Duration of Initial Empirical Antibiotic Therapy and Outcomes in Very Low Birth Weight Infants

Role of the Microbiome in Neonatal Infection: Pathogenesis and Implications for Management

The human microbiome refers to the collective genome of microorganisms, including bacteria, fungi, and viruses residing on human body surfaces that are in contact with the environment. Together these communities protect against invasive infections. Conversely, when disrupted, the microbiome can be the source of pathogens causing invasive infection. Interventions to manipulate it via probiotics, antibiotics, and fecal transplantation are available. The risk benefit of these interventions remains unclear. In this review, the authors discuss evidence linking the gut microbiome to neonatal sepsis and also discuss the challenges for translating this knowledge into better clinical care.

Re-Thinking the Norms of Antibiotic Prescribing in the Neonatal Intensive Care Unit

Antibiotics are among the most commonly prescribed medications in neonatal care. Newborns are particularly vulnerable to severe infections and the adverse effects associated with inappropriate antibiotic use. Antibiotic stewardship programs are designed to actively monitor antimicrobial resistance, encourage the judicious use of antibiotics, and collaborate with infection control programs and pharmacy departments to curb the spread of resistant organisms. In this article, the authors will examine studies assessing the impact of excessive antibiotic use and explore the effectiveness of various stewardship strategies aimed at reducing unnecessary antibiotic consumption.

Machine Learning Models as Early Warning Systems for Neonatal Infection

Neonatal infections pose a significant threat to the health of newborns. Associated morbidity and mortality risks underscore the urgency of prompt diagnosis and treatment with appropriate empiric antibiotics. Delay in treatment can be fatal; thus, early detection improves outcomes. However, diagnosing early is a challenge as signs and symptoms of neonatal infection are non-specific and overlap with non-infectious conditions. Machine learning (ML) offers promise in early detection, utilizing various data sources and methodologies. However, ML models require rigorous validation and consideration of various challenges, including false alarms and user acceptance requiring careful integration and ongoing evaluation for successful implementation.

Impact of NICE clinical guidelines for prevention and treatment of neonatal infections on antibiotic use in very preterm infants in England and Wales: an interrupted time series analysis

OBJECTIVE

To assess the impact of publication of UK National Institute for Health and Care Excellence (NICE) guidelines on the prevention and treatment of early-onset infections (EOIs) in neonates (clinical guideline 149 (CG149), published in 2012, and its 2021 update (NG195) on antibiotic use in very preterm infants.

DESIGN

Interrupted time series analysis using data from the National Neonatal Research Database.

SETTING

Neonatal units in England and Wales.

PARTICIPANTS

Infants born at 22-31 weeks' gestation from 1 January 2010 to 31 December 2022 and survived to discharge.

INTERVENTIONS

Publication of CG149 (August 2012) and NG195 (April 2021).

MAIN OUTCOME MEASURES

Measures of antibiotic use, aggregated by month of birth: antibiotic use rate (AUR), the proportion of care days in receipt of at least one antibiotic; percentage of infants who received ≥1 day of antibiotics on days 1-3 for EOI and after day 3 for late-onset infection (LOI); percentage who received ≥1 prolonged antibiotic course ≥5 days for EOI and LOI.

RESULTS

96% of infants received an antibiotic during inpatient stay. AUR declined at publication of CG149, without further impact at NG195 publication. There was no impact of CG149 on the underlying trend in infants receiving ≥1 day antibiotics for EOI or LOI, but post-NG195 the monthly trend began to decline for EOI (-0.20%, -0.26 to -0.14) and LOI (-0.23%, -0.33 to -0.12). Use of prolonged antibiotic courses for EOI and LOI declined at publication of CG149 and for LOI this trend accelerated post-NG195.

CONCLUSIONS

Publications of NICE guidance were associated with reductions in antibiotic use; however neonatal antibiotic exposure remains extremely high.

Antimicrobial utilisation patterns between 2013 and 2022 in Canadian neonates born at less than 33 weeks gestation: a retrospective cohort study

Background

Excessive antimicrobial exposure is associated with an increase in neonatal mortality, morbidities and adverse neurodevelopment. Canadian Neonatal Network has been promoting judicious antimicrobial use through the Evidence-based Practice for Improving Quality processes. Our objective was to evaluate the antimicrobial consumption among neonates in tertiary neonatal intensive care units (NICU) in Canada in the recent decade.

Methods

This is a retrospective cohort study including data from very preterm infants (born at <33 weeks gestational age) admitted to all NICUs in Canada between January 1, 2013, and December 31, 2022. Nationwide antimicrobial utilization rate (AUR) benchmarking started in 2016, and quality improvement initiatives were continued in the subsequent years to promote judicious use of antimicrobials across the network. AUR is defined as the number of days with ≥1 antimicrobial divided by the total patient days (PD). Culture-proven sepsis refers to a neonate with positive culture of pathogens in blood and/or cerebrospinal fluid. The outcomes were evaluated during pre- (2013-2017) and post-intervention periods (2018-2022). Interrupted time-series analysis was used, and comparison of AUR calculated per each 3-month time block and the slope changes were conducted across the pre- and post-intervention periods regarding total patients and subgroups.

Findings

A total of 41,253 infants were included, with 22,644 (55%) being male. The AUR was significantly lower among infants from the post- vs. those from the pre-intervention periods (152 vs. 184, p < 0.0001). Among 35,670 infants without culture-proven sepsis or necrotizing enterocolitis ≥ Stage 2, AUR was significantly lower in the post-intervention group vs. the pre-intervention group (110 vs. 136, p < 0.0001). Interrupted time-series showed significant reduction in AUR during both pre- and post-intervention periods among all infants with and without culture proven sepsis or necrotizing enterocolitis ≥ Stage 2 (all p < 0.0001), as well as those born at <29 weeks gestational age.

Interpretation

A comprehensive, network-wide quality improvement initiatives led to a significant and sustained reduction in antimicrobial use among preterm infants born at <33 weeks gestational age with and without culture-proven sepsis or necrotizing enterocolitis ≥ Stage 2.

Funding

This study was supported by the Canadian Institutes of Health Research Project Grant 2019 (201903PJT-420294-CA2-CAAA-245530), matched funding from the British Columbia Women's Health Foundation and start-up funding from the Women and Children's Health Research Institute, University of Alberta. The coordinating center in Toronto is funded by the Canadian Institutes of Health Research grant for the Canadian Preterm Birth Network (PBN 150642).

Management of neonates at risk of early onset sepsis: a probability-based approach and recent literature appraisal : Update of the Swiss national guideline of the Swiss Society of Neonatology and the Pediatric Infectious Disease Group Switzerland

In Switzerland and other high-income countries, one out of 3000 to 5000 term and late preterm neonates develops early onset sepsis (EOS) associated with a mortality of around 3%, while incidence and mortality of EOS in very preterm infants are substantially higher. Exposure to antibiotics for suspected EOS is disproportionally high compared to the incidence of EOS with consequences for future health and antimicrobial resistance (AMR). A safe reduction of unnecessary antibiotic treatment has to be a major goal of new management strategies and guidelines. Antibiotics should be administered immediately in situations with clinical signs of septic shock. Group B streptococcus (GBS) and Escherichia coli (E. coli) are the leading pathogens of EOS. Amoxicillin combined with an aminoglycoside remains the first choice for empirical treatment. Serial physical examinations are recommended for all neonates with risk factors for EOS. Neonates without any clinical signs suggestive of EOS should not be treated with antibiotics. In Switzerland, we do not recommend the use of the EOS calculator, a risk stratification tool, due to its unclear impact in a population with an observed antibiotic exposure below 3%. Not all neonates with respiratory distress should be empirically treated with antibiotics. Isolated tachypnea or respiratory distress starting immediately after delivery by elective caesarean section or a clearly assessed alternative explanation than EOS for clinical signs may point towards a low probability of sepsis. On the other hand, unexplained prematurity with risk factors has an inherent higher risk of EOS. Before the start of antibiotic therapy, blood cultures should be drawn with a minimum volume of 1 ml in a single aerobic blood culture bottle. This standard procedure allows antibiotics to be stopped after 24 to 36 h if no pathogen is detected in blood cultures. Current data do not support the use of PCR-based pathogen detection in blood as a standard method. Lumbar puncture is recommended in blood culture-proven EOS, critical illness, or in the presence of neurological symptoms such as seizures or altered consciousness. The accuracy of a single biomarker measurement to distinguish inflammation from infection is low in neonates. Therefore, biomarker guidance is not a standard part of decision-making regarding the start or stop of antibiotic therapy but may be used as part of an algorithm and after appropriate education of health care teams. Every newborn started on antibiotics should be assessed for organ dysfunction with prompt initiation of respiratory and hemodynamic support if needed. An elevated lactate may be a sign of poor perfusion and requires a comprehensive assessment of the clinical condition. Interventions to restore perfusion include fluid boli with crystalloids and catecholamines. Neonates in critical condition should be cared for in a specialized unit. In situations with a low probability of EOS, antibiotics should be stopped as early as possible within the first 24 h after the start of therapy. In cases with microbiologically proven EOS, reassessment and streamlining of antibiotic therapy in neonates is an important step to minimize AMR.

CONCLUSION

 This guideline, developed through a critical review of the literature, facilitates a probability-based approach to the management of neonates at risk of early onset sepsis.

WHAT IS KNOWN

• Neonatal exposure to antibiotics is disproportionally high compared with the incidence of early onset sepsis with implications for future health and antimicrobial resistance.

WHAT IS NEW

• A probability-based approach may facilitate a more balanced management of neonatal sepsis and antibiotic stewardship.

Antibiotics and beyond: Unraveling the dynamics of bronchopulmonary dysplasia in very preterm infants

BACKGROUND

Bronchopulmonary dysplasia (BPD) remains a significant challenge in neonatal care. Prenatal inflammation and neonatal sepsis contribute to the multifactorial nature of BPD. A potential association between empirical antibiotic therapy and BPD risk has been proposed due to microbiota dysbiosis in very low birth weight premature infants.

METHODS

A single centered retrospective cohort study of preterm infants (24-32 weeks gestation) from 2014 to 2021. The study compared groups that received empirical antibiotics in the first days of life and those that did not receive any antibiotic in the first days of life. The primary outcomes studied were BPD, death, and the combined outcome of BPD/death. Statistical analysis employed t-tests, Mann-Whitney U, Chi-square, and logistic regression.

RESULTS

Of 454 preterm infants, 61.5% received antibiotics. This group had lower gestational age, birth weight, and Apgar scores. Antibiotic use was associated with higher incidence of BPD (35.5% vs. 10.3%), death (21.5% vs. 8.6%), and combined outcomes (54.5% vs. 18.3%). In multivariate analysis, antibiotic use independently associated with BPD (OR 2.58, p < 0.001) and combined outcome BPD/death (OR 2.06, p < 0.02). Antenatal corticosteroids provided protection against BPD, but not mortality.

CONCLUSION

This study suggests an association between early empirical antibiotic use and BPD in preterm infants, emphasizing the need for judicious antibiotic practices in neonatal care.

Impact of antibiotic duration and type on short- and long-term outcomes in very-low-birthweight infants

AIM

To determine the association between the duration and types of antibiotic exposure and the occurrence of short- and long-term outcomes among preterm, very-low-birthweight (VLBW) infants.

METHODS

Retrospective cohort study of VLBW infants born <32 weeks gestation between January 2017-December 2021. Association between antibiotic exposure and the occurrence of death and/or major morbidities, and neurodevelopmental impairment (NDI) at 18-24 months corrected age, was evaluated.

RESULTS

A total of 728 infants were included-median gestation 28 weeks (IQR 26, 30) and median birthweight 1070g (IQR 850, 1300). Compared to no antibiotics, antibiotics exposure >3 days was significantly associated with increased risk of mortality and/or bronchopulmonary dysplasia (BPD)-adjusted odds ratio (AOR) 2.0 (95% CI 1.1-3.8; p=0.03), 3.5 (95% CI 1.6-7.8; p=0.01) and 3.8 (95% CI 1.6-9.0; p<0.001) corresponding to antibiotic exposure of 4-7 days, 8-14 and >14 days, respectively. Additional exposure to broad-spectrum antibiotics was associated with AOR of 3.2 (95% CI 1.6-6.5; p<0.01) for death and/or BPD. There was no significant association between antibiotic exposure and NDI.

CONCLUSION

Infants who received >3 days of antibiotics and/or additional broad-spectrum antibiotics had significantly increased odds of death and/or BPD compared to no exposure. Antibiotic exposure was not significantly associated with NDI in our population.

High cumulative antibiotic exposure in extremely low birth weight infants during the first month of life: Risk factors and clinical outcomes

BACKGROUND

Extremely low birthweight (ELBW) infants invariably receive multiple antibiotic therapies during hospitalization. However, the causes of high cumulative antibiotic exposure, as well as the impact of such exposure on the outcomes of preterm infants, particularly long-term neurodevelopmental outcomes, remain to be elucidated. Furthermore, the cumulative effects of simultaneous use of multiple antibiotics are often overlooked.

METHODS

We included ELBW infants born between January 1, 2016, and December 31, 2020. The duration of antibiotic therapy was calculated as Days of Therapy (DOT), with each antibiotic administered during the first month of life added cumulatively. The infants were divided into two groups: the low cumulative antibiotic exposure group and the high cumulative antibiotic exposure group.

RESULTS

Of 453 eligible ELBW infants, 358 met the inclusion criteria. Multivariable logistic regression indicated a low birthweight [adjusted odds ratio (aOR) 0.996, 95% confidence interval (CI) 0.994, 0.998], chorioamnionitis (aOR 2.195, 95% CI 1.145, 4.210), sepsis (aOR 2.538, 95% CI 1.417, 4.544), and necrotizing enterocolitis (aOR 11.798, 95% CI 2.637, 52.784) as independent factors associated with high cumulative antibiotic exposure. These infants were associated with poor short-term outcomes, including mortality (aOR 9.031, 95% CI 2.433, 33.448), moderate to severe bronchopulmonary dysplasia (aOR 2.895, 95% CI 1.471, 5.699), and retinopathy of prematurity necessitating therapy (aOR 2.503, 95% CI 1.363, 4.597). Although infants in the low cumulative antibiotic exposure group had higher neurodevelopmental scores across all three BSID-III domains at each corrected age compared to those in the high cumulative antibiotic exposure group, the cumulative antibiotic exposure did not significantly influence the score changes in the linear mixed-effects models.

CONCLUSIONS

High cumulative antibiotic exposure in early life is associated with adverse short-term outcomes in ELBW infants. The impacts on long-term neurodevelopmental require further investigation. When prescribing antibiotics to infants, caution should be exercised to avoid unnecessary exposure.

Wide use of broad-spectrum antibiotics in very low birth weight infants with spontaneous focal intestinal perforation-is it really justified?

PURPOSE

Very low birth weight (VLBW) infants are at a risk of spontaneous focal intestinal perforation (FIP). Treatment includes supportive care, antibiotics, and drainage with/without surgery. Broad-spectrum antibiotic agents like carbapenems are applied frequently, although their use is not well-supported by the limited evidence of causal pathogens. We hypothesize that the use of carbapenems may not be necessary in VLBW infants with FIP. Our primary objective was to evaluate the antimicrobial use in VLBW infants with FIP in a cohort of the German Neonatal Network (GNN). The secondary objective was to characterize a subset in detail as a benchmark for future targets of stewardship.

METHODS

Data on VLBW infants with FIP was collected prospectively within the GNN, a collaboration of 68 neonatal intensive care units (NICU). With regards to the primary objective, patient characteristics and antimicrobial treatment were extracted from the predefined GNN database. To address our secondary objective, an additional on-site assessment of laboratory and microbiological culture results were performed.

RESULTS

In the GNN cohort, 613/21,646 enrolled infants (2.8%) developed FIP requiring surgery. They were frequently treated with carbapenems (500/613 (81.6%)) and vancomycin (497/613 (81.1%)). In a subset of 124 VLBW infants, 77 (72.6%) had proof of gram-positive bacteria in the abdominal cavity, coagulase-negative staphylococci (CoNS) predominantly. Despite the low prevalence of gram-negative bacteria (n = 6 (4.8%)), the combination of meropenem and vancomycin was prescribed most frequently (n = 96 (78.0%)).

CONCLUSION

The use of carbapenems as broad-spectrum antimicrobials agents might not be justified in most VLBW infants with FIP. Knowledge on the development of the neonatal gut microbiota, local resistance patterns and individual microbiological findings should be taken into consideration when implementing antimicrobial stewardship programs (ASPs).

The microbiome in pregnancy and early life-Highlights from the 11th Maria Delivoria-Papadopoulos Perinatal Symposium

This review was based on a symposium that examined novel aspects of the microbiome during pregnancy and early life and explored papers published by the lecturers. For example, it showed that bacterial extracellular vesicles derived from the microbiome harboured in various maternal niches, carried bacterial deoxyribonucleic acid, were isolated from the placenta and may have confounded placental microbiome studies. Maternal diet was responsible for the composition and diversity of breast milk microbiota, and may have shaped the offspring's microbiome and influenced their immune components. Probiotics and antibiotics administered perinatally may have had beneficial but also long-lasting adverse effects on offspring.

Prospective antimicrobial stewardship interventions by multidisciplinary teams to reduce neonatal antibiotic use in South Africa: The Neonatal Antimicrobial Stewardship (NeoAMS) study

BACKGROUND

Hospitalized neonates are vulnerable to infection and have high rates of antibiotic utilization.

METHODS

Fourteen South African neonatal units (seven public, seven private sector) assembled multidisciplinary teams involving neonatologists, microbiologists, pharmacists, and nurses to implement prospective audit and feedback neonatal antimicrobial stewardship (NeoAMS) interventions. The teams attended seven online training sessions. Pharmacists conducted weekday antibiotic prescription reviews in the neonatal intensive care unit and/or neonatal wards providing feedback to the clinical teams. Anonymized demographic and NeoAMS interventions data were aggregated for descriptive purposes and statistical analysis.

FINDINGS

During the 20-week NeoAMS intervention in 2022, 565 neonates were enrolled. Pharmacists evaluated seven hundred antibiotic prescription episodes; rule-out sepsis (180; 26%) and culture-negative sepsis (138; 20%) were the most frequent indications for antibiotic prescription. For infection episodes with an identified pathogen, only 51% (116/229) of empiric treatments provided adequate antimicrobial coverage. Pharmacists recommended 437 NeoAMS interventions (0·6 per antibiotic prescription episode), with antibiotic discontinuation (42%), therapeutic drug monitoring (17%), and dosing (15%) recommendations most frequent. Neonatal clinicians' acceptance rates for AMS recommendations were high (338; 77%). Mean antibiotic length of therapy decreased by 24% from 9·1 to 6·9 days (0·1 day decrease per intervention week; P = 0·001), with the greatest decline in length of therapy for culture-negative sepsis (8·2 days (95% CI 5·7-11·7) to 5·9 days (95% CI 4·6-7·5); P = 0·032).

INTERPRETATION

This neonatal AMS programme was successfully implemented in heterogenous and resource-limited settings. Pharmacist-recommended AMS interventions had high rates of clinician acceptance. The NeoAMS intervention significantly reduced neonatal antibiotic use, particularly for culture-negative sepsis.

FUNDING

A grant from Merck provided partial support.

Prevention Strategies and Management of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a serious intestinal disease which primarily affects preterm infants. The pathogenesis of NEC is multifactorial. Thus, it is complicated to study, prevent, and manage.

Purpose of Review

The purpose of this review is to provide a comprehensive summary of recent research and provide recommendations for the prevention and management of NEC. Currently, management is supportive and non-specific and long-term outcomes for surgical NEC are poor.

Recent Findings

The most important strategy to prevent NEC is to provide preterm infants with a human milk diet, minimize exposure to antibiotics and avoid medications that disturb the intestinal microbiome.

Summary

Strategies to optimize the infant's intestinal microbiome are critical, as disturbances in the intestinal microbiome composition are a major factor in the pathogenesis of this disease. Optimizing maternal health is also vital to prevent prematurity and neonatal morbidity. Ongoing research holds promise for the implementation of new diagnostic modalities, preventive strategies, and medical treatment options to improve outcomes for premature infants.

Early parenteral nutrition is associated with improved growth in very low birth weight infants: a retrospective study

OBJECTIVE

To assess the association between early initiation of parenteral nutrition (PN) and body growth in preterm infants with very low birth weight (VLBW).

DESIGN

Causal inference analysis with confounders preselected by causal diagram based on the NeoNutriNet cohort containing data of infants born between 2011 and 2014 from 13 hospitals from 5 continents.

PATIENTS

Neonates with birth weight ≤1500 g.

INTERVENTIONS

PN initiated within the first day of life (early PN) versus within day 2-5 (delayed PN).

MAIN OUTCOME MEASURES

The primary outcome was body weight z-scores at postmenstrual age (PMA) 36 weeks or early discharge or death, whichever comes first (WT z-score END). Secondary outcomes included WT z-scores at week 1 and 4 of life (WT z-scores CA1 and CA4), corresponding growth velocities (GVs), mortality and incidence of necrotising enterocolitis (NEC), and duration and episodes of antibiotic treatment.

RESULTS

In total, 2151 infants were included in this study and 2008 infants were in the primary outcome analysis. Significant associations of early PN were found with WT z-score END (adjusted mean difference, 0.14 (95% CI 0.05 to 0.23)), CA4 (β, 0.09 (0.04 to 0.14)) and CA1 (0.04 (0.01 to 0.08)), and GV PMA 36 weeks (1.02 (0.46 to 1.58)) and CA4 (1.03 (0.56 to 1.49), all p<0.001), but not with GV CA1 (p>0.05). No significant associations with mortality, incidence of NEC or antibiotic use was found (all p>0.05).

CONCLUSIONS

For VLBW infants, PN initiated within the first day of life is associated with improved in-hospital growth.

Antibiotics, Analgesic Sedatives, and Antiseizure Medications Frequently Used in Critically Ill Neonates: A Narrative Review

Antibiotic, analgesic sedative, and antiseizure medications are among the most commonly used medications in preterm/sick neonates, who are at high risk of nosocomial infections, central nervous system complications, and are exposed to numerous painful/stressful procedures. These severe and potentially life-threatening complications may have serious short- and long-term consequences and should be prevented and/or promptly treated. The reported variability in the medications used in neonates indicates the lack of adequate neonatal studies regarding their effectiveness and safety. Important obstacles contributing to inadequate studies in preterm/sick infants include difficulties in obtaining parental consent, physicians' unwillingness to recruit preterm infants, the off-label use of many medications in neonates, and other scientific and ethical concerns. This review is an update on the use of antimicrobials (antifungals), analgesics (sedatives), and antiseizure medications in neonates, focusing on current evidence or knowledge gaps regarding their pharmacokinetics, indications, safety, dosage, and evidence-based guidelines for their optimal use in neonates. We also address the effects of early antibiotic use on the intestinal microbiome and its association with long-term immune-related diseases, obesity, and neurodevelopment (ND). Recommendations for empirical treatment and the emergence of pathogen resistance to antimicrobials and antifungals are also presented. Finally, future perspectives on the prevention, modification, or reversal of antibiotic resistance are discussed.

28 NICUs participating in a quality improvement collaborative targeting early-onset sepsis antibiotic use

OBJECTIVE

There is widespread overuse of antibiotics in neonatal intensive care units (NICUs). The objective of this study was to safely reduce antibiotic use in participating NICUs by targeting early-onset sepsis (EOS) management.

STUDY DESIGN

Twenty-eight NICUs participated in this statewide multicenter antibiotic stewardship quality improvement collaborative. The primary aim was to reduce the total monthly mean antibiotic utilization rate (AUR) by 25% in participant NICUs.

RESULT

Aggregate AUR was reduced by 15.3% (p < 0.001). There was a wide range in improvement among participant NICUs. There were no increases in EOS rates or nosocomial infection rates related to the intervention.

CONCLUSION

Participation in this multicenter NICU antibiotic stewardship collaborative targeting EOS was associated with an aggregate reduction in antibiotic use. This study informs efforts aimed at sustaining improvements in NICU AURs.

Early Antibiotic Exposure and Bronchopulmonary Dysplasia in Very Preterm Infants at Low Risk of Early-Onset Sepsis

Importance

The overutilization of antibiotics in very preterm infants (VPIs) at low risk of early-onset sepsis (EOS) is associated with increased mortality and morbidities. Nevertheless, the association of early antibiotic exposure with bronchopulmonary dysplasia (BPD) remains equivocal.

Objective

To evaluate the association of varying durations and types of early antibiotic exposure with the incidence of BPD in VPIs at low risk of EOS.

Design, Setting, and Participants

This national multicenter cohort study utilized data from the Chinese Neonatal Network (CHNN) which prospectively collected data from January 1, 2019, to December 31, 2021. VPIs less than 32 weeks' gestational age or with birth weight less than 1500 g at low risk of EOS, defined as those born via cesarean delivery, without labor or rupture of membranes, and no clinical evidence of chorioamnionitis, were included. Data analysis was conducted from October 2022 to December 2023.

Exposure

Early antibiotic exposure was defined as the total number of calendar days antibiotics were administered within the first week of life, which were further categorized as no exposure, 1 to 4 days of exposure, and 5 to 7 days of exposure.

Main Outcomes and Measures

The primary outcome was the composite of moderate to severe BPD or mortality at 36 weeks' post menstrual age (PMA). Logistic regression was employed to assess factors associated with BPD or mortality using 2 different models.

Results

Of the 27 176 VPIs included in the CHNN during the study period (14 874 male [54.7%] and 12 302 female [45.3%]), 6510 (23.9%; 3373 male [51.8%] and 3137 female [48.2.%]) were categorized as low risk for EOS. Among them, 1324 (20.3%) had no antibiotic exposure, 1134 (17.4%) received 1 to 4 days of antibiotics treatment, and 4052 (62.2%) received 5 to 7 days of antibiotics treatment. Of the 5186 VPIs who received antibiotics, 4098 (79.0%) received broad-spectrum antibiotics, 888 (17.1%) received narrow-spectrum antibiotics, and 200 (3.9%) received antifungals or other antibiotics. Prolonged exposure (5-7 days) was associated with increased likelihood of moderate to severe BPD or death (adjusted odds ratio [aOR], 1.23; 95% CI, 1.01-1.50). The use of broad-spectrum antibiotics (1-7 days) was also associated with a higher risk of moderate to severe BPD or death (aOR, 1.27; 95% CI, 1.04-1.55).

Conclusions and Relevance

In this cohort study of VPIs at low risk for EOS, exposure to prolonged or broad-spectrum antibiotics was associated with increased risk of developing moderate to severe BPD or mortality. These findings suggest that VPIs exposed to prolonged or broad-spectrum antibiotics early in life should be monitored for adverse outcomes.

Antimicrobial Stewardship Programs in Neonates: A Meta-Analysis

BACKGROUND AND OBJECTIVES

Neonatal sepsis is a significant contributor to mortality and morbidity; however, the uncontrolled use of antimicrobials is associated with significant adverse effects. Our objective with this article is to review the components of neonatal antimicrobial stewardship programs (ASP) and their effects on clinical outcomes, cost-effectiveness, and antimicrobial resistance.

METHODS

We selected randomized and nonrandomized trials and observational and quality improvement studies evaluating the impact of ASP with a cutoff date of May 22, 2023. The data sources for these studies included PubMed, Medline, Embase, Cochrane CENTRAL, Web of Science, and SCOPUS. Details of the ASP components and clinical outcomes were extracted into a predefined form.

RESULTS

Of the 4048 studies retrieved, 70 studies (44 cohort and 26 observational studies) of >350 000 neonates met the inclusion criteria. Moderate-certainty evidence reveals a significant reduction in antimicrobial initiation in NICU (pooled risk difference [RD] 19%; 95% confidence interval [CI] 14% to 24%; 21 studies, 27 075 infants) and combined NICU and postnatal ward settings (pooled RD 8%; 95% CI 6% to 10%; 12 studies, 358 317 infants), duration of antimicrobial agents therapy (pooled RD 20%; 95% CI 10% to 30%; 9 studies, 303 604 infants), length of therapy (pooled RD 1.82 days; 95% CI 1.09 to 2.56 days; 10 studies, 157 553 infants), and use of antimicrobial agents >5 days (pooled RD 9%; 95% CI 3% to 15%; 5 studies, 9412 infants). Low-certainty evidence reveals a reduction in economic burden and drug resistance, favorable sustainability metrices, without an increase in sepsis-related mortality or the reinitiation of antimicrobial agents. Studies had heterogeneity with significant variations in ASP interventions, population settings, and outcome definitions.

CONCLUSIONS

Moderate- to low-certainty evidence reveals that neonatal ASP interventions are associated with reduction in the initiation and duration of antimicrobial use, without an increase in adverse events.

Early procalcitonin assays may reduce antibiotic exposure in premature newborn infants

AIM

The diagnosis of early-onset neonatal sepsis (EOS) remains difficult. The main aim was to study the effect of a new algorithm for EOS, which includes the level of procalcitonin in umbilical cord blood, on the exposure to antibiotic therapy of premature newborn infants.

METHODS

This was a monocentric, observational and retrospective study with before-and-after design. The duration and dose of antibiotic therapy provided as well as the morbidity and mortality were compared in two groups, one included 01 May 2015-30 November 2015 when procalcitonin was not used, and one after the change 01 November 2016-30 May 2017 when procalcitonin was used in a hospital setting in Nice, France.

RESULTS

Sixty newborn infants were included in the before group and 54 in the after group. Antibiotic therapy was stopped after 24 h for 18 newborn infants in the after group and four in the before group, and after 48 h for 26 newborn infants in the after group and 10 in the before group.

CONCLUSION

The implementation of a new decision-making algorithm including early procalcitonin assay of premature newborn infants significantly reduced exposure to antibiotics without modifying mortality or morbidity.

A Neonatologist-Driven Antimicrobial Stewardship Program in a Neonatal Tertiary Care Center in Oman

OBJECTIVE

The overuse of antimicrobials in neonates is not uncommon and has resulted in a global health crisis of antibiotic resistance. This study aimed to evaluate changes associated with a neonatologist-driven antimicrobial stewardship program (ASP) in antibiotic usage.

STUDY DESIGN

We conducted a pre-post retrospective cohort study in a tertiary care hospital in Oman. Neonates admitted in 2014 to 2015 were considered as the pre-ASP cohort. In 2016, a neonatologist-driven ASP was launched in the unit. The program included the optimization and standardization of antibiotic use for early- and late-onset sepsis using the Centers for Disease Control and Prevention's "broad principles," an advanced antimicrobial decision-support system to resolve contentious issues, and placed greater emphasis on education and behavior modification. Data from the years 2016 to 2019 were compared with previous data. The outcome of interest included days of therapy (DOT) for antimicrobials. Baseline characteristics and outcomes were compared using standard statistical measures.

RESULTS

The study included 2,098 neonates in the pre-ASP period and 5,464 neonates in the post-ASP period. There was no difference in baseline characteristics. The antibiotic use decreased from 752 DOT per 1,000 patient-days (PD) in the pre-ASP period to 264 DOT in the post-ASP period (64.8% reduction, p < 0.001). The proportion of neonates who received any antibiotics declined by 46% (pre-ASP = 1,161/2,098, post-ASP = 1,676/5,464). The most statistically significant reduction in DOT per 1,000 PD was observed in the use of cefotaxime (82%), meropenem (74%), and piperacillin-tazobactam (74%). There was no change in mortality, culture-positive microbial profile, or multidrug-resistant organism incidence in the post-ASP period.

CONCLUSION

Empowering frontline neonatologists to drive ASPs was associated with a sustained reduction in antibiotic utilization.

KEY POINTS

· Overuse of antimicrobials is not uncommon in neonatal intensive care units.. · ASPs and infection control and prevention measures may help in decreasing antibiotic consumption and culture-positive sepsis.. · Empowering frontline neonatologists resulted in a sustained decrease in antimicrobial use without extra resources or financial burden..

Use of Rapid Molecular Polymerase Chain Reaction in Early Detection of Bacteremia in Neonates Prior to Blood Culture Positivity: A Pilot Study

OBJECTIVE

There has been national strive to decrease the time needed to identify microorganisms in blood culture samples to reduce antibiotic use. This study evaluated rapid molecular polymerase chain reaction (PCR) use in identifying microorganisms in negative culture bottles from neonates with suspected bacterial blood stream infection at 20 to 24 hours of incubation.

STUDY DESIGN

All blood specimens from neonates with suspected blood stream infection were included. Specimens were incubated using a standard blood culturing instrument that would flag positive if bacterial growth was detected. If the specimen was flagged positive at <20 hours, it was tested by PCR and plated for identification as per standard protocol. In our design, if specimen was not flagged at 20 hours of incubation, the bottle was sterilely accessed and a sample was obtained for PCR testing. The bottle would be returned for incubation for 120 hours or until flagged positive.

RESULTS

A total of 192 blood specimens were included. Four specimens flagged positive at <20 hours and were all found to be positive by PCR. All other samples did not flag positive by 20 hours of incubation and were tested by PCR between 20 and 24 hours. One sample tested positive via PCR at 21.6 hours then flagged positive on the culturing instrument at 23.5 hours. All other specimens were negative by PCR and remained culture negative at 120 hours. The positive and negative predictive value of PCR verified by blood culture were both equal to 1.0.

CONCLUSION

Using rapid molecular PCR on blood culture specimens at 20 to 24 hours of incubation provides 100% true negative results possibly allowing providers to discontinue antibiotics at 24 hours.

KEY POINTS

· Antibiotic overuse leads to adverse neonatal outcomes.. · Molecular PCR may have true negative results.. · Larger study is needed to discontinue antibiotics earlier..

Neurodevelopmental Outcome after Culture-Proven or So-Called Culture-Negative Sepsis in Preterm Infants

(1) Background: Prematurity is a serious condition associated with long-term neurological disability. This study aimed to compare the neurodevelopmental outcomes of preterm neonates with or without sepsis. (2) Methods: This single-center retrospective case-control study included infants with birth weight < 1500 g and/or gestational age ≤ 30 weeks. Short-term outcomes, brain MRI findings, and severe functional disability (SFD) at age 24 months were compared between infants with culture-proven or culture-negative sepsis or without sepsis. A chi-squared test or Mann-Whitney U test was used to compare the clinical and instrumental characteristics and the outcomes between cases and controls. (3) Results: Infants with sepsis (all sepsis n = 76; of which culture-proven n = 33 and culture-negative n = 43) were matched with infants without sepsis (n = 76). Compared with infants without sepsis, both all sepsis and culture-proven sepsis were associated with SFD. In multivariate logistic regression analysis, SFD was associated with intraventricular hemorrhage (OR 4.7, CI 1.7-13.1, p = 0.002) and all sepsis (OR 3.68, CI 1.2-11.2, p = 0.021). (4) Conclusions: All sepsis and culture-proven sepsis were associated with SFD. Compared with infants without sepsis, culture-negative sepsis was not associated with an increased risk of SFD. Given the association between poor outcomes and culture-proven sepsis, its prevention in the neonatal intensive care unit is a priority.

Association between Antenatal Antibiotic Exposure and Bronchopulmonary Dysplasia: A Systematic Review and Bayesian Model-Averaged Meta-Analysis

INTRODUCTION

Antenatal antibiotic exposure has been suggested as a risk factor for bronchopulmonary dysplasia (BPD). We aimed to summarize the evidence from randomized controlled trials (RCTs) and observational studies on this potential association.

METHODS

PubMed/Medline and Embase databases were searched. BPD was classified as BPD28 (supplemental oxygen during 28 days or at postnatal day 28), BPD36 (supplemental oxygen at 36 weeks postmenstrual age), BPD36 or death, and BPD-associated pulmonary hypertension (BPD-PH). Bayesian model-averaged (BMA) meta-analysis was used to calculate Bayes factors (BFs). The BF10 is the ratio of the probability of the data under the alternative hypothesis (H1) over the probability of the data under the null hypothesis (H0).

RESULTS

We included 6 RCTs and 27 observational studies (126,614 infants). Regarding BPD28, BMA showed that the evidence in favor of H0 (lack of association with antenatal antibiotics) was weak for the RCTS (BF10 = 0.506, 6 studies) and moderate for the observational studies (BF10 = 0.286, 10 studies). Regarding BPD36, the evidence in favor of H0 was moderate for the RCTs (BF10 = 0.127, 2 studies) and weak for the observational studies (BF10 = 0.895, 14 studies). Evidence in favor of H0 was also weak for the associations with BPD36 or death (BF10 = 0.429, 2 studies) and BPD-PH (BF10 = 0.384, 2 studies). None of the meta-analyses showed evidence in favor of H1.

CONCLUSIONS

The currently available evidence suggests a lack of association between antenatal antibiotics and BPD. However, our results should not be interpreted as an argument for widespread use of antibiotics in the setting of preterm delivery.

Bolus Feeding Via Gastric Versus Oral Routes in Very Preterm Neonates

BACKGROUND

We intend to investigate the association of bolus orogastric tube (BOG) and nipple bottle (N) feedings with postnatal growth in very premature neonates (VPN: gestational age between 28 and 33 weeks).

MATERIAL AND METHODS

The days of life (DOL) to achieve full combined oral and gastric enteral nutrition (FEN) and attain body weight (BW) of 2200 g (Wt22) and the length of hospitalization (LOH) were retrospectively associated with clinical and BOG and N feeding-related variables via multivariate regression analyses. Correlations were performed to ascertain the strength of associations.

RESULTS

In a cohort of 127 VPN, FEN demonstrated negative associations with gestational age (GA) and LOH and Wt22 with birth weight (BW). FEN showed positive associations with nil by mouth and intravenous fluid-nutrition days and with DOL to start and achieve full nipple feeding. LOH was associated with days on antibiotics and DOL to start and achieve full nipple feeding. Wt22 was associated with DOL to achieve full nipple feeding. The start day of BOG feeding had no independent associations and weak, highly significant positive correlations with Wt22, LOH, and FEN.

CONCLUSION

Bolus orogastric tube feeding has no independent implications for postnatal growth, duration of hospitalization, or chronological age to attain full enteral nutrition in VPN unless combined with nipple feeding to provide enteral nutrition. Oral bottle feeding accelerates postnatal catch-up growth and full enteral nutrition acquisition while reducing hospitalization duration. Initiating nipple feeding at 32 weeks of postmenstrual age may be safe in stable VPN. Antibiotic therapy increases hospitalization duration.

Variation in antibiotic consumption in very preterm infants-a 10 year population-based study

OBJECTIVES

Wide variations in antibiotic use in very preterm infants have been reported across centres despite similar rates of infection. We describe 10 year trends in use of antibiotics and regional variations among very preterm infants in Norway.

PATIENTS AND METHODS

All live-born very preterm infants (<32 weeks gestation) admitted to any neonatal unit in Norway during 2009-18 were included. Main outcomes were antibiotic consumption expressed as days of antibiotic therapy (DOT) per 1000 patient days (PD), regional variations in use across four health regions, rates of sepsis and sepsis-attributable mortality and trends of antibiotic use during the study period.

RESULTS

We included 5296 infants: 3646 (69%) were born at 28-31 weeks and 1650 (31%) were born before 28 weeks gestation with similar background characteristics across the four health regions. Overall, 80% of the very preterm infants received antibiotic therapy. The most commonly prescribed antibiotics were the combination of narrow-spectrum β-lactams and aminoglycosides, but between 2009 and 2018 we observed a marked reduction in their use from 100 to 40 DOT per 1000 PD (P < 0.001). In contrast, consumption of broad-spectrum β-lactams remained unchanged (P = 0.308). There were large variations in consumption of vancomycin, broad-spectrum β-lactams and first-generation cephalosporins, but no differences in sepsis-attributable mortality across regions.

CONCLUSIONS

The overall antibiotic consumption was reduced during the study period. Marked regional variations remained in consumption of broad-spectrum β-lactams and vancomycin, without association to sepsis-attributable mortality. Our results highlight the need for antibiotic stewardship strategies to reduce consumption of antibiotics that may enhance antibiotic resistance development.

Duration of Simultaneous Exposure to High-Risk and Lower-Risk Nephrotoxic Antimicrobials in the Neonatal Intensive Care Unit (NICU) and Future Adolescent Kidney Health

OBJECTIVE

To determine whether greater duration of simultaneous exposure to antimicrobials with high nephrotoxicity risk combined with lower-risk antimicrobials (simultaneous exposure) in the neonatal intensive care unit (NICU) is associated with worse later kidney health in adolescents born preterm with very low birth weight (VLBW).

STUDY DESIGN

Prospective cohort study of participants born preterm with VLBW (<1500 g) as singletons between January 1, 1992, and June 30, 1996. We defined simultaneous exposure as a high-risk antimicrobial, such as vancomycin, administered with a lower-risk antimicrobial on the same date in the NICU. Outcomes were serum creatinine, estimated glomerular filtration rate (eGFR), and first-morning urine albumin-creatinine ratio (ACR) at age 14 years. We fit multivariable linear regression models with days of simultaneous exposure and days of nonsimultaneous exposure as main effects, adjusting for gestational age, birth weight, and birth weight z-score.

RESULTS

Of the 147 out of 177 participants who had exposure data, 97% received simultaneous antimicrobials for mean duration 7.2 days (SD 5.6). No participant had eGFR <90 ml/min/1.73 m2. The mean ACR was 15.2 mg/g (SD 38.7) and 7% had albuminuria (ACR >30 mg/g). Each day of simultaneous exposure was associated only with a 1.04-mg/g higher ACR (95% CI 1.01 to 1.06).

CONCLUSIONS

Despite frequent simultaneous exposure to high-risk combined with lower-risk nephrotoxic antimicrobials in the NICU, there were no clinically relevant associations with worse kidney health identified in adolescence. Although future studies are needed, these findings may provide reassurance in a population thought to be at increased risk of chronic kidney disease.

Pharmacokinetic and Pharmacodynamic Considerations of Antibiotic Use in Neonates

The selection of an appropriate dose of a given antibiotic for a neonate not only requires knowledge of the drug's basic pharmacokinetic (PK) and pharmacodynamic (PD) properties but also the profound effects that organ development might have on the volume of distribution and clearance, both of which may affect the PK/PD of a drug. Interest has grown in alternative antibiotic dosing strategies that are better aligned with the antibiotic's PK and PD properties. These strategies should be used in conjunction with minimum inhibitory concentration measurements and therapeutic drug monitoring to measure their potential success. They can also guide the clinician in tailoring the delivery of antibiotics to suit an individual patient's needs. Model-informed precision dosing, such as Bayesian forecasting dosing software (which incorporates PK/PD population models), may be utilized to optimize antibiotic exposure in neonatal populations. Consequently, optimizing the antibiotic dose and exposure in each newborn requires expertise in different fields. It drives the collaboration of physicians together with lab technicians and quantitative clinical pharmacologists.

Ampicillin and Gentamicin Treatment for Early Onset Neonatal Sepsis: When One Size Does Not Fit All

Based on in vitro susceptibilities and the concern for emergence of resistance and long-term safety, ampicillin plus gentamicin remains the recommended antibiotic regimen for early onset neonatal sepsis. Our objective was to identify potential limitations of this regimen based on clinical and pathogen characteristics while minimizing risks associated with prolonged antibiotic exposure. We identified 43 gram-negative pathogens in 42 patients. Escherichia coli (E coli) occurred in 50% and Streptococcus agalactiae in 23.8% of patient. Ampicillin resistance was common, particularly in E coli (85.7%). Mortality was 23.8%, all due to E coli. We found that E coli is the most frequent pathogen and has a high mortality particularly in neonates < 1500 g; mortality is high with the current dosing strategy when E coli is resistant to ampicillin even when sensitive to gentamicin; resistance to gentamicin remains low but seems to be increasing while resistance to third-generation cephalosporins remains very low.

[Establishment of a nomogram model for predicting the risk of early-onset sepsis in very preterm infants]

OBJECTIVES

To identify risk factors associated with early-onset sepsis (EOS) in very preterm infants and develop a nomogram model for predicting the risk of EOS.

METHODS

A retrospective analysis was conducted on 344 very preterm infants delivered at the First Affiliated Hospital of Zhengzhou University and admitted to the Department of Neonatology between January 2020 and December 2022. These infants were randomly divided into a training set (241 infants) and a validating set (103 infants) in a 7:3 ratio. The training set was further divided into two groups based on the presence or absence of EOS: EOS (n=64) and non-EOS (n=177). Multivariate logistic regression analysis was performed to identify risk factors for EOS in the very preterm infants. The nomogram model was developed using R language and validated using the validating set. The discriminative ability, calibration, and clinical utility of the model were assessed using receiver operating characteristic (ROC) curve analysis, calibration curve analysis, and decision curve analysis, respectively.

RESULTS

The multivariate logistic regression analysis revealed that gestational age, need for tracheal intubation in the delivery room, meconium-stained amniotic fluid, serum albumin level on the first day of life, and chorioamnionitis were risk factors for EOS in very preterm infants (P<0.05). The area under the ROC curve for the training set was 0.925 (95%CI: 0.888-0.963), and that for the validating set was 0.796 (95%CI: 0.694-0.898), confirming the model's good discrimination. The Hosmer-Lemeshow goodness-of-fit test suggested that the model was well-fitting (P=0.621). The calibration curve analysis and decision curve analysis demonstrated that the model had high predictive efficacy and clinical applicability.

CONCLUSIONS

Gestational age, need for tracheal intubation in the delivery room, meconium-stained amniotic fluid, serum albumin level on the first day of life, and chorioamnionitis are significantly associated with the development of EOS in very preterm infants.The nomogram model for predicting the risk of EOS in very preterm infants, constructed based on these factors, has high predictive efficacy and clinical applicability.

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.

Short-course antibiotic therapy for pneumonia in the neonatal intensive care unit

OBJECTIVE

To determine the adherence and safety outcomes of a 5-day antibiotic course with a "time-out" for treatment of "blood culture-negative" pneumonia in the NICU.

STUDY DESIGN

Prospective surveillance of all infants diagnosed with pneumonia at 7 NICUs from 8/2020-12/2021. Safety outcomes were defined a priori by re-initiation of antibiotic therapy within 14 days after discontinuation and overall and sepsis-related mortality.

RESULTS

128 infants were diagnosed with 136 episodes of pneumonia; 88% (n = 119) were treated with 5 days of definitive antibiotic therapy. Antibiotics were restarted within 14 days in 22 (16%) of the 136 pneumonia episodes. However, only 3 (3%) of the 119 episodes of pneumonia treated for 5 days had antibiotics restarted for pneumonia. Mortality was 5% (7/128); 5 of the 7 deaths were assessed as sepsis-related.

CONCLUSION

Adherence to the 5-day definitive antibiotic treatment for "culture-negative" pneumonia was high and the intervention seemed safe.

Association of delivery risk phenotype with early-onset sepsis in preterm infants

OBJECTIVE

To determine delivery risk phenotype-specific incidence of early-onset sepsis (EOS) among preterm infants.

STUDY DESIGN

Retrospective cohort study of infants born <35 weeks' gestation at four perinatal centers during 2017-2021. Infants were classified into one of six delivery risk phenotypes incorporating delivery mode, presence of labor, and duration of rupture of membranes (ROM). The primary outcome was EOS incidence within the overall cohort and each risk phenotype.

RESULTS

Among 2937 preterm infants, 21 had EOS (0.7%, or 7.1 cases/1000 preterm infants). The majority of EOS cases (13/21, 62%) occurred in the setting of prolonged ROM ≥ 18 h, with a phenotype incidence of 23.8 cases/1000 preterm infants. There were no EOS cases among infants born by cesarean section without ROM (with or without labor), nor via cesarean section with ROM < 18 h without labor.

CONCLUSION

Delivery risk phenotyping may inform EOS risk stratification in preterm infants.

Implementation of a 24-hour empiric antibiotic duration for negative early-onset sepsis evaluations to reduce early antibiotic exposure in premature infants

OBJECTIVE

Antibiotic exposure increases the risk of morbidity and mortality in premature infants. Many centers use at least 48 hours of antibiotics in the evaluation of early-onset sepsis (EOS, <72 hours after birth), yet most important pathogens grow within 24 hours. We investigated the safety and efficacy of reducing empiric antibiotic duration to 24 hours.

DESIGN

Quality improvement study.

SETTING

A tertiary-care neonatal intensive care unit.

PATIENTS

Inborn infants <35 weeks gestational age at birth (ie, preterm) admitted January 2019 through December 2020.

INTERVENTION

In December 2019, we changed the recommended duration of empiric antibiotics for negative EOS evaluations from 48 hours to 24 hours.

RESULTS

Patient characteristics before and after the intervention were similar. After the intervention, 71 preterm infants (57%) with negative EOS evaluations received ≤24 hours of antibiotics, an increase from 15 (10%) before the intervention. These 71 infants comprised 77% of infants with negative EOS blood cultures after excluding those treated as clinical sepsis (≥5 days of antibiotics). For all negative EOS blood cultures, the mean treatment duration decreased by 0.5 days from 3.9 days to 3.4 days. This finding equated to 2.4 fewer antibiotic days per 100 patient days for negative EOS blood cultures but similar antibiotic days per 30 patient days (7.2 days vs 7.5 days). This measure did not change over time. Subsequent sepsis evaluations <7 days after a negative EOS blood culture did not increase. Excluding contaminants, the median time to positivity was 13.2 hours (range, 8-23) in 8 positive blood cultures.

CONCLUSION

Implementation of a 24-hour antibiotic course for negative EOS evaluations safely reduced antibiotic exposure in 77% of infants <35 weeks gestational age at birth in whom EOS was ruled out. All clinically significant pathogens grew within 24 hours.

Blood culture collection practices in NICU; A national survey

Background

Sepsis is the leading cause of mortality and morbidity in neonates. Blood cultures are the gold standard in diagnosing neonatal sepsis; however, there are currently no consensus guidelines for blood culture collection in neonates and significant practice variation exists in Neonatal Intensive Care Units (NICUs) globally.

Objective

To examine current practices in obtaining blood cultures in the evaluation of neonatal sepsis in NICUs across Canada.

Methods

A nine-item electronic survey was sent to each of the 29 level-3 NICUs in Canada, which are equipped to provide highly specialized care for newborns.

Results

Responses were received from 90% (26/29) of sites. Sixty-five percent (17/26) of sites have blood culture collection guidelines for the investigation of neonatal sepsis. Forty-eight percent (12/25) of sites routinely target 1.0 mL per culture bottle. In late-onset sepsis (LOS), 58% (15/26) of sites process one aerobic culture bottle, whereas four sites routinely add anaerobic culture bottles. In early-onset sepsis (EOS) in very low birth weight infants (BW <1.5 kg), 73% (19/26) of sites use umbilical cord blood, and 72% (18/25) use peripheral venipuncture. Two sites routinely collect cord blood for culture in EOS. Only one site applies the concept of differential time-to-positivity to diagnose central-line-associated bloodstream infection.

Conclusions

There is significant practice variation in methods used to obtain blood cultures in level-3 NICUs across Canada. Standardization of blood culture collection practices can provide reliable estimates of the true incidence of neonatal sepsis and help to develop appropriate antimicrobial stewardship strategies.

Antibiotic therapy and necrotizing enterocolitis

Antibiotic therapy remains a cornerstone of treatment of both medical and surgical presentations of necrotizing enterocolitis (NEC). However, guidelines regarding the administration of antibiotics for the treatment of NEC are lacking and practices vary amongst clinicians. Although the pathogenesis of NEC is unknown, there is consensus that the infant gastrointestinal microbiome contributes to the disease. The presumed connection between dysbiosis and NEC has prompted some to study whether early prophylactic enteral antibiotics can prevent NEC. Yet others have taken an opposing approach, studying whether perinatal antibiotic exposure increases the risk of NEC by inducing a state of dysbiosis. This narrative review summarizes what is known about antibiotics and their association with the infant microbiome and NEC, current antibiotic prescribing practices for infants with medical and surgical NEC, as well as potential strategies to further optimize the use of antibiotics in this population of infants.

Short-course empiric antibiotic therapy for possible early-onset sepsis in the NICU

OBJECTIVE

On 2/2019, the Neonatal Antimicrobial Stewardship Program at Nationwide Children's Hospital recommended reducing empirical antibiotic therapy for early-onset sepsis (EOS) from 48 to 24 hours with a TIME-OUT. We describe our experience with this guideline and assess its safety.

METHODS

Retrospective review of newborns evaluated for possible EOS at 6 NICUs from 12/2018-7/2019. Safety endpoints were re-initiation of antibiotics within 7 days after discontinuation of the initial course, positive bacterial blood or cerebrospinal fluid culture in the 7 days after antibiotic discontinuation, and overall and sepsis-related mortality.

RESULT

Among 414 newborns evaluated for EOS, 196 (47%) received a 24 hour rule-out sepsis antibiotic course while 218 (53%) were managed with a 48 hour course. The 24-hour rule-out group were less likely to have antibiotics re-initiated and did not differ in the other predefined safety endpoints.

CONCLUSION

Antibiotic therapy for suspected EOS may be discontinued safely within 24 hours.

Duration of Neonatal Antibiotic Exposure in Preterm Infants in Association with Health and Developmental Outcomes in Early Childhood

Over 90% of preterm neonates are, often empirically, exposed to antibiotics as a potentially life-saving measure against sepsis. Long-term outcome in association with antibiotic exposure (NABE) has insufficiently been studied after preterm birth. We investigated the association of NABE-duration with early-childhood developmental and health outcomes in preterm-born children and additionally assessed the impact of GA on outcomes. Preterm children (GA < 30 weeks) participating in a multicenter cohort study were approached for follow-up. General expert-reviewed health questionnaires on respiratory, atopic and gastrointestinal symptoms were sent to parents of children > 24 months' corrected age (CA). Growth and developmental assessments (Bayley Scales of Infant and Toddler Development (BSID) III) were part of standard care assessment at 24 months' CA. Uni- and multivariate regressions were performed with NABE (per 5 days) and GA (per week) as independent variables. Odds ratios (OR) for health outcomes were adjusted (aOR) for confounders, where appropriate. Of 1079 infants whose parents were approached, 347 (32%) responded at a mean age of 4.6 years (SD 0.9). In children with NABE (97%), NABE duration decreased by 1.6 days (p < 0.001) per week of gestation. Below-average gross-motor development (BSID-III gross-motor score < 8) was associated with duration of NABE (aOR = 1.28; p = 0.04). The aOR for constipation was 0.81 (p = 0.04) per gestational week. Growth was inversely correlated with GA. Respiratory and atopic symptoms were not associated with NABE, nor GA. We observed that prolonged NABE after preterm birth was associated with below-average gross-motor development at 24 months' CA, while a low GA was associated with lower weight and stature Z-scores and higher odds for constipation.

New strategies to Reduce Unnecessary Antibiotic Use in the NICU: A Quality Improvement Initiative

Introduction

Early-onset sepsis (EOS) and late-onset Sepsis (LOS) are common diagnoses entertained in sick newborns treated in neonatal intensive care units (NICUs), and antibiotics are the medications most prescribed in NICUs. Antibiotic stewardship programs have an important impact on limiting unnecessary antibiotic use.

Methods

Following the Model for Improvement, between 2/1/16 and 1/31/17, at a level 3 NICU, a multidisciplinary team implemented PDSA cycles to promote antibiotic stewardship practices for newborns at risk of EOS and LOS. The main goal was to decrease the antibiotic usage rate (AUR) safely. Primary strategies included discontinuing antibiotics within 24 hours of life if the newborn was stable, and the blood culture was negative for EOS and implementing an "antibiotic time-out" during rounds.

Results

For all newborns admitted to our NICU, the AUR decreased, for EOS from 137 to 32 days per 1000 patient days (77% reduction) and for LOS from 277 to 121 days per 1000 patient days (56% reduction). We demonstrated the sustainability of both EOS-AUR and LOS-AUR during the 2 years postcompletion of the intervention period. There were no adverse effects of reducing the AUR.

Conclusion

Interventions that reduce unnecessary antibiotic use in the NICU are safe and prevent excessive antibiotic exposure.

Less is more: Antibiotics at the beginning of life

Antibiotic exposure at the beginning of life can lead to increased antimicrobial resistance and perturbations of the developing microbiome. Early-life microbiome disruption increases the risks of developing chronic diseases later in life. Fear of missing evolving neonatal sepsis is the key driver for antibiotic overtreatment early in life. Bias (a systemic deviation towards overtreatment) and noise (a random scatter) affect the decision-making process. In this perspective, we advocate for a factual approach quantifying the burden of treatment in relation to the burden of disease balancing antimicrobial stewardship and effective sepsis management.

Antimicrobial use among paediatric inpatients at hospital sites within the Canadian Nosocomial Infection Surveillance Program, 2017/2018

BACKGROUND

Antimicrobial resistance threatens the ability to successfully prevent and treat infections. While hospital benchmarks regarding antimicrobial use (AMU) have been well documented among adult populations, there is less information from among paediatric inpatients. This study presents benchmark rates of antimicrobial use (AMU) for paediatric inpatients in nine Canadian acute-care hospitals.

METHODS

Acute-care hospitals participating in the Canadian Nosocomial Infection Surveillance Program submitted annual AMU data from paediatric inpatients from 2017 and 2018. All systemic antimicrobials were included. Data were available for neonatal intensive care units (NICUs), pediatric ICUs (PICUs), and non-ICU wards. Data were analyzed using days of therapy (DOT) per 1000 patient days (DOT/1000pd).

RESULTS

Nine hospitals provided paediatric AMU data. Data from seven NICU and PICU wards were included. Overall AMU was 481 (95% CI 409-554) DOT/1000pd. There was high variability in AMU between hospitals. AMU was higher on PICU wards (784 DOT/1000pd) than on non-ICU (494 DOT/1000pd) or NICU wards (333 DOT/1000pd). On non-ICU wards, the antimicrobials with the highest use were cefazolin (66 DOT/1000pd), ceftriaxone (59 DOT/1000pd) and piperacillin-tazobactam (48 DOT/1000pd). On PICU wards, the antimicrobials with the highest use were ceftriaxone (115 DOT/1000pd), piperacillin-tazobactam (115 DOT/1000pd), and cefazolin (111 DOT/1000pd). On NICU wards, the antimicrobials with the highest use were ampicillin (102 DOT/1000pd), gentamicin/tobramycin (78 DOT/1000pd), and cefotaxime (38 DOT/1000pd).

CONCLUSIONS

This study represents the largest collection of antimicrobial use data among hospitalized paediatric inpatients in Canada to date. In 2017/2018, overall AMU was 481 DOT/1000pd. National surveillance of AMU among paediatric inpatients is necessary for establishing benchmarks and informing antimicrobial stewardship efforts.

Restrictive Use of Empirical Antibiotics Is Associated with Improved Short Term Outcomes in Very Low Birth Weight Infants: A Single Center, Retrospective Cohort Study from China

Antibiotics are essential for treating neonatal sepsis, but abuse or inappropriate use of antibiotics have harmful adverse effects. The inappropriate use of antibiotics has led to the significant increase in bacterial antimicrobial resistance in the neonatal intensive care unit (NICU). The aim of this study was to retrospectively analyze the changes in antibiotic usages in a NICU after the implementation of an antibiotic stewardship program and to determine the impact of this implementation on the short-term clinical outcomes of very low birth weight (VLBW) infants. The antibiotic stewardship program was initiated in the NICU in early 2015. For analysis, all eligible VLBW infants born from 1 January 2014 to 31 December 2016 were enrolled, and we classified the year 2014 as pre-stewardship, 2015 as during stewardship, and 2016 as post-stewardship. A total of 249 VLBW infants, including 96 cases in the 2014 group, 77 cases in the 2015 group, and 76 cases in the 2016 group, were included for final analysis. Empirical antibiotics were used in over 90% of VLBW infants in all three groups during their NICU stay. Over the 3-year period, the duration of an initial antibiotic course was significantly reduced. The proportion of patients receiving an initial antibiotic course for ≤3 days gradually increased (2.1% vs. 9.1% vs. 38.2%, p < 0.001), while the proportion of babies treated with an initial antibiotic course >7 days significantly decreased (95.8% vs. 79.2% vs. 39.5%, p < 0.001). The total days of antibiotic usage during the entire NICU stay also showed a significant reduction (27.0 vs. 21.0 vs. 10.0, p < 0.001). After adjusting for confounders, the reduction in antibiotic usage was associated with decreased odds of having an adverse composite short-term outcome (aOR = 5.148, 95% CI: 1.598 to 16.583, p = 0.006). To assess the continuity of antibiotic stewardship in the NICU, data from 2021 were also analyzed and compared to 2016. The median duration of an initial antibiotic course further decreased from 5.0 days in 2016 to 4.0 days in 2021 (p < 0.001). The proportion of an initial antibiotic course in which antibiotics were used for ≤3 days increased (38.2% vs. 56.7%, p = 0.022). Total antibiotic usage days during the entire NICU stay also decreased from 10.0 days in 2016 to 7.0 days in 2021 (p = 0.010). The finding of this study strongly suggests that restricting antibiotic use in VLBW infants is beneficial and can be achieved safely and effectively in China.

The Association between Prolonged Antibiotic Use in Culture Negative Infants and Length of Hospital Stay and Total Hospital Costs

OBJECTIVE

 This study aimed to determine if prolonged antibiotic use at birth in neonates with a negative blood culture increases the total cost of hospital stay.

STUDY DESIGN

 This was a retrospective study performed at a 60-bed level IV neonatal intensive care unit. Neonates born <30 weeks of gestation or <1,500 g between 2016 and 2018 who received antibiotics were included. A multivariate linear regression analysis was conducted to determine if clinical factors contributed to increased hospital cost or length of stay.

RESULTS

 In total, 190 patients met inclusion criteria with 94 infants in the prolonged antibiotic group and 96 in the control group. Prolonged antibiotic use was associated with an increase length of hospital stay of approximately 31.87 days, resulting in a $69,946 increase in total cost of hospitalization.

CONCLUSION

 Prolonged antibiotics in neonates with negative blood culture were associated with significantly longer hospital length of stay and increased total cost of hospitalization.

KEY POINTS

· Prolonged antibiotic use at birth is associated with prolonged hospital stay.. · Prolonged antibiotic use at birth is associated with increased cost of hospitalization.. · Prolonged antibiotic use at birth is associated with increased days on total parenteral nutrition.. · Prolonged antibiotic use at birth is associated with increased subsequent courses of antibiotics..

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 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.

Effectiveness of a neonatal intensive care unit-specific antimicrobial stewardship program: A ten-year review

OBJECTIVE

To evaluate the change in consumption of specific antibiotics in a neonatal intensive care unit after the implementation of an antimicrobial stewardship program (ASP).

DESIGN

Retrospective cohort study between January 1, 2010, and December 31,2019.

SETTING

The neonatal intensive care unit at British Columbia Women's Hospital (Vancouver Canada), a tertiary-care center.

PATIENTS

Admitted neonates prescribed antibiotics.

METHODS

We implemented an ASP with an early implementation phase starting in January 2014 (period 2) and a later phase starting in January 2017 (period 3). Patient demographics were collected, including birth weight, gestational age, history of necrotizing enterocolitis (NEC), and surgical operations from existing databases. Interrupted time-series analysis was used, and comparison of antibiotic days of therapy (DOT) averages were conducted across the preimplementation period (period 1), period 2, and period 3 regarding total patients and subgroups.

RESULTS

We identified 4,512 infants. There was a significant decrease in DOT from 472 (95% confidence interval [CI], 431-517) in period 1 to 405 (95% CI, 367-446) in period 2 to 313 (95% CI, 280-350) in period 3. We detected a significant decrease in the use of ampicillin, aminoglycosides, cloxacillin, and linezolid but not in vancomycin or cefotaxime. Subgroup analyses of infants <1,500 g and those without NEC or surgery showed decreases in the use of cloxacillin, aminoglycosides, and linezolid.

CONCLUSIONS

The implementation of an ASP was associated with a significant decrease in the overall DOT and use of certain antibiotics. This study presents important targets for ongoing ASP work.

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.

The impact of early empirical antibiotics treatment on clinical outcome of very preterm infants: a nationwide multicentre study in China

BACKGROUND

Infants with rule-out infections are responsible for the majority of empirical antibiotics treatment (EAT) in neonatal intensive care units (NICUs), particularly very preterm infants (VPIs). Antibiotic overuse has been linked to adverse outcomes. There is a paucity of data on the association between EAT and clinical outcomes (containing the nutritional outcomes) of VPIs without infection-related morbidities.

METHODS

Clinical data of VPIs admitted in 28 hospitals in 20 provinces of China from September 2019 to December 2020 were collected. EAT of VPIs was calculated as the number of days with initial usage in the first week after birth, and then categorized into 3 groups (antibiotic exposure: none, 1-4 days, and > 4 days). Clinical characteristics, nutritional status , and the short-term clinical outcomes among 3 groups were compared and analyzed.

RESULTS

In total, 1834 VPIs without infection-related morbidities in the first postnatal week were enrolled, including 152 cases (8.3%) without antibiotics, 374 cases (20.4%) with EAT ≤4 days and 1308 cases (71.3%) with EAT > 4 days. After adjusting for the confounding variables, longer duration of EAT was associated with decreased weight growth velocity and increased duration of reach of full enteral feeding in EAT > 4 days group (aβ: -4.83, 95% CI: - 6.12 ~ - 3.53; aβ: 2.77, 95% CI: 0.25 ~ 5.87, respectively) than those receiving no antibiotics. In addition, the risk of feeding intolerance (FI) in EAT > 4 days group was 4 times higher than that in non-antibiotic group (aOR: 4.14, 95%CI: 1.49 ~ 13.56) and 1.8 times higher than that in EAT ≤4 days group (aOR: 1.82, 95%CI: 1.08 ~ 3.17). EAT > 4 days was also a risk factor for greater than or equal to stage 2 necrotizing enterocolitis (NEC) than those who did not receive antibiotics (aOR: 7.68, 95%CI: 1.14 ~ 54.75) and those who received EAT ≤4 days antibiotics (aOR: 5.42, 95%CI: 1.94 ~ 14.80).

CONCLUSIONS

The EAT rate among uninfected VPIs was high in Chinese NICUs. Prolonged antibiotic exposure was associated with decreased weight growth velocity, longer duration of reach of full enteral feeding, increased risk of feeding intolerance and NEC ≥ stage 2. Future stewardship interventions to reduce EAT use should be designed and implemented.

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].

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.