Prolonged duration of early antibiotic therapy in extremely premature infants

Necrotizing Enterocolitis in Very Low Birth Weight Neonates: A Natural History Study

OBJECTIVE

 We characterize the most recent natural history of necrotizing enterocolitis (NEC), as this is an essential first step in guiding the prevention and treatment of this disease in the present day.

STUDY DESIGN

 We performed a retrospective cohort study of neonates who were born at 23 to 29 weeks' gestation and birth weight <1,500 g who received care from the Pediatrix Medical Group between 2004 and 2019. We assessed the incidence of medical and surgical NEC and the patterns of initial antibiotic treatment to develop a contemporary cohort for further analysis. Among patients discharged between 2015 and 2019, we characterized the stage-specific risk factors for patients diagnosed with medical or surgical NEC, as well as patterns of disease onset, progression, biomarkers, and outcomes. We used the same approach to characterize patients diagnosed with suspected NEC.

RESULTS

 Among 34,032 patients in the contemporary cohort, 1,150 (3.4%) were diagnosed with medical NEC and 543 (1.6%) were diagnosed with surgical NEC. The temporal pattern of disease onset was different for medical and surgical NEC, with gestational age- and birth weight-specific risk disparities emerging earlier in surgical NEC. Thirty-day mortality was much greater among surgical NEC patients (medical NEC 16.4% vs. surgical NEC 43.0%), as were rates of various in-hospital and long-term outcomes. Suspected NEC was diagnosed in 1,256 (3.7%) patients, among whom risk factors and disease onset, progression, and outcomes closely resembled those of medical NEC.

CONCLUSION

 Analyzing data from a contemporary cohort enabled us to characterize the current, stage-specific natural history of NEC, including novel insights into suspected NEC. Future studies could leverage this cohort to characterize how specific patient characteristics, care processes, or biomarkers may influence or predict disease outcomes.

KEY POINTS

· The incidence of NEC has reached a stable baseline in recent years.. · Risk factors for NEC vary in a stage-specific manner.. · The stage-specific onset and progression of NEC differ by gestational age and birth weight..

Syndecan-1 Level, a Marker of Endothelial Glycocalyx Degradation, Is Associated With Fetal Exposure to Chorioamnionitis and Is a Potential Biomarker for Early-Onset Neonatal Sepsis

The goal of this investigation was to identify the association between Syndecan-1 (S1) serum levels in preterm newborns exposed to chorioamnionitis (CA) in utero and the potential of S1 as a biomarker of early-onset neonatal sepsis. A cohort of preterm newborns born <33 weeks gestational age was recruited. Within 48 hours of birth, 0.5 mL of blood was drawn to obtain S1 levels, measured via ELISA. Placentas were examined and classified as having (1) no CA, (2) CA without umbilical cord involvement, or (3) CA with inflammation of the umbilical cord (funisitis). S1 levels were compared between preterm newborns without exposure to CA verus newborns with exposure to CA (including with and without funisitis). Preterm newborns exposed to CA were found to have significantly elevated S1 levels compared to those unexposed. Although S1 levels could not differentiate fetal exposure to CA from exposure to CA with funisitis, the combined CA groups had significantly higher S1 levels compared to those not exposed to CA. S1 level has the potential to become a clinically useful biomarker that could assist in the management of mothers and preterm newborns with CA and funisitis. Furthermore, S1 level could aid in the diagnosis and treatment of early-onset neonatal sepsis.

Application of Advanced Molecular Methods to Study Early-Onset Neonatal Sepsis

Early-onset sepsis (EOS) is a global health issue, considered one of the primary causes of neonatal mortality. Diagnosis of EOS is challenging because its clinical signs are nonspecific, and blood culture, which is the current gold-standard diagnostic tool, has low sensitivity. Commonly used biomarkers for sepsis diagnosis, including C-reactive protein, procalcitonin, and interleukin-6, lack specificity for infection. Due to the disadvantages of blood culture and other common biomarkers, ongoing efforts are directed towards identifying innovative molecular approaches to diagnose neonates at risk of sepsis. This review aims to gather knowledge and recent research on these emerging molecular methods. PCR-based techniques and unrestricted techniques based on 16S rRNA sequencing and 16S-23S rRNA gene interspace region sequencing offer several advantages. Despite their potential, these approaches are not able to replace blood cultures due to several limitations; however, they may prove valuable as complementary tests in neonatal sepsis diagnosis. Several microRNAs have been evaluated and have been proposed as diagnostic biomarkers in EOS. T2 magnetic resonance and bioinformatic analysis have proposed potential biomarkers of neonatal sepsis, though further studies are essential to validate these findings.

Heart rate and oxygen saturation patterns in very low birth weight infants with early onset sepsis and histologic chorioamnionitis

BACKGROUND

Chorioamnionitis and early onset sepsis (EOS) in very low birth weight (VLBW,< 1500 g) infants may cause a systemic inflammatory response reflected in patterns of heart rate (HR) and oxygenation measured by pulse oximetry (SpO2). Identification of these patterns might inform decisions about duration of antibiotic therapy after birth.

OBJECTIVE

Compare early HR and SpO2 patterns in VLBW infants with or without early onset sepsis (EOS) or histologic chorioamnionitis (HC).

STUDY DESIGN

Retrospective study of placental pathology and HR and SpO2 in the first 72 h from birth in relation to EOS status for inborn VLBW NICU patients 2012-2019.

RESULT

Among 362 VLBW infants with HR and SpO2 data available, clinical, or culture-positive EOS occurred in 91/362 (25%) and HC in 81/355 (22%). In univariate analysis, EOS was associated with higher mean HR, lower mean SpO2, and less negative skewness of HR in the first 3 days after birth. HC was associated with higher standard deviation and skewness of HR but no difference in SpO2. In multivariable modeling, significant risk factors for EOS were mean HR, gestational age, HC, mean SpO2, and skewness of SpO2.

CONCLUSION

HR and SpO2 patterns differ shortly after birth in VLBW infants exposed to HC or with EOS, likely reflecting a systemic inflammatory response.

Clinical Dilemma Involving Treatments for Very Low-Birth-Weight Infants and the Potential Risk of Necrotizing Enterocolitis: A Narrative Literature Review

Necrotizing enterocolitis (NEC) is a critical gastrointestinal emergency with substantial morbidity and mortality risks, especially for very low-birth-weight (VLBW) infants, and unclear multifactorial pathophysiology. Whether common treatments for VLBW infants increase the NEC risk remains controversial. Indomethacin (utilized for patent ductus arteriosus) offers benefits but is concerning because of its vasoconstrictive impact on NEC susceptibility. Similarly, corticosteroids used to treat bronchopulmonary dysplasia may increase vulnerability to NEC by compromising immunity and altering the mesenteric blood flow. Histamine-2 receptor blockers (used to treat gastric bleeding) may inadvertently promote NEC by affecting bacterial colonization and translocation. Doxapram (used to treat apnea) poses a risk of gastrointestinal disturbance via gastric acid hypersecretion and circulatory changes. Glycerin enemas aid meconium evacuation but disrupt microbial equilibrium and trigger stress-related effects associated with the NEC risk. Prolonged antibiotic use may unintentionally increase the NEC risk. Blood transfusions for anemia can promote NEC via interactions between the immune response and ischemia-reperfusion injury. Probiotics for NEC prevention are associated with concerns regarding sepsis and bacteremia. Amid conflicting evidence, this review unveils NEC risk factors related to treatments for VLBW infants, offers a comprehensive overview of the current research, and guides personalized management strategies, thereby elucidating this clinical dilemma.

Antibiotic safety among neonates and paediatrics in a public hospital: KwaZulu-Natal

Background

The World Health Organization (WHO) guidelines recommend the empiric treatment of infections before definitive treatment begins. However, ethical concerns limit the availability of clinical trials in neonates and paediatrics to fully ascertain the safety profile of antibiotics in these populations.

Aim

This study aimed to quantify the use of antibiotics among neonates and paediatrics and commented on the use, rationale and appropriateness of antibiotics prescribed.

Setting

A secondary level public sector hospital located in Durban, KwaZulu-Natal.

Methods

Demographic and treatment information of neonates and paediatrics were collected retrospectively from January 2022 to June 2022. Data were obtained from patient files and extracted for analysis using Microsoft Excel®. Analytical and descriptive statistics were used to analyse patient demographics and treatment variables.

Results

A total of 568 antibiotics, issued to 389 patients, were reviewed. Penicillins (40.1%), aminoglycosides (24.3%) and combination penicillin-beta-lactam inhibitors (23.3%) were identified as the most frequently prescribed antibiotics for inpatients. Most antibiotics prescribed to inpatients were for complications associated with pre-term birth (66.9%). Combination penicillin-beta-lactam inhibitors (34.7%), penicillins (29.5%) and cephalosporins (29.5%) were the most frequently prescribed antibiotics to outpatients. A correlation was found between the route of administration and the duration of therapy; the intravenous route (63.6%) was preferred over the oral route (36.4%) for administration.

Conclusion

Many broad-spectrum antibiotics were prescribed, thus increasing the risk of resistance. Antibiotics were being prescribed according to the guidelines; however, there is still a need for therapeutic drug monitoring to ensure the continuation of rational drug use.

Contribution

There was evidence of rational use of antibiotics in the public hospital (KwaZulu-Natal), in keeping with economic and availability factors.

Early antibiotic exposure in very-low birth weight infants and infection risk at 3-7 days after birth

OBJECTIVE

To determine rates of late-onset infection (LOI) during postnatal days 3-7 among preterm infants, based on antibiotic exposure during days 0-2.

STUDY DESIGN

Retrospective cohort study of infants born <1500 grams and ≤30 weeks gestation, 2005-2018. We analyzed the incidence and microbiology of LOI at days 3-7 based on antibiotic exposure during postnatal days 0-2.

RESULTS

The cohort included 88,574 infants, of whom 85% were antibiotic-exposed. Fewer antibiotic-exposed compared to unexposed infants developed LOI (1.5% vs. 2.1%; adjusted hazard ratio, 0.28, 95% CI 0.24-0.33). Among antibiotic-exposed compared to unexposed infants, Gram-negative (38% vs. 28%, p = 0.002) and fungal (11% vs. 1%, p < 0.001) species were more commonly isolated, and gram-positive organisms (49% vs. 70%, p < 0.001) were less commonly isolated.

CONCLUSIONS

We observed low overall rates of LOI at days 3-7 after birth, but antibiotic exposure from birth was associated with lower rates, and with differing microbiology, compared to no exposure.

The Nonbacterial Microbiome: Fungal and Viral Contributions to the Preterm Infant Gut in Health and Disease

The intestinal microbiome is frequently implicated in necrotizing enterocolitis (NEC) pathogenesis. While no particular organism has been associated with NEC development, a general reduction in bacterial diversity and increase in pathobiont abundance has been noted preceding disease onset. However, nearly all evaluations of the preterm infant microbiome focus exclusively on the bacterial constituents, completely ignoring any fungi, protozoa, archaea, and viruses present. The abundance, diversity, and function of these nonbacterial microbes within the preterm intestinal ecosystem are largely unknown. Here, we review findings on the role of fungi and viruses, including bacteriophages, in preterm intestinal development and neonatal intestinal inflammation, with potential roles in NEC pathogenesis yet to be determined. In addition, we highlight the importance of host and environmental influences, interkingdom interactions, and the role of human milk in shaping fungal and viral abundance, diversity, and function within the preterm intestinal ecosystem.

Fighting Antimicrobial Resistance in Neonatal Intensive Care Units: Rational Use of Antibiotics in Neonatal Sepsis

Antibiotics are the most frequently prescribed drugs in neonatal intensive care units (NICUs) due to the severity of complications accompanying neonatal sepsis. However, antimicrobial drugs are often used inappropriately due to the difficulties in diagnosing sepsis in the neonatal population. The reckless use of antibiotics leads to the development of resistant strains, rendering multidrug-resistant pathogens a serious problem in NICUs and a global threat to public health. The aim of this narrative review is to provide a brief overview of neonatal sepsis and an update on the data regarding indications for antimicrobial therapy initiation, current guidance in the empirical antimicrobial selection and duration of therapy, and indications for early discontinuation.

Influences of Initial Empiric Antibiotics with Ampicillin plus Cefotaxime on the Outcomes of Neonates with Respiratory Failure: A Propensity Score Matched Analysis

Background: Empiric antibiotics are often prescribed in critically ill and preterm neonates at birth until sepsis can be ruled out. Although the current guideline suggests narrow-spectrum antibiotics, an upgrade in antibiotics is common in the neonatal intensive care unit. The impacts of initial broad-spectrum antibiotics on the outcomes of critically ill neonates with respiratory failure requiring mechanical intubation have not been well studied. Methods: A total of 1162 neonates from a tertiary level neonatal intensive care unit (NICU) in Taiwan who were on mechanical ventilation for respiratory distress/failure at birth were enrolled, and neonates receiving ampicillin plus cefotaxime were compared with those receiving ampicillin plus gentamicin. Propensity score-matched analysis was used to investigate the effects of ampicillin plus cefotaxime on the outcomes of critically ill neonates. Results: Ampicillin plus cefotaxime was more frequently prescribed for intubated neonates with lower birth weight, higher severity of illness, and those with a high risk of early-onset sepsis. Only 11.1% of these neonates had blood culture-confirmed early-onset sepsis and/or congenital pneumonia. The use of ampicillin plus cefotaxime did not significantly contribute to improved outcomes among neonates with early-onset sepsis. After propensity score-matched analyses, the critically ill neonates receiving ampicillin plus cefotaxime had significantly worse outcomes than those receiving ampicillin plus gentamicin, including a higher risk of late-onset sepsis caused by multidrug-resistant pathogens (11.2% versus 7.1%, p = 0.027), longer duration of hospitalization (median [IQR], 86.5 [47–118.8] days versus 78 [45.0–106.0] days, p = 0.002), and a significantly higher risk of in-hospital mortality (14.2% versus 9.6%, p = 0.023). Conclusions: Ampicillin plus cefotaxime should not be routinely prescribed as the empiric antibiotics for critically ill neonates at birth because they were associated with a higher risk of infections caused by multidrug-resistant pathogens and final worse outcomes.

Early Empirical Antibiotics and Adverse Clinical Outcomes in Infants Born Very Preterm: A Population-Based Cohort

OBJECTIVE

The objective of this study was to evaluate the association between empirical antibiotic therapy in the first postnatal week in uninfected infants born very preterm and the risk of adverse outcomes until discharge.

STUDY DESIGN

Population-based, nationwide registry study in Norway including all live-born infants with a gestational age <32 weeks surviving first postnatal week without sepsis, intestinal perforation, or necrotizing enterocolitis (NEC) between 2009 and 2018. Primary outcomes were severe NEC, death after the first postnatal week, and/or a composite outcome of severe morbidity (severe NEC, severe bronchopulmonary dysplasia [BPD], severe retinopathy of prematurity, late-onset sepsis, or cystic periventricular leukomalacia). The association between empirical antibiotics and adverse outcomes was assessed using multivariable logistic regression models, adjusting for known confounders.

RESULTS

Of 5296 live-born infants born very preterm, 4932 (93%) were included. Antibiotics were started in first postnatal week in 3790 of 4932 (77%) infants and were associated with higher aOR of death (aOR 9.33; 95% CI: 1.10-79.5, P = .041), severe morbidity (aOR 1.88; 95% CI: 1.16-3.05, P = .01), and severe BPD (aOR 2.17; 95% CI: 1.18-3.98; P = .012), compared with those not exposed. Antibiotics ≥ 5 days were associated with higher odds of severe NEC (aOR 2.27; 95% CI: 1.02-5.06; P = .045). Each additional day of antibiotics was associated with 14% higher aOR of death or severe morbidity and severe BPD.

CONCLUSIONS

Early and prolonged antibiotic exposure within the first postnatal week was associated with severe NEC, severe BPD, and death after the first postnatal week.

Cardiorespiratory signature of neonatal sepsis: development and validation of prediction models in 3 NICUs

BACKGROUND

Heart rate characteristics aid early detection of late-onset sepsis (LOS), but respiratory data contain additional signatures of illness due to infection. Predictive models using cardiorespiratory data may improve early sepsis detection. We hypothesized that heart rate (HR) and oxygenation (SpO₂) data contain signatures that improve sepsis risk prediction over HR or demographics alone.

METHODS

We analyzed cardiorespiratory data from very low birth weight (VLBW, <1500 g) infants admitted to three NICUs. We developed and externally validated four machine learning models to predict LOS using features calculated every 10 m: mean, standard deviation, skewness, kurtosis of HR and SpO₂, and cross-correlation. We compared feature importance, discrimination, calibration, and dynamic prediction across models and cohorts. We built models of demographics and HR or SpO₂ features alone for comparison with HR-SpO₂ models.

RESULTS

Performance, feature importance, and calibration were similar among modeling methods. All models had favorable external validation performance. The HR-SpO₂ model performed better than models using either HR or SpO₂ alone. Demographics improved the discrimination of all physiologic data models but dampened dynamic performance.

CONCLUSIONS

Cardiorespiratory signatures detect LOS in VLBW infants at 3 NICUs. Demographics risk-stratify, but predictive modeling with both HR and SpO₂ features provides the best dynamic risk prediction.

IMPACT

Heart rate characteristics aid early detection of late-onset sepsis, but respiratory data contain signatures of illness due to infection. Predictive models using both heart rate and respiratory data may improve early sepsis detection. A cardiorespiratory early warning score, analyzing heart rate from electrocardiogram or pulse oximetry with SpO₂, predicts late-onset sepsis within 24 h across multiple NICUs and detects sepsis better than heart rate characteristics or demographics alone. Demographics risk-stratify, but predictive modeling with both HR and SpO₂ features provides the best dynamic risk prediction. The results increase understanding of physiologic signatures of neonatal sepsis.

Early antibiotic use and incidence of necrotising enterocolitis in very preterm infants: a protocol for a UK based observational study using routinely recorded data

INTRODUCTION

Necrotising enterocolitis (NEC) remains a major contributor to preterm mortality and morbidity. Prolonged duration of antibiotic therapy after delivery is associated with later NEC development but recent evidence suggests that absence of antibiotic treatment after delivery may also increase NEC risk. We will explore this controversy using a large pre-existing dataset of preterm infants in the UK.

METHODS AND ANALYSIS

This is a retrospective cohort study using data from UK National Neonatal Research Database (NNRD) for infants born 1 January 2012 to 31 December 2020. Eligible infants will be <32 weeks gestation, alive on day 3. Primary outcome is development of severe NEC, compared in infants receiving early antibiotics (days 1-2 after birth) and those not. Subgroup analysis on duration of early antibiotic exposure will also occur. Secondary outcomes are: late onset sepsis, total antibiotic use, predischarge mortality, retinopathy of prematurity, intraventricular haemorrhage, bronchopulmonary dysplasia, focal intestinal perforation and any abdominal surgery. To address competing risks, incidence of death before day 7, 14 and 28 will be analysed. We will perform logistic regression and propensity score matched analyses. Statistical analyses will be guided by NEC risk factors, exposures and outcome presented in a causal diagram. These covariates include but are not limited to gestational age, birth weight, small for gestational age, sex, ethnicity, delivery mode, delivery without labour, Apgar score, early feeding and probiotic use. Sensitivity analyses of alternate NEC definitions, specific antibiotics and time of initiation will occur.

ETHICS AND DISSEMINATION

We will use deidentified data from NNRD, which holds permissions for the original data, from which parents can opt out and seek study-specific research ethics approval. The results will help to determine optimal use of early antibiotics for very preterm infants.

IMPLICATIONS

This data will help optimise early antibiotic use in preterm infants.

TRIAL REGISTRATION NUMBER

ISRCTN55101779.

Neonatal infections: Insights from a multicenter longitudinal research collaborative

For more than 30 years, the Neonatal Research Network (NRN) has conducted studies addressing the epidemiology of neonatal infections, including incidence, microbiology, maternal and neonatal risk factors, associated clinical findings, and outcomes. These studies have provided clinicians and policymakers critical data needed to inform national guidance for infection risk assessment and support daily practice. Further, NRN studies have prompted research into optimal approaches to infection diagnosis, treatment, and antimicrobial stewardship. In this article, we summarize the key findings of NRN infection-related studies, with an emphasis on those published in 2000 or later.

Pathogen Distribution and Antimicrobial Resistance of Early Onset Sepsis in Very Premature Infants: A Real-World Study

INTRODUCTION

Early onset sepsis (EOS) remains a potentially fatal newborn condition, especially in very preterm infants. Data on the pathogen distribution and antibiotic susceptibility patterns of EOS among very preterm infants are scarce but essential for the choice of empirical antibiotic administration. We sought to assess the epidemiologic characteristics and antibiotic susceptibility patterns of pathogens causing EOS among a cohort of very preterm infants in China.

METHODS

This prospective, observational study included a cohort of infants born at a gestational age (GA) less than 32 weeks of 32 newborn intensive care units (NICUs) in China between January 1, 2018 and December 31, 2020. EOS was defined by isolation of pathogenic species from blood culture within 72 h of birth.

RESULTS

A total of 108 EOS cases (18.4 per 1000 admissions) were identified among 5865 very preterm infants. Incidence of EOS increased with the decrease of GA and birthweight. Escherichia coli (n = 44, 40.7%) was the most common pathogen, followed by Klebsiella spp. (n = 10, 9.3%). The distribution and proportion of pathogenic bacteria varied significantly by GA. E. coli and Klebsiella spp. showed high resistance to ampicillin and third-generation cephalosporins, while they showed good susceptibility to carbapenem antibiotics and piperacillin-tazobactam.

CONCLUSION

Our data demonstrated that pathogens causing neonatal EOS showed high rates of resistance to ampicillin and third-generation cephalosporins. This raised questions about the best empirical antibiotic choice for preterm infants suspected of having EOS in low- and middle-income countries (LMICs).

Antibiotic exposure prevents acquisition of beneficial metabolic functions in the preterm infant gut microbiome

BACKGROUND

Aberrations in the preterm microbiome following antibiotic therapy have been reported in previous studies. The objective of this study was to probe potential underlying mechanisms between this observation and susceptibility to adverse prematurity-related outcomes.

RESULTS

Metagenomic shotgun sequencing was performed on 133 stool and 253 skin samples collected at 1 and 3 weeks of age from 68 infants born at <36 weeks postmenstrual age and birth weight <2000 g. After accounting for gestational age and maternal antibiotics, the distribution of organisms in all samples and the corresponding metabolic pathway abundance were compared between infants exposed to postnatal antibiotics and antibiotics-naïve infants. In antibiotic-naïve infants, gestational and postnatal age imparted similar trajectories on maturation of the microbial community and associated metabolic functional capacity, with postnatal age exerting greater contribution. Antibiotic exposure was associated with reversal in maturation trajectory from the first week to the third week of age (p< 0.001). Butyrate-producing genera, including Clostridium and Blautia, were significantly more abundant in antibiotic-naïve neonates at 3 weeks postnatal age. Correspondingly, metabolic pathways required for short-chain fatty acid synthesis were significantly increased in antibiotic-naïve infants, but not in antibiotic-exposed neonates, at 3 weeks after birth.

CONCLUSIONS

Early brief antibiotic exposure markedly disrupts developmental trajectory of the neonatal microbiome and its corresponding functional capacity. Our findings may provide a mechanistic explanation for the known associations between antibiotic use and adverse outcomes in preterm infants. Video Abstract.

Prevention of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is considered to be one of the most devastating intestinal diseases seen in neonatal intensive care. Measures to treat NEC are often too late, and we need effective preventative measures to alleviate the burden of this disease. The purpose of this review is to summarize currently used measures, and those showing future promise for prevention.

The center-effect on outcomes for infants born at less than 25 weeks

Marked variation exists in the care of infants born at <25 weeks' gestation. The center or location where a fetus or infant is cared for influences outcomes at very early gestational ages. Understanding this "center-effect," including characteristics associated with centers that have high survival of births at <25 weeks' gestation, may inform future studies and guide care practices to improve outcomes. This review focuses on the impact that the location or center of birth has on survival and other important outcomes for infants born at <25 weeks' gestation. We review potential sources of variation in care practices and other factors that might explain the "center-effect."

Prolonged antibiotic therapy increased necrotizing enterocolitis in very low birth weight infants without culture-proven sepsis

OBJECTIVES

We aimed to identify the factors associated with necrotizing enterocolitis (NEC) and to assess the associations of the initial empirical antibiotic therapy (IEAT) duration and antibiotic therapy duration/hospital stay ratio (A/H ratio) before NEC with subsequent NEC in very low birth weight (VLBW) infants with gestational age less than 32 weeks without proven sepsis.

METHODS

A retrospective study was conducted at the NICU of the First Affiliated Hospital of Medical University of Anhui province from June 2015 to May 2022, and 567 VLBW infants with gestational age less than 32 weeks were included in the study. We divided the VLBW infants into those with and without NEC according to modified Bell's criteria. We then used descriptive statistics to identify the factors associated with NEC and multivariate analyses to evaluate the associations of IEAT duration and A/H ratio with the occurrence of NEC.

RESULTS

Of the 567 VLBW neonates admitted to our center, 547 survived and reached the normal discharge criteria. Fifty-one infants (8.99%) were diagnosed as showing NEC. Infants with NEC had a longer total parenteral nutrition time, total enteral nutrition time, and IEAT duration, as well as a higher A/H ratio than those without NEC. In multivariate analyses adjusted for the other factors, IEAT duration was associated with an increased odds of NEC [odds ratio (OR) = 1.267; 95% confidence interval (CI), 1.128-1.423], and the A/H ratio was also associated with increased odds of NEC (OR = 8.718; 95% CI, 2.450-31.030). For the A/H ratio, the area under the curve (AUC) was 0.767 and the ideal cutoff was 0.357, and the sensitivity and specificity were 0.843 and 0.645, respectively.

CONCLUSION

Prolonged antibiotic therapy may increase the risk of NEC in VLBW infants with a gestational age of fewer than 32 weeks and should be used with caution.

Association between duration of early empiric antibiotics and necrotizing enterocolitis and late-onset sepsis in preterm infants: a multicenter cohort study

The threshold to initiate empiric antibiotics for suspicion of early-onset sepsis (EOS) is low in preterm infants. Antibiotics' effects on short-term outcomes have recently been debated. We aimed at exploring the extent of early empiric antibiotic exposure (EEAE) in preterm infants and the association between the duration of EEAE with necrotizing enterocolitis (NEC) and late-onset sepsis (LOS) within different EEAE groups. EEAE practice for suspicion of EOS was evaluated in all included infants (gestational age < 30 weeks) born in 9 centers in the Netherlands and Belgium between Oct. 2014 and Jan. 2019. EEAE association with NEC and LOS development was analyzed by multivariate regression. After excluding 56 EOS cases, 1259 infants were included. A total of 1122 infants (89.1%) were exposed to empirical antibiotics for the suspicion of EOS of whom 802 (63.7%) had short (≤ 72 h) and 320 (25.4%) prolonged EEAE (> 72 h). Infants with EEAE ≤ 72 h had a lower incidence of NEC compared to both infants without EEAE (adjusted odds ratio (aOR) 0.39; 95% confidence interval (CI) [0.19-0.80]; p = 0.01) and with prolonged EEAE (> 72 h) (aOR [95%CI]: 0.58 [0.35-0.96]; p = 0.03). With every additional day of EEAE, LOS incidence decreased (aOR [95%CI]: 0.90 [0.85-0.97]; p = 0.003).

CONCLUSION

Almost 90% of preterm infants who have negative blood culture results in the first 72 h of life are exposed to EEAE under suspicion of EOS. One-fourth has prolonged EEAE. Duration of EEAE was differently associated with NEC and LOS incidence. The effects of antibiotics, and potentially induced microbial dysbiosis related to development of NEC and LOS, should further be explored.

WHAT IS KNOWN

• Preterm infants often receive antibiotics empirically directly after birth for suspicion of early-onset sepsis. • The effects of the duration of early empirical antibiotic exposure on the risk for necrotizing enterocolitis and late-onset sepsis are debated.

WHAT IS NEW

• Almost 90% of preterm infants with a gestational age below 30 weeks are exposed to antibiotics empirically after birth despite negative culture results. In a quarter of these culture-negative infants, empirical antibiotics are prolonged. • A short course of empirical antibiotics (≤72h) is associated with decreased odds for necrotizing enterocolitis compared to both prolonged (>72h) or no empirical antibiotics after birth. Furthermore, every additional day of empirical antibiotic exposure is associated with decreased risk for late-onset sepsis in the first month of life.

Diagnosis of neonatal sepsis: the past, present and future

Sepsis remains a significant cause of neonatal mortality and morbidity, especially in low- and middle-income countries. Neonatal sepsis presents with nonspecific signs and symptoms that necessitate tests to confirm the diagnosis. Early and accurate diagnosis of infection will improve clinical outcomes and decrease the overuse of antibiotics. Current diagnostic methods rely on conventional culture methods, which is time-consuming, and may delay critical therapeutic decisions. Nonculture-based techniques including molecular methods and mass spectrometry may overcome some of the limitations seen with culture-based techniques. Biomarkers including hematological indices, cell adhesion molecules, interleukins, and acute-phase reactants have been used for the diagnosis of neonatal sepsis. In this review, we examine past and current microbiological techniques, hematological indices, and inflammatory biomarkers that may aid sepsis diagnosis. The search for an ideal biomarker that has adequate diagnostic accuracy early in sepsis is still ongoing. We discuss promising strategies for the future that are being developed and tested that may help us diagnose sepsis early and improve clinical outcomes. IMPACT: Reviews the clinical relevance of currently available diagnostic tests for sepsis. Summarizes the diagnostic accuracy of novel biomarkers for neonatal sepsis. Outlines future strategies including the use of omics technology, personalized medicine, and point of care tests.

The microbiome, guard or threat to infant health

Despite improvements in survival for very low birthweight (VLBW) premature infants, there continues to be significant morbidity for these infants at remarkable cost to the healthcare system. Concurrent development of the preterm infant intestine alongside the gut microbiome in the clinical setting rather than in the protected in utero environment where it would usually occur creates significant vulnerabilities for the infant's immature intestine and immune system, resulting in devastating illness and neurological injury. However, the microbiome also has the capacity to promote healthy development. Studies of parallel gut microbiome and preterm infant development have given key insight into the impact of the microbiome on intestinal as well as neural development and may provide potential therapeutic targets to prevent preterm infant morbidities.

Malnutrition, poor post-natal growth, intestinal dysbiosis and the developing lung

In extremely preterm infants, poor post-natal growth, intestinal dysbiosis and bronchopulmonary dysplasia are common, and each is associated with long-term complications. The central hypothesis that this review will address is that these three common conditions are interrelated. Challenges to studying this hypothesis include the understanding that malnutrition and poor post-natal growth are not synonymous and that there is not agreement on what constitutes a normal intestinal microbiota in this evolutionarily new population. If this hypothesis is supported, further study of whether "correcting" intestinal dysbiosis in extremely preterm infants reduces postnatal growth restriction and/or bronchopulmonary dysplasia is indicated.

Antibiotic Stewardship for the Neonatologist and Perinatologist

Antibiotic use is common in the neonatal intensive care unit. The density and heterogeneity of antibiotic prescribing suggests inappropriate and overuse of these agents. Potential antibiotic stewardship targets include sepsis, necrotizing enterocolitis, and perioperative prophylaxis. Diagnostic stewardship principles, including appropriately obtained cultures, may be leveraged to decrease unnecessary antibiotic prescribing. Strategies including guideline development, prospective audit and feedback, and formulary restriction have been successfully deployed in the neonatal intensive care unit to improve the quality of antibiotic prescribing. Implementation of antibiotic stewardship in the neonatal intensive care unit requires multidisciplinary collaboration between neonatologists, surgeons, infectious diseases specialists, pharmacists, and nurses.

Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is an inflammatory disease affecting premature infants. Intestinal microbial composition may play a key role in determining which infants are predisposed to NEC and when infants are at highest risk of developing NEC. It is unclear how to optimize antibiotic therapy in preterm infants to prevent NEC and how to optimize antibiotic regimens to treat neonates with NEC. This article discusses risk factors for NEC, how dysbiosis in preterm infants plays a role in the pathogenesis of NEC, and how probiotic and antibiotic therapy may be used to prevent and/or treat NEC and its sequelae.

Biomarkers for the Diagnosis of Neonatal Sepsis

Neonatal sepsis is a major cause of morbidity and mortality in neonates and is challenging to diagnose. Infants manifest nonspecific clinical signs in response to sepsis; these signs may be caused by noninfectious conditions. Time to antibiotics affects neonatal sepsis outcome, so clinicians need to identify and treat neonates with sepsis expeditiously. Clinicians use serum biomarkers to measure inflammation and infection and assess the infant's risk of sepsis. However, current biomarkers lack sufficient sensitivity or specificity to be consider useful diagnostic tools. Continued research to identify novel biomarkers as well as novel ways of measuring them is sorely needed.

Prolonged Post-Discontinuation Antibiotic Exposure in Very Low Birth Weight Neonates at Risk for Early-Onset Sepsis

BACKGROUND

Premature, very low birth weight (VLBW) neonates are at risk for early-onset sepsis and receive ampicillin and gentamicin post-birth. Antimicrobial stewardship supports short-course antibiotics, but how long antibiotic concentrations remain therapeutic post-last dose is unknown.

METHODS

Using Monte Carlo simulations (NONMEM 7.3), we analyzed antibiotic exposures in a retrospective cohort of 34 689 neonates (<1500 g, 22-27 weeks of gestation). Therapeutic exposure for ampicillin and gentamicin was evaluated relative to the minimum inhibitory concentration (MIC) for common pathogens (MIC 0.25-8 mcg/mL for group B streptococcus [GBS] and Escherichia coli). Post-discontinuation antibiotic exposure (PDAE) was defined as the time from the last dose to time when concentration decreased below MIC.

RESULTS

Neonates had a median (range) gestational age of 26 (22-27) weeks and BW, 790 g (400-1497) . All ampicillin dosing regimens (50-100 mg/kg every 8-12 hours for 2-6 doses) achieved therapeutic exposures > MIC range. After the last dose, the PDAE mean (95% confidence interval [CI]) ranged from 34 to 50 hours (17-79) for E. coli (MIC 8) and 82 to 104 hours (95% CI: 39-122) for GBS (MIC 0.25); longer PDAE occurred with higher dose, shorter interval, and longer course. Short-course ampicillin (2 doses, 50 mg/kg every 12 hours) provided PDAE 34 hours for E. coli and 82 hours for GBS. Single-dose 5 mg/kg gentamicin provided PDAE > MIC 2 for 26 hours.

CONCLUSIONS

In VLBW neonates, ampicillin exposure remains therapeutic long after the last dose. Short-course ampicillin provided therapeutic exposures throughout the typical blood culture incubation period.

Routine Early Antibiotic Use in SymptOmatic Preterm Neonates: A Pilot Randomized Controlled Trial

We enrolled 98 infants (gestational age <33 weeks) in a pilot randomized trial of antibiotics vs no antibiotics; 55 were randomized (lower maternal infectious risk; symptoms expected for gestation). Adverse events did not differ significantly between the randomization arms. This trial establishes a framework for a larger multicentered trial.

Delivery-based criteria for empiric antibiotic administration among preterm infants

OBJECTIVE

Determine impact of using delivery criteria to initiate antibiotics among very low birth weight (VLBW) and extremely low birth weight (ELBW) infants. STUDY DESIGN: Single site cohort study from 01/01/2009 to 01/31/2020. After 04/2017, infants delivered by Cesarean section, without labor or membrane rupture were categorized as low-risk for early-onset infection and managed without empiric antibiotics. We determined effect of this guideline by pre-post, and interrupted time-series analyses.

RESULTS

After 04/2017, antibiotic initiation ≤3 days decreased among low-risk VLBW (62% vs. 13%, p < 0.001) and low-risk ELBW (88% vs. 21%, p < 0.001) infants. In time series analysis, guideline was associated with decreased initiation among low-risk ELBW infants. In contrast, low-risk VLBW infants demonstrated decreased antibiotic initiation throughout study period. Incidence of confirmed infection, death, or transfer ≤7 days age was unchanged.

CONCLUSION

Delivery criteria may be used to optimize early antibiotic initiation among preterm infants without short-term increase in adverse outcomes.

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.

Antibiotics and the developing intestinal microbiome, metabolome and inflammatory environment in a randomized trial of preterm infants

Antibiotic use in neonates can have detrimental effects on the developing gut microbiome, increasing the risk of morbidity. A majority of preterm neonates receive antibiotics after birth without clear evidence to guide this practice. Here microbiome, metabolomic, and immune marker results from the routine early antibiotic use in symptomatic preterm Neonates (REASON) study are presented. The REASON study is the first trial to randomize symptomatic preterm neonates to receive or not receive antibiotics in the first 48 h after birth. Using 16S rRNA sequencing of stool samples collected longitudinally for 91 neonates, the effect of such antibiotic use on microbiome diversity is assessed. The results illustrate that type of nutrition shapes the early infant gut microbiome. By integrating data for the gut microbiome, stool metabolites, stool immune markers, and inferred metabolic pathways, an association was discovered between Veillonella and the neurotransmitter gamma-aminobutyric acid (GABA). These results suggest early antibiotic use may impact the gut-brain axis with the potential for consequences in early life development, a finding that needs to be validated in a larger cohort.Trial Registration This project is registered at clinicaltrials.gov under the name "Antibiotic 'Dysbiosis' in Preterm Infants" with trial number NCT02784821.

Infection control and other stewardship strategies in late onset sepsis, necrotizing enterocolitis, and localized infection in the neonatal intensive care unit

Suspected or proven late onset sepsis, necrotizing enterocolitis, urinary tract infections, and ventilator associated pneumonia occurring after the first postnatal days contribute significantly to the total antibiotic exposures in neonatal intensive care units. The variability in definitions and diagnostic criteria in these conditions lead to unnecessary antibiotic use. The length of treatment and choice of antimicrobial agents for presumed and proven episodes also vary among centers due to a lack of supportive evidence and guidelines. Implementation of robust antibiotic stewardship programs can encourage compliance with appropriate dosages and narrow-spectrum regimens.

Association of early life antibiotics and health outcomes: Evidence from clinical studies

Preterm infants are susceptible to infections that can rapidly progress to disastrous outcomes. Antibiotics are lifesaving, but their prolonged and inappropriate use are associated with adverse outcomes. In this review, we discuss the current status of antimicrobial use in the preterm neonatal population, and the challenges in determining the initiation, duration, and choice of antibiotics. Finally, we review the clinical studies on the potential consequences of prolonged antimicrobial exposure in prematurely born infants.

Antibiotic stewardship for early-onset sepsis

Antibiotics are administered to the vast majority of preterm newborns and to a substantial proportion of term infants in the hours after birth due to risk for early-onset sepsis. The approaches taken to determine which newborns should be evaluated for early-onset sepsis, and what type and duration of antibiotics are administered, are important elements of neonatal antibiotic stewardship. The use of multivariate prediction models for sepsis risk assessment among infants born ≥35 weeks' gestation can safely reduce the use of empiric antibiotic therapy. Approaches incorporating serial physical examination may also contribute to decreasing empiric antibiotic exposure among such infants. Among infants born <35 weeks' gestation, delivery characteristics can be used to identify preterm infants at low enough risk of early infection that empiric therapies are not required. Data informing the epidemiology, microbiology and antibiotic susceptibility patterns of early-onset sepsis pathogens can be used to optimize antibiotic choice for empiric and targeted antibiotic therapy to ensure that effective therapies are administered, while decreasing the risks associated with broad-spectrum antibiotic exposure. Optimal use of blood culture and time to positivity data can also contribute to decreasing the risks associated with prolonged antibiotic administration in the face of sterile cultures.

Prevalence of potentially inappropriate prescribing in older adults in Jordan: Application of the STOPP criteria

OBJECTIVES

To measure the prevalence of cases of potentially inappropriate prescribing (PIP) for older patients and to identify the risk factors for identified cases of PIP.

METHODS

STOPP criteria version 2 were used for identifying cases of PIP for older patients (>65 years) who were admitted to a tertiary hospital in Jordan over a period of 18 months. Data were collected by prospectively reviewing the clinical and prescription records of included patients. Descriptive analysis, univariate analysis and multiple linear regression were used to analyse the results.

RESULTS

Upon admission, during hospitalisation and on discharge, 144, 182 and 156 cases of PIP were identified, respectively. There was a statistically significant association between the number of prescribed medications and cases of PIP during the hospital journey (P < .05).

CONCLUSION

Inappropriate prescribing of medications is highly prevalent among older patients. Application of validated (STOPP) criteria can help to detect and direct development of interventions to prevent PIP occurrence among older patients.

Clinical values of common biomarkers for efficacy monitoring of antibiotics in early-onset neonatal sepsis

BACKGROUND

To investigate the clinical values of the common biomarkers including blood routine (B-Rt), C-reactive protein (CRP), serum amyloid A (SAA) and procalcitonin (PCT) for efficacy monitoring of antibiotics in early-onset neonatal sepsis (EONS).

METHODS

The clinical and laboratory data of 78 neonates with confirmed EONS in the neonatal intensive care unit (NICU) of our center from July 1, 2019 to June 30, 2020 were retrospectively analyzed. All the subjects were treated with cefotiam (50 mg/kg q12h) and augmentin (30 mg/kg q12h) within 12 hours after birth. Blood samples were collected 0-12 hours after birth for blood culture, measurements of B-Rt, CRP and SAA. Subsequently, blood sampling was performed at intervals of 12-24, 24-48, 48-96, and 96-144 hours for measurements of B-Rt, CRP, SAA and PCT. Statistical analyses were performed in the SPSS 20.0 software package. P value of <0.05 was considered statistically significant.

RESULTS

WBC count showed no significant change among different intervals (12-24, 24-48, 48-96, and 96-144 hours); in contrast, NEU%, CRP, SAA and PCT significantly differed across all intervals. SAA had sensitivities of 75.86%, 93.1%, 44.83%, and 3.45%, respectively; specificities of 100% across all intervals; and AUCs of 0.879 (P<0.0001), 0.966 (P<0.0001), 0.724 (P<0.0001), and 0.500, respectively (P=1). PCT had sensitivities of 100%, 100%, 79.31%, and 51.72%, respectively; specificities of 100% across all intervals; and AUCs of 1 (P<0.0001), 1 (P<0.0001), 0.793 (P<0.0001), and 0.517 (P>0.8551), respectively.

CONCLUSIONS

WBC count, NEU% and CRP showed no clinical significance for any intervals for efficacy monitoring of antibiotic treatment. SAA and PCT had similar monitoring values at 12-24 and 24-48 hours. SAA is thus more valuable than PCT for efficacy monitoring of antibiotics at the 48-96 and even at the 96-144 hours intervals in EONS.

Translational Advances in Pediatric Nutrition and Gastroenterology: New Insights from Pig Models

Pigs are increasingly important animals for modeling human pediatric nutrition and gastroenterology and complementing mechanistic studies in rodents. The comparative advantages in size and physiology of the neonatal pig have led to new translational and clinically relevant models of important diseases of the gastrointestinal tract and liver in premature infants. Studies in pigs have established the essential roles of prematurity, microbial colonization, and enteral nutrition in the pathogenesis of necrotizing enterocolitis. Studies in neonatal pigs have demonstrated the intestinal trophic effects of akey gut hormone, glucagon-like peptide 2 (GLP-2), and its role in the intestinal adaptation process and efficacy in the treatment of short bowel syndrome. Further, pigs have been instrumental in elucidating the physiology of parenteral nutrition-associated liver disease and the means by which phytosterols, fibroblast growth factor 19, and a new generation of lipid emulsions may modify disease. The premature pig will continue to be a valuable model in the development of optimal infant diets (donor human milk, colostrum), specific milk bioactives (arginine, growth factors), gut microbiota modifiers (pre-, pro-, and antibiotics), pharmaceutical drugs (GLP-2 analogs, FXR agonists), and novel diagnostic tools (near-infrared spectroscopy) to prevent and treat these pediatric diseases.

Impact of Early-Onset Sepsis and Antibiotic Use on Death or Survival with Neurodevelopmental Impairment at 2 Years of Age among Extremely Preterm Infants

OBJECTIVE

To evaluate the hypothesis that early-onset sepsis increases risk of death or neurodevelopmental impairment (NDI) among preterm infants; and that among infants without early-onset sepsis, prolonged early antibiotics alters risk of death/NDI.

STUDY DESIGN

Retrospective cohort study of infants born at the Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network centers (2006-2014) at 22-26 weeks of gestation and birth weight 401-1000 g. Early-onset sepsis defined as growth of a pathogen from blood or cerebrospinal fluid culture ≤72 hours after birth. Prolonged early antibiotics was defined as antibiotics initiated ≤72 hours and continued ≥5 days without culture-confirmed infection, necrotizing enterocolitis, or spontaneous perforation. Primary outcome was death before follow-up or NDI assessed at 18-26 months corrected age. Poisson regression was used to estimate adjusted relative risk (aRR) and CI for early-onset sepsis outcomes. A propensity score for receiving prolonged antibiotics was derived from early clinical factors and used to match infants (1:1) with and without prolonged antibiotic exposure. Log binomial models were used to estimate aRR for outcomes in matched infants.

RESULTS

Among 6565 infants, those with early-onset sepsis had higher aRR (95% CI) for death/NDI compared with infants managed with prolonged antibiotics (1.18 [1.06-1.32]) and to infants without prolonged antibiotics (1.23 [1.10-1.37]). Propensity score matching was achieved for 4362 infants. No significant difference in death/NDI (1.04 [0.98-1.11]) was observed with or without prolonged antibiotics among the matched cohort.

CONCLUSIONS

Early-onset sepsis was associated with increased risk of death/NDI among extremely preterm infants. Among matched infants without culture-confirmed infection, prolonged early antibiotic administration was not associated with death/NDI.

The challenges of neonatal sepsis management

OBJECTIVES

To present current evidence on the etiology, risk factors, diagnosis, and management of early and late neonatal sepsis.

SOURCE OF DATA

Non-systematic review of the Medline (PubMed), Scopus, Web of Science, Cochrane, and Google Scholar databases regarding the following terms: neonatal sepsis, early neonatal sepsis, late neonatal sepsis, empirical antibiotic therapy, sepsis calculator, vancomycin, newborn, preterm newborn.

DATA SYNTHESIS

Neonatal sepsis is a frequent cause of neonatal morbidity and mortality. Its diagnosis is difficult. Continuous observation of the patient is critical to diagnostic suspicion. When neonatal sepsis is suspected, bacteriological tests should be collected. Vancomycin should not be routinely using in the empirical antibiotic regimen in late neonatal sepsis, and the main protective mechanisms against neonatal sepsis are handwashing and the use of breast milk.

CONCLUSIONS

Newborns constitute a group that is more vulnerable to sepsis. Knowledge of risk factors and etiological agents allows a better approach to the newborn with sepsis.

The Role of Glycosaminoglycans in Protection from Neonatal Necrotizing Enterocolitis: A Narrative Review

Necrotizing enterocolitis, a potentially fatal intestinal inflammatory disorder affecting primarily premature infants, is a significant cause of morbidity and mortality in neonates. While the etiology of the disease is, as yet, unknown, a number of risk factors for the development of necrotizing enterocolitis have been identified. One such risk factor, formula feeding, has been shown to contribute to both increased incidence and severity of the disease. The protective influences afforded by breastfeeding are likely attributable to the unique composition of human milk, an extremely potent, biologically active fluid. This review brings together knowledge on the pathogenesis of necrotizing enterocolitis and current thinking on the instrumental role of one of the more prominent classes of bioactive components in human breast milk, glycosaminoglycans.

Intestinal dysbiosis and necrotizing enterocolitis: assessment for causality using Bradford Hill criteria

In recent years, several studies have shown that premature infants who develop NEC frequently display enteric dysbiosis with increased Gram-negative bacteria for several days to weeks prior to NEC onset. The importance of these findings, for the possibility of a causal role of these bacteria in NEC pathogenesis, and for potential value of gut dysbiosis as a biomarker of NEC, is well-recognized. In this review, we present current evidence supporting the association between NEC in premature infants and enteric dysbiosis, and its evaluation using the Bradford Hill criteria for causality. To provide an objective appraisal, we developed a novel scoring system for causal inference. Despite important methodological and statistical limitations, there is support for the association from several large studies and a meta-analysis. The association draws strength from strong biological plausibility of a role of Gram-negative bacteria in NEC and from evidence for temporality, that dysbiosis may antedate NEC onset. The weakness of the association is in the low level of consistency across studies, and the lack of specificity of effect. There is a need for an improved definition of dysbiosis, either based on a critical threshold of relative abundances or at higher levels of taxonomic resolution.