Epidemiology of necrotizing enterocolitis--Part I: Changing regional trends in extremely preterm infants over 14 years

Mortality and extrauterine growth restriction of necrotizing enterocolitis in very preterm infants with heart disease: a multi-center cohort study

Congenital heart disease (CHD) and patent ductus arteriosus (PDA) are risk factors of necrotizing enterocolitis (NEC) in infants. However, it is unclear whether the prognosis of NEC is different between very preterm infants (VPIs) with and without heart diseases. This was an observational cohort study that enrolled VPIs (born between 24+0 and 31+6 weeks) admitted to 79 tertiary neonatal intensive care units (NICU) in the Chinese Neonatal Network (CHNN) between 2019 and 2021. The exposure was CHD or isolated PDA, and VPIs with NEC were divided into three groups: complicated with CHD, with isolated PDA, and without heart diseases. The primary outcomes were NEC-related adverse outcomes (death or extrauterine growth restriction (EUGR)). Logistic regression models were used to adjust potential confounders and calculate the odds ratios (ORs) and 95% confidential intervals (CIs) for each outcome. A total of 1335 VPIs with NEC were enrolled in this study, including 65 VPIs with CHD and 406 VPIs with isolated PDA. The VPIs with heart diseases had smaller gestational ages and lower body weights at birth, more antenatal steroids use, and requiring inotrope prior to the onset of NEC. While suffering from NEC, there was no significant increased risks in NEC-related death in VPIs with either CHD (adjusted OR [aOR]: 1.10; 95% CI: 0.41-2.50) or isolated PDA (aOR: 1.25; 95% CI 0.82-1.87), and increased risks in EUGR were identified in either survival VPIs with CHD (aOR: 2.35; 95% CI: 1.31-4.20) or isolated PDA (aOR: 1.53; 95% CI: 1.16-2.01) in survivors. The composite outcome (death or EUGR) was also more often observed in VPIs with either CHD (aOR: 2.07; 95% confidence interval [CI]: 1.20-3.60) or isolated PDA (aOR: 1.51; 95% CI: 1.17-1.94) than that without heart diseases. VPIs with either CHD or isolated PDA were associated with significantly prolonged duration of fasting, extended time to achieve full enteral feeding, and longer ventilation duration and hospitalization duration. Similar characteristics were also seen in VPIs with isolated PDA, with the exception that VPIs with CHD are more likely to undergo surgical intervention and maintain a prolonged fast after NEC.     Conclusion: In VPIs with NEC, CHD and isolated PDA are associated with an increased risk in worse outcomes. We recommend that VPIs with cardiac NEC be managed with aggressive treatment and nutrition strategies to prevent EUGR. What is Known: • CHD and PDA are risk factors for NEC in infants, which can lead to adverse outcomes such as death and EUGR. • NEC in infants with heart disease differs clinically from that in infants without heart disease and should be recognized as a separate disease process. What is New: • CHD and isolated PDA are associated with increased risks of EUGR in VPIs with NEC. • Risk factors associated with VPIs with cardiac NEC suggested these patients should be managed with aggressive treatment and nutrition strategies to adverse outcomes.

Remote ischemic conditioning in necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a devastating intestinal inflammatory disorder, most prevalent in premature infants, and associated with a high mortality rate that has remained unchanged in the past two decades. NEC is characterized by inflammation, ischemia, and impaired microcirculation in the intestine. Preclinical studies by our group have led to the discovery of remote ischemic conditioning (RIC) as a promising non-invasive intervention in protecting the intestine against ischemia-induced damage during early-stage NEC. RIC involves the administration of brief reversible cycles of ischemia and reperfusion in a limb (similar to taking standard blood pressure measurement) which activate endogenous protective signaling pathways that are conveyed to distant organs such as the intestine. RIC targets the intestinal microcirculation and by improving blood flow to the intestine, reduces the intestinal damage of experimental NEC and prolongs survival. A recent Phase I safety study by our group demonstrated that RIC was safe in preterm infants with NEC. A phase II feasibility randomized controlled trial involving 12 centers in 6 countries is currently underway, to investigate the feasibility of RIC as a treatment for early-stage NEC in preterm neonates. This review provides a brief background on RIC as a therapeutic strategy and summarizes the progression of RIC as a treatment for NEC from preclinical investigation to clinical evaluation.

Remote ischaemic conditioning in necrotising enterocolitis: a phase I feasibility and safety study

OBJECTIVE

Remote ischaemic conditioning (RIC) improves the outcome of experimental necrotising enterocolitis (NEC) by preserving intestinal microcirculation. The feasibility and safety of RIC in preterm infants with NEC are unknown. The study aimed to assess the feasibility and safety of RIC in preterm infants with suspected or confirmed NEC.

DESIGN

Phase I non-randomised pilot study conducted in three steps: step A to determine the safe duration of limb ischaemia (up to 4 min); step B to assess the safety of 4 repeated cycles of ischaemia-reperfusion at the maximum tolerated duration of ischaemia determined in step A; step C to assess the safety of applying 4 cycles of ischaemia-reperfusion on two consecutive days.

SETTING

Level III neonatal intensive care unit, The Hospital for Sick Children (Toronto, Canada).

PATIENTS

Fifteen preterm infants born between 22 and 33 weeks gestational age.

INTERVENTION

Four cycles of ischaemia (varying duration) applied to the limb via a manual sphygmomanometer, followed by reperfusion (4 min) and rest (5 min), repeated on two consecutive days.

OUTCOMES

The primary outcomes were (1) feasibility defined as RIC being performed as planned in the protocol, and (2) safety defined as perfusion returning to baseline within 4 min after cuff deflation.

RESULTS

Four cycles/day of limb ischaemia (4 min) followed by reperfusion (4 min) and a 5 min gap, repeated on two consecutive days was feasible and safe in all neonates with suspected or confirmed NEC.

CONCLUSIONS

This study is pivotal for designing a future randomised controlled trial to assess the efficacy of RIC in preterm infants with NEC.

TRIAL REGISTRATION NUMBER

NCT03860701.

Blood transcriptomic markers of necrotizing enterocolitis in preterm pigs

BACKGROUND

Necrotizing enterocolitis (NEC), a severe gut disorder in preterm infants, is difficult to predict due to poor specificity and sensitivity of clinical signs and biomarkers. Using preterm piglets as a model, we hypothesized that early development of NEC affects blood gene expression, potentially related to early systemic immune responses.

METHODS

A retrospective analysis of clinical, tissue, and blood data was performed on 129 formula-fed piglets with NEC diagnosis at necropsy on day 5. Subgroups of NEC (n = 20) and control piglets (CON, n = 19) were analyzed for whole-blood transcriptome.

RESULTS

Preterm piglets had variable NEC lesions, especially in the colon region, without severe clinical signs (e.g. normal growth, activity, hematology, digestion, few piglets with bloody stools). Transcriptome analysis showed 344 differentially expressed genes (DEGs) between NEC and CON piglets. Validation experiment showed that AOAH, ARG2, FKBP5, PAK2, and STAT3 were among the genes affected by severe lesions on day 5, when analyzed in whole blood and in dried blood spots (DBS).

CONCLUSION

Whole-blood gene expressions may be affected in preterm pigs before clinical signs of NEC get severe. Blood gene expression analysis, potentially using DBS samples, is a novel tool to help identify new early biomarkers of NEC.

IMPACT

Preterm pig model was used to investigate if blood transcriptomics could be used to identify new early blood biomarkers of NEC progression. Whole-blood transcriptome revealed upregulation of target genes in NEC cases when clinical symptoms are subtle, and mainly colon regions were affected. Differential NEC-associated gene expressions could be detected also in dried blood spots, potentially allowing easy collection of small blood volumes in infants.

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.

Global incidence of Necrotizing Enterocolitis: a systematic review and Meta-analysis

BACKGROUND

Necrotizing Enterocolitis (NEC) is a major cause of morbidity and mortality in the Neonatal Intensive Care Unit (NICU), yet the global incidence of NEC has not been systematically evaluated. We conducted a systematic review and meta-analysis of cohort studies reporting the incidence of NEC in infants with Very Low Birth Weight (VLBW).

METHODS

The databases searched included PubMed, MEDLINE, the Cochrane Library, EMBASE and grey literature. Eligible studies were cohort or population-based studies of newborns including registry data reporting incidence of NEC. Incidence were pooled using Random Effect Models (REM), in the presence of substantial heterogeneity. Additional, bias adjusted Quality Effect Models (QEM) were used to get sensitivity estimates. Subgroup analysis and meta-regression were used to explore the sources of heterogeneity. Funnel plots as appropriate for ratio measures were used to assess publication bias.

RESULTS

A systematic and comprehensive search of databases identified 27 cohort studies reporting the incidence of NEC. The number of neonate included in these studies was 574,692. Of this 39,965 developed NEC. There were substantial heterogeneity between studies (I2 = 100%). The pooled estimate of NEC based on REM was 7.0% (95% CI: 6.0-8.0%). QEM based estimate (6.0%; 95% CI: 4.0-9.0%) were also similar. Funnel plots showed no evidence of publication bias. Although, NEC estimates are similar across various regions, some variation between high and low income countries were noted. Meta regression findings showed a statistically significant increase of NEC over time, quantified by the publication year.

CONCLUSION

Seven out of 100 of all VLBW infants in NICU are likely to develop NEC. However, there were considerable heterogeneity between studies. High quality studies assessing incidence of NEC along with associated risk factors are warranted.

Incidence, Treatment, and Outcome Trends of Necrotizing Enterocolitis in Preterm Infants: A Multicenter Cohort Study

Background: Data regarding the incidence and mortality of necrotizing enterocolitis trends are scarce in the literature. Recently, some preventive strategies have been confirmed (probiotics) or increased (breastfeeding rate). This study aims to describe the trends of necrotizing enterocolitis incidence, treatment, and mortality over the last decade in Spain. Methods: Multicenter cohort study with data from the Spanish Neonatal Network-SEN1500 database. The study period comprised from January 2005 to December 2017. Preterm infants <32 weeks of gestational age at birth without major congenital malformations were included for analysis. The main study outcomes were necrotizing enterocolitis incidence, co-morbidity (bronchopulmonary dysplasia, late-onset sepsis, cystic periventricular leukomalacia, retinopathy of prematurity, acute kidney injury), mortality, and surgical/non-surgical treatment. Results: Among the 25,821 included infants, NEC incidence was 8.8% during the whole study period and remained stable when comparing 4-year subperiods. However, more cases were surgically treated (from 48.8% in 2005-2008 to 70.2% in 2015-2017, p < 0.001). Mortality improved from 36.7% in the 2005-2008 to 26.6% in 2015-2017 (p < 0.001). Breastfeeding rates improved over the studied years (24.3% to 40.5%, p < 0.001), while gestational age remained invariable (28.5 weeks, p = 0.20). Prophylactic probiotics were implemented during the study period in some units, reaching 18.6% of the patients in 2015-2017. Conclusions: The incidence of necrotizing enterocolitis remained stable despite the improvement regarding protective factors frequency. Surgical treatment became more frequent over the study period, whereas mortality decreased.

Development of the NEC-Zero Toolkit: Supporting Reliable Implementation of Necrotizing Enterocolitis Prevention and Recognition

The goal of the NEC-Zero project is to reduce the burden of necrotizing enterocolitis (NEC) by increasing access to evidence-based tools to help clinicians and parents integrate evidence into daily care. It involves (a) human milk feeding with prioritized mother's own milk; (b) use of a unit-adopted standardized feeding protocol; (c) a unit-adopted strategy for timely recognition that integrates risk awareness and a structured communication tool when symptoms develop; and (d) stewardship of empiric antibiotics and avoidance of antacids. A toolkit for caregivers and parents was developed to make implementation consistent. For clinicians the toolkit includes: the GutCheck^NEC risk score, a structured communication tool, the "Avoiding NEC" checklist, and the NEC-Zero website. For parents, NEC-Zero tools include the website, three educational brochures in English and Spanish, and a collaborative care video produced with the NEC Society. This article describes the toolkit and how it has been accessed and used.

Developing routinely recorded clinical data from electronic patient records as a national resource to improve neonatal health care: the Medicines for Neonates research programme

Background

Clinical data offer the potential to advance patient care. Neonatal specialised care is a high-cost NHS service received by approximately 80,000 newborn infants each year.

Objectives

(1) To develop the use of routinely recorded operational clinical data from electronic patient records (EPRs), secure national coverage, evaluate and improve the quality of clinical data, and develop their use as a national resource to improve neonatal health care and outcomes. To test the hypotheses that (2) clinical and research data are of comparable quality, (3) routine NHS clinical assessment at the age of 2 years reliably identifies children with neurodevelopmental impairment and (4) trial-based economic evaluations of neonatal interventions can be reliably conducted using clinical data. (5) To test methods to link NHS data sets and (6) to evaluate parent views of personal data in research.

Design

Six inter-related workstreams; quarterly extractions of predefined data from neonatal EPRs; and approvals from the National Research Ethics Service, Health Research Authority Confidentiality Advisory Group, Caldicott Guardians and lead neonatal clinicians of participating NHS trusts.

Setting

NHS neonatal units.

Participants

Neonatal clinical teams; parents of babies admitted to NHS neonatal units.

Interventions

In workstream 3, we employed the Bayley-III scales to evaluate neurodevelopmental status and the Quantitative Checklist of Autism in Toddlers (Q-CHAT) to evaluate social communication skills. In workstream 6, we recruited parents with previous experience of a child in neonatal care to assist in the design of a questionnaire directed at the parents of infants admitted to neonatal units.

Data sources

Data were extracted from the EPR of admissions to NHS neonatal units.

Main outcome measures

We created a National Neonatal Research Database (NNRD) containing a defined extract from real-time, point-of-care, clinician-entered EPRs from all NHS neonatal units in England, Wales and Scotland (n = 200), established a UK Neonatal Collaborative of all NHS trusts providing neonatal specialised care, and created a new NHS information standard: the Neonatal Data Set (ISB 1595) (see http://webarchive.nationalarchives.gov.uk/±/http://www.isb.nhs.uk/documents/isb-1595/amd-32–2012/index_html; accessed 25 June 2018).

Results

We found low discordance between clinical (NNRD) and research data for most important infant and maternal characteristics, and higher prevalence of clinical outcomes. Compared with research assessments, NHS clinical assessment at the age of 2 years has lower sensitivity but higher specificity for identifying children with neurodevelopmental impairment. Completeness and quality are higher for clinical than for administrative NHS data; linkage is feasible and substantially enhances data quality and scope. The majority of hospital resource inputs for economic evaluations of neonatal interventions can be extracted reliably from the NNRD. In general, there is strong parent support for sharing routine clinical data for research purposes.

Limitations

We were only able to include data from all English neonatal units from 2012 onwards and conduct only limited cross validation of NNRD data directly against data in paper case notes. We were unable to conduct qualitative analyses of parent perspectives. We were also only able to assess the utility of trial-based economic evaluations of neonatal interventions using a single trial. We suggest that results should be validated against other trials.

Conclusions

We show that it is possible to obtain research-standard data from neonatal EPRs, and achieve complete population coverage, but we highlight the importance of implementing systematic examination of NHS data quality and completeness and testing methods to improve these measures. Currently available EPR data do not enable ascertainment of neurodevelopmental outcomes reliably in very preterm infants. Measures to maintain high quality and completeness of clinical and administrative data are important health service goals. As parent support for sharing clinical data for research is underpinned by strong altruistic motivation, improving wider public understanding of benefits may enhance informed decision-making.

Future work

We aim to implement a new paradigm for newborn health care in which continuous incremental improvement is achieved efficiently and cost-effectively by close integration of evidence generation with clinical care through the use of high-quality EPR data. In future work, we aim to automate completeness and quality checks and make recording processes more ‘user friendly’ and constructed in ways that minimise the likelihood of missing or erroneous entries. The development of criteria that provide assurance that data conform to prespecified completeness and quality criteria would be an important development. The benefits of EPR data might be extended by testing their use in large pragmatic clinical trials. It would also be of value to develop methods to quality assure EPR data including involving parents, and link the NNRD to other health, social care and educational data sets to facilitate the acquisition of lifelong outcomes across multiple domains.

Study registration

This study is registered as PROSPERO CRD42015017439 (workstream 1) and PROSPERO CRD42012002168 (workstream 3).

Funding

The National Institute for Health Research Programme Grants for Applied Research programme (£1,641,471). Unrestricted donations were supplied by Abbott Laboratories (Maidenhead, UK: £35,000), Nutricia Research Foundation (Schiphol, the Netherlands: £15,000), GE Healthcare (Amersham, UK: £1000). A grant to support the use of routinely collected, standardised, electronic clinical data for audit, management and multidisciplinary feedback in neonatal medicine was received from the Department of Health and Social Care (£135,494).

Relationship of Necrotizing Enterocolitis Rates to Adoption of Prevention Practices in US Neonatal Intensive Care Units

BACKGROUND

Applying quality improvement methods has reduced necrotizing enterocolitis (NEC) in some neonatal intensive care units (NICUs) by 40% to 90%.

PURPOSE

This study was conducted to (1) examine relationships between adoption of prevention practices using the NEC-Zero adherence score and NEC rates, and (2) describe implementation strategies NICUs use to prevent NEC.

METHODS

A descriptive cross-sectional correlational study was completed among US quality improvement-focused NICUs. Relationships of the NEC-Zero adherence score to NEC rates were examined. Subgroup analyses explored relationships of a human milk adherence subscore and differences between high NEC rate (≥8%) and low NEC rate (≤2%) NICUs.

RESULTS

NICUs (N = 76) ranged in size from 18 to 114 beds. The mean adherence score was 7.3 (standard deviation = 1.7; range, 3-10). The 10-point adherence score was not related to the NEC rate. The human milk subscore related to lower NEC rates (Rho = -0.26, P = .049), as was colostrum for oral care (Rho = -0.27, P = .032). The units that used a feeding protocol showed higher NEC rates (Rho = 0.27, P = .03), although very few addressed the use of effective implementation strategies to track adherence or to ensure consistency among clinicians. The units that used colostrum for oral care were more likely to adopt strategies to limit inappropriate antibiotic exposure (Rho = 0.34, P = .003).

IMPLICATIONS FOR PRACTICE

Broader use of evidence-based implementation strategies could bolster delivery of NEC prevention practices. Maternal lactation support is paramount.

IMPLICATIONS FOR RESEARCH

Future studies are needed to identify how individual clinicians deliver prevention practices, to find the extent to which this relates to overall delivery of prevention, and to study effects of bundles on NEC outcomes.

Behavioural and neurodevelopmental impairment at school age following necrotising enterocolitis in the newborn period

AIM

The aim of this study was to evaluate long-term behavioural and neurodevelopmental complications of neonatal necrotizing enterocolitis at school age.

METHOD

This was a historic cohort study comparing all surviving children born in Denmark between 1st of January 2002 and 31st of December 2011 with a diagnosis of necrotizing enterocolitis to a group of children without necrotizing enterocolitis, but same gestational age, birth weight and year of birth. Outcomes were investigated through a parental questionnaire. The primary outcome was the Strength and Difficulties Questionnaire score and secondary outcomes were cerebral palsy and impaired head growth.

RESULTS

Response rates were 50% (163 of 328) and 36% (237 of 652) among children with and without necrotizing enterocolitis, respectively. There was a higher rate of abnormal Strength and Difficulties score (23.9 versus 17.8%), moderate/severe cerebral palsy (3.1 versus 0.9%) and small head circumference for age (11.7 versus 7.2%) among children with necrotizing enterocolitis. However, these differences were all statistically insignificant and did not change significantly by adjustment for potential confounders.

CONCLUSION

To our knowledge, this study includes the largest cohort of necrotizing enterocolitis children evaluated for possible long-term complications at school age. The increased risks of behavioural- and neurodevelopmental impairments were statistically insignificant, moderate in magnitude and may be of little clinical importance for management in the neonatal period or when planning follow-up.

Necrotizing Enterocolitis Cases Associated with Nosocomial Enterovirus Transmission in a Neonatal Unit

Infectious agents including viruses are thought to play a role in the pathogenesis of necrotizing enterocolitis, a well-known gastrointestinal emergency in newborns. Enteroviruses are common pathogens in neonates and have been associated with outbreaks in neonatal units. Enterovirus-associated necrotizing enterocolitis has been described in 3 preterms. Spatiotemporal and molecular analyses have provided evidence of nosocomial transmission.

Incidence of neonatal necrotising enterocolitis in high-income countries: a systematic review

OBJECTIVE

To conduct a systematic review of neonatal necrotising enterocolitis (NEC) rates in high-income countries published in peer-reviewed journals.

METHODS

We searched MEDLINE, Embase and PubMed databases for observational studies published in peer-reviewed journals. We selected studies reporting national, regional or multicentre rates of NEC in 34 Organisation for Economic Co-operation and Development countries. Two investigators independently screened studies against predetermined criteria. For included studies, we extracted country, year of publication in peer-reviewed journal, study time period, study population inclusion and exclusion criteria, case definition, gestation or birth weight-specific NEC and mortality rates.

RESULTS

Of the 1888 references identified, 120 full manuscripts were reviewed, 33 studies met inclusion criteria, 14 studies with the most recent data from 12 countries were included in the final analysis. We identified an almost fourfold difference, from 2% to 7%, in the rate of NEC among babies born <32 weeks' gestation and an almost fivefold difference, from 5% to 22%, among those with a birth weight <1000 g but few studies covered the entire at-risk population. The most commonly applied definition was Bell's stage ≥2, which was used in seven studies. Other definitions included Bell's stage 1-3, definitions from the Centers for Disease Control and Prevention, International Classification for Diseases and combinations of clinical and radiological signs as specified by study authors.

CONCLUSION

The reasons for international variation in NEC incidence are an important area for future research. Reliable inferences require clarity in defining population coverage and consistency in the case definition applied. PROSPERO INTERNATIONAL PROSPECTIVE REGISTER OF SYSTEMATIC REVIEWS REGISTRATION NUMBER: CRD42015030046.

Congenital Heart Disease Increases Mortality in Neonates With Necrotizing Enterocolitis

Background: Studies on the influence of congenital heart disease (CHD) on neonates with necrotizing enterocolitis (NEC) have produced varied results. We therefore examined the influence of CHD on NEC outcomes. Methods: We carried out a retrospective single-center study including infants with confirmed NEC, treated between 2004 and 2017. We excluded patients with isolated patent ductus arteriosus or pulmonary hypertension (n = 45) and compared outcomes of patients with hemodynamically relevant CHD (n = 38) and those without CHD (n = 91). Results: Patients with CHD were more mature than those without CHD [gestational age, median, 95% confidence interval (CI95), 37.1, 34.5-37.2w, vs. 32.6, 31.9-33.3w; P < 0.01]. The presence of CHD did not influence the frequencies of severe disease (overall 21% Bell stage III), nor surgical interventions (overall 30%), the occurrence of intestinal complications (overall 13%), nor the duration of hospitalization (overall 38 days in survivors). The overall mortality as well as NEC-related mortality was increased with the presence of CHD, being 50% (19 out of 38) and 13% (5 out of 38), respectively, when compared to patients without CHD, being 8% (7 out of 91) and 3% (3 out of 91). The presence of CHD and of advanced NEC stage III were independent predictors of NEC-associated fatalities with multivariable odds ratios (CI95) of 7.0, 1.3-39.5 for CHD, and of 3.4, 1.6-7.5 for stage III disease. Conclusions: While some outcome parameters in neonates with NEC remained unaffected by the presence of CHD, the mortality risk for patients with CHD was seven times higher than without CHD.

Effects of probiotics on experimental necrotizing enterocolitis: a systematic review and meta-analysis

BackgroundMeta-analyses of randomized controlled trials (RCTs) suggest that probiotics decrease the risk of necrotizing enterocolitis (NEC) in preterm infants. Many animal RCTs have evaluated probiotics for preventing NEC. We systematically reviewed the literature on this topic.MethodsThe protocol for systematic review of animal intervention studies (SYRCLE) was followed. Medline, Embase, ISI Web of Science, e-abstracts from the Pediatric Academic Society meetings, and other neonatal conferences were searched in December 2015 and August 2016. RCTs comparing probiotics vs. placebo/no probiotic were included.ResultsA total of 29 RCTs were included (Rats: 16, Mice: 7, Piglets: 3, Quail: 2, Rabbit: 1; N~2,310), with 21 reporting on histopathologically confirmed NEC; remaining 8 assessed only pathways of probiotic benefits. Twenty of the 21 RCTs showed that probiotics significantly reduced NEC. Pooling of data was possible for 16/21 RCTs. Meta-analysis using random-effects model showed that probiotics significantly decreased the risk of NEC (203/641 (31.7%) vs. 344/571 (60.2%); relative risk: 0.51; 95% confidence interval (CI): 0.42-0.62; P<0.00001; I2=44%; number needed to treat: 4; 95% CI: 2.9, 4.3).ConclusionProbiotics significantly reduced NEC via beneficial effects on immunity, inflammation, tissue injury, gut barrier, and intestinal dysbiosis.

Expert consensus to weight an adherence score for audit and feedback of practices that prevent necrotizing enterocolitis in very low birth weight infants

OBJECTIVE

Necrotizing enterocolitis (NEC) is a catastrophic abdominal complication threatening the life of premature infants, but adoption of prevention and early recognition practices differs as do NEC rates in Neonatal Intensive Care Units (NICUs). The purpose of this research was to validate and weight an evidence-based adherence score (aka NEC-Zero Adherence Score) to prevent and foster timely recognition of NEC.

STUDY DESIGN

An electronic Delphi (e-Delphi) approach was used to identify consensus. NEC experts were recruited via the NEC Society and surveyed until consensus and stability criteria for the Delphi were met (≥70% consensus and mean responses changed <15% between rounds).

RESULTS

Expert panelists (n=22) were experienced (M=17.6, SD 11years) and predominately physicians (68%) or neonatal nurse practitioners (18%). Consensus (>70% by item) supported a 10 point score. Points were distributed across 1) an exclusive human milk diet (5 points), 2) standardized feeding protocols (3 points), 3) antibiotic stewardship (1 point), and 4) a unit-specified approach to early recognition (1 point). Withholding feeding during transfusion was controversial (M=0.50, SD 0.73) and met consensus criteria to drop from the score.

CONCLUSIONS

Holding feeding during transfusion was dropped from the score. Relationships between the score and unit NEC rates as well as its utility for use in audit and feedback should be studied in the future.

Maternal hypertensive disorders are associated with increased use of respiratory support but not chronic lung disease or poorer neurodevelopmental outcomes in preterm neonates at <29 weeks of gestation

AIM

To assess whether maternal hypertensive disorders in pregnancies result in higher respiratory requirements, risk of chronic lung disease (CLD) and poorer neurodevelopmental outcome in <29-week premature neonates.

METHODS

This is a multicentre, retrospective cohort study, within a geographically defined area in Australia, served by a network of 10 neonatal intensive care units (NICUs), consisting of infants <29 weeks of gestational age who were admitted to NICUs between 1998 and 2004. Outcome measures included hospital survival, perinatal complications and functional disability at 2-3 years follow-up.

RESULTS

A total of 2549 mothers and infants were included in the study; 379 (14.9%) mothers had hypertensive disorders during pregnancy. Follow-up data were obtained for 1473 (74.8%) infants at 2-3 years. Infants exposed to pre-eclampsia had a higher need for supplemental surfactant therapy (odds ratio (OR): 2.004, 95% confidence interval (CI): 1.51-2.66), longer duration of mechanical ventilation (7.0 days vs. 4.0 days), were associated with a higher incidence of CLD (OR: 1.40, 95% CI: 1.12-1.76) and received post-natal steroids for CLD (OR: 1.82, 95% CI: 1.43-2.31) and home oxygen (OR: 1.47, 95% CI: 1.11-1.95). Multivariable analysis showed that hypertensive disease of pregnancy was not significantly associated with the development of CLD in this cohort (OR: 1.103, 95% CI: 0.845-1.441). Multivariable analysis of long-term neurodevelopmental data available for the 1473 follow-up infants showed no significant difference in outcomes with or without exposure to maternal hypertensive disease.

CONCLUSION

Maternal hypertensive disease of pregnancy does not increase the risk of CLD or long-term neurodevelopmental complications in infants born at <29 weeks of gestation.

Multiple strains probiotics appear to be the most effective probiotics in the prevention of necrotizing enterocolitis and mortality: An updated meta-analysis

BACKGROUND

Some oral probiotics have been shown to prevent necrotizing enterocolitis (NEC) and decrease mortality effectively in preterm very low birth weight (PVLBW) infants. However, it is unclear whether a single probiotic or a mixture of probiotics is most effective for the prevention of NEC.

OBJECTIVE

A meta-analysis was conducted by reviewing the most up to date literature to investigate whether multiple strains probiotics are more effective than a single strain in reducing NEC and death in PVLBW infants.

DATA SOURCES

Relevant studies were identified by searches of the MEDLINE, EMBASE, and Cochrane CENTRAL databases, from 2001 to 2016.

DATA EXTRACTION AND SYNTHESIS

The inclusion criteria were randomized controlled trials of any enteral probiotic supplementation that was initiated within the first 7 days and continued for at least 14 days in preterm infants (≤ 34 weeks' gestation) and/or those of a birth weight ≤1500 g.

RESULTS

A total of 25 trials (n = 7345 infants) were eligible for inclusion in the meta-analysis using a fixed-effects model. Multiple strains probiotics were associated with a marked reduction in the incidence of NEC, with a pooled OR of 0.36 (95% CI, 0.24-0.53; P < .00001). Single strain probiotic using Lactobacillus species had a borderline effect in reducing NEC (OR of 0.60; 95% CI 0.36-1.0; P = .05), but not mortality. Multiple strains probiotics had a greater effectiveness in reducing mortality and were associated with a pooled OR of 0.58 (95% CI, 0.43-0.79; P = .0006). Trials using single strain of Bifidobacterium species and Saccharomyces boulardii did not reveal any beneficial effects in terms of reducing NEC or mortality.

CONCLUSION

This updated report found that multiple strains probiotics appear to be the most feasible and effective strategy for the prevention of NEC and reduction of mortality in PVLBW neonates. Further clinical trials should focus on which probiotic combinations are most effective.

Surgical necrotizing enterocolitis

Although currently available data are variable, it appears that the incidence of surgical necrotizing enterocolitis (NEC) has not decreased significantly over the past decade. Pneumoperitoneum and clinical deterioration despite maximal medical therapy remain the most common indications for operative treatment. Robust studies linking outcomes with specific indications for operation are lacking. Promising biomarkers for severe NEC include fecal calprotectin and S100A12; serum fatty acid-binding protein; and urine biomarkers. Recent advances in ultrasonography make this imaging modality more useful in identifying surgical NEC and near-infrared spectroscopy (NIRS) is being actively studied. Another fairly recent finding is that regionalization of care for infants with NEC likely improves outcomes. The neurodevelopmental outcomes after surgical treatment are known to be poor. A randomized trial near completion will provide robust data regarding neurodevelopmental outcomes after laparotomy versus drainage as the initial operative treatment for severe NEC.

Does rapid enteral feeding increase intestinal morbidity in very low birth weight infants? A retrospective analysis

PURPOSE

To investigate the association of a standardized rapid enteral feeding strategy (established in 2011 in our unit) with intestinal morbidity in very low birth weight (VLBW) infants.

METHODS

A total of 301 inborn VLBW infants were included in this single-centre retrospective cohort study. We compared the incidence of intestinal morbidity (defined as necrotizing enterocolitis or intestinal perforation) in slowly enterally fed infants in 2008-2010 (10 ml/kg/day increase of milk feeds) to a corresponding cohort of rapidly enterally fed infants in 2011-2013 (20 ml/kg/day increase of milk feeds). Univariate and multivariable logistic and linear regression analyses, respectively, were performed to control for confounding variables.

RESULTS

Both groups were similar regarding baseline demographic and perinatal characteristics. In univariate modeling, intestinal morbidity did not significantly differ between the two groups (p = 0.25), neither did all-cause mortality nor incidence of late onset sepsis in multivariable modeling. In contrast, length of hospital stay (HS) and duration of parenteral nutrition (PEN) were significantly shorter in the rapid group (HS: -8.35 days, p = 0.012 and PEN: -7.13 days, p < 0.001).

CONCLUSIONS

Implementation of a more rapid enteral feeding regime is safe in VLBW infants and may significantly shorten length of HS and PEN in this cohort.

Necrotizing enterocolitis: new insights into pathogenesis and mechanisms

Necrotizing enterocolitis (NEC) is the most frequent and lethal disease of the gastrointestinal tract of preterm infants. At present, NEC is thought to develop in the premature host in the setting of bacterial colonization, often after administration of non-breast milk feeds, and disease onset is thought to be due in part to a baseline increased reactivity of the premature intestinal mucosa to microbial ligands as compared with the full-term intestinal mucosa. The increased reactivity leads to mucosal destruction and impaired mesenteric perfusion and partly reflects an increased expression of the bacterial receptor Toll-like receptor 4 (TLR4) in the premature gut, as well as other factors that predispose the intestine to a hyper-reactive state in response to colonizing microorganisms. The increased expression of TLR4 in the premature gut reflects a surprising role for this molecule in the regulation of normal intestinal development through its effects on the Notch signalling pathway. This Review will examine the current approach to the diagnosis and treatment of NEC, provide an overview of our current knowledge regarding its molecular underpinnings and highlight advances made within the past decade towards the development of specific preventive and treatment strategies for this devastating disease.

15-Hydroxyprostaglandin Dehydrogenase Protein Expression in Human Fetal Membranes With and Without Subclinical Inflammation

Prostaglandins play a central role in the stimulation and maintenance of both term and preterm labor. 15-Hydroxyprostaglandin dehydrogenase (PGDH), localized primarily to chorion trophoblasts, is the key enzyme responsible for the metabolism of prostaglandins. In preterm chorion, levels of PGDH protein and activity were lower when compared to term and were further reduced with the presence of infection, but effects of subclinical inflammation and membrane rupture on PGDH expression are not known. Our objectives were (1) to determine the relative expression of PGDH in amnion and chorion and (2) to determine the effect of preterm premature rupture of membranes (PPROM) and (3) subclinical inflammation on PGDH protein expression in preterm fetal membranes. Fetal membranes were collected from women with idiopathic preterm labor. Patients were divided into preterm birth (1) <32 weeks with PPROM (n = 6), (2) <32 weeks with intact membranes (n = 11), (3) >or=32 and <37 weeks with PPROM (n = 10), and (4) >or=32 and <37 weeks with intact membranes (n = 10). Different antibodies were used to detect protein expression and localization of PGDH in amnion and chorion from these patients using both Western blotting and immunohistochemistry. Antibody T (AbT) localized PGDH to chorion trophoblasts, whereas antibody C (AbC) detected immunoreactive (ir) PGDH predominantly in the amnion mesenchyme. By Western blot, AbT showed a stronger 29-kDa ir-PGDH band whereas with AbC, a stronger 55-kDa ir-PGDH signal was detected. 55-kDa ir-PGDH was significantly higher in PPROM amnion, specifically in the <32 weeks group (P < .05) and with PPROM >24 hours (P < .05). No change was detected in the 29-kDa ir-PGDH in either amnion or chorion with gestational age or the presence and absence of PPROM. In addition, neither form of ir-PGDH was altered significantly with or without subclinical inflammation. ir-PGDH is detectable in both chorion trophoblasts and amnion, especially in the mesenchyme; however, the predominant form of the enzyme differs in the 2 tissues. PPROM and subclinical inflammation do not appear to affect the levels of 29-kDa ir-PGDH protein in the fetal membranes. The differential expression of 55-kDa ir-PGDH in preterm amnion with and without PPROM supports the need for a better understanding of the different forms of PGDH.

Oral immunoglobulin for preventing necrotizing enterocolitis in preterm and low birth weight neonates

BACKGROUND

Necrotizing enterocolitis (NEC) is the most common emergency involving the gastrointestinal tract occurring in the neonatal period. There have been published reports that suggest that oral immunoglobulins (Ig)A and IgG produce an immunoprotective effect in the gastrointestinal mucosa.

OBJECTIVES

To determine the effect of oral immunoglobulin on the incidence of necrotizing enterocolitis and other complications in preterm or low birth weight (or both) neonates.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Group. We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library 2016, Issue 1), PubMed (1966 to January 2016), CINAHL (1982 to January 2016) and EMBASE (1980 to January 2016) and conference proceedings.

SELECTION CRITERIA

All randomized or quasi-randomised controlled trials where oral immunoglobulins were used as prophylaxis against NEC in preterm (less than 37 weeks' gestation) or low birth weight (less than 2500 gram), or both, neonates.

DATA COLLECTION AND ANALYSIS

We performed data collection and analysis in accordance with the standard methods of the Cochrane Neonatal Review Group.

MAIN RESULTS

The search identified five studies on oral immunoglobulin for the prevention of NEC of which three met the inclusion criteria. In this review of the three eligible trials (including 2095 neonates), the oral administration of IgG or an IgG/IgA combination did not result in a significant reduction in the incidence of definite NEC (typical risk ratio (RR) 0.84, 95% confidence interval (CI) 0.57 to 1.25; typical risk difference (RD) -0.01, 95% CI -0.03 to 0.01; 3 studies, 1840 infants), suspected NEC (RR 0.84, 95% CI 0.49 to 1.46; RD -0.01, 95% CI -0.02 to 0.01; 1 study, 1529 infants), need for surgery (typical RR 0.21, 95% CI 0.02 to 1.75; typical RD -0.03, 95% CI -0.06 to 0.00; 2 studies, 311 infants) or death from NEC (typical RR 1.10, 95% CI 0.47 to 2.59; typical RD 0.00, 95% CI -0.01 to 0.01; 3 studies, 1840 infants).

AUTHORS' CONCLUSIONS

Based on the available trials, the evidence does not support the administration of oral immunoglobulin for the prevention of NEC. There are no randomized controlled trials of oral IgA alone for the prevention of NEC.

Outcome in neonates with necrotizing enterocolitis and patent ductus arteriosus

BACKGROUND

There is no agreement of the influence of patent ductus arteriosus (PDA) on outcomes in patients with necrotizing enterocolitis (NEC). In this study, we assessed the influence of PDA on NEC outcomes.

METHODS

A retrospective study of 131 infants with established NEC was performed. Outcomes (death, disease severity, need for surgery, hospitalization duration), as well as multiple clinical parameters were compared between NEC patients with no congenital heart disease (n=102) and those with isolated PDA (n=29). Univariate, multivariate and stepwise logistic regression analyses were performed.

RESULTS

Birth weight and gestational age were significantly lower in patients with PDA [median (95% CI): 1120 g (1009-1562 g), 28.4 wk (27.8-30.5 wk)] than in those without PDA [median (95% CI): 1580 g (1593-1905 g), 32.4 wk (31.8-33.5 wk); P<0.05]. The risk of NEC-attributable fatality was higher in NEC patients with PDA (35%) than in NEC patients without PDA (14%)[univariate odds ratio (OR)=3.3, 95% CI: 1.8-8.6, P<0.05; multivariate OR=2.4, 95% CI: 0.82-2.39, P=0.111]. Significant independent predictors for non-survival within the entire cohort were advanced disease severity stage III (OR=27.9, 95% CI: 7.4-105, P<0.001) and birth weight below 1100 g (OR=5.7, 95% CI: 1.7-19.4, P<0.01).

CONCLUSIONS

In patients with NEC, the presence of PDA is associated with an increased risk of death. However, when important differences between the two study groups are controlled, only birth weight and disease severity may independently predict mortality.

Necrotizing Enterocolitis among Very-Low-Birth-Weight Infants in Korea

Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency and remains a major cause of mortality for very-low-birth-weight infants (VLBWI) requiring surgery. To date, there have been no large-scale studies evaluating the incidence, associated clinical factors and outcomes of NEC for VLBWI in Korea. The 2,326 VLBWI of a total 2,386 Korean Neonatal Network (KNN) cohort born with a birth weight below 1,500 g between January 2013 to June 2014 were included in this analysis. The overall incidence of NEC (stage ≥ 2) among VLBWI in Korea was 6.8%; 149 infants had NEC stage ≥ 2 and 2,177 infants did not have NEC. Surgery was performed for 77 (53%) of the infants in the NEC group. NEC was related to lower gestational age (GA) and birth weight (P < 0.001). Multivariate logistic regression analysis demonstrated that NEC was consistently related to hypotension within one week after birth (OR 2.0, 95% CI 1.0-3.9). With respect to outcome, the NEC group had longer times to reach 100 mL/kg/day feeding (P < 0.001), longer TPN duration (P < 0.001) and hospitalization (P = 0.031) and higher PVL (P < 0.001) and mortality rate (P < 0.001). When the medical and surgical NEC groups were compared, GA was significantly lower and PDA was more found in the surgical NEC group. The overall incidence of NEC in Korea is similar to that of other multicenter studies. In addition to GA and birth weight, hypotension within a week of life is significantly related to NEC.

A novel scoring system to predict the development of necrotizing enterocolitis totalis in premature infants

BACKGROUND/PURPOSE

Necrotizing enterocolitis totalis (NEC-totalis) is the severest form of NEC, with mortality rate of almost 100% even in the busiest neonatal centers. Despite such a prognosis, its risk factors remain elusive. We seek to identify clinical and laboratory parameters that differentiate NEC-totalis from NEC, and to use these factors to develop a scoring system to identify patients at risk for NEC-totalis upon presentation.

METHOD

NEC patients were identified from our electronic medical record using ICD9 code. Diagnosis of NEC-totalis was based on operative and autopsy reports. Patients were divided into 2 groups: NEC-but-no-totalis and NEC-totalis. Clinical/laboratory data were obtained for each group. T-test, multivariate logistic regression and backward stepwise regression analysis were performed to identify risk factors for NEC-totalis and these risk factors were formulated into a "Totalis Score."

RESULT

Among 157 NEC patients, 13 had NEC-totalis. NEC-totalis patients, compared to NEC alone, had fewer platelets, older age at diagnosis of NEC and greater phosphorus and creatinine levels. A 0-5 point scale "Totalis Score" based on these risk factors had sensitivity of 92% and a specificity of 78% for the diagnosis of NEC-totalis.

CONCLUSION

Low platelet, high phosphorus, high creatinine and older age at diagnosis of NEC were associated with a greater risk of developing NEC-totalis.

Discrimination of GutCheck(NEC): a clinical risk index for necrotizing enterocolitis

OBJECTIVE

Better measures are needed to identify infants at risk for developing necrotizing enterocolitis (NEC) and facilitate communication about risk across transitions. Although NEC is multi-factorial, quantification of composite risk for NEC in an individual infant is not clearly defined. The objective of this study was to describe the derivation, validation and calibration testing of a novel clinical NEC risk index, GutCheck(NEC). Individual risk factors were weighted to assess composite odds of developing NEC. GutCheck(NEC) is designed to improve communication about NEC risk and coordination of care among clinicians across an infant's clinical course.

STUDY DESIGN

On the basis of a synthesis of research evidence about NEC risk and an e-Delphi study including 35 neonatal experts, we identified NEC risk factors believed by the experts to be most relevant for a NEC risk index, then applied a logistic model building process to derive and validate GutCheck(NEC). De-identified data from the Pediatrix BabySteps Clinical Data Warehouse (discharge date 2007 to 2011) were split into three samples for derivation, validation and calibration. By comparing infants with medical NEC, surgical NEC and those who died to infants without NEC, we derived the logistic model using the un-matched derivation set. Discrimination was then tested in a case-control matched validation set and an un-matched calibration set using receiver operating characteristic curves.

RESULT

Sampled from a cohort of 58 820 infants, the randomly selected derivation set (n=35 013) revealed nine independent risk factors (gestational age, history of packed red blood cell transfusion, unit NEC rate, late-onset sepsis, multiple infections, hypotension treated with inotropic medications, Black or Hispanic race, outborn status and metabolic acidosis) and two risk reducers (human milk feeding on both days 7 and 14 of life, and probiotics). Unit NEC rate carried the most weight in the summed score. Validation using a 2:1 matched case-control sample (n=360) demonstrated fair to good discrimination. In the calibration set (n=23 447), GutCheck(NEC) scores (range 0 to 58) discriminated those infants who developed surgical NEC (area under the curve (AUC)=0.84, 95% confidence interval (CI) 0.82 to 0.84) and NEC leading to death (AUC=0.83, 95% CI 0.81 to 0.85), more accurately than medical NEC (AUC= 0.72, 95% CI 0.70 to 0.74).

CONCLUSION

GutCheck(NEC) represents weighted composite risk for NEC and discriminated infants who developed NEC from those who did not with very good accuracy. We speculate that targeting modifiable NEC risk factors could reduce national NEC prevalence.

Lactobacillus rhamnosus HN001 decreases the severity of necrotizing enterocolitis in neonatal mice and preterm piglets: evidence in mice for a role of TLR9

Necrotizing enterocolitis (NEC) is the leading cause of death from gastrointestinal disease in premature infants and develops partly from an exaggerated intestinal epithelial immune response to indigenous microbes. There has been interest in administering probiotic bacteria to reduce NEC severity, yet concerns exist regarding infection risk. Mechanisms of probiotic activity in NEC are unknown although activation of the microbial DNA receptor Toll-like receptor-9 (TLR9) has been postulated. We now hypothesize that the Gram-positive bacterium Lactobacillus rhamnosus HN001 can attenuate NEC in small and large animal models, that its microbial DNA is sufficient for its protective effects, and that protection requires activation of the Toll-like receptor 9 (TLR9). We now show that oral administration of live or UV-inactivated Lactobacillus rhamnosus HN001 attenuates NEC severity in newborn mice and premature piglets, as manifest by reduced histology score, attenuation of mucosal cytokine response, and improved gross morphology. TLR9 was required for Lactobacillus rhamnosus-mediated protection against NEC in mice, as the selective decrease of TLR9 from the intestinal epithelium reversed its protective effects. Strikingly, DNA of Lactobacillus rhamnosus HN001 reduced the extent of proinflammatory signaling in cultured enterocytes and in samples of resected human ileum ex vivo, suggesting the therapeutic potential of this probiotic in clinical NEC. Taken together, these findings illustrate that Lactobacillus rhamnosus HN001 is an effective probiotic for NEC via activation of the innate immune receptor TLR9 and that Lactobacillus rhamnosus DNA is sufficient for its protective effects, potentially reducing concerns regarding the infectious risk of this novel therapeutic approach.

Risk of necrotizing enterocolitis in very-low-birth-weight infants with isolated atrial and ventricular septal defects

OBJECTIVE

Necrotizing enterocolitis (NEC) is associated with a significant morbidity and mortality in premature infants. We sought to identify the frequency of NEC in very-low-birth-weight infants with isolated ventricular septal defects (VSDs) or atrial septal defects (ASDs) using a large multicenter database.

STUDY DESIGN

We identified a cohort of infants with birth weight <1500 g cared for in 312 neonatal intensive care units (NICUs) managed by the Pediatrix Medical Group between 1997 and 2010. We examined the association between the presence of an ASD or a VSD with development of NEC using logistic regression to control for small-for-gestational age status, antenatal steroid use, antenatal antibiotic use, gestational age, sex, race, Apgar score at 5 min and method of delivery.

RESULT

Of the 98 523 infants who met inclusion criteria, 1904 (1.9%) had an ASD, 1943 (2.0%) had a VSD and 146 (0.1%) had both. The incidence of NEC was 6.2% in infants without septal defects, 9.3% in those with an ASD, 7.8% in those with a VSD, and 10.3% in infants with both an ASD and a VSD. Compared with infants without septal defects, the adjusted odds ratios for developing NEC for each group-ASD alone, VSD alone and ASD with VSD-were 1.26 (95% confidence interval 1.07 to 1.49), 1.27 (1.07 to 1.51) and 1.79 (1.03 to 3.12), respectively.

CONCLUSION

The presence of an ASD or a VSD was associated with NEC in this cohort of premature infants.

Clinical importance of a fixed bowel loop in the treatment of necrotizing enterocolitis

BACKGROUND

The need for surgical treatment in neonates with necrotizing enterocolitis (NEC) is associated with high mortality. Although pneumoperitoneum and progressive disease are generally accepted indications for surgery, it is unclear whether a fixed bowel loop (FBL) should prompt surgery.

OBJECTIVE

To determine the relationship between an FBL, type of treatment, and death in the management of NEC.

METHODS

Retrospective analysis (January 2000-December 2011) of all neonates with definite NEC in a tertiary neonatal intensive care unit. FBL was defined as a persistent (i.e. >24 h) dilated intestinal segment present on serial abdominal X-rays.

RESULTS

NEC was diagnosed in 141 neonates (median gestational age 30 weeks; median birth weight 1,340 g). An FBL was reported in 38 (27%) patients, of whom 18 were treated surgically. Mortality among FBL patients was independent of the type of treatment (surgical versus conservative): 8/18 and 7/20, respectively (p = 0.55). Of the 103 patients without FBL, 37 (36%) were treated surgically, which is comparable to the FBL group. Again, mortality was not related to the type of treatment (surgical versus conservative): 5/37 and 6/66, respectively (p = 0.49). The presence of an FBL was associated with mortality: more patients with an FBL (15/38, 39%) died than without an FBL (11/103, 11%; odds ratio 5.45, 95% confidence interval 2.21-13.45; p < 0.01).

CONCLUSIONS

In NEC patients, an FBL is associated with increased mortality. On its own it has moderate significance to guide treatment. Nevertheless, because it reflects disease severity, early recognition is important and prompt (surgical) treatment should be considered.

Antenatal steroid exposure and outcomes of very premature infants: a regional cohort study

OBJECTIVE

To compare mortality, short-term morbidity and long-term neurodevelopmental outcomes of <29 week premature infants with antenatal steroid exposure (none, incomplete and complete).

PATIENTS AND METHODS

Multicentre retrospective cohort study, within a geographically defined area in Australia served by a network of 10 neonatal intensive care units (NICUs), of infants <29 weeks gestational age, admitted to NICUs between 1998 and 2004. Outcome measures included hospital survival, perinatal complications and functional disability at 2-3 years follow-up.

RESULTS

2549 neonates were included; 319 (12.5%) received no exposure to steroids. Hospital mortality (OR 0.59, 95% CI 0.45 to 0.76, p<0.001, intraventricular haemorrhage (IVH) (OR 0.58, 95% CI 0.42 to 0.81, p=0.001) and necrotising entercolitis (NEC) (OR 0.62, 95% CI 0.42 to 0.91, p=0.018) was less likely in infants with any steroid exposure. Any steroid exposure was associated with less need for surfactant (OR 0.41, 95% CI 0.30 to 0.57, p<0.001) and mechanical ventilation (OR 0.30, 95% CI 0.17 to 0.52, p<0.001). Subgroup analyses demonstrated differences in outcomes only with complete steroid coverage and not with incomplete coverage. Survival benefit and reduction in the incidence of severe IVH was evident from 24 to 28 weeks. Long-term neurodevelopmental data available for 1473 survivors showed no significant difference in outcomes with steroid exposure after multivariate analysis.

CONCLUSIONS

Exposure to a complete course of antenatal steroids is associated with higher infant survival rates, lower rates of severe IVH and NEC compared to an incomplete course or no exposure. Any exposure to steroids reduces the risk of moderate cerebral palsy, however, long-term neurodevelopmental outcome may not be affected by steroid exposure.

The challenges facing training in pediatric surgery worldwide

Like most specialties, pediatric surgery is becoming more complex, and changes to health systems have not always been in the best interests of trainees or their surgical teachers. This paper outlines four of the current challenges faced by training boards in pediatric surgery worldwide, and documents their implications for the future training of pediatric surgeons.

Epidemiology and trends of necrotizing enterocolitis in Sweden: 1987-2009

OBJECTIVE

To investigate temporal, seasonal, and geographic variations in the incidence of necrotizing enterocolitis (NEC) and its relation to early infant survival in the Swedish population and in subgroups based on gestational age, birth weight, and gender.

METHODS

In the Swedish birth cohort of 1987 through 2009 all children with a diagnosis of NEC were identified in the National Patient Register, the Swedish Medical Birth Register, and the National Cause of Death Register. NEC incidence, early mortality, and seasonality were analyzed with descriptive statistics, Poisson regression, and auto regression.

RESULTS

The overall incidence of NEC was 3.4 in 10,000 live births, higher in boys than in girls (incidence rate ratio 1.22, 95% confidence interval 1.06-1.40, P = .005), with a peak in November and a trough in May, and increased with an average of ~5% a year during the study period. In most subgroups, except the most immature, an initial decrease was followed by a steady increase. Seven-day mortality decreased strongly in all subgroups over the entire study period (annual incidence rate ratio 0.96, 95% confidence interval 0.95-0.96, P < .001). This was especially marked in the most premature and low birth weight infants.

CONCLUSIONS

After an initial decrease, the incidence of NEC has increased in Sweden during the last decades. An association with the concurrent dramatically improved early survival seems likely.

Prevention of necrotizing enterocolitis in preterm very low birth weight infants: is it feasible?

Necrotizing enterocolitis (NEC) is still one of the most catastrophic intestinal emergencies in preterm very low-birth weight infants. Primary prevention of NEC should be the priority, since NEC frequently progresses from nonspecific signs, to extensive necrosis within a matter of hours with medical or surgical treatment, making successful treatment and secondary prevention difficult to achieve. Currently available strategies for primary prevention of NEC include antenatal glucocorticosteroids, breast milk feeding, cautious feeding strategy, fluid restriction and probiotics. Nonetheless, based on current research evidence, mixed flora probiotics, and/or breast milk feeding, would appear to be the most effective feasible methods in the prevention of NEC at present.

Early Versus Late Minimal Enteral Feeding in Weeks Preterm Growth-Restricted neonates with Abnormal Antenatal Doppler Studies

Abstract Background: Preterm and growth-restricted babies are at high risk of milk intolerance and necrotising enterocolitis, as well as post-natal growth failure. Objective: To evaluate the effects of an "early" enteral feeding regimen, starting on day 2 after birth compared to late enteral feeding, starting on day 6 after birth in preterm growth restricted babies with abnormal antenatal Doppler studies regarding the incidence of NEC and feeding intolerance. Patients and Methods: Babies with gestational age below 37 weeks, and with birth weight below 10th centile for gestational age, will be randomly allocated to an "early" or "late" enteral feeding regimen. Results: Hundred-thirty three infants enrolled in the study: 66 received early feeding and 67 received delayed feeding. The incidence of NEC and feeding intolerance was not significantly different between the two groups. Conclusion: Early minimal enteral feeding (MEF) of preterm infants with IUGR and abnormal antenatal Doppler results may not have a significant effect on the incidence of NEC or feeding intolerance.

Episodes of apnea, desaturation and bradycardia and the development of necrotizing enterocolitis in preterm infants: a case-control study

OBJECTIVE

To investigate for any association between episodes of apnea, desaturation and bradycardia and necrotizing enterocolitis (NEC).

METHODS

Case-control study in infants of gestational age < 30 weeks. For each NEC case we selected two controls. During the period from 2001 to 2007, data were extracted from the nurse's notes of the patient's medical records. A p < 0.05 was statistically significant.

RESULTS

A total of 38 out of 394 infants had NEC (9.6%). There were no significant differences in baseline characteristics between the 2 groups, except for a lower proportion of infants who were receiving breast milk in the NEC group (p = 0.02). There was no difference in the overall number of apneas & bradycardias or severe episodes of desaturation & bradycardia between the 2 groups.

CONCLUSION

No association between episodes of apnea, severe desaturations or bradycardia and development of NEC was observed in this preterm population.

Incidence and timing of presentation of necrotizing enterocolitis in preterm infants

OBJECTIVES

To examine the variation in the incidence and to identify the timing of the presentation of necrotizing enterocolitis (NEC) in a cohort of preterm infants within the Canadian Neonatal Network (CNN).

METHODS

This was a population-based cohort of 16 669 infants with gestational age (GA) <33 weeks, admitted to 25 NICUs participating in the CNN between January 1, 2003, and December 31(,) 2008. Variations in NEC incidence among the participating NICUs for the study period were examined. We categorized early-onset NEC as occurring at <14 days of age and late-onset NEC occurring at ≥14 days. Multivariate logistic regression analysis was performed to identify risk factors for early-onset NEC.

RESULTS

The overall incidence of NEC was 5.1%, with significant variation in the risk adjusted incidence among the participating NICUs in the CNN. Early-onset NEC occurred at a mean of 7 days compared with 32 days for late-onset NEC. Early-onset NEC infants had lower incidence of respiratory distress syndrome, patent ductus treated with indomethacin, less use of postnatal steroids, and shorter duration of ventilation days. Multivariate logistic regression analysis identified that greater GA and vaginal delivery were associated with increased risk of early-onset NEC.

CONCLUSIONS

Among infants <33 weeks' gestation, NEC appears to present at mean age of 7 days in more mature infants, whereas onset of NEC is delayed to 32 days of age in smaller, lower GA infants. Further studies are required to understand the etiology of this disease process.

Risk factors for necrotizing enterocolitis totalis: a case-control study

OBJECTIVE

The objective of this study was to compare demographic and clinical events in three groups of preterm neonates: those with necrotizing enterocolitis totalis (NEC-T), those with NEC non-totalis (NEC non-T) and in preterm patients without NEC.

STUDY DESIGN

This retrospective case-control study was conducted at Yale New Haven Children's Hospital using patient data from January 1991 to December 2007. Study patients were less than 36 weeks of gestational age (GA) at birth, without gastrointestinal (GI) malformations. Cases (NEC-T) were diagnosed at operation or at autopsy with observation of >80% necrosis of the GI tract. Two control groups were assigned: Group 1 or NEC non-T and Group II or Non-NEC. Two to four controls per case were matched to cases by GA at birth±2 weeks. Demographic and clinical data for the day of diagnosis and retrospectively up to 7 days preceding diagnosis were recorded for those with NEC-T and NEC. Group II controls were matched for date of birth and day of life, in addition to GA at birth.

RESULT

A total of 14 075 patients were admitted to the Newborn Special Care Unit during the study interval. Overall 328 patients (2.3%) developed NEC≥Bell's Stage II; 39 patients met inclusion criteria for NEC-T case status; 148 NEC non-T and 110 non-NEC controls were assigned. In the comparison of NEC T and NEC non-T neonates, use of breast milk was associated with decreased risk of NEC-T, adjusted odds ratio (OR)=0.26, 95% confidence interval (CI) of OR=0.08-0.085, P=0.03. When NEC T and non-NEC patients were compared, having reached full-enteral feeds before the date of diagnosis of the matched case (adjusted OR=28.5, 95% CI of OR=2.7-299, P=0.005) and use of breast milk (adjusted OR=0.09, 95% CI of OR=0.02-0.56, P=0.01) were significantly different between the two groups.

CONCLUSION

Breast milk usage was significantly associated with decreased occurrence of NEC-T in our comparison of NEC-T, NEC non-T and non-NEC patients. Although there were some differences, the majority of demographic and clinical variables assessed were not shown to be significantly different between cases and controls. This highlights the need for more biological data in assessing risk of developing NEC-T.

Peritoneal drainage versus laparotomy as initial surgical treatment for perforated necrotizing enterocolitis or spontaneous intestinal perforation in preterm low birth weight infants

BACKGROUND

Standard surgical management of infants with perforated necrotizing enterocolitis (NEC) or spontaneous intestinal perforation (SIP) is laparotomy with the resection of the necrotic or perforated segments of the intestine. Peritoneal drainage is an alternative approach to the management of such infants.

OBJECTIVES

To evaluate the benefits and risks of peritoneal drainage compared to laparotomy as the initial surgical treatment for perforated NEC or SIP in preterm infants.

SEARCH STRATEGY

Cochrane Central Register of Controlled Trials (CENTRAL), (The Cochrane Library 2010, Issue 3), MEDLINE (1966 to July 2010), EMBASE (1980 to July 2010), CINAHL (1982 to July 2010), previous reviews and cross-references were searched. Abstracts of paediatric academic society meetings were also searched (online: 2000 to 2009; handsearching Pediatric Research: 1995 to 2000).

SELECTION CRITERIA

All randomised or quasi-randomised controlled trials in preterm (< 37 weeks gestation), low birth weight (< 2500 g) infants with perforated NEC or SIP allocated to peritoneal drainage or laparotomy as initial surgical treatment.

DATA COLLECTION AND ANALYSIS

Data were excerpted from the trial reports and analysed according to the standards of the Cochrane Neonatal Review Group.

MAIN RESULTS

Only two randomised controlled trials (RCT) met the eligibility criteria. Overall, no significant differences were seen between the peritoneal drainage and laparotomy groups regarding the incidence of mortality within 28 days of the primary procedure (28/90 versus 30/95; typical relative risk (RR) 0.99, 95% CI 0.64 to 1.52; N = 185, two trials); mortality by 90 days after the primary procedure (typical RR 1.05, 95% CI 0.71 to 1.55; N = 185, two trials) and the number of infants needing total parenteral nutrition for more than 90 days (typical RR 1.18, 95% CI 0.72 to 1.95; N = 116, two trials). Nearly 50% of the infants in the peritoneal drainage group could avoid the need for laparotomy during the study period (44/90 versus 95/96; typical RR 0.49, 95% CI 0.39 to 0.61; N = 186, two trials). One study found that the time to attain full enteral feeds in infants ≤ 1000 g was prolonged in the peritoneal drainage group (mean difference (MD) 20.77, 95% CI 3.62 to 37.92).

AUTHORS' CONCLUSIONS

Evidence from two RCTs suggests no significant benefits or harms of peritoneal drainage over laparotomy. However, due to the very small sample size, clinically significant differences may have easily been missed. No firm recommendations can be made for clinicians. Large multicentre randomised controlled trials are needed to address this question definitively.

New insights into the pathogenesis and treatment of necrotizing enterocolitis: Toll-like receptors and beyond

Necrotizing enterocolitis (NEC) is the leading cause of death from gastrointestinal disease in the preterm infant. The dismal results of current treatment for NEC highlight the urgent need for greater understanding of the pathogenesis of this disease, and the importance of discovering novel, molecular-specific therapies for it. Current dogma indicates that NEC development reflects an abnormal response by the premature infant to the microbial flora that colonizes the gastrointestinal tract, although the mechanisms that mediate these abnormal bacterial-enterocyte interactions and the reasons for the particularly increased susceptibility of the premature infant to the development of NEC remain incompletely explained. Recent evidence has shed light on an emerging role for the Toll-like receptors (TLRs) of the innate immune system as central players in the pathways that signal in response to enteric bacteria resulting in the development of NEC. We now review recent advances in the field of NEC and identify several exciting potential avenues for novel treatments by focusing on abnormal TLR4 signaling in the premature intestine in the pathogenesis of NEC. In so doing, we seek to offer new hope to the patients and their families who are affected by this devastating disorder.

Metronidazole population pharmacokinetics in preterm neonates using dried blood-spot sampling

OBJECTIVES

To characterize the population pharmacokinetics of metronidazole in preterm neonates.

PATIENTS AND METHODS

Data were collected prospectively from 32 preterm neonates who received intravenous metronidazole for the treatment of or prophylaxis against necrotizing enterocolitis. Dried blood spots (n = 203) on filter paper were analyzed by high-performance liquid chromatography, and the data were subjected to pharmacokinetic analysis performed by using nonlinear mixed-effect modeling.

RESULTS

A 1-compartment model best described the data. Significant covariates were weight (WT) and postmenstrual age (PMA). The final population models for metronidazole clearance (CL) and volume of distribution (V) were: CL = 0.0247 × (WT/1.00)(0.75) × (1 + 0.107 × [PMA - 30]) and V = 0.726 × WT, where CL is in liters per hour, WT is in kilograms, PMA is in weeks, and V is in liters. This model predicts that the half-life of metronidazole decreases rapidly from ∼40 hours at 25 weeks' PMA to 19 hours at 32 weeks' PMA, after which it starts to plateau. This decrease in half-life is the result of a 5-fold increase in CL compared with only a 2.5-fold increase in V during the same period.

CONCLUSIONS

Currently, there are no specific dose recommendations for metronidazole in preterm neonates. However, a dosing scheme for preterm neonates that takes into consideration both the weight and PMA has been suggested and should avoid administration of doses that are excessive or more frequent than necessary.

Updated meta-analysis of probiotics for preventing necrotizing enterocolitis in preterm neonates

OBJECTIVE

Systematic reviews of randomized, controlled trials (RCTs) indicate lower mortality and necrotizing enterocolitis (NEC) and shorter time to full feeds after probiotic supplementation in preterm (<34 weeks' gestation) very low birth weight (VLBW; birth weight <1500 g) neonates. The objective of this study was to update our 2007 systematic review of RCTs of probiotic supplementation for preventing NEC in preterm VLBW neonates.

METHODS

We searched in March 2009 the Cochrane Central register; Medline, Embase, and Cinahl databases; and proceedings of the Pediatric Academic Society meetings and gastroenterology conferences. Cochrane Neonatal Review Group search strategy was followed. Selection criteria were RCTs of any enteral probiotic supplementation that started within first 10 days and continued for > or =7 days in preterm VLBW neonates and reported on stage 2 NEC or higher (Modified Bell Staging).

RESULTS

A total of 11 (N = 2176), including 4 new (n = 783), trials were eligible for inclusion in the meta-analysis by using a fixed-effects model. The risk for NEC and death was significantly lower. Risk for sepsis did not differ significantly. No significant adverse effects were reported. Trial sequential analysis) showed 30% reduction in the incidence of NEC (alpha = .05 and .01; power: 80%).

CONCLUSIONS

The results confirm the significant benefits of probiotic supplements in reducing death and disease in preterm neonates. The dramatic effect sizes, tight confidence intervals, extremely low P values, and overall evidence indicate that additional placebo-controlled trials are unnecessary if a suitable probiotic product is available.