Diagnosis and Management of Necrotizing Enterocolitis: An International Survey of Neonatologists and Pediatric Surgeons

Bedside Ultrasound for Early Diagnosis of Necrotizing Enterocolitis: A Pilot Study

OBJECTIVE

 This study aimed to assess whether bedside ultrasound (BUS) as the first imaging modality allows an earlier diagnosis of necrotizing enterocolitis (NEC) compared with abdominal radiography.

STUDY DESIGN

 A before-after controlled study in preterm infants with suspected NEC. The intervention group (October 2019-October 2021) received BUS as the first imaging modality and was managed accordingly to BUS findings. The control group (October 2015-September 2019) received radiography as the first imaging modality. The main outcome was NEC confirmation at the time of initial imaging. Secondary outcomes included time to diagnosis, laboratory data, and treatment requirements.

RESULTS

 Thirty-five episodes of suspected NEC with 14 (40%) confirmed NEC cases and 49 episodes of suspected NEC with 22 (44.9%) confirmed NEC cases were included in the intervention and control groups, respectively. In the intervention group, 11 of 14 (78.6%) NEC cases were confirmed at initial evaluation compared with 5 of 22 (22.7%) in the control group (p = 0.001). Infants in the intervention group developed thrombocytopenia and coagulopathy less frequently, were exposed to less radiation, and required less days of parenteral nutrition compared with the control group (p < 0.05).

CONCLUSION

 The use of BUS as the first imaging modality allowed an earlier diagnosis and timely treatment of NEC compared with abdominal radiography.Key Points · This is the first study that has assessed the role of BUS as the first imaging modality in NEC.. · BUS improves early diagnosis of NEC compared with abdominal radiography.. · BUS shortens time to NEC confirmation and treatment initiation which may reduce clinical severity of the NEC episode..

Risk factor analysis and nomogram prediction model construction for NEC complicated by intestinal perforation

OBJECTIVE

To investigate the clinical characteristics of neonatal necrotizing enterocolitis (NEC) complicated by intestinal perforation and predict the incidence of intestinal perforation in NEC.

METHODS

Neonates diagnosed with NEC at the Affiliated Hospital of Zunyi Medical University from January 2012 to May 2022 were enrolled, and the clinical data were collected and analyzed retrospectively. The patients were divided into two groups based on intestinal perforation occurrence or not. Mann-Whitney U tests, t-tests, chi-square tests, and fisher's exact tests were performed between-group comparisons. Logistic and lasso regressions were applied to screen independent risk factors for concomitant bowel perforation, and R software (RMS package) was used to formulate the nomogram prediction model. In addition, the receiver operating curve (ROC) and the calibration curve were drawn to verify the predictive power, while decision curve analysis (DCA) was constructed to evaluate the clinical applicability of the nomogram model.

RESULTS

One hundred eighty neonates with NEC were included, of which 48 had intestinal perforations, and 132 did not; the overall incidence of intestinal perforation was 26.67% (48/180). Bloody stool (OR = 5.60), APTT ≥ 50 s (OR = 3.22), thrombocytopenia (OR = 4.74), and hypoalbuminemia (OR = 5.56) were identified as independent risk variables for NEC intestinal perforation (P < 0.05) through multivariate logistic regression analysis. These factors were then applied to develop a nomogram prediction model (C-index = 0.838) by using the R software. The area under the curve (AUC) for the nomogram in the training and validation cohorts were 0.838 (95% Cl: 0.768, 0.908) and 0.802 (95% CI: 0.659, 0.944), respectively. The calibration curve shown that the nomogram has a good predictive ability for predicting the risk of intestinal perforation occurrence. And the decision curve and clinical impact curve analyses demonstrated good clinical utility of the nomogram model.

CONCLUSION

We found that Bloody stool, APTT ≥ 50 s, Thrombocytopenia, and hypoalbuminemia could be used as independent risk factors for predicting intestinal perforation in neonates with NEC. The nomogram model based on these variables had high predictive values to identify NEC patients with intestinal perforation.

Degree of Uncertainty in Reporting Imaging Findings for Necrotizing Enterocolitis: A Secondary Analysis from a Pilot Randomized Diagnostic Trial

Diagnosis of necrotizing enterocolitis (NEC) relies heavily on imaging, but uncertainty in the language used in imaging reports can result in ambiguity, miscommunication, and potential diagnostic errors. To determine the degree of uncertainty in reporting imaging findings for NEC, we conducted a secondary analysis of the data from a previously completed pilot diagnostic randomized controlled trial (2019-2020). The study population comprised sixteen preterm infants with suspected NEC randomized to abdominal radiographs (AXRs) or AXR + bowel ultrasound (BUS). The level of uncertainty was determined using a four-point Likert scale. Overall, we reviewed radiology reports of 113 AXR and 24 BUS from sixteen preterm infants with NEC concern. The BUS reports showed less uncertainty for reporting pneumatosis, portal venous gas, and free air compared to AXR reports (pneumatosis: 1 [1-1.75) vs. 3 [2-3], p < 0.0001; portal venous gas: 1 [1-1] vs. 1 [1-1], p = 0.02; free air: 1 [1-1] vs. 2 [1-3], p < 0.0001). In conclusion, we found that BUS reports have a lower degree of uncertainty in reporting imaging findings of NEC compared to AXR reports. Whether the lower degree of uncertainty of BUS reports positively impacts clinical decision making in infants with possible NEC remains unknown.

To feed or not to feed during therapeutic hypothermia in asphyxiated neonates: a systematic review and meta-analysis

The practice of withholding feed during therapeutic hypothermia (TH) in neonates with hypoxemic ischemic encephalopathy (HIE) is based on conventions rather than evidence. Recent studies suggest that enteral feeding might be safe during TH. We systematically compared the benefits and harms of enteral feeding in infants undergoing TH for HIE. We searched electronic databases and trial registries (MEDLINE, CINAHL, Embase, Web of Science, and CENTRAL) until December 15, 2022, for studies comparing enteral feeding and non-feeding strategies. We performed a random-effects meta-analysis using RevMan 5.4 software. The primary outcome was the incidence of stage II/III necrotizing enterocolitis (NEC). Other outcomes included the incidence of any stage NEC, mortality, sepsis, feed intolerance, time to full enteral feeds, and hospital stay. Six studies ((two randomized controlled trials (RCTs) and four nonrandomized studies of intervention (NRSIs)) enrolling 3693 participants were included. The overall incidence of stage II/III NEC was very low (0.6%). There was no significant difference in the incidence of stage II/III NEC in RCTs (2 trials, 192 participants; RR, 1.20; 95% CI: 0.53 to 2.71, I², 0%) and NRSIs (3 studies, no events in either group). In the NRSIs, infants in the enteral feeding group had significantly lower sepsis rates (four studies, 3500 participants, RR, 0.59; 95% CI: 0.51 to 0.67, I²-0%) and lower all-cause mortality (three studies, 3465 participants, RR: 0.43; 95% CI: 0.33 to 0.57, I²-0%) than the infants in the "no feeding" group. However, no significant difference in mortality was observed in RCTs (RR: 0.70; 95% CI: 0.28 to 1.74, I²-0%). Infants in the enteral feeding group achieved full enteral feeding earlier, had higher breastfeeding rates at discharge, received parenteral nutrition for a shorter duration, and had shorter hospital stays than the control group.  Conclusion: In late preterm and term infants with HIE, enteral feeding appears safe and feasible during the cooling phase of TH. However, there is insufficient evidence to guide the timing of initiation, volume, and feed advancement. What is Known: • Many neonatal units withhold enteral feeding during therapeutic hypothermia, fearing an increased risk of complications (feed intolerance and necrotizing enterocolitis). • The overall risk of necrotizing enterocolitis in late-preterm and term infants is extremely low (< 1%). What is New: • Enteral feeding during therapeutic hypothermia is safe and does not increase the risk of necrotizing enterocolitis, hypoglycemia, or feed intolerance. It may reduce the incidence of sepsis and all-cause mortality until discharge.

Comparison and Investigation of Exosomes from Human Amniotic Fluid Stem Cells and Human Breast Milk in Alleviating Neonatal Necrotizing Enterocolitis

In view of the devastating impact of neonatal necrotizing enterocolitis (NEC) on newborns, the research on its intervention is particularly important. Although exosomes from human amniotic fluid stem cells (AFSC) and human breast milk (HBM) can protect against NEC, their mechanisms remain unclear. Here, we intend to compare the intervention effects of two types of exosomes on NEC mouse model and reveal their respective regulatory mechanisms. In general, both AFSC-derived exosomes (AFSC-exos) and HBM-derived exosomes (HBM- exos) can alleviate NEC- associated intestinal injury, significantly reduce NEC score, and reduce systemic and ileal inflammation and NEC related brain injury during experimental NEC. However, the mode and mechanism of action of the two sources of exosomes were not identical. In vivo, the number of ileal crypts was more significantly restored after HBM-exos intervention than AFSC-exos, and in vitro, HBM-exos preferentially inhibited the inflammatory response of intestinal epithelial cells (IECs), whereas AFSC-exos preferentially regulated the migration of IECs. Mechanistically, GO and KEGG analyses revealed the different therapeutic mechanisms of AFSC-exos and HBM-exos in NEC. Taken together, our results illustrate that AFSC-exos and HBM-exos reduce the severity of experimental NEC and intestinal damage through different mechanisms, supporting the potential of cell-free or breast milk free exosome therapy for NEC.

Graphical Abstract

Bedside Ultrasound for Early Diagnosis of Necrotizing Enterocolitis: A Pilot Study

OBJECTIVE

 This study aimed to assess whether bedside ultrasound (BUS) as the first imaging modality allows an earlier diagnosis of necrotizing enterocolitis (NEC) compared with abdominal radiography.

STUDY DESIGN

 A before-after controlled study in preterm infants with suspected NEC. The intervention group (October 2019-October 2021) received BUS as the first imaging modality and was managed accordingly to BUS findings. The control group (October 2015-September 2019) received radiography as the first imaging modality. The main outcome was NEC confirmation at the time of initial imaging. Secondary outcomes included time to diagnosis, laboratory data, and treatment requirements.

RESULTS

 Thirty-five episodes of suspected NEC with 14 (40%) confirmed NEC cases and 49 episodes of suspected NEC with 22 (44.9%) confirmed NEC cases were included in the intervention and control groups, respectively. In the intervention group, 11 of 14 (78.6%) NEC cases were confirmed at initial evaluation compared with 5 of 22 (22.7%) in the control group (p = 0.001). Infants in the intervention group developed thrombocytopenia and coagulopathy less frequently, were exposed to less radiation, and required less days of parenteral nutrition compared with the control group (p < 0.05).

CONCLUSION

 The use of BUS as the first imaging modality allowed an earlier diagnosis and timely treatment of NEC compared with abdominal radiography.Key Points · This is the first study that has assessed the role of BUS as the first imaging modality in NEC.. · BUS improves early diagnosis of NEC compared with abdominal radiography.. · BUS shortens time to NEC confirmation and treatment initiation which may reduce clinical severity of the NEC episode..

Three-hourly versus two-hourly feeding interval in stable preterm infants: an updated systematic review and meta-analysis of randomized controlled trials

Evidence from randomized controlled trials (RCTs) suggests that three-hourly feeding is safe and might help achieve full feeds earlier in preterm infants. We systematically compared the benefits and harms of three-hourly and two-hourly feeding schedules in preterm infants. We searched electronic databases (MEDLINE, CINAHL, Embase, Web of Science, and Scopus) and trial registries until November 16, 2021, for RCTs comparing the two feeding schedules. We did a random-effects meta-analysis using RevMan 5.4 software. The primary outcome was the incidence of stage II or III necrotizing enterocolitis (NEC). Other outcomes were the incidence of any stage NEC, mortality, time to full enteral feeds, and hospital stay. Six trials (872 participants) are included. There was no significant difference in the incidence of stage II/III NEC (3 trials; 530 participants; RR 1.39; 95% CI: 0.53, 3.65; I² - 0%, low certainty), and any stage NEC (5 studies; 767 participants; RR 0.98; 95% CI: 0.53, 1.82; I² -0%, very low certainty) between three and two-hourly feeding groups. There was no difference in achieving full feeds (5 trials; 755 participants; MD: - 0.0 days; 95% CI: - 0.32, 0.31, low certainty) or other outcomes. On subgroup analysis, neonates with birthweight < 1000 g and in the three-hourly feeding regime achieved full enteral feeds slower than those in the two-hourly feeding group (1 trial; 84 participants; MD: 2.9 days, 95% CI: 1.16, 4.64, low certainty).

CONCLUSION

In stable preterm infants (1000-1500 g), three-hourly feeding can be followed safely. In infants < 1000 g, there is insufficient evidence to advise on an optimal feeding interval, although a 2-h interval might be preferable.Prospero Registration Number: CRD42021246568.

WHAT IS KNOWN

• Most of the units follow two-hourly feeding schedules without any evidence. • Recent trials suggest that the three hourly feeding schedules can be safely followed in stable preterm infants.

WHAT IS NEW

• Low certainty evidence suggests that three-hourly feeding is safe in stable preterm infants (1000-1500 grams). • In infants with birthweight <1000 grams, two-hourly feeding may be considered as it was associated with a shorter time to full feeds in subgroup analysis.

A new intestinal ultrasound integrated approach for the management of neonatal gut injury

Clinical management of gut injury has been a challenge to the clinician since the first description of necrotizing enterocolitis (NEC) about 50 years ago, and it is still poorly defined. Most of the diagnostic markers are non-specific, and there is no consensus yet on a reliable gold standard for diagnosis. This report describes our approach to integrating point of care intestinal ultrasound (IUS) as the primary radiological assessment modality with other clinical and biochemical markers.

CONCLUSIONS

This is the first clinical guideline integrating point of care IUS as a routine assessment of the gut injury. This integrated algorithm improves the quality of care of the gut injury, provides a more accurate diagnosis of NEC, and differentiates other categories of gut injury.

WHAT IS KNOWN

• Necrotizing enterocolitis is a poorly defined disease, and the routine assessment relying on AXR does not differentiate NEC from other categories of gut injury.

WHAT IS NEW

• Integrating point of care IUS with the routine clinical assessment of gut injury enables the gut injury to be classified according to the triggering factors and severity; this helps target the appropriate management.

Interpretable prediction of necrotizing enterocolitis from machine learning analysis of premature infant stool microbiota

Background

Necrotizing enterocolitis (NEC) is a common, potentially catastrophic intestinal disease among very low birthweight premature infants. Affecting up to 15% of neonates born weighing less than 1500 g, NEC causes sudden-onset, progressive intestinal inflammation and necrosis, which can lead to significant bowel loss, multi-organ injury, or death. No unifying cause of NEC has been identified, nor is there any reliable biomarker that indicates an individual patient’s risk of the disease. Without a way to predict NEC in advance, the current medical strategy involves close clinical monitoring in an effort to treat babies with NEC as quickly as possible before irrecoverable intestinal damage occurs. In this report, we describe a novel machine learning application for generating dynamic, individualized NEC risk scores based on intestinal microbiota data, which can be determined from sequencing bacterial DNA from otherwise discarded infant stool. A central insight that differentiates our work from past efforts was the recognition that disease prediction from stool microbiota represents a specific subtype of machine learning problem known as multiple instance learning (MIL).

Results

We used a neural network-based MIL architecture, which we tested on independent datasets from two cohorts encompassing 3595 stool samples from 261 at-risk infants. Our report also introduces a new concept called the “growing bag” analysis, which applies MIL over time, allowing incorporation of past data into each new risk calculation. This approach allowed early, accurate NEC prediction, with a mean sensitivity of 86% and specificity of 90%. True-positive NEC predictions occurred an average of 8 days before disease onset. We also demonstrate that an attention-gated mechanism incorporated into our MIL algorithm permits interpretation of NEC risk, identifying several bacterial taxa that past work has associated with NEC, and potentially pointing the way toward new hypotheses about NEC pathogenesis. Our system is flexible, accepting microbiota data generated from targeted 16S or “shotgun” whole-genome DNA sequencing. It performs well in the setting of common, potentially confounding preterm neonatal clinical events such as perinatal cardiopulmonary depression, antibiotic administration, feeding disruptions, or transitions between breast feeding and formula.

Conclusions

We have developed and validated a robust MIL-based system for NEC prediction from harmlessly collected premature infant stool. While this system was developed for NEC prediction, our MIL approach may also be applicable to other diseases characterized by changes in the human microbiota.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12859-022-04618-w.

Hyponatremia at the onset of necrotizing enterocolitis is associated with intestinal surgery and higher mortality

It has previously been shown that hyponatremia reflects the severity of inflammation in pediatric gastrointestinal diseases. Interpretation of electrolyte disorders is a common, but not well studied challenge in neonatology, especially in the context of early detection of necrotizing enterocolitis and bowel necrosis. The aim of this study was to assess if hyponatremia, or a decrease in plasma sodium level, at the onset of necrotizing enterocolitis (NEC) is associated with intestinal ischemia/necrosis requiring bowel resection and/or NEC-related deaths. This was a retrospective cohort study including patients with verified NEC (Bell's stage ≥ 2) during the period 2009-2014. Data on plasma sodium 1-3 days before and at the onset of NEC were collected. The exposure was hyponatremia, defined as plasma sodium < 135 mmol/L and a decrease in plasma sodium. Primary outcome was severe NEC, defined as need for intestinal resection due to intestinal ischemia/necrosis and/or NEC-related death within 2 weeks of the onset of NEC. Generalized linear models were applied to analyze the primary outcome and presented as odds ratio. A total of 88 patients with verified NEC were included. Fifty-four (60%) of them had severe NEC. Hyponatremia and a decrease in plasma sodium at onset of NEC were associated with increased odds of severe NEC (OR crude 3.91, 95% CI (1.52-10.04) and 1.19, 95% CI (1.07-1.33), respectively). Also, a sub-analysis, excluding infants with pneumoperitoneum during the NEC episode, showed an increased odds ratio for severe NEC in infants with hyponatremia (OR 23.0, 95% CI (2.78-190.08)).

CONCLUSIONS

The findings of hyponatremia and/or a sudden decrease in plasma sodium at the onset of NEC are associated with intestinal surgery or death within 2 weeks.

WHAT IS KNOWN

• Clinical deterioration, despite optimal medical treatment, is a relative indication for surgery in infants with necrotizing enterocolitis. • Hyponatremia is a common condition in preterm infants from the second week of life.

WHAT IS NEW

• Hyponatremia and a decrease in plasma sodium level at the onset of necrotizing enterocolitis are positively associated with need of surgery or death within 2 weeks. • In infants with necrotizing enterocolitis, without pneumoperitoneum, where clinical deterioration despite optimal medical treatment is the only indication for surgery, hyponatremia, or a decrease in plasma sodium level can predict the severity of the disease.

Necrotizing enterocolitis in the preterm: newborns medical and nutritional Management in a Single-Center Study

Necrotizing enterocolitis (NEC) is a typical disorder of preterm newborns, with a high mortality and morbidity rate. The therapeutic and nutritional management of disease depends on several factors. Its prognosis is linked, in addition to the severity of the disease and the need for surgery, to a correct enteral feeding in these patients. This study aims to identify the clinical characteristics of 18 patients with NEC, evaluating the different therapeutic paths undertaken, the type of formula used and the survival rate of this population. Average time of enteral nutrition before the NEC onset was 11,3 ± 11,6 days, with an average fasting period since the onset of 24 ± 18.9 days. 77.8% of patients received surgery and resumed enteral nutrition 17.7 ± 17.9 days after the intervention. The overall survival rate of our cohort was 55.5%. More prospective studies are needed to evaluate the long-term outcomes of survived children with NEC.

NIRS as a biomarker of bowel ischaemia & surgical pathology: A meta-analysis of studies in newborns

OBJECTIVE

We performed a meta-analysis on Near-infrared Spectroscopy (NIRS) as a biomarker of bowel ischaemia.

SUMMARY BACKGROUND DATA

NIRS allows non-invasive assessment of gastrointestinal regional oxygen saturation (GrSO₂). Studies to date have focused on the feasibility of NIRS in clinical practice and its reproducibility. GrSO₂ can be used alone, or in conjunction with cerebral NIRS to give a Cerebral Splanchnic Oxygenation Ratio (CSOR). We assess published data on abdominal NIRS as a marker of bowel ischaemia.

METHODS

A literature review was conducted using the PRISMA method. Data on GrSO₂ and CSOR in controls and patients with confirmed ischaemia was included in a meta-analysis, and used to identify a diagnostic threshold.

RESULTS

14 studies were identified. Meta-analysis demonstrated that GrSO₂ (p < 0.01) and CSOR (p < 0.01) were significantly lower in neonates with bowel pathology associated with ischaemia than controls. Area under the curve for GrSO₂ was 0.80, with Youden's index highest (0.52) at a GrSO₂ of 42% (specificity 91% and sensitivity 62%). For CSOR, area under the curve is 0.89, with Youden's index highest (0.69) at 0.76 (specificity of 80%, sensitivity 90%).

CONCLUSIONS

Splanchnic NIRS correlates with bowel ischaemia. Low GrSO₂ is consistently associated with ischaemia, although a specific cut off level in each patient is hard to define. However, values below 42% correlate strongly with ischaemia while values above 52% are more suggestive of patients without bowel pathology. CSOR of below 0.76 is strongly suggestive of ischaemia. Trends within individuals are likely to be able to provide even more clinically correlatable and diagnostic data.

How to interpret lactate

The association between hyperlactataemia and poorer outcomes in acutely unwell adults and children is well recognised. Blood lactate testing has become readily available in acute settings and is considered a first-line investigation in international guidelines for the management of sepsis. However, while healthcare professionals do appreciate the value of measuring blood lactate in acute severe illness, its clinical significance and interpretation remain less well understood. In this paper, we present the evidence for the use of lactate as a diagnostic test and prognostic marker in acutely unwell children.

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.

Survey on antibiotic regimens for necrotizing enterocolitis prescribed by Chinese pediatricians in 2020

Background

Necrotizing enterocolitis (NEC) is a serious intestinal inflammatory disease in neonates, and intravenous antibiotics constitute the main therapeutic strategy. Studies have shown that substantial variation in the selection of antibiotic regimens for NEC remains in many countries. The variability in antibiotic therapy selection in China is unclear.

Methods

A cross-sectional study using an online questionnaire regarding antibiotic regimens for NEC was conducted among pediatricians working in tertiary hospitals in China.

Results

A total of 284 pediatricians from 29 provinces completed the survey; 37.9% of them administered one antibiotic, 56.7% administered two antibiotics and 2.4% administered three antibiotics. The top three single-antibiotic regimens for NEC were beta-lactamase inhibitors (n=66, 41.5%), carbapenems (n=46, 28.9%) and cephalosporins (n=33, 20.8%). Twenty combinations of two antibiotics were identified, and the top three combinations were beta-lactamase inhibitors and antianaerobic agents (n=49, 19.6%), carbapenems and glycopeptides (n=42, 16.8%), and cephalosporins and antianaerobic agents (n=37, 14.8%). Regarding the therapeutic duration of antibiotic treatment, 77.5% (n=220) of the pediatricians chose 5–10 days for stage II NEC, and 79.6% (n=226) chose 7–14 days for stage III NEC. Forty-three percent (n=122) of the respondents preferred to use carbapenems when NEC was diagnosed, and 83.3% (n=135) adjusted the antibiotics to carbapenems if a patient’s medical condition deteriorated or if the therapeutic efficacy was poor.

Conclusion

This survey revealed that carbapenems were the most common antibiotics selected when NEC was diagnosed or a patient’s condition deteriorated, but the duration of the course of treatment for NEC varied substantially among doctors.

Antibiotic Treatments and Patient Outcomes in Necrotizing Enterocolitis

OBJECTIVE

This study aimed to examine the impact of different antibiotic treatments on necrotizing enterocolitis (NEC) outcomes.

STUDY DESIGN

Patient outcomes, including total parenteral nutrition and hospitalization durations, abdominal surgeries, intestinal strictures, and mortality data, were analyzed and compared by various antibiotic groups and treatment durations for 160 NEC patients managed at the Women and Children's Hospital of Buffalo between 2008 and 2016.

RESULTS

Fourteen different antibiotics were used for NEC, most commonly ampicillin, gentamicin, and metronidazole (AGM). Medical (vs. surgical) NEC patients more likely received AGM (37 vs. 6%, p < 0.001). Surgical (vs. medical) NEC patients more likely received vancomycin (80 vs. 30%, p < 0.001) and antipseudomonal agents (69 vs. 15%, p < 0.001). For medical NEC there were no outcome differences between patients receiving only AGM versus those receiving other treatments; in patients receiving AGM, there were no outcome differences in durations of ≤10 days versus longer courses.

CONCLUSION

Antibiotic use for NEC varies substantially without definite outcome differences. Particularly with medical NEC, AGM for ≤10 days had comparable outcomes to other treatments. In light of growing concern for short and longer term adverse effects with early-life antibiotic exposure, narrow-spectrum and shorter course NEC treatment may be preferred.

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

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

Predicting intestinal recovery after necrotizing enterocolitis in preterm infants

BACKGROUND

Intestinal recovery after NEC is difficult to predict in individuals. We evaluated whether several biomarkers predict intestinal recovery after NEC in preterm infants.

METHODS

We measured intestinal tissue oxygen saturation (r_intSO₂) and collected urinary intestinal-fatty acid binding protein (I-FABP_u) levels 0-24 h and 24-48 h after NEC onset, and before and after the first re-feed. We assessed intestinal recovery in two ways: time to full enteral feeding (FEFt; below or equal/above group's median) and development of post-NEC complications (recurrent NEC/post-NEC stricture). We determined whether the r_intSO₂, its range, and I-FABP_u differed between groups.

RESULTS

We included 27 preterm infants who survived NEC (Bell's stage ≥ 2). Median FEFt was 14 [IQR: 12-23] days. Biomarkers only predicted intestinal recovery after the first re-feed. Mean r_intSO₂ ≥ 53% combined with mean r_intSO_2range ≥ 50% predicted FEFt < 14 days with OR 16.7 (CI: 2.3-122.2). The r_intSO_2range was smaller (33% vs. 51%, p < 0.01) and I-FABP_u was higher (92.4 vs. 25.5 ng/mL, p = 0.03) in case of post-NEC stricture, but not different in case of recurrent NEC, compared with infants without complications.

CONCLUSION

The r_intSO₂, its range, and I-FABP_u after the first re-feed after NEC predicted intestinal recovery. These biomarkers have potential value in individualizing feeding regimens after NEC.

Gastric Residual to Predict Necrotizing Enterocolitis in Preterm Piglets As Models for Infants

BACKGROUND

Necrotizing enterocolitis (NEC) is a serious intestinal inflammatory disease in preterm infants. High volume of gastric residual (GR) after oral feedings is often used as a predictor of NEC, but evidence is limited. Using NEC-sensitive preterm piglets as models, we hypothesized that GR mass and related plasma biomarkers predict early onset of NEC.

METHODS

In total, 258 newborn preterm piglets were fed bovine milk-based formulas for 5 days. At euthanasia, the stomach, small intestine, and colon were evaluated for NEC lesions. Mass, acidity, gastrin, and bile acid levels were determined for GR content, together with gastrin, glucagon-like peptide 2 (GLP-2), and gastric inhibitory polypeptide (GIP) levels in plasma.

RESULTS

In total, 48% of piglets had NEC lesions in the small intestine and/or colon. These piglets had higher GR mass (+32%, P < 0.001) and lower gastric bile acid concentrations (-22%, P < 0.05) than piglets without NEC lesions. The positive and negative predictive values for these markers were 34%-61%. Gastric acidity, gastrin, GLP-2, and GIP levels were similar for piglets with and without NEC lesions.

CONCLUSION

Elevated GR mass correlates positively with NEC lesions but may be a poor predictor of NEC, even when combined with other biomarkers. More knowledge about gastric emptying and gut transit in preterm neonates is required to understand how GR volume and composition relate to morbidities, such as NEC, in preterm neonates.

Nutrition in Necrotizing Enterocolitis and Following Intestinal Resection

This review aims to discuss the role of nutrition and feeding practices in necrotizing enterocolitis (NEC), NEC prevention, and its complications, including surgical treatment. A thorough PubMed search was performed with a focus on meta-analyses and randomized controlled trials when available. There are several variables in nutrition and the feeding of preterm infants with the intention of preventing necrotizing enterocolitis (NEC). Starting feeds later rather than earlier, advancing feeds slowly and continuous feeds have not been shown to prevent NEC and breast milk remains the only effective prevention strategy. The lack of medical treatment options for NEC often leads to disease progression requiring surgical resection. Following resection, intestinal adaptation occurs, during which villi lengthen and crypts deepen to increase the functional capacity of remaining bowel. The effect of macronutrients on intestinal adaptation has been extensively studied in animal models. Clinically, the length and portion of intestine that is resected may lead to patients requiring parenteral nutrition, which is also reviewed here. There remain significant gaps in knowledge surrounding many of the nutritional aspects of NEC and more research is needed to determine optimal feeding approaches to prevent NEC, particularly in infants younger than 28 weeks and <1000 grams. Additional research is also needed to identify biomarkers reflecting intestinal recovery following NEC diagnosis individualize when feedings should be safely resumed for each patient.

Cardiac and Inflammatory Necrotizing Enterocolitis in Newborns Are Not the Same Entity

Background: Necrotizing enterocolitis (NEC) is an often-fatal neonatal disease involving intestinal hyperinflammation leading to necrosis. Despite ongoing research, (1) conflicting results and (2) comorbidities of NEC patients make early NEC detection challenging and may complicate therapy development. Most research suggests that NEC pathogenesis is multifactorial, involving a combination of (1) gut prematurity; (2) abnormal bacterial colonization; and (3) ischemia-reperfusion (I/R) injury. As neutrophil extracellular traps (NETs) partially mediate I/R injury and drive inflammation in NEC, we hypothesized that NETs contribute to NEC development; particularly in cardiac patients. Methods: A retrospective analysis of baseline characteristics, clinical signs, laboratory parameters, and imaging was conducted for surgically verified NEC cases over 10 years. Patients were stratified into two groups: (1) prior medically or surgically treated cardiac disease (cardiac NEC) and (2) no cardiac comorbidities (inflammatory NEC). Additionally, histology was reassessed for neutrophil activation and NETs formation. Results: A total of 110 patients (cNEC 43/110 vs. iNEC 67/110) were included in the study, with cNEC neonates being significantly older than iNEC neonates (p = 0.005). While no significant differences were found regarding clinical signs and imaging, laboratory parameters revealed that cNEC patients have significantly increased leucocyte (p = 0.024) and neutrophil (p < 0.001) counts. Both groups also differed in pH value (p = 0.011). Regarding histology: a non-significant increase in staining of myeloperoxidase within the cNEC group could be found in comparison to iNEC samples. Neutrophil elastase (p = 0.012) and citrullinated histone H3 stained (p = 0.041) slides showed a significant markup for neonates diagnosed with cNEC in comparison to neonates with iNEC. Conclusion: The study shows that many standardized methods for diagnosing NEC are rather unspecific. However, differing leucocyte and neutrophil concentrations for iNEC and cNEC may indicate a different pathogenesis and may aid in diagnosis. As we propose that iNEC is grounded rather in sepsis and neutropenia, while cNEC primarily involves I/R injuries, which involves neutrophilia and NETs formation, it is plausible that I/R injury due to interventions for cardiac comorbidities results in pronounced neutrophil activation followed by a hyperinflammation reaction and NEC. However, prospective studies are necessary to validate these findings and to determine the accuracy of the potential diagnostic parameters.

Clinical Characteristics of Necrotizing Enterocolitis in Preterm Patients With and Without Persistent Ductus Arteriosus and in Patients With Congenital Heart Disease

Background: Diagnosis and management of NEC is based on clinical, radiological, and laboratory findings. Discrimination of pathogens for an improved understanding of NEC in preterm infants and NEC in infants with congenital heart disease has been previously discussed and enables evaluation of further NEC biomarkers. Patients and Methods: Within a study period of 11 years (2008-2019), we identified 107 patients with a diagnosis of NEC at our primary care center. Thirty-six out of 54 patients suffering from NEC in high Bell stages who underwent surgery met inclusion criteria. These patients were classified according to their cardiac status, and analyses of clinical factors influencing NEC were conducted. Additionally, clinical factors associated with a fulminant course of NEC were examined. Univariable and multivariable analyses were performed. Results: The study populations consisted of 12 preterm infants with NEC but without patent ductus arteriosus (PT-NEC), seven preterm infants with NEC and patent ductus arteriosus (PDA-NEC), and 17 infants with NEC and congenital heart disease (CHD-NEC). Blood flow in intestinal vessels was impaired in infants with PDA-NEC and CDH-NEC. Therefore, we used logistic regression to compare PDA-NEC and CDH-NEC infants with PT-NEC infants: positive bacterial culture of intraoperative swabs (p = 0.0199; odds ratio: 21.9) and macroscopic intestinal necrosis (p = 0.0033; odds ratio: 43.5) were observed more frequently in the first group. Furthermore, multiple regression analysis determined the NEC localization (p = 0.0243) as a significant factor correlated with a fulminant course. Compared to a NEC exclusively localized in the colon, there is a 5.8-fold increased risk of a fulminant course when the small intestine is affected and a 42-fold increase of risk when both small intestine and colon were affected. Conclusion: An early diagnosis and timely surgical intervention of NEC, especially in infants with PDA and CDH may be considered to avoid major bowel necrosis (resulting in loss of intestinal tissue) and multiple operations.

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.

Laparoscopy to Assist Surgical Decisions Related to Necrotizing Enterocolitis in Preterm Neonates

Aim of the Study: Necrotizing enterocolitis (NEC) is a devastating intestinal disease that mainly affects preterm infants. Despite advancements in neonatal care, mortality of NEC remains high and controversies exist regarding the most appropriate time for surgical intervention and challenging of diagnosing NEC. Using a pig model of NEC, we aimed to examine if laparoscopy is feasible for diagnosis of NEC. Methods: Preterm caesarean-delivered piglets (n = 42) were fed with increasing amounts of infant formula up to 5 days to induce NEC. On days 3-5, we examined the intestine by laparoscopy under general anesthesia. The bowel was examined by tilting the pigs from supine position to the left and right side. Macroscopic NEC lesions were identified and graded according to a macroscopic scoring system, then a laparotomy was performed to rule out any organ injury and missed NEC lesions. Results: Visible NEC lesions (scores 4-6) were found in 26% (11/42) of the piglets. A positive predictive value of 100% was found for laparoscopy as a diagnostic marker of NEC in both colon and the small intestine. One piglet had a higher NEC score in the small intestine found at laparotomy, than at laparoscopy, resulting in a sensitivity of 67%, and a specificity of 100% for the small intestine. Conversely, both the sensitivity and specificity for colon was 100%. Acceptable levels of agreement was found, with minimal proportional bias in both colon and the small intestine for laparoscopy and laparotomy. Ultrasound examination had a lower sensitivity of 67% and specificity of 63%. All piglets were respiratory and circulatory stable during the procedure. Conclusions: In preterm piglets, laparoscopy is a feasible tool to diagnose NEC with a high positive predictive value and a high specificity.

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.

Sepsis and Oxidative Stress in the Newborn: From Pathogenesis to Novel Therapeutic Targets

Sepsis is at present one of the leading causes of morbidity and mortality in the neonatal population. Together with inflammation, oxidative stress is involved in detrimental pathways activated during neonatal sepsis, eventually leading to organ dysfunction and death. The redox cascade during sepsis is mainly initiated by IL-6 and IL-8 stimulation in newborns and includes multiple noxious processes, as direct cell damage induced by reactive oxygen species, activation of gene expression leading to amplification of inflammation and oxidative stress, and impairment of mitochondrial function. Once proinflammatory and prooxidant pathways are established as stimulated by causing pathogens, self-maintaining unfavorable redox cycles ensue, leading to oxidative stress-related cellular damage, independently from the activating pathogens themselves. Despite antioxidant systems are induced during neonatal sepsis, as an adaptive response to an increased oxidative burden, a condition of redox imbalance favoring oxidative pathways occurs, resulting in increased markers of oxidative stress damage. Therefore, antioxidant treatment would exert beneficial effects during neonatal sepsis, potentially interrupting prooxidant pathways and preventing the maintenance of detrimental redox cycles that cannot be directly affected by antibiotic treatment. Among others, antioxidant agents investigated in clinical settings as adjunct treatment for neonatal sepsis include melatonin and pentoxifylline, both showing promising results, while novel antioxidant molecules, as edaravone and endothelin receptor antagonists, are at present under investigation in animal models. Finally, mitochondria-targeted antioxidant treatments could represent an interesting line of research in the treatment of neonatal sepsis.

Toll-Like Receptor-Mediated Intestinal Inflammatory Imbalance in the Pathogenesis of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) remains the leading cause of death from gastrointestinal disease in premature infants and attacks the most fragile patients at a time when they appear to be the most stable. Despite significant advances in our overall care of the premature infant, NEC mortality remains stubbornly high. There is no specific treatment for NEC beyond broad-spectrum antibiotics and intestinal resection, and current efforts have focused on preventive strategies. Over the past decade, we have proposed a unifying hypothesis to explain the pathogenesis of NEC in premature infants that suggests that NEC develops in response to an imbalance between exaggerated proinflammatory signaling in the mucosa of the premature gut leading to mucosal injury, which is not countered effectively by endogenous repair processes, and in the setting of impaired mesenteric perfusion leads to intestinal ischemia and disease development. One of the most important pathways that mediates the balance between injury and repair in the premature intestine, and that plays a key role in NEC pathogenesis, is Toll-like receptor 4 (TLR4), which recognizes lipopolysaccharide on gram-negative bacteria. This review focuses on the role that the TLR4-mediated imbalance between proinflammatory and anti-inflammatory signaling in the premature intestinal epithelium leads to the development of NEC, and will explore how an understanding of the role of TLR4 in NEC pathogenesis has led to the identification of novel preventive or treatment approaches for this devastating disease.