Tocolytic Agents on Prevention of Preterm Delivery, Neonatal Morbidity, and Mortality: Is There a Consensus? A Review of the Literature

Preterm delivery presents the main cause of neonatal morbidity and mortality worldwide. The rate of preterm delivery is 12% to 13% in the United States, of which 29% concerns preterm deliveries before 34 weeks of gestation. Basic parameter of prevention strategy is implementation of tocolytic therapy in cases of threatened preterm labor. Several therapeutic approaches have been proposed, among which betamimetic agonists, calcium channel blockers, magnesium sulfate, oxytocin receptor blockers, nitrates, and prostaglandin inhibitors, whereas new alternatives such as usage of thiocolchicoside have also been reported. This article is one among few that aims to review the comparative effectiveness of various tocolytic agents regarding prevention of preterm delivery, impact on perinatal morbidity and mortality, neonatal health status, and maternal complications. Main conclusions of recent randomized control trials and meta-analyses are summarized to assess about which agents consensus already exists on their effectiveness, which agents should be further studied to achieve conclusions, as well as those that are rather unlikely to have significant tocolytic impact or any other benefit on neonatal outcome.

Preterm infant gut colonization in the neonatal ICU and complete restoration 2 years later

Preterm infants in a neonatal intensive care unit (NICU) are exposed to multidrug-resistant bacteria previously adapted to the hospital environment. The aim of the present study was to characterize the bacterial antibiotic-resistant high-risk lineages colonizing preterm infants during their NICU stay and their persistence in faeces after 2 years. A total of 26 preterm neonates were recruited between October 2009 and June 2010 and provided 144 faecal samples. Milk samples (86 mother's milk, 35 human donor milk and 15 formula milk) were collected at the same time as faecal samples. An additional faecal sample was recovered in 16 infants at the age of 2 years. Samples were plated onto different selective media, and one colony per morphology was selected. Isolates were identified by 16S rDNA nucleotide sequence and MALDI-TOF. Antibiotic susceptibility (agar dilution), genetic diversity (RAPD, PFGE and MLST) and virulence factors (only in enterococcal and staphylococcal isolates) were determined by PCR. A high proportion of antibiotic-resistant high-risk clones was detected in both faecal and milk samples during the NICU admittance. Almost all infants were colonized by Enterococcus faecalis ST64 and Enterococcus faecium ST18 clones, while a wider genetic diversity was observed for the Gram-negative isolates. Multidrug-resistant high-risk clones were not recovered from the faecal samples of the 2-year-olds. In conclusion, the gut of preterm infants admitted to the NICU might be initially colonized by antibiotic-resistant and virulent high-risk lineages, which are later replaced by antibiotic-susceptible community ones.

What really causes necrotising enterocolitis?

Background. One of the most serious gastrointestinal disorders occurring in neonates is necrotising enterocolitis (NEC). It is recognised as the most common intra-abdominal emergency and is the leading cause of short bowel syndrome. With extremely high mortality and morbidity, this enigmatic disease remains a challenge for neonatologists around the world as its definite aetiology has yet to be determined. As current medical knowledge stands, there is no single well-defined cause of NEC. Instead, there are nearly 20 risk factors that are proposed to increase the likelihood of developing NEC. Aims and Objectives. The aim of this project was to conduct a comprehensive literature review around the 20 or so well-documented and less well-documented risk factors for necrotising enterocolitis. Materials and Methods. Searches of the Medline, Embase, and Science direct databases were conducted using the words "necrotising enterocolitis + the risk factor in question" for example, "necrotising enterocolitis + dehydration." Search results were ordered by relevance with bias given to more recent publications. Conclusion. This literature review has demonstrated the complexity of necrotising enterocolitis and emphasised the likely multifactorial aetiology. Further research is needed to investigate the extent to which each risk factor is implicated in necrotising enterocolitis.

Ampicillin versus penicillin in the empiric therapy of extremely low-birthweight neonates at risk of early onset sepsis

BACKGROUND

There are no comparative data on the impact of different empiric antibiotic regimens on early bowel colonization as well as on clinical efficacy in extremely low-birthweight (ELBW) neonates at risk of early onset sepsis (EOS).

METHODS

A subgroup analysis was carried out of ELBW neonates recruited into a two-center, prospective, cluster randomized study comparing ampicillin and penicillin both combined with gentamicin, within the first 72 h of life. A composite primary end-point (need for change of antibiotics within 72 h and/or 7 day all-cause mortality) and the rate and duration of colonization by opportunistic aerobic microorganisms were assessed using hierarchical models corrected for study center and period.

RESULTS

In the ampicillin (n= 36) and penicillin (n= 39) groups change of antibiotics, 7 day mortality and the composite end-point occurred at similar rates. Neonatal intensive care unit mortality for infants with gestational age <26 weeks was lower in the ampicillin group. Ampicillin treatment was associated with a higher colonization rate by Klebsiella pneumoniae, including ampicillin-resistant strains.

CONCLUSION

Preliminary data indicate an urgent need for adequately powered studies of early antibiotic therapy in the subpopulation of ELBW neonates at risk of EOS.

Mucosal surveillance cultures in predicting Gram-negative late-onset sepsis in neonatal intensive care units

This study aimed to examine the spectrum and time course of gut and nasopharyngeal colonization with Gram-negative micro-organisms, and to define the value of surveillance cultures in predicting late-onset sepsis in neonates admitted to neonatal intensive care units. Nasopharyngeal and rectal swabs were collected on admission and twice weekly thereafter in 278 neonates admitted within the first 72 h of life with risk factors of early-onset sepsis. Sterile body fluid cultures were obtained on admission and subsequently as clinically indicated. Approximately half of the rectal (693/1250, 55%) and nasopharyngeal (558/1153, 48%) samples but only 6% (32/555) of the sterile fluid samples in 26 patients were culture positive for Gram-negative organisms. In total, 2108 invasive and mucosal culture pairs were analysed. The overall sensitivity, specificity, and positive and negative predictive values of a mucosal sample to predict late-onset sepsis were 27%, 66%, 4% and 94%, respectively. Patients with pre-existing colonization with Klebsiella pneumoniae (P = 0.011), Klebsiella oxytoca (P = 0.002), Escherichia coli (P = 0.003), Stenotrophomonas spp. (P = 0.003) and Pseudomonas spp. (P ≤ 0.001) were more likely to develop late-onset sepsis. No such association was found for Acinetobacter baumannii, Serratia spp. or Enterobacter cloacae. In conclusion, routine mucosal cultures are inefficient for the prediction of Gram-negative late-onset sepsis in neonatal intensive care units. However, targeted screening for specific organisms in an outbreak (e.g. Klebsiella spp., E. coli, Stenotrophomonas spp. and Pseudomonas spp.) may offer an opportunity to improve infection control measures and enable timely initiation of appropriate antibiotic therapy.