National prospective surveillance study of necrotizing enterocolitis in neonatal intensive care units

Particular genomic and virulence traits associated with preterm infant-derived toxigenic Clostridium perfringens strains

Clostridium perfringens is an anaerobic toxin-producing bacterium associated with intestinal diseases, particularly in neonatal humans and animals. Infant gut microbiome studies have recently indicated a link between C. perfringens and the preterm infant disease necrotizing enterocolitis (NEC), with specific NEC cases associated with overabundant C. perfringens termed C. perfringens-associated NEC (CPA-NEC). In the present study, we carried out whole-genome sequencing of 272 C. perfringens isolates from 70 infants across 5 hospitals in the United Kingdom. In this retrospective analysis, we performed in-depth genomic analyses (virulence profiling, strain tracking and plasmid analysis) and experimentally characterized pathogenic traits of 31 strains, including 4 from CPA-NEC patients. We found that the gene encoding toxin perfringolysin O, pfoA, was largely deficient in a human-derived hypovirulent lineage, as well as certain colonization factors, in contrast to typical pfoA-encoding virulent lineages. We determined that infant-associated pfoA+ strains caused significantly more cellular damage than pfoA- strains in vitro, and further confirmed this virulence trait in vivo using an oral-challenge C57BL/6 murine model. These findings suggest both the importance of pfoA+ C. perfringens as a gut pathogen in preterm infants and areas for further investigation, including potential intervention and therapeutic strategies.

The chance of spontaneous patent ductus arteriosus closure in preterm infants born before 32 weeks of gestation is high and continues to increase until 5 years of follow-up

AIM

The primary aim was to estimate premature infants' spontaneous patent ductus arteriosus closure rate. Secondly, to identify criteria associated with the chance of spontaneous closure.

METHODS

We performed a retrospective cohort study of 167 infants born before 32 weeks of gestation and diagnosed with a patent ductus arteriosus between 1 January 2008 and 31 December 2017. The spontaneous patent ductus arteriosus closure event rate was evaluated using the Kaplan-Meier estimator.

RESULTS

The spontaneous closure rate within the first year of life was 66% (95% CI 58%-73%), increasing to 80% (95% CI 72%-86%) five years after birth. When including both spontaneous closure and closure following treatment, 96% (95% CI 86%-100%) closed within 5 years after birth. The chance of spontaneous closure was reduced in the case of a large patent ductus arteriosus: OR 0.16 (95% CI 0.05-0.52), left atrial enlargement: OR 0.16 (95% CI 0.05-0.51), and pulmonary hypertension: OR 0.23 (95% CI 0.07-0.74).

CONCLUSION

The chance of spontaneous closure in premature infants born between 23 and 32 weeks of gestation was high, and the incidence continued increasing until 5 years of follow-up.

Effect of a Multi-Strain Probiotic on the Incidence and Severity of Necrotizing Enterocolitis and Feeding Intolerances in Preterm Neonates

Background: Necrotizing enterocolitis (NEC) is a multifactorial disease, causing inflammation of the bowel. The exact root of NEC is still unknown, but a low weight and gestational age at birth are known causes. Furthermore, antibiotic use and abnormal bacterial colonization of the premature gut are possible causes. Premature neonates often experience feeding intolerances that disrupts the nutritional intake, leading to poor growth and neurodevelopmental impairment. Methods: We conducted a double-blind, placebo-controlled, randomized clinical trial to investigate the effect of a multi-strain probiotic formulation (LabinicTM) on the incidence and severity of NEC and feeding intolerances in preterm neonates. Results: There were five neonates in the placebo group who developed NEC (Stage 1A−3B), compared to no neonates in the probiotic group. Further, the use of probiotics showed a statistically significant reduction in the development of feeding intolerances, p < 0.001. Conclusion: A multi-strain probiotic is a safe and cost-effective way of preventing NEC and feeding intolerances in premature neonates.

Association between timing of re-introduction of enteral feeding and short-term outcomes following laparotomy for necrotising enterocolitis

PURPOSE

To investigate the relationship between timing of re-introduction of feeds following surgery for Necrotising Enterocolitis (NEC) and important early outcomes.

METHODS

Secondary analysis of prospectively collected data from paediatric surgical units in UK/Ireland of infants who underwent laparotomy for NEC between 01/03/2013 and 28/02/2014. Multivariable logistic regression analysis was used to compare the relationship of early (≤ 7 days) and later (8-27 days) re-introduction of feeding after surgery on death or need for PN at 28 days, correcting for known cofounders.

RESULTS

41/143 infants (29%) received early and 102/143 infants (71%) had delayed reintroduction of feeding. Infants in the early feeding group had a higher gestational age at birth, higher proportion of growth restriction, lower inotrope requirement, and weremore likely to have undergone primary anastomosis. Following adjustment there was no statistically significant difference detected in the rate of death or need for PN at 28 days, adjusted OR 0.4 (95% CI 0.2-1.1), noting the limited statistical power of this comparison.

CONCLUSIONS

There is no evidence from this study to support a minimum period of 7 days nil by mouth post laparotomy for infants with NEC. Early feed reintroduction following laparotomy for NEC is safe in appropriate cases.

LEVEL OF EVIDENCE

Level II - Treatment Study Group; Prospective comparative study.

Necrotizing Enterocolitis and Its Predictors Among Preterm Neonates Admitted in Neonatal Intensive Care Units of Gurage Zone Public Hospitals, Southwest Ethiopia, 2021

Background

Necrotizing Enter colitis (NEC) is the most common multifactorial and devastating gastrointestinal emergency which primarily affects premature infants. The purpose of this study was to identify the prevalence of Necrotizing Enterocolitis and its associated factors among preterm neonates admitted to Neonatal Intensive Care Units in Gurage Zone hospitals.

Methods

Institution-based cross-sectional study design was employed. The simple Random Sampling Technique was applied to collect the data using a structured questionnaire. Data were cleaned, checked for inconsistencies, coded and entered via EPI data 3.1, and exported to Stata version 14 for further analysis. The data were processed by Stata 14 to estimate the prevalence of necrotizing enterocolitis.

Results

The prevalence of Necrotizing Enterocolitis among neonates was 28 (9.7%) 95% CI of 6. 8–13.7%. Birth weight (AOR: 7.33 95% CI (2.04: 26.38)), presence of maternal infection (AOR: 6.09, 95% CI (1.31:28.26)), length of hospital stay (AOR: 3.28, 95% CI (1.20, 8.96)), and initiating trophic feeding (AOR: 5.89, 95% CI (2.27: 15.33)) were associated with neonatal necrotizing enterocolitis.

Conclusion

The prevalence of Necrotizing Enterocolitis among preterm neonates was significant and special attention is needed for premature neonates with low birth weight and born from mothers with infection during pregnancy. Minimizing the length of hospital stay will be very useful to prevent the occurrence of Necrotizing Enterocolitis.

The predictors of necrotizing enterocolitis in newborns with low birth weight: A retrospective analysis

There are needs to investigate the influencing factors of necrotizing enterocolitis (NEC) in low birth weight (LBW) newborns, to provide insights into the clinical management of NEC.This study was a retrospective cohort study. Infants admitted to our hospital from January 1, 2019 to June 30, 2021 were selected. The clinical characteristics of NEC and no-NEC infants were evaluated. Logistic regression analyses were conducted to assess the risk factors of NEC in LBW infants.A total of 192 LBW infants were included, the incidence of NEC in LBW infants was 35.42%. There were significant differences in the congenital heart disease, sepsis, breastfeeding, blood transfusion and probiotics feeding between NEC and no-NEC group (all P < .05), and there were no significant differences in birth weight, gestational age, mother's pregnancy-induced hypertension, premature rupture of fetal membrane, amniotic fluid pollution, fetal asphyxia, neonatal respiratory distress syndrome and mechanical ventilation between NEC and no-NEC group (all P > .05). Congenital heart disease (OR: 2.128, 95% CI: 1.103-3.511), sepsis (OR: 1.630, 95% CI: 1.022-2.549), and blood transfusion (OR: 1.451, 95% CI: 1.014-2.085) were the independent risk factors for NEC in LBW infants, and breastfeeding (OR: 0.494, 95% CI: 0.023-0.928), probiotics feeding (OR: 0.816, 95% CI: 0.782-0.982) were the protective factors for the NEC in LBW infants. The prognosis of NEC infants undergone surgery treatment was better than that of infants undergone conservative treatments (P = .043).The incidence of NEC in LBW is high, which is affected by many factors, and comprehensive interventions targeted on the risk and protective factors should be made to improve the prognosis of LBW infants.

Newborns with Bloody Stools-At the Crossroad between Efficient Management of Necrotizing Enterocolitis and Antibiotic Stewardship

The onset of bloody stools in neonates often results in antibiotic treatment for suspected necrotizing enterocolitis (NEC). Food protein-induced allergic proctocolitis (FPIAP) is an often-neglected differential diagnosis. We performed a retrospective analysis of antibiotic exposure at our tertiary center from 2011 to 2020 that included three time periods of differing antimicrobial stewardship goals. We compared these data with the conventional treatment guidelines (modified Bell's criteria). In our cohort of 102 neonates with bloody stools, the length of antibiotic exposure was significantly reduced from a median of 4 to 2 days. The proportion of treated neonates decreased from 100% to 55% without an increase in negative outcomes. There were 434 antibiotic days. Following a management strategy according to modified Bell's criteria would have led to at least 780 antibiotic days. The delayed initiation of antibiotic treatment was observed in 7 of 102 cases (6.9%). No proven NEC case was missed. Mortality was 3.9%. In conclusion, with FPIAP as a differential diagnosis of NEC, an observational management strategy in neonates with bloody stools that present in a good clinical condition seems to be justified. This may lead to a significant reduction of antibiotic exposure. Further prospective, randomized trials are needed to prove the safety of this observational approach.

Low technology, mild controlled hypothermia for necrotizing enterocolitis treatment: an initiative to improve healthcare to preterm neonates

Necrotizing enterocolitis (NEC) treatment remains unchanged for years. Data suggest that mild controlled hypothermia could potentially improve NEC outcomes. Our units presented unfavourable outcomes on NEC. The aim was to assess our experience with low technology, mild controlled hypothermia on NEC outcomes, and improve preterm infants' healthcare. This was a single-center quality improvement study with retrospective cohort design at the neonatal intensive care unit in the university hospital. Forty-three preterm infants with NEC (Modified Bell's Stage II/III) were included: 19 in the control group (2015-2018) and 24 in the hypothermia group (2018-2020). The control group received standard treatment (fasting, abdominal decompression, and broad-spectrum antibiotics). The hypothermia group underwent cooling to 35.5 °C for 48 h after NEC diagnosis, along with conventional treatment. The primary outcomes are intestinal perforation, need for surgery, duration of parenteral nutrition, death, and extensive resection of the small intestine. There was no statistical difference in the NEC score. The hypothermia group required less surgery (aRR 0.40; 95% CI 0.19-0.85), presented less bowel perforation (aRR 0.39; 95% CI 0.18; 0.83), had a shorter duration of parenteral nutrition (aHR 5.28; 95% CI 1.88-14.89), did not need extensive intestinal resection, (0 vs 15.7%), and did not experience any deaths (0 vs 31.6%).Conclusions: In our experience, low technology, mild controlled hypothermia was feasible, not related to adverse effects, and effective treatment for NEC Modified Bell's Stage II/III. It avoided surgery, bowel perforation, and extensive intestinal resection; reduced mortality; and shortened parenteral nutrition duration. What is Known: • New approaches have been proposed to avoid enterocolitis incidence; however, the treatment of enterocolitis stage 2 has been the same for decades, and unfavourable outcomes remain despite conventional management. • Studies suggest that hypothermia can be an alternative to enterocolitis treatment. What is New: • Mild controlled hypothermia can be an additional practice to treat enterocolitis stage 2, is feasible, and is not related to adverse effects to preterm infants. • It can decrease surgery needs, duration of parenteral nutrition, and death and avoids extensive intestinal resection in preterm infants.

The Prevalence of Necrotizing Enterocolitis and Associated Factors Among Enteral Fed Preterm and Low Birth Weight Neonates Admitted in Selected Public Hospitals in Addis Ababa, Ethiopia: A Cross-sectional Study

Necrotizing enterocolitis (NEC) remains to be the most critical and frequent gastrointestinal disorder understood in neonatal intensive care units (NICU). The presented study was intended to assess the prevalence of NEC and associated factors among enteral Fed preterm and low birth weight neonates. Institution based retrospective cross-sectional study was conducted on 350 enteral Fed preterm and low birth weight neonates who were admitted at selected public hospitals of Addis Ababa from March 25/2020 to May 10/2020. The data were collected through neonates' medical record chart review. A total of 350 participants were enrolled in to the study with the response rate of 99.43%. One hundred eighty-four (52.6%) of them were male. The majority 123 (35.1%) of them were (32 + 1 to 34) weeks gestational age. The prevalence of NEC was (25.4%) (n = 89, [95% CI; 21.1, 30.0]). Being ≤28 weeks gestational age (AOR = 3.94, 95% CI [2.67, 9.97]), being (28 + 1 to 32 weeks) gestational age (AOR = 3.65, 95% CI [2.21, 8.31]), birth weight of 1000 to 1499 g (AOR = 2.29, 95% CI [1.22, 4.33]), APGAR score ≤3 (AOR = 2.34, 95% CI [1.32, 4.16]), prolonged labor (AOR = 2.21, 95% CI [1.35, 6.38]), maternal chronic disease particularly hypertension (AOR = 3.2, 95% CI [1.70, 5.90]), chorioamnionitis (AOR = 4.8, 95% CI [3.9, 13]), failure to breath/resuscitated (AOR = 2.1, 95% CI [1.7, 4.4]), CPAP ventilation (AOR = 3.7, 95% CI [1.50, 12.70]), mixed milk (AOR = 3.58, 95% CI [2.16, 9.32]) were factors significantly associated with NEC. Finally, the prevalence of NEC in the study area was high. So that, initiating the programs that could minimize this problem is required to avoid the substantial morbidity and mortality associated with NEC.

Hepatic oxidative injury: role of mitochondrial dysfunction in necrotizing enterocolitis

PURPOSE

Necrotizing enterocolitis (NEC) is a severe neonatal gastrointestinal disease that can cause damage to remote organs. Previous studies have shown that inflammatory and oxidative injury occur in the liver during NEC. Mitochondrial DNA (mtDNA) plays an important role in hepatic injuries of many other diseases. We aimed to investigate the mechanism of mitochondrial dysfunction in hepatic oxidative injury during NEC.

METHODS

NEC was induced in C57BL/6 mice (approval: 44032) by hypoxia, gavage feeding with hyperosmolar formula, and lipopolysaccharide administration from postnatal days 5 to 9 (n = 15). Two additional groups with hypoxia only (n = 10) and hypoxia and hyperosmolar formula (n = 13) were also examined. Breastfed pups were used as control (n = 15). Liver was harvested on postnatal day 9. Gene expressions of mtDNA markers cytochrome c oxidase subunit 3 (COX3), cytochrome b (CYTB) and NADH-ubiquinone oxidoreductase chain 1 (ND1) were measured by real-time qPCR. Mitochondrial morphology marker HSP60 and oxidative stress marker NRF2 were detected by immunofluorescence staining and compared between NEC and control. Data were presented as mean ± SD and compared using Student's t test; p < 0.05 was considered significant.

RESULTS

Gene expression of mtDNA markers (COX3, CYTB, and ND1) were significantly decreased in the liver of NEC mice relative to control, hypoxia alone, and hypoxia with hyperosmolar formula. Immunofluorescence showed depletion of HSP60 indicating decreased mitochondria in NEC liver relative to control. Furthermore, a higher protein expression of NRF2 was observed indicating higher oxidative stress in NEC liver relative to control.

CONCLUSIONS

Intestinal injury in experimental NEC leads to a systemic inflammatory response affecting the liver. Hepatic oxidative injury in NEC is characterized by decreased mitochondria and mtDNA depletion. This study provides insight into the mechanism of liver injury in NEC.

Perforated Acute Appendicitis in a Six-Day-Old Neonate: A Rare Differential Diagnosis of Neonatal Peritonitis

Acute appendicitis is a rare diagnosis of acute abdomen in neonates which is associated with high mortality due to late diagnosis. Here, we presented a case of acute neonatal appendicitis in a 6-year-old full-term infant with Down syndrome and pulmonary atresia with ventricular septal defect. The patient underwent surgery and postoperative critical care. However, he died on postoperative day 5 due to worsening sepsis and decompensated hemodynamic instability.

Prophylactic Probiotic Supplementation for Preterm Neonates-A Systematic Review and Meta-Analysis of Nonrandomized Studies

Systematic review and meta-analyses of randomized controlled trials (RCTs) show that probiotics reduce the risk of necrotizing enterocolitis (NEC ≥ Stage II), late onset sepsis (LOS), all-cause mortality, and feeding intolerance in preterm neonates. Data from observational studies is important to confirm probiotic effects in clinical practice. We aimed to compare outcomes before and after implementing routine probiotic supplementation (RPS) in preterm neonates (<37 weeks of gestation) by performing a systematic review of non-RCTs using Cochrane methodology. Databases including PubMed, The Cumulative Index to Nursing and Allied Health Literature (CINAHL), Embase, Cochrane Central library, and Google Scholar were searched in May 2020. A meta-analysis was performed using a random effects model. Categorical measure of effect size was expressed as OR and 95% CI. Statistical heterogeneity was assessed by the chi-squared test, I2 statistic. The level of evidence (LOE) was summarized using GRADE (Grading of Recommendations Assessment, Development, and Evaluation) guidelines. Primary outcomes were NEC ≥ Stage II, LOS, and all-cause mortality. Secondary outcomes included probiotic sepsis. Thirty good-quality non-RCTs (n = 77,018) from 18 countries were included. The meta-analysis showed RPS was associated with significantly reduced: 1) NEC ≥ Stage II (30 studies, n = 77,018; OR: 0.60; 95% CI: 0.50, 0.73; P <0.00001, I2: 65%; LOE: Moderate), 2) LOS: (21 studies, n = 65,858; OR: 0.85; 95% CI: 0.74, 0.97; P = 0.02, I2: 74%; LOE: Low), and 3) all-cause mortality (27 non-RCTs, n = 70,977; OR: 0.77; 95% CI: 0.68, 0.88; P = 0.0001, I2: 49%; LOE: Low). Subgroups: 1) extremely low birth weight (ELBW: birth weight <1000 g) neonates: RPS was associated with significantly reduced NEC ≥ Stage II (4.5% compared with 7.9%). However, there was no difference in LOS and mortality. 2) Multistrain RPS was more effective than single strain. One study reported 3 nonfatal cases of probiotic sepsis. In summary, moderate- to low-quality evidence indicates that RPS was associated with significantly reduced NEC ≥ Stage II, LOS, and all-cause mortality in neonates <37 weeks of gestation and NEC ≥ Stage II in ELBW neonates.

Contemporary Outcomes for Infants with Necrotizing Enterocolitis-A Systematic Review

OBJECTIVE

To develop an accurate understanding of outcomes for necrotizing enterocolitis (NEC) to inform parental counseling, clinical care, and research agendas.

STUDY DESIGN

A systematic review of recent (January 2010-January 2018) large cohort studies reporting outcomes of infants who developed NEC. Only studies reporting national, regional, or multicenter outcomes of NEC in high income countries were included. Outcomes assessed were mortality, neurodevelopmental outcome, and intestinal failure. Meta-analyses were used to generate summary statistics for these outcomes.

RESULTS

Of 1375 abstracts, 38 articles were included. Overall mortality was 23.5% in all neonates with confirmed NEC (Bell stage 2a+) (95% CI 18.5%-28.8%), 34.5% (30.1%-39.2%) for neonates that underwent surgery for NEC, 40.5% (37.2%-43.8%) for extremely low birthweight infants (<1000 g), and 50.9% (38.1%-63.5%) for extremely low birthweight infants with surgical NEC. Studies examining causes of neonatal mortality showed NEC is responsible for around 1 in 10 of all neonatal deaths. Neurodevelopmental disability was reported in 4 studies at between 24.8% and 61.1% (1209 total NEC cases). Three studies reported intestinal failure with an incidence of 15.2%-35.0% (n = 1370). The main limitation of this review is the lack of an agreed definition for diagnosing NEC and the differences in the way that outcomes are reported.

CONCLUSIONS

Mortality following NEC remains high. These contemporary data inform clinical care and justify ongoing research efforts. All infants with NEC should have long-term neurodevelopmental assessment. Data on the long-term risk of intestinal failure are limited.

TRIAL REGISTRATION

CRD42018094791.

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).

Does Surgical Management Alter Outcome in Necrotizing Enterocolitis?

Necrotizing enterocolitis occurs in 14% of infants less than 1000 g. Preoperative management varies widely, and the only absolute indication for surgery is pneumoperitoneum. Multiple biomarkers and scoring systems are under investigation, but clinical practice is still largely driven by surgeon judgment. Outcomes in panintestinal disease are poor, and multiple creative approaches are used to preserve bowel length. Overall, recovery is complicated in the short and long term. Major sequelae are stricture, short gut syndrome, and neurodevelopmental impairment. Resolving controversies in surgical necrotizing enterocolitis care requires multicenter collaboration for centralized data and tissue repositories, benchmarking, and carrying out prospective randomized controlled trials.

Clinical characteristic comparison of low birth weight and very low birth weight preterm infants with neonatal necrotizing enterocolitis: a single tertiary center experience from eastern China

PURPOSE

This study aims to understand the clinical characteristics of preterm neonatal necrotizing enterocolitis (NEC) to improve the medical management level.

METHODS

The clinical characteristics of preterm NEC infants with low birth weight (LBW, ≥ 1500 g) and very low birth weight (VLBW, < 1500 g) were compared. Then, clinical information, including demographics, surgical interventions and morbidity, were collected.

RESULTS

A total of 149 preterm NEC infants (60 with VLBW and 89 with LBW) were enrolled. Their median birth weight and gestational age were 1600 g and 31 weeks, respectively. Respiratory support and surfactant therapy were more frequent in VLBW infants (90% vs. 38% and 75% vs. 21.3%) than in LBW infants. In addition, 70.5% of these infants were fed by formula before the NEC occurred. Prematurity-associated morbidities were significantly higher in VLBW infants. Furthermore, 12.8% of all NEC infants died at discharge, and mortality was more prevalent in VLBW infants (21.7% vs. 6.7%). The most frequently received surgeries were enterostomy (n = 58), primary anastomosis (n = 42), and peritoneal drainage (n = 2). Multifocal, localized and pan-intestinal disease occurred in 77.5%, 19.6% and three infants, respectively. Furthermore, postoperative complications occurred more frequently in VLBW infants.

CONCLUSION

The overall mortality was 12.8% for infants who had a larger mean gestational age and birth weight, when compared to that in developed countries. Higher rate of formula feeding might be an important risk factor for NEC development. Furthermore, mortality and morbidities, especially nutrition-associated complications, were more frequent in VLBW infants.

An update on the human and animal enteric pathogen Clostridium perfringens

Clostridium perfringens, a rapid-growing pathogen known to secrete an arsenal of >20 virulent toxins, has been associated with intestinal diseases in both animals and humans throughout the past century. Recent advances in genomic analysis and experimental systems make it timely to re-visit this clinically and veterinary important pathogen. This Review will summarise our understanding of the genomics and virulence-linked factors, including antimicrobial potentials and secreted toxins of this gut pathogen, and then its up-to-date clinical epidemiology and biological role in the pathogenesis of several important human and animal-associated intestinal diseases, including pre-term necrotising enterocolitis. Finally, we highlight some of the important unresolved questions in relation to C. perfringens-mediated infections, and implications for future research directions.

Early Serum Gut Hormone Concentrations Associated With Time to Full Enteral Feedings in Preterm Infants

OBJECTIVES

The primary objective of this study was to evaluate early postnatal serum gut hormone concentrations in preterm infants as predictors of time to full enteral feedings. The secondary objective was to identify infant characteristics and nutritional factors that modulate serum gut hormone concentrations and time to full enteral feedings.

METHODS

Sixty-four preterm infants less than 30 weeks of gestation were included in this retrospective cohort study. Serum gut hormone concentrations at postnatal days 0 and 7 were measured using enzyme-linked immunosorbent assays. Linear regression and mediation analyses were performed.

RESULTS

Median (interquartile range) serum concentrations of glucose-dependent insulinotropic peptide (GIP) and peptide YY (PYY) on postnatal day 7 were 31.3 pg/mL (18.2, 52.3) and 1181.7 pg/mL (859.0, 1650.2), respectively. GIP and PYY concentrations on day 7 were associated with days to full enteral feedings after adjustment for confounders (β = -1.1, P = 0.03; and β = -0.002, P = 0.02, respectively). Nutritional intake was correlated with serum concentrations of GIP and PYY on postnatal day 7 and time to full enteral feedings. Mediation analysis revealed that the effect of serum gut hormone concentrations on time to full enteral feedings was not fully explained by nutritional intake. Intrauterine growth restriction, mechanical ventilation on postnatal day 7, and patent ductus arteriosus treated with indomethacin were associated with longer time to full enteral feedings.

CONCLUSIONS

Serum concentrations of GIP and PYY on postnatal 7 are independently associated with time to full enteral feedings. The link between serum gut hormone concentrations and time to full enteral feedings is not fully mediated by nutritional factors, suggesting an independent mechanism underlying the influence of gut hormones on feeding tolerance and time to full enteral feedings.

The Neurodevelopmental Perspective of Surgical Necrotizing Enterocolitis: The Role of the Gut-Brain Axis

This state-of-the-art review article aims to highlight the most recent evidence about the therapeutic options of surgical necrotizing enterocolitis, focusing on the molecular basis of the gut-brain axis in relevance to the neurodevelopmental outcomes of primary peritoneal drainage and primary laparotomy. Current evidence favors primary laparotomy over primary peritoneal drainage as regards neurodevelopment in the surgical treatment of necrotizing enterocolitis. The added exposure to inhalational anesthesia in infants undergoing primary laparotomy is an additional confounding variable but requires further study. The concept of the gut-brain axis suggests that bowel injury initiates systemic inflammation potentially affecting the developing central nervous system. Signals about microbes in the gut are transduced to the brain and the limbic system via the enteric nervous system, autonomic nervous system, and hypothalamic-pituitary axis. Preterm infants with necrotizing enterocolitis have significant differences in the diversity of the microbiome compared with preterm controls. The gut bacterial flora changes remarkably prior to the onset of necrotizing enterocolitis with a predominance of pathogenic organisms. The type of initial surgical approach correlates with the length of functional gut and microbiome equilibrium influencing brain development and function through the gut-brain axis. Existing data favor patients who were treated with primary laparotomy over those who underwent primary peritoneal drainage in terms of neurodevelopmental outcomes. We propose that this is due to the sustained injurious effect of the remaining diseased and necrotic bowel on the developing newborn brain, in patients treated with primary peritoneal drainage, through the gut-brain axis and probably not due to the procedure itself.

Necrotizing enterocolitis in premature infants and newborns

Necrotizing enterocolitis (NEC) is the most common acquired disease of the gastrointestinal tract (GIT) in premature infants and newborns. It is defined as an ulcerative inflammation of the intestinal wall. The clinical signs of incipient NEC are often very discrete, and range from localized intestinal symptoms to generalized signs of sepsis. NEC is classified depending on its severity into disease states according to the modified Bell's Classification. Treatment of NEC ranges, depending on its severity, from a conservative therapeutic approach to surgery with resection of the affected parts of the intestine. Mortality is considerably high in extremely small preterm infants reaching up to 42% of the affected children. Measures such as breastfeeding or alternatively nutrition with pasteurized human donor milk from a milk bank, administration of probiotics, avoidance of histamine type II receptor antagonists, and restrictive antibiotic treatment should be considered early on for prevention of NEC.

Necrotizing enterocolitis symposium: Epidemiology and early diagnosis

Despite decades of research on necrotizing enterocolitis (NEC), the outlook for infants afflicted by this devastating disease is all too often bleak. The aim of this symposium at the BAPS conference in Amsterdam was to highlight recent advances in the knowledge of the epidemiology and diagnosis of NEC. There were important contributions on the disease in the United Kingdom, both from a neonatal and from a surgical point of view, whereas colleagues from the Netherlands and elsewhere in Europe shared their insights into novel diagnostic tools, both biofluid and imaging based.

LEVEL OF EVIDENCE

Level V.

A UK wide cohort study describing management and outcomes for infants with surgical Necrotising Enterocolitis

The Royal College of Surgeons have proposed using outcomes from necrotising enterocolitis (NEC) surgery for revalidation of neonatal surgeons. The aim of this study was therefore to calculate the number of infants in the UK/Ireland with surgical NEC and describe outcomes that could be used for national benchmarking and counselling of parents. A prospective nationwide cohort study of every infant requiring surgical intervention for NEC in the UK was conducted between 01/03/13 and 28/02/14. Primary outcome was mortality at 28-days. Secondary outcomes included discharge, post-operative complication, and TPN requirement. 236 infants were included, 43(18%) of whom died, and eight(3%) of whom were discharged prior to 28-days post decision to intervene surgically. Sixty infants who underwent laparotomy (27%) experienced a complication, and 67(35%) of those who were alive at 28 days were parenteral nutrition free. Following multi-variable modelling, presence of a non-cardiac congenital anomaly (aOR 5.17, 95% CI 1.9–14.1), abdominal wall erythema or discolouration at presentation (aOR 2.51, 95% CI 1.23–5.1), diagnosis of single intestinal perforation at laparotomy (aOR 3.1 95% CI 1.05–9.3), and necessity to perform a clip and drop procedure (aOR 30, 95% CI 3.9–237) were associated with increased 28-day mortality. These results can be used for national benchmarking and counselling of parents.

Early feeding tolerance in small for gestational age infants with normal versus abnormal antenatal Doppler characteristics

OBJECTIVES

To determine differences in feeding tolerance amongst preterm small for gestational age (SGA) infants with normal versus abnormal umbilical artery Doppler flow defined as absent or reversed end diastolic flow (AREDF).

METHODS

This was a retrospective cohort study of infants <35 weeks gestational age (GA) and birth weight (BW) <10th percentile. Day of initiation of feeds, days to full feeds and CRIB II scores were the primary outcomes. Clinical characteristics were compared between the groups of SGA infants with normal and AREDF. Multivariable regression models were fit to the data to adjust for potential confounders of the association of AREDF and feeding intolerance.

RESULTS

120 infants with normal and 64 infants with AREDF were included. The infants with AREDF were smaller (971 g vs. 1183 g, p = 0.0002), less mature (29.9 wks vs. 31.2 wks, p = 0.0009), had higher CRIB II score (7.2 vs. 5.2, p = 0.0033), started feeding later (4.1 days vs. 3.3 days, p = 0.020) and advanced slower to full feeds (17.7 days vs. 13.7 days, p = 0.0017). Necrotizing enterocolitis was similar between the groups (p = 0.18). After adjusting for confounders, Doppler flow was no longer a significant predictor of the initiation (p = 0.37) and advancement of feeds (p = 0.44).

CONCLUSIONS

Infants with AREDF are sicker at birth and have more feeding difficulties; after adjusting for BW and GA, Doppler flow was no longer a significant predictor of feeding intolerance.

Current Research on the Epidemiology, Pathogenesis, and Management of Necrotizing Enterocolitis

Despite decades of research on necrotizing enterocolitis, we still do not fully understand the pathogenesis of the disease, or how to prevent or how to treat it. However, as a result of recent significant advances in the microbiology, molecular biology, and cell biology of the intestine of preterm infants and infants with necrotizing enterocolitis, there is some hope that research into this devastating disease will yield some important translation into effective prevention, more rapid diagnosis, and novel therapies.

[Analysis of population characteristics of infants affected by necrotizing enterocolitis in a tertiary centre in the last 12 years]

BACKGROUND

Necrotizing enterocolitis is the most lethal gastrointestinal emergency in the neonatal period. Incidence and mortality have remained stable in recent years despite advances in neonatal intensive care. The aim of this study is to show the general characteristics of patients diagnosed with necrotizing enterocolitis at Teresa Herrera's Hospital (La Coruna, Spain) in the last 12years.

MATERIAL AND METHODS

This study makes a retrospective and prospective descriptive analysis, evaluating the medical records and collecting radiological demographic variables, gestational data, perinatal history, clinical, analytical and perinatal therapeutic management and events in patients diagnosed with and treated for necrotizing enterocolitis between 2003 and 2015.

RESULTS

A total of 124 patients met the criteria for inclusion in the study. The mean gestational age of our patients was 33 weeks and remained stable compared with other studies. The average weight of our patients was 1,873g. In our series of cases there was a progressive and significant increase in maternal age and the rate of artificial pregnancies and multiple births. In our series 38.7% of our patients required surgical treatment and the fatality rate was 11.4%.

DISCUSSION

Despite advances in pre- and perinatal care necrotizing enterocolitis represents the leading cause of premature mortality. Incidence has remained unchanged in recent decades. More studies are required to identify both, risk and protective factors to reduce the morbidity and mortality of this entity.

Incidence and enteral feed antecedents of severe neonatal necrotising enterocolitis across neonatal networks in England, 2012-13: a whole-population surveillance study

BACKGROUND

Necrotising enterocolitis is a neonatal gastrointestinal inflammatory disease with high mortality and severe morbidity. This disorder is growing in global relevance as birth rates and survival of babies with low gestational age improve. Population data are scant and pathogenesis is incompletely understood, but enteral feed exposures are believed to affect risk. We aimed to quantify the national incidence of severe necrotising enterocolitis, describe variation across neonatal networks, and investigate enteral feeding-related antecedents of severe necrotising enterocolitis.

METHODS

We undertook a 2-year national surveillance study (the UK Neonatal Collaborative Necrotising Enterocolitis [UKNC-NEC] Study) of babies born in England to quantify the burden of severe or fatal necrotising enterocolitis confirmed by laparotomy, leading to death, or both. Data on all liveborn babies admitted to neonatal units between Jan 1, 2012, and Dec 31, 2013, were obtained from the National Neonatal Research Database. In the subgroup of babies born before a gestational age of 32 weeks, we did a propensity score analysis of the effect of feeding in the first 14 postnatal days with own mother's milk, with or without human donor milk and avoidance of bovine-origin formula, or milk fortifier, on the risk of developing necrotising enterocolitis.

FINDINGS

During the study period, 118 073 babies were admitted to 163 neonatal units across 23 networks, of whom 14 678 were born before a gestational age of 32 weeks. Overall, 531 (0·4%) babies developed severe necrotising enterocolitis, of whom 247 (46·5%) died (139 after laparotomy). 462 (3·2%) of 14 678 babies born before a gestational age of 32 weeks developed severe necrotising enterocolitis, of whom 222 (48·1%) died. Among babies born before a gestational age of 32 weeks, the adjusted network incidence of necrotising enterocolitis ranged from 2·51% (95% CI 1·13-3·60) to 3·85% (2·37-5·33), with no unusual variation from the adjusted national incidence of 3·13% (2·85-3·42), despite variation in feeding practices. The absolute risk difference for babies born before a gestational age of 32 weeks who received their own mother's milk within 7 days of birth was -0·88% (95% CI -1·15 to -0·61; relative risk 0·69, 95% CI 0·60 to 0·78; number needed to treat to prevent one case of necrotising enterocolitis 114, 95% CI 87 to 136). For babies who received no compared with any bovine-origin products within 14 days of birth, the absolute risk difference was -0·65% (-1·01 to -0·29; relative risk 0·61, 0·39 to 0·83; number needed to treat 154, 99 to 345). We were unable to assess the effect of human donor milk as use was low.

INTERPRETATION

Early feeding of babies with their own mother's milk and avoidance of bovine-origin products might reduce the risk of necrotising enterocolitis, but the absolute reduction is small. Owing to the rarity of severe necrotising enterocolitis, international collaborations are needed for adequately powered preventive trials.

FUNDING

National Institute for Health Research.

Antenatal Magnesium Sulfate, Necrotizing Enterocolitis, and Death among Neonates < 28 Weeks Gestation

Objective This study aims to examine the relationship between antenatal magnesium sulfate (MgSO4) and neonatal death and/or severe necrotizing enterocolitis (NEC) among infants < 28 weeks. Methods Secondary analysis of a multicenter randomized trial of antenatal MgSO4 versus placebo administered to women to prevent death and cerebral palsy. Neonates < 28 weeks were included. The primary outcome was neonatal death before NICU discharge, and/or severe NEC (Bell criteria stage II/III). Neonates with and without death/severe NEC were compared. Results A total of 697 neonates met the criteria. Out of which 150 (21.5%) died and/or were diagnosed with severe NEC. Antenatal MgSO4 exposure was not associated with death/severe NEC in infants < 28 weeks. In a subgroup analysis of neonates < 26 weeks, treatment group assignment to antenatal MgSO4 was associated with an increased odds of death/severe NEC (adjusted odds ratio: 1.90, 95% confidence interval: 1.12-3.22, p = 0.017). Conclusions Among neonates < 26 weeks, antenatal MgSO4 was associated with death and severe NEC. Further prospective study in larger populations is needed.

Necrotizing enterocolitis: controversies and challenges

Necrotizing enterocolitis is a devastating intestinal disease that affects ~5% of preterm neonates. Despite advancements in neonatal care, mortality remains high (30–50%) and controversy still persists with regards to the most appropriate management of neonates with necrotizing enterocolitis. Herein, we review some controversial aspects regarding the epidemiology, imaging, medical and surgical management of necrotizing enterocolitis and we describe new emerging strategies for prevention and treatment.

Human Milk Fortification Increases Bnip3 Expression Associated With Intestinal Cell Death In Vitro

OBJECTIVES

The aim of the present study was to determine the in vitro effect(s) of a bovine-based human breast milk fortifier (HMF) on human intestinal cells. HMF increases the expression of BCL2/adenovirus E1B 19 kDa protein-interacting protein (Bnip3) and cell death; the prostaglandin analogue misoprostol will rescue this effect.

METHODS

Cultured intestinal cells were exposed to in vitro-digested human breast milk (BM) ± HMF. Intracellular oxidation, cell damage/cell death, and BNIP3 expression were measured after exposure.

RESULTS

In vitro-digested BM + HMF significantly increased intracellular oxidation, cell damage, and cell death in enterocyte cell cultures compared with either saline or BM controls, an effect that was rescued by the prostaglandin analogue, misoprostol. Bnip3 transcript and Bnip3 protein levels were significantly increased in vitro after treatment with BM + HMF. We also provide evidence that transfection of enterocytes with Bnip3 increases cell death, an effect that is rescued by a nonfunctional Bnip3 splice variant.

CONCLUSIONS

Our data support the hypothesis that HMF increases intestinal Bnip3 in vitro, and that the gene product triggers cell death. We suggest that misoprostol is a promising therapy, which may reduce intestinal cell death.

Outcomes and costs of surgical treatments of necrotizing enterocolitis

BACKGROUND AND OBJECTIVES

Despite previous studies demonstrating no difference in mortality or morbidity, the various surgical approaches for necrotizing enterocolitis (NEC) in infants have not been evaluated economically. Our goal was to compare total in-hospital cost and mortality by using propensity score-matched infants treated with peritoneal drainage alone, peritoneal drainage followed by laparotomy, or laparotomy alone for surgical NEC.

METHODS

Utilizing the California OSHPD Linked Birth File Dataset, 1375 infants with surgical NEC between 1999 and 2007 were retrospectively propensity score matched according to intervention type. Total in-hospital costs were converted from longitudinal patient charges. A multivariate mixed effects model compared adjusted costs and mortality between groups.

RESULTS

Successful propensity score matching was performed with 699 infants (peritoneal drainage, n = 101; peritoneal drainage followed by laparotomy, n = 172; and laparotomy, n = 426). Average adjusted cost for peritoneal drainage followed by laparotomy was $398,173 (95% confidence interval [CI]: 287,784-550,907), which was more than for peritoneal drainage ($276,076 [95% CI: 196,238-388,394]; P = .004) and similar to laparotomy ($341,911 [95% CI: 251,304-465,186]; P = .08). Adjusted mortality was highest after peritoneal drainage (56% [95% CI: 34-75]) versus peritoneal drainage followed by laparotomy (35% [95% CI: 19-56]; P = .01) and laparotomy (29% [95% CI: 19-56]; P < .001). Mortality for peritoneal drainage was similar to laparotomy.

CONCLUSIONS

Propensity score-matched analysis of surgical NEC treatment found that peritoneal drainage followed by laparotomy was associated with decreased mortality compared with peritoneal drainage alone but at significantly increased costs.

Potential economic impacts from improving breastfeeding rates in the UK

RATIONALE

Studies suggest that increased breastfeeding rates can provide substantial financial savings, but the scale of such savings in the UK is not known.

OBJECTIVE

To calculate potential cost savings attributable to increases in breastfeeding rates from the National Health Service perspective.

DESIGN AND SETTINGS

Cost savings focussed on where evidence of health benefit is strongest: reductions in gastrointestinal and lower respiratory tract infections, acute otitis media in infants, necrotising enterocolitis in preterm babies and breast cancer (BC) in women. Savings were estimated using a seven-step framework in which an incidence-based disease model determined the number of cases that could have been avoided if breastfeeding rates were increased. Point estimates of cost savings were subject to a deterministic sensitivity analysis.

RESULTS

Treating the four acute diseases in children costs the UK at least £89 million annually. The 2009-2010 value of lifetime costs of treating maternal BC is estimated at £959 million. Supporting mothers who are exclusively breast feeding at 1 week to continue breast feeding until 4 months can be expected to reduce the incidence of three childhood infectious diseases and save at least £11 million annually. Doubling the proportion of mothers currently breast feeding for 7-18 months in their lifetime is likely to reduce the incidence of maternal BC and save at least £31 million at 2009-2010 value.

CONCLUSIONS

The economic impact of low breastfeeding rates is substantial. Investing in services that support women who want to breast feed for longer is potentially cost saving.

The outcome of critically ill neonates undergoing laparotomy for necrotising enterocolitis in the neonatal intensive care unit: a 10-year review

PURPOSE

To evaluate outcomes in critically ill neonates with necrotising enterocolitis (NEC) undergoing a laparotomy in the neonatal intensive care unit (NICU).

METHODS

This is a retrospective review of neonates diagnosed with NEC who underwent a laparotomy on NICU between 2001 and 2011. Demographic, diagnostic, operative and outcome data were analysed. Nonparametric comparison was used. Data are reported as median (range).

RESULTS

221 infants with NEC were referred for surgical evaluation; 182 (82%) underwent surgery; 15 (8%) required a laparotomy on NICU. Five had NEC totalis, 4 multifocal disease and 6 focal disease. Five had an open and close laparotomy, 8 stoma with/without bowel resection and 2 bowel resection and primary anastomosis. Ten (67%) died at a median of 6.5-hours (2-72) postoperatively; 2 died at 72 and 264-days. The 30-day mortality rate was higher (p=0.01) among infants undergoing a laparotomy on NICU (10/15; 67%) than in theatre (54/167; 32%). There was no significant difference in mean Paediatric Index of Mortality 2 Scores between survivors and nonsurvivors (p=0.55). Three (20%) infants remain alive with no or minimal disability at 1.4 (0.5-7.5) years.

CONCLUSION

Laparotomy for NEC on NICU is a treatment option for neonates who are too unstable to transfer to theatre. However, with 67% dying within 6.5-hours and a further 13% after months in hospital, we must consider whether surgery is always in their best interests. Development of a prediction model to help distinguish those at highest risk of long-term morbidity and mortality could help with decision making in this difficult situation.

Inter-rater agreement in the evaluation of abdominal radiographs for necrotizing enterocolitis

PURPOSE

Abdominal radiographs are frequently employed in the surveillance of patients with necrotizing enterocolitis (NEC), with typical findings well described. Clinicians interpret and act upon these films at different intervals, however, and inter-rater agreement has not been evaluated to date.

METHODS

Thirty abdominal radiographs of premature infants were distributed to attending radiologists (4), pediatric surgeons (4), and trainees (4), who evaluated for findings of NEC from a list of eight potential choices (1=normal, 8=perforation). Fleiss's Kappa (FK) was used to evaluate concordance between multiple raters with 0-0.2=slight association and 0.8-1=almost perfect agreement.

RESULTS

Practicing surgeons had an FK of 0.77 overall (95% CI: 0.67-0.87), but demonstrated poor agreement when evaluating decubitus films (FK: 0.39, 95% CI:0.12-0.65). Radiologists had excellent inter-rater agreement (FK: 0.81, 95% CI: 0.74-0.88), but had only modest agreement with surgeons (FK: 0.59, 95% CI: 0.56-0.63) and poor agreement for decubitus films (FK: 0.15, 95% CI: 0.47-0.26). Surgical and radiology trainees had fair agreement with their respective attendings (0.60, 95% CI: 0.55-0.65 and 0.64, 95% CI: 0.60-0.69, respectively).

CONCLUSIONS

While inter-rater agreement was good-excellent among attending staff, it was only moderate between radiologists and surgeons and between trainees and their attendings. This highlights the importance of inter-disciplinary and hierarchical communication to optimize clinical decision-making. Decubitus films may be of limited value in evaluating patients with NEC.

Royal Australasia of Surgeons Guest Lecture. Necrotizing enterocolitis: prevention, treatment, and outcome

Necrotizing enterocolitis (NEC) remains a very serious disease, particularly in premature infants. This review describes various aspects of the diagnosis and treatment of the disease. The pathogenesis of NEC is not completely understood, and risk factors include formula enteral feeding and bacterial involvement. Prevention of the disease is desirable, and the most robust evidence is linked to the protective effet of human milk and probiotics. The medical and surgical management has not changed significantly in the last 20 years. Insertions of peimary peritoneal drainage in comparison with laparotomy remain controversial, and this uncertainty stimulated the development of two randomized controlled trials. Neither definitely demonstrated an advantage of either periotneal drainage or laparotomy over the other. The advantage offered by a stoma compared to primary intestinal anastomosis is currently investigated in a multicenter randomized controlled trial (STAT Trial). The mortality of the disease remains high, and new therapeutic interventions are needed. Novel forms of treatment that can improve the outcome of this disease are currently under investigation. These include whole-body moderately controlled hypothermia and administration of amniotic fluid stem cells.

Mortality and management of surgical necrotizing enterocolitis in very low birth weight neonates: a prospective cohort study

BACKGROUND

Necrotizing enterocolitis (NEC) is a leading cause of death in very low birth weight (VLBW) neonates. The overall mortality of NEC is well documented. However, those requiring surgery appear to have increased mortality compared with those managed medically. The objective of this study was to establish national birth-weight-based benchmarks for the mortality of surgical NEC and describe the use and mortality of laparotomy vs peritoneal drainage.

STUDY DESIGN

There were 655 US centers that prospectively evaluated 188,703 VLBW neonates (401 to 1,500 g) between 2006 and 2010. Survival was defined as living in-hospital at 1-year or hospital discharge.

RESULTS

There were 17,159 (9%) patients who had NEC, with mortality of 28%; 8,224 patients did not receive operations (medical NEC, mortality 21%) and 8,935 were operated on (mortality 35%). On multivariable regression, lower birth weight, laparotomy, and peritoneal drainage were independent predictors of mortality (p < 0.0001). In surgical NEC, a plateau mortality of around 30% persisted despite birth weights >750 g; medical NEC mortality fell consistently with increasing birth weight. For example, in neonates weighing 1,251 to 1,500 g, mortality was 27% in surgical vs 6% in medical NEC (odds ratio [OR] 6.10, 95% CI 4.58 to 8.12). Of those treated surgically, 6,131 (69%) underwent laparotomy only (mortality 31%), 1,283 received peritoneal drainage and a laparotomy (mortality 34%), and 1,521 had peritoneal drainage alone (mortality 50%).

CONCLUSIONS

Fifty-two percent of VLBW neonates with NEC underwent surgery, which was accompanied by a substantial increase in mortality. Regardless of birth weight, surgical NEC showed a plateau in mortality at approximately 30%. Laparotomy was the more frequent method of treatment (69%) and of those managed by drainage, 46% also had a laparotomy. The laparotomy alone and drainage with laparotomy groups had similar mortalities, while the drainage alone treatment cohort was associated with the highest mortality.

Intestinal microcirculatory dysfunction and neonatal necrotizing enterocolitis

OBJECTIVE

Based on the observation that coagulation necrosis occurs in the majority of neonatal necrotizing enterocolitis (NEC) patients, it is clear that intestinal ischemia is a contributing factor to the pathogenesis of NEC. However, the published studies regarding the role of intestinal ischemia in NEC are controversial. The aim of this paper is to review the current studies regarding intestinal microcirculatory dysfunction and NEC, and try to elucidate the exact role of intestinal microcirculatory dysfunction in NEC.

DATA SOURCES

The studies cited in this review were mainly obtained from articles listed in Medline and PubMed. The search terms used were "intestinal microcirculatory dysfunction" and "neonatal necrotizing enterocolitis".

STUDY SELECTION

Mainly original milestone articles and critical reviews written by major pioneer investigators in the field were selected.

RESULTS

Immature regulatory control of mesentery circulation makes the neonatal intestinal microvasculature vulnerable. When neonates are subjected to stress, endothelial cell dysfunction occurs and results in vasoconstriction of arterioles, inflammatory cell infiltration and activation in venules, and endothelial barrier disruption in capillaries. The compromised vasculature increases circulation resistance and therefore decreases intestinal perfusion, and may eventually progress to intestinal necrosis.

CONCLUSION

Intestinal ischemia plays an important role through the whole course of NEC. New therapeutic agents targeting intestinal ischemia, like HB-EGF, are promising therapeutic agents for the treatment of NEC.

Assessment of uterine artery and aortic isthmus Doppler recordings as predictors of necrotizing enterocolitis

OBJECTIVE

The purpose of this study was to evaluate whether changes of uterine arteries and aortic isthmus Doppler blood flow recordings could enhance the prediction of necrotizing enterocolitis.

STUDY DESIGN

Doppler characteristics of the uterine artery, umbilical and middle cerebral arteries, ductus venosus, and aortic isthmus were reviewed in 123 growth-restricted fetuses who were then divided into 2 groups: with and without necrotizing enterocolitis.

RESULTS

Twelve of 123 newborn infants (9%) expressed necrotizing enterocolitis. This group showed significant association between necrotizing enterocolitis and bilateral notching on the uterine artery (83.3% vs 29.7%; P < .001), uterine artery mean resistance index (83.3% vs 36.9%; P < .002), aortic isthmus diastolic blood flow velocity integrals (Z score: -7.32 vs -3.99; P = .028), and absent or negative "a" wave on the ductus venosus (17% vs 1.8%; P = .021). With the use of logistic regression, uterine bilateral notching could predict necrotizing enterocolitis with a sensitivity of 83.3% and a specificity of 70.3%.

CONCLUSION

More than any other variable, uterine bilateral notching should be recognized as a strong risk factor for necrotizing enterocolitis.

In vitro cow's milk protein-specific inflammatory and regulatory cytokine responses in preterm infants with necrotizing enterocolitis and sepsis

Enteral feeding with cow's milk formula is associated with neonatal necrotizing enterocolitis (NEC) and sepsis. Dietary antigen sensitization may play a role in promoting and/or sustaining inflammation in both conditions. Aiming at investigating cow's milk protein (CMP)-specific cytokine responses in preterm infants with NEC and sepsis, 14 babies with NEC, 14 matched healthy controls, and 10 septic controls were recruited. Unstimulated and stimulated peripheral blood mononuclear cells (PBMCs) secreting IFN-γ, IL-4, IL-10, and TGF-β1 were counted by the single-cell enzyme-linked immunospot (ELISPOT) assay. During the acute phase of NEC, patients showed a general pattern of a high level of cytokine secretion both when unstimulated and stimulated by mitogen [phytohaemagglutinin (PHA)] and CMPs: beta-lactoglobulin (β-lg) and casein. These responses were more marked to β-lg for IFN-γ, IL-4, and IL-10 than TGF-β1. Cytokine responses in sepsis were lower than in NEC (lowest in healthy controls, with a minimal TGF-β1 response). At term, lower frequencies of cytokine-secreting cells were elicited than during the acute phase, except for TGF-β1 secreting cells, which increased at term (in response to PHA and CMPs) particularly following not only NEC but also sepsis.