Predicting disease severity of necrotizing enterocolitis: how to identify infants for future novel therapies

Time to recovery from necrotizing enterocolitis and its predictors among neonates admitted to Neonatal Intensive Care Unit in Bahir Dar, Ethiopia: A retrospective follow up study, 2022

BACKGROUND

Necrotizing enterocolitis is one of the most common, life-threatening, gastrointestinal disorders in neonates. The recovery time for neonates with NEC varies depending on disease severity, prompt diagnosis, and effective treatment. Therefore, this study was intended to assess the time to recover from necrotizing enterocolitis and its' predictors among neonates admitted to Neonatal Intensive Care Unit in Bahir Dar City, Ethiopia.

METHODS

An institution-based retrospective follow-up study design was employed. A sample of 361 medical records of neonates with necrotizing enterocolitis was selected using systematic random sampling. Diagnosis of NEC in this study required clinical, laboratory and radiographic findings. The survival function was described using Kaplan Meier survival curve and log-rank test. Bivariate and multivariate Cox-proportional hazard (Cox-PH) regression models were used for analysis.

RESULTS

The median recovery time from necrotizing enterocolitis for neonates in the neonatal intensive care unit was 12 days. The multivariable Cox-PH model showed that neonates classified as Stage III NEC (AHR: 0.42, 95% CI = 0.23-0.77) and those exposed to perinatal asphyxia (AHR: 0.51, 95% CI: 0.35-0.74) had a negative impact on NEC recovery time. However, neonates with a birth weight of 1500-2499gm (AHR: 1.65, 95% CI: 1.05-2.58) and a platelet count greater than 150,000 (AHR: 1.75, 95% CI: 1.24-2.48) had a positive effect on NEC recovery time.

CONCLUSION

The recovery time for neonates in the neonatal intensive care unit with necrotizing enterocolitis was longer. Comorbidities and advanced stage of NEC were associated with prolonged recovery time from NEC. However, neonates with better platelet count and birth weight greater than 1500mg had shorter recovery time from NEC.

Clinical value of prokineticin 2 in the diagnosis of neonatal necrotizing enterocolitis

BACKGROUND

Necrotizing enterocolitis (NEC) is an inflammatory and necrotizing intestinal emergency that occurs in preterm infants and low birth weight newborns; however, no specific serum biomarkers for the diagnosis of NEC has been identified so far.

METHODS

Serum samples were collected from healthy neonatal controls and patients with NEC newly admitted to the Children's Hospital of Chongqing Medical University. ELISA was used to measure serum PK2 levels, and ROC curve analysis was sued to evaluate the diagnostic efficacy of PK2 and other clinical biomarkers.

RESULTS

Serum PK2 levels in the NEC group (n = 53) were significantly lower than those in the control group (n = 18), but increased to near-normal levels after the postoperative recovery period. The NLR value of NEC group was higher than that of control group (P < 0.05). There was no significant difference in WBC and PLT count between NEC group and control group (P > 0.05). Serum CRP and PCT levels in NEC group were significantly higher than those in control group (P < 0.001 for CRP and P < 0.05 for PCT, respectively). After surgery, serum CRP, NLR and PCT levels were lower than before surgery, while serum PK2 levels were higher than before surgery (P < 0.05). The areas under the ROC curve (AUC) of PK2, PCT and CRP for the diagnosis of NEC were 0.837, 0.662 and 0.552, respectively. The AUC of PK2 combined with PCT, PK2 combined with CRP, and PK2 combined with PCT and CRP were 0.908, 0.854 and 0.981, respectively. PK2 exhibited the highest diagnostic efficacy for NEC.

CONCLUSION

PK2 has higher diagnostic efficacy than PCT and CRP in the diagnosis of NEC; the combination of PK2 and PCT or CRP can significantly improve its diagnostic efficiency, especially when the three are combined at the same time.

Role of innate T cells in necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a destructive gastrointestinal disease primarily affecting preterm babies. Despite advancements in neonatal care, NEC remains a significant cause of morbidity and mortality in neonatal intensive care units worldwide and the etiology of NEC is still unclear. Risk factors for NEC include prematurity, very low birth weight, feeding with formula, intestinal dysbiosis and bacterial infection. A review of the literature would suggest that supplementation of prebiotics and probiotics prevents NEC by altering the immune responses. Innate T cells, a highly conserved subpopulation of T cells that responds quickly to stimulation, develops differently from conventional T cells in neonates. This review aims to provide a succinct overview of innate T cells in neonates, encompassing their phenotypic characteristics, functional roles, likely involvement in the pathogenesis of NEC, and potential therapeutic implications.

SNAPPE-II and MDAS scores as predictors for surgical intervention in very low birth weight neonates with necrotizing enterocolitis

BACKGROUND

Necrotizing enterocolitis (NEC) is the most common life-threatening gastrointestinal emergency in preterm and term neonates, with the majority of cases affecting neonates classified as very low birth weight (VLBW, bw <1500 g). Scores for neonatal acute physiology-perinatal extension-II (SNAPPE-II) and metabolic derangement acuity score (MDAS) have been developed and utilized to assess neonatal morbidity and mortality including the subset of VLBW neonates. Serial SNAPPE-II and MDAS scores have been reported in neonates with necrotizing enterocolitis to assist in surgical management, yielding mixed results.

OBJECTIVE

To determine the relationship between clinical and/or laboratory deterioration using SNAPPE-II and MDAS scores measured at the time of NEC diagnosis and surgical management of NEC.

METHODS

We retrospectively evaluated preterm neonates ≥23 weeks gestational age who developed pneumatosis intestinalis on radiographic imaging coupled with clinical signs of NEC. SNAPPE-II and MDAS scores were calculated within twelve hours of birth and within twelve hours of initial finding of pneumatosis intestinalis. Baseline characteristics and clinical variables between those who did and did not require surgical intervention were compared. Logistic regression and receiver - operator characteristics (ROC) curve analyses were also performed, and areas under the curve (AUC) computed, to assess the performance of SNAPPE-II and MDAS scoring systems to differentiate neonates with NEC in the two groups.

RESULTS

Sixty-four neonates were evaluated in our study of which 20 required surgical management of NEC. While the baseline SNAPPE-II and MDAS scores did not differ between the surgical management and medical management only groups, when rescored within 12 h of NEC diagnosis, the surgical management group had significantly higher SNAPPE -II (38 (18.5-69) vs. 19 (10-34.5), p = .04) and MDAS (2.5 (1-3) vs. 1 (0-2), p = .0004) scores. The AUCs for MDAS 0.77 (95% CI 0.65-0.89 and 0.71 (95% CI 0.57-0.85) for SNAPPE-II, indicating an acceptable level of diagnostic ability of both scoring systems to differentiate between those who did and did not need surgical management.

CONCLUSION

SNAPPE II and MDAS scores performed within 12 h of NEC diagnosis may be useful in predicting which preterm VLBW neonates will require surgical intervention.

A systematic review and meta-analysis of the role of Doppler ultrasonography of the superior mesenteric artery in detecting neonates at risk of necrotizing enterocolitis

The role of postnatal Doppler measurements of the superior mesenteric artery (SMA) in detecting neonates at risk of necrotizing enterocolitis (NEC) remains uncertain; therefore, we systematically reviewed and meta-analyzed the existing evidence regarding the usefulness of SMA Doppler measurements in detecting neonates at risk for NEC. We used the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines, and we included studies which reported the following Doppler ultrasonography indices: peak systolic velocity, end-diastolic velocity, time average mean velocity, differential velocity, pulsatility index (PI) and resistive index. Eight studies were eligible for inclusion in the meta-analysis. Evidence suggested that, during the first postnatal day, neonates who developed NEC had a significantly higher peak systolic velocity (mean difference of 2.65 cm/s (95% confidence interval [CI] 1.23, 4.06, overall effect Z=3.66, P<0.001)), higher PI (mean difference of 1.52 (95% CI 0.00, 3.04, Z=1.96, P=0.05)) and higher resistive index (mean difference of 1.09 (95% CI 0.59, 1.60, Z=4.24, P<0.001)), compared to neonates who did not develop NEC. However, our findings do not support a strong association between the Doppler ultrasound indices and development of NEC at the time of disease onset. This meta-analysis suggests that first postnatal day SMA Doppler parameters, namely peak systolic velocity, PI and resistive index, are higher in neonates who develop NEC. On the other hand, the aforementioned indices are of uncertain significance once the diagnosis of NEC has been established.

Prediction of High Bell Stages of Necrotizing Enterocolitis Using a Mathematic Formula for Risk Determination

Necrotizing enterocolitis (NEC) continues to cause high morbidity and mortality. Identifying early predictors for severe NEC is essential to improve therapy and optimize timing for surgical intervention. We present a retrospective study of patients with NEC, treated between 2010 and 2020, trying to identify factors influencing the severity of NEC. Within the study period, 88 affected infants with NEC or NEC-like symptoms are analyzed. A multiple logistic regression analysis reveals the following three independent predictors for NEC in Bell stage III: red blood cell transfusion (p = 0.027 with odds ratio (OR) = 3.298), sonographic findings (p = 0.037; OR = 6.496 for patients with positive vs. patients without pathological findings) and cardiac anatomy (p = 0.015; OR = 1.922 for patients with patent ductus arteriosus (PDA) vs. patients with congenital heart disease (CHD); OR = 5.478/OR = 2.850 for patients with CHD/PDA vs. patients without cardiac disease). Results are summarized in a clinical score for daily application in clinical routine. The score is easy to apply and combines clinically established parameters, helping to determine the timing of surgical intervention.

The benefits, limitations and opportunities of preclinical models for neonatal drug development

Increased research to improve preclinical models to inform the development of therapeutics for neonatal diseases is an area of great need. This article reviews five common neonatal diseases - bronchopulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis, perinatal hypoxic-ischemic encephalopathy and neonatal sepsis - and the available in vivo, in vitro and in silico preclinical models for studying these diseases. Better understanding of the strengths and weaknesses of specialized neonatal disease models will help to improve their utility, may add to the understanding of the mode of action and efficacy of a therapeutic, and/or may improve the understanding of the disease pathology to aid in identification of new therapeutic targets. Although the diseases covered in this article are diverse and require specific approaches, several high-level, overarching key lessons can be learned by evaluating the strengths, weaknesses and gaps in the available models. This Review is intended to help guide current and future researchers toward successful development of therapeutics in these areas of high unmet medical need.

Vagal Tone and Proinflammatory Cytokines Predict Feeding Intolerance and Necrotizing Enterocolitis Risk

BACKGROUND

Necrotizing enterocolitis (NEC) is the leading cause of death due to gastrointestinal disease in preterm neonates; yet, clinicians lack reliable and noninvasive predictive tools.

PURPOSE

We aimed to test that diminished high-frequency heart rate variability (HF-HRV) and elevated levels of proinflammatory cytokines would have utility in NEC prediction.

METHODS

In this multisite prospective study, we enrolled 250 preterm (26-34 weeks' postmenstrual age [PMA]) neonates with physiological stability at 72 hours of life. HRV was measured noninvasively using electrocardiograhic data from standardized cardiorespiratory monitors at postnatal week 1 of life and weekly thereafter until 35 weeks' PMA or discharge; blood was collected for cytokines at postnatal weeks 1 and 3. NEC was diagnosed via Modified Bell's Staging Criteria.

RESULTS

HF-HRV was decreased at weeks 1 and 2 in neonates (47% females) who developed feeding intolerance or stage 2+ NEC. In addition, these neonates displayed elevated levels of IL-8 at week 1 and increased levels of IL-1β, IL-6, TNF-α, and IL-8 at week 3 of life. Low HF-HRV was associated with elevated IL-6 or IL-8 levels at weeks 1 and 3 of life. Logistic regression indicated that only HF-HRV was a significant predictor of feeding intolerance or NEC development.

IMPLICATIONS FOR PRACTICE AND RESEARCH

HRV is a promising noninvasive modality for NEC risk detection. The association of low HF-HRV with elevated proinflammatory cytokines provides evidence for a putative role of the vagal cholinergic pathway in NEC pathogenesis. Future studies should focus on application of these techniques to test clinical therapeutics.Video Abstract available at https://journals.lww.com/advancesinneonatalcare/Pages/videogallery.aspx?autoPlay=false&videoId=54.

Effect of Feeding Strategies on the Development of Fulminant Necrotizing Enterocolitis

INTRODUCTION

 Necrotizing enterocolitis (NEC) causes significant neonatal morbidity. A subset of infants experience precipitous decline and death from fulminant-NEC (F-NEC). We sought to determine the effect of feeding practices on the development of this more virulent form of NEC.

MATERIALS AND METHODS

 Premature neonates developing Bell's stage II or III NEC between May 2011 and June 2017 were reviewed. Infants were stratified as having NEC or F-NEC, defined as NEC-totalis or NEC causing rapid decline and death within 72 hours. Risk factors extracted included demographics, gestational age, and weight at NEC diagnosis. Feeding data extracted included age at first feed, caloric density, type of feed (breast milk or formula), and whether full volume feeds were reached. Univariate analysis and multivariate analysis were performed.

RESULTS

 A total of 98 patients were identified, of which 80 were included. In total, 57 patients had NEC and 23 had F-NEC. Reaching full volume feeds was associated with F-NEC on both univariate and multivariate analysis (37.9 vs. 4.5%; odds ratio: 67, 95% confidence interval: 6.606-2041, p = 0.003). Infants developing F-NEC achieved full feeds earlier (22.5 vs. 19.8 days, p = 0.025) on univariate but not multivariate analysis. There was no difference in the rates of NEC and F-NEC among infants receiving breast milk (standard or fortified) or formula (standard or increased caloric density; p = 0.235).

CONCLUSION

 Among premature neonates with NEC, reaching full volume feedings was associated with a nearly 70-fold increased risk of F-NEC. Assuming it was possible to predict an infant's development of NEC, alternative feeding regimens might reduce the risk of F-NEC in this population.

Predictive factors for surgical treatment in preterm neonates with necrotizing enterocolitis: a multicenter case-control study

Necrotizing enterocolitis (NEC) is one of the most common and lethal gastrointestinal diseases in preterm infants. Early recognition of infants in need for surgical intervention might enable early intervention. In this multicenter case-control study, performed in nine neonatal intensive care units, preterm born infants (< 30 weeks of gestation) diagnosed with NEC (stage ≥ IIA) between October 2014 and August 2017 were divided into two groups: (1) medical (conservative treatment) and (2) surgical NEC (sNEC). Perinatal, clinical, and laboratory parameters were collected daily up to clinical onset of NEC. Univariate and multivariate logistic regression analyses were applied to identify potential predictors for sNEC. In total, 73 preterm infants with NEC (41 surgical and 32 medical NEC) were included. A low gestational age (p value, adjusted odds ratio [95%CI]; 0.001, 0.91 [0.86-0.96]), no maternal corticosteroid administration (0.025, 0.19 [0.04-0.82]), early onset of NEC (0.003, 0.85 [0.77-0.95]), low serum bicarbonate (0.009, 0.85 [0.76-0.96]), and a hemodynamically significant patent ductus arteriosus for which ibuprofen was administered (0.003, 7.60 [2.03-28.47]) were identified as independent risk factors for sNEC.Conclusions: Our findings may support the clinician to identify infants with increased risk for sNEC, which may facilitate early decisive management and consequently could result in improved prognosis. What is Known: • In 27-52% of the infants with NEC, a surgical intervention is indicated during its disease course. • Absolute indication for surgical intervention is bowel perforation, whereas fixed bowel loop or clinical deterioration highly suggestive of bowel perforation or necrosi, is a relative indication. What is New: • Lower gestational age, early clinical onset, and no maternal corticosteroids administration are predictors for surgical NEC. • Low serum bicarbonate in the 3 days prior clinical onset and patent ductus arteriosus for which ibuprofen was administered predict surgical NEC.

Protective effects of different doses of human milk on neonatal necrotizing enterocolitis

We aim to summarize the evidence focusing on the effects of various doses of human milk on the risk of neonatal necrotizing enterocolitis (NEC). The eligible articles in the study were those investigating the association between human milk and NEC published before June 26, 2019, in the PubMed, EMBASE, the Cochrane Library, VIP database, CNKI database, and Wangfang database. The included criteria were as follows: premature infants of <37 weeks; randomly controlled trials (RCTs); those fed by mother's own milk or donor human milk; studies focused on the comparison of human milk and formula milk, involving various breast milk doses; and NEC-related studies. Compared with the exclusive formula, the incidence of NEC in the infants fed by exclusive human milk was significantly lower. The incidence of NEC in the infants fed by exclusive human milk was significantly lower than that of partial human milk [risk ratio (RR) = 0.54, 95% confidence interval (95% CI): 0.36-0.79, P < .05]. The incidence of NEC in the infants fed mainly by human milk was significantly lower than that of mainly fed by formula. Incidence of NEC in the infants fed by exclusive human milk was significantly lower than that of any formula (RR = 0.49, 95% CI: 0.34-0.71, P < .05). In summary, this meta-analysis was based on the RCTs involving the prevention of NEC using human milk. Exclusive human milk and partial human milk reduced the incidence of NEC in premature infants, especially in the those fed by high proportion of human milk. In addition, more RCTs are needed to further validate such conclusion.

Early Doppler Ultrasound in the Superior Mesenteric Artery and the Prediction of Necrotizing Enterocolitis in Preterm Neonates

OBJECTIVES

The purpose of this study was to reveal the correlation between superior mesenteric artery (SMA) blood flow in the first 12 hours of life and the risk of necrotizing enterocolitis (NEC) in preterm neonates.

METHODS

We conducted a prospective study. There were 104 preterm neonates included in our study. The SMA blood flow of each neonate was measured during the first 12 hours of life if the hemodynamic situation was stable. The results of Doppler ultrasound were confidential to the neonatologists and nurses. All of the demographics, comorbidities, and outcomes were recorded and analyzed.

RESULTS

Among all of the demographics and comorbidities, the gestational age was related to the measurements of SMA blood flow. We conducted a single-factor analysis of the occurrence of NEC, including the peak systolic velocity (PSV), end-diastolic velocity, time-averaged mean velocity, differential velocity (DV), resistive index, and pulsatility index. A higher PSV (median [interquartile range], 54.165 [42.423-68.463] versus 42.195 [34.278-48.553] cm/s; P = .027) and DV (median [interquartile range], 47.445 [35.010-60.043] versus 32.565 [27.545-39.073] cm/s; P = .020) were significantly related to the risk of NEC. In the logistic analysis including gestational age, PSV, and DV, NEC was significantly associated with gestational age (odds ratio [95% confidence interval], 0.644 [0.456-0.908]; P = .012) and DV (odds ratio [95% confidence interval], 1.144 [1.058-1.237]; P < .01). The area under the receiver operating characteristic curve for the DV was 0.768, with sensitivity 0.875 and specificity 0.604. The cutoff value of the DV was 34.835 cm/s.

CONCLUSIONS

From this single-center study, we can see the promising value of Doppler ultrasound for the prediction of NEC, but further research is needed.

Maternal and placental risk factors associated with the development of necrotizing enterocolitis (NEC) and its severity

BACKGROUND/PURPOSE

Antenatal factors play an important role in NEC. This study aimed to identify antenatal risk factors associated with the development of NEC, the role of the placental alterations, and the presence of prenatal signs predisposing to a severe NEC.

MATERIALS/METHODS

Data of NEC patients including antenatal findings [preeclampsia, diabetes, cholestasis, abnormal antenatal umbilical artery flow (AAUF), clinical chorioamnionitis (CC), and histology of placentas] were compared to unaffected cases between 2002 and 2016 in a single center. Unaffected infants were matched for gestational age. Newborns with cardiovascular diseases were excluded. Bivariate and multivariate analyses were performed.

RESULTS

We identified 136 cases and 134 controls. The group of mothers of NEC-neonates had a higher prevalence of preeclampsia, CC, and AAUF. Histology of Placentas from 123/136 cases and 126/133 unaffected newborns was available. Chorioamnionitis was significantly more present in NEC cases vs controls. There weren't differences in vascular anomalies and necrotic alterations. Multivariate analysis identified AAUF, CC and histological chorioamnionitis (HC) as predictors of NEC. Bivariate tests show that preeclampsia and HC occurred more often in severe cases of NEC.

CONCLUSION

This study suggests that AAUF, CC, and HC can independently predict the risk of NEC. Preeclampsia and HC seem associated to more severe cases.

LEVEL OF EVIDENCE

IIIA.

An update on biomarkers of necrotizing enterocolitis

Necrotizing enterocolitis (NEC) remains a devastating surgical emergency with high morbidity and mortality in preterm infants. Slow but steady progress has been made in past years searching for novel biomarkers of NEC, for both surveillance and diagnostic purposes. This review primarily focuses on recent discoveries: clinical applications of different categories of biomarkers for surveillance, early diagnosis, and predicting severity and prognosis; and understanding of pathophysiological mechanisms as a basis to rationalize the search for 'gut-associated specific biomarkers' of NEC. An important next step is to collaborate with our industrial partners to develop point-of-care tests, and to discover novel and gut-associated specific biomarkers that can be used for surveillance and early diagnosis of NEC in routine clinical settings.

Mutational spectrum of PTS gene and in silico pathological assessment of a novel variant in Mexico

BACKGROUND

Tetrahydrobiopterin (BH4) is the cofactor for 6-pyruvoyl-tetrahydropterin synthase (PTPS); it is involved in BH4 biosynthesis and is encoded by PTS gene. Its deficiency (PTPSD) is characterized by hyperphenylalaninemia (HPA) and deficit in central monoamine neurotransmitters. We describe the clinical and mutational spectrum of five patients with PTPSD, from four unrelated Mexican families. All patients had symptomatic diagnosis and presented severe early neurological manifestations and HPA.

METHODS

Clinical and biochemical data from studied patients were recorded. Responsible PTPSD genotypes was determined by direct and bidirectional Sanger DNA sequencing of the six PTS coding exons and their exon-intron borders, and these were directly searched in the available relatives. The novel PTS missense variant [NM_3000317.2:331G > T, p.(Ala111Ser)] was subjected to in silico, to predict a possible deleterious effect.

RESULTS

Diminished fetal movements were perceived as a uniform characteristic in the studied group. DNA sequencing showed two known p.(Arg25∗) and p.(Val132TyrFs∗19) and the novel missense p.(Ala111Ser) PTS variants, the latter representing potentially a frequent PTPSD-responsible allele (50%, 4/8) in Mexican patients. In silico protein modeling analysis of the p.(Ala111Ser) variant revealed loss of hydrophobic interactions between the alanine and neighboring valines, suggesting that these changes in polarity may be detrimental for enzyme function, structure and/or stability.

CONCLUSIONS

This work contributes to the knowledge of PTPS molecular spectrum. The delayed diagnosis of these patients emphasizes the importance of considering BH4 metabolism defects in the differential diagnosis of HPA, especially for countries that are beginning their HPA newborn screening programs.

Differential correlations between maternal hair levels of tobacco and alcohol with fetal growth restriction clinical subtypes

Maternal exposure to tobacco and alcohol is a known cause, among others, for fetal growth restriction (FGR). Clinically, FGR can be subclassified into two forms: intrauterine growth restriction (IUGR) and small for gestational age (SGA), based on the severity of the growth retardation, and abnormal uterine artery Doppler or cerebro-placental ratio. This study aimed at investigating any differential correlation between maternal exposures to these toxins with the two clinical forms of FGR. Therefore, a case-control study was conducted in Barcelona, Spain. Sixty-four FGR subjects, who were further subclassified into IUGR (n = 36) and SGA (n = 28), and 89 subjects matched appropriate-for-gestational age (AGA), were included. The levels of nicotine (NIC) and ethyl glucuronide (EtG), biomarkers of tobacco and alcohol exposure, respectively, were assessed in the maternal hair in the third trimester. Our analysis showed 65% of the pregnant women consumed alcohol, 25% smoked, and 19% did both. The odds ratios (ORs) of IUGR were 21 times versus 14 times for being SGA with maternal heavy smoking, while with alcohol consumption the ORs for IUGR were 22 times versus 37 times for the SGA group. The differential correlations between these toxins with the two subtypes of FGR suggest different mechanisms influencing fetal weight. Our alarming data of alcohol consumption during pregnancy should be considered for further confirmation among Spanish women.

The role of imaging in the management of necrotising enterocolitis: a multispecialist survey and a review of the literature

Objectives

To investigate current practices and perceptions of imaging in necrotising enterocolitis (NEC) according to involved specialists, put them in the context of current literature, and identify needs for further investigation.

Methods

Two hundred two neonatologists, paediatric surgeons, and radiologists answered a web-based questionnaire about imaging in NEC at their hospitals. The results were descriptively analysed, using proportion estimates with 95% confidence intervals.

Results

There was over 90% agreement on the value of imaging for confirmation of the diagnosis, surveillance, and guidance in decisions on surgery as well as on abdominal radiography as the first-choice modality and the most important radiographic signs. More variation was observed regarding some indications for surgery and the use of some ultrasonographic signs. Fifty-eight per cent stated that ultrasound was used for NEC at their hospital. Examination frequency, often once daily or more but with considerable variations, and projections used in AR were usually decided individually rather than according to fixed schedules. Predicting the need of surgery was regarded more important than formal staging.

Conclusion

Despite great agreement on the purposes of imaging in NEC and the most important radiographic signs of the disease, there was considerable diversity in routines, especially regarding examination frequency and the use of ultrasound. Apart from continuing validation of ultrasound, important objectives for future studies include definition of the supplementary roles of both imaging modalities in relation to other diagnostic parameters and evaluation of various imaging routines in relation to timing of surgery, complications, and mortality rate.

Key Points

• Imaging is an indispensable tool in the management of necrotising enterocolitis

• Predicting the need of surgery is regarded more important than formal staging

• There is great consensus on important signs of NEC on abdominal radiography

• There is more uncertainty regarding the role of ultrasound

• Individualised management is preferred over standardised diagnostic algorithms

Electronic supplementary material

The online version of this article (10.1007/s00330-018-5362-x) contains supplementary material, which is available to authorized users.

Significance of dynamic evolution of TNF-α, IL-6 and intestinal fatty acid-binding protein levels in neonatal necrotizing enterocolitis

To study the significance of dynamic evolution of serum tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6) and intestinal fatty acid-binding protein (I-FABP) levels in neonatal necrotizing enterocolitis (NEC). A total of 45 NEC child patients, 45 non-NEC child patients and 45 healthy newborns were enrolled. After the day age, weight, gestational week and delivery mode were matched, the serum TNF-α, IL-6 and I-FABP levels at 6, 24 and 72 h after admission were measured via ELISA method, and their correlations with prognosis were analyzed. The levels of serum TNF-α and IL-6 in NEC and non-NEC group reached the peak at 24 h and fell at 72 h; there were no differences in each time point between the two groups (P>0.05), but the levels of serum TNF-α and IL-6 were higher than those in the control group (P<0.05). The level of serum I-FABP in NEC and non-NEC group reached the peak at 6 h, and it fell at 72 h in NEC group and 24 h in non-NEC group; the level of I-FABP in each time point in NEC was significantly higher than that in non-NEC group, and the level was the lowest in healthy group; the differences were statistically significant (P<0.05). There were 40 cases of survival and 5 cases of death (11.1%) in NEC group, while there were 43 cases of survival and 2 cases of death (4.4%) in non-NEC group. There were no differences in serum TNF-α and IL-6 levels at different times between surviving child patients and dead child patients in NEC group (P>0.05), but the levels of serum I-FABP in surviving child patients at 6 h and 24 h were significantly lower than those in dead child patients (P<0.05), and there was no difference at 72 h (P>0.05). There were no differences in serum TNF-α, IL-6 and I-FABP levels at different times between surviving and dead child patients in non-NEC group (P>0.05). Serum I-FABP level and its dynamic evolution may be important indexes of early diagnosis and prognosis evaluation of NEC.

Heavy metals exposure levels and their correlation with different clinical forms of fetal growth restriction

Background

Prenatal heavy metals exposure has shown a negative impact on birth weight. However, their influence on different clinical forms of fetal smallness was never assessed.

Objectives

To investigate whether there is a differential association between heavy metals exposure and fetal smallness subclassification into intrauterine growth restriction (IUGR) and small-for-gestational age (SGA).

Method

In this prospective case-control study, we included 178 mother–infant pairs; 96 of appropriate for gestational age (AGA) and 82 of small fetuses diagnosed in third trimester. The small ones were further subclassified into IUGR, n = 49 and SGA, n = 33. Cadmium (Cd), mercury (Hg), lead (Pb), arsenic (As) and zinc (Zn) levels were measured in the maternal and cord serum, and in the placentas of the three groups.

Results

Maternal serum level of Cd (p<0.001) was higher in the small fetuses compared to AGA. Fetal serum level of Cd (p<0.001) was increased in the small fetuses compared to AGA. Fetal serum level of Hg (p<0.05) showed an increase in SGA compared to both IUGR and AGA. Fetal serum level of Zn was increased in the AGA (p < 0.001) compared to each of the small fetuses groups. Only differences in the levels between the small fetuses’ subgroups were detected in the fetal serum levels of Cd and Hg. Fetal birth weight was negatively correlated with the fetal serum level of Cd (p < 0.001). No differences in the placental heavy metal levels were observed among the groups.

Conclusion

Fetal serum levels of Cd showed differential correlation between small fetuses' clinical subclassification, which together with the increased Cd levels in both maternal and fetal serum of the small fetuses reinforce the negative influence of heavy metals on birth weight. These findings provide more opportunities to verify the role of heavy metals exposure in relation to small fetuses’ subclassification.

Surgical necrotizing enterocolitis

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

Pathogenesis of NEC: Impact of an altered intestinal microbiome

Necrotizing enterocolitis (NEC), a disease most commonly seen in preterm infants, often presents without warning and is associated with very high mortality and morbidity. Progress in the prevention and treatment of NEC has been slow. In this article, we will discuss some of the reasons as to why this progress has been slow. We will describe some of the factors that appear to be highly associated and important components in the pathophysiology of NEC. We will discuss the intestinal microbial environment of the fetus as well as the preterm infant and how interaction of dysbiosis with an immature gastrointestinal tract combined with dietary factors play a role in the pathogenesis of NEC. Testable hypotheses are discussed as well as how these may lead to not only a better understanding of the pathophysiology of the disease but also the preventative strategies.

Maternal and Placental Risk Factors for Developing Necrotizing Enterocolitis in Very Preterm Infants

BACKGROUND

Despite the clinical relevance of necrotizing enterocolitis (NEC), it remains difficult to predict which preterm infants are more likely to develop NEC. Contrary to the neonatal risk factors for the development of NEC, little information is available regarding maternal (prenatal) risk factors. We aimed to identify maternal risk factors associated with the subsequent development of NEC in very preterm infants and to determine whether the placental inflammatory lesions were related to the NEC.

METHODS

This retrospective cohort study examined newborns born at < 32 weeks (n=354) between July 2003 and July 2014 at a university teaching hospital. Medical records of eligible newborns and their mothers were reviewed. Maternal blood white blood cell and differential counts were measured at admission and the placentas were examined histologically after delivery. The primary outcome measure was NEC Bell Stage≥IIa. Bivariate analyses and multivariate logistic regression were used for the statistical analyses.

RESULTS

NEC was diagnosed in 26 of 354 very preterm infants (7.3%), including 19 Stage II and seven Stage III infants. Multivariate regression analysis identified maternal neutrophil-to-lymphocyte ratio [odds ratio (OR)=1.08, p=0.002], multiparity (OR=3.41, p=0.013), and birth weight (OR=0.07 per kg increase, p=0.01), but not clinical and histological chorioamnionitis and funisitis as significant predictors of NEC.

CONCLUSION

Maternal neutrophil-to-lymphocyte ratio, parity, and birth weight can independently predict the risk of NEC in very preterm infants, whereas clinical and histological chorioamnionitis and funisitis are not predictive of NEC.

Current Knowledge of Necrotizing Enterocolitis in Preterm Infants and the Impact of Different Types of Enteral Nutrition Products

Preterm infants are extremely vulnerable to a range of morbidities and mortality. Underdeveloped cardiac, respiratory, gastrointestinal, and immune systems in the preterm period increase the risk of necrotizing enterocolitis (NEC), a serious disease of the gut. NEC affects 5-12% of very-low birth-weight infants, leads to surgery in 20-40% of cases, and is fatal in 25-50% of cases. There are multiple factors that may contribute to NEC, but the exact cause is not yet fully understood. Severe cases can result in intestinal resection or death, and the health care costs average >$300,000/infant when surgical management is required. Different types of nutrition may affect the onset or progression of NEC. Several studies have indicated that bovine milk-based infant formulas lead to a higher incidence of NEC in preterm infants than does human milk (HM). However, it is not clear why HM is linked to a lower incidence of NEC or why some infants fed an exclusively HM diet still develop NEC. An area that has not been thoroughly explored is the use of semielemental or elemental formulas. These specialty formulas are easy to digest and absorb in the gut and may be an effective nutritional intervention for reducing the risk of NEC. This review summarizes what is known about the factors that contribute to the onset and progression of NEC, discusses its health care cost implications, and explores the impact that different formulas and HM have on this disease.

A Causal Network Analysis of the Fatty Acid Metabolome in African-Americans Reveals a Critical Role for Palmitoleate and Margarate

Fatty acids are important sources of energy and possible predictors and etiologic factors in many common complex pathologies such as cardiovascular disease, diabetes, and certain forms of cancers. While fatty acids are thought to covary with each other, their underlying causal networks have not been fully elucidated. This study reports the identification and analysis of a statistical causal network among 15 mostly long-chain fatty acids. In an African-American population sample and using the Genome granularity-Directed Acyclic Graph (GDAG) algorithm, we determined directions or causal relationships in the fatty acid metabolome. A directed causal network was constructed that revealed 29 significant edges among the 15 nodes (p < 0.001). We report that two fatty acid metabolites, palmitoleate and margarate, which originate from dietary intake, together influence every other fatty acid in the network. On the other hand, despite its high connectivity, dihomo-linoleate did not appear to play an important role over the whole fatty acid network. These findings collectively suggest possible strategic entry points for new treatments or preventive modalities against diseases affected by fatty acid metabolites such as cardiovascular disease, diabetes, and obesity. Further studies examining the embedded substructure of the fatty acid metabolite networks in independent population samples would be timely and warranted as we move toward novel postgenomic diagnostics and therapeutics.

The antecedents and correlates of necrotizing enterocolitis and spontaneous intestinal perforation among infants born before the 28th week of gestation

OBJECTIVE

To identify antecedents of "medical" necrotizing enterocolitis (mNEC), "surgical" NEC (sNEC), and spontaneous intestinal perforation (SIP) in newborns delivered before 28 weeks gestation.

STUDY DESIGN

Prospective multicenter cohort study. During study period, 2002- 2004, women delivering before 28 weeks gestation at one of 14 participating institutions were enrolled. Well defined antenatal and postnatal variables were collected. Bivariate analyses were performed to identify candidates for developing multinomial multivariable time-oriented logistic regression models.

RESULTS

Of the 1320 infants, 5% had mNEC, 6% had sNEC, and 4% had SIP. Antecedents of mNEC included mother's identification as Black, consumption of aspirin during the pregnancy, and vaginal bleeding after the 12th week of gestation. For sNEC the antecedents were maternal self- support, obesity and anemia during the pregnancy, birth before the 24th week, birth weight ≤750gm, and receipt of fresh frozen plasma (FFP) during the first postnatal week. An infant was at increased risk of SIP if the placenta had increased syncytial knots, birth occurred before the 24th week, and received FFP during the first week.

CONCLUSIONS

Maternal and neonatal characteristics might help identify at-risk ELGANs for NEC and SIP, who then may potentially benefit from targeted preventive strategies.

Early Detection of Necrotizing Enterocolitis by Fecal Volatile Organic Compounds Analysis

OBJECTIVES

To test the hypothesis that fecal volatile organic compounds (VOCs) analysis by electronic nose (eNose) allows for early detection of necrotizing enterocolitis (NEC).

STUDY DESIGN

In 3 neonatal intensive care units, fecal samples of infants born at gestational age ≤ 30 weeks were collected daily, up to the 28th day of life. Included infants were allocated in 3 subgroups: NEC, sepsis, and matched controls. Three time windows were defined: (1) T-5,-4 (5 and 4 days before diagnosis); (2) T-3,-2 (3 and 2 days before diagnosis); and (3) T-1,0 (day before and day of diagnosis). Three subgroups were analyzed by eNose.

RESULTS

Fecal VOC profiles of infants with NEC (n = 13) could significantly be discriminated from matched controls (n = 14) at T-3,-2 (area under the curve ± 95% CI, P value, sensitivity, specificity: 0.77 ± 0.21, P = .02, 83%, 75%); the accuracy increased at T-1,0 (0.99 ± 0.04, P ≤ .001, 89%, 89%). VOC profiles of infants with NEC were also significantly different from those with sepsis (n = 31) at T-3,-2 (0.80 ± 0.17, P = .004, 83%, 75%), but not at T-1,0 (0.64 ± 0.18, P = .216, 89%, 57%).

CONCLUSIONS

In this proof of principle study, we observed that fecal VOC profiles of infants with NEC could be discriminated from controls, from 2-3 days predating onset of clinical symptoms. Our observations suggest that VOC-profiling by eNose has potential as a noninvasive tool for the early prediction of NEC.

Propofol administration to the maternal-fetal unit improved fetal EEG and influenced cerebral apoptotic pathway in preterm lambs suffering from severe asphyxia

BACKGROUND

Term and near-term infants are at high risk of developing brain injury and life-long disability if they have suffered from severe perinatal asphyxia. We hypothesized that propofol administration to the maternal-fetal unit can diminish cerebral injury in term and near-term infant fetuses in states of progressive severe asphyxia.

METHODS

Forty-four late preterm lambs underwent total umbilical cord occlusion (UCO) or sham treatment in utero. UCO resulted in global asphyxia and cardiac arrest. After emergency cesarean section under either maternal propofol or isoflurane anesthesia, the fetuses were resuscitated and subsequently anesthetized the same way as their mothers.

RESULTS

Asphyctic lambs receiving isoflurane showed a significant increase of total and low-frequency spectral power in bursts indicating seizure activity and more burst-suppression with a marked increase of interburst interval length during UCO. Asphyctic lambs receiving propofol showed less EEG changes. Propofol increased levels of anti-apoptotic B-cell lymphoma-extra large (Bcl-xL) and phosphorylated STAT-3 and reduced the release of cytochrome c from the mitochondria and the protein levels of activated cysteinyl aspartate-specific protease (caspase)-3, -9, and N-methyl-d-aspartate (NMDA) receptor.

CONCLUSIONS

Improvement of fetal EEG during and after severe asphyxia could be achieved by propofol treatment of the ovine maternal-fetal unit. The underlying mechanism is probably the reduction of glutamate-induced cytotoxicity by down-regulation of NMDA receptors and an inhibition of the mitochondrial apoptotic pathway.

[Serious adverse side effects after pupillary dilation in preterm infants]

PURPOSE

This study aimed at investigating serious side effects of the pupillary dilation protocol used in Caen University Hospital for the screening of retinopathy of prematurity. This protocol includes one drop of phenylephrine 5% and two drops of tropicamide 0.5% instilled at a 5-minute interval.

PATIENTS AND METHODS

This retrospective study included all premature infants with a birth weight less than or equal to 1500 g and/or a gestational age less than or equal to 30 gestational weeks, hospitalized in the neonatal intensive care unit of Caen University Medical Center, having ocular fundus examinations for retinopathy of prematurity screening between 2009 and 2014. The medical records of patients who died or developed necrotizing enterocolitis were reviewed to analyze the imputability of the two eye drops used for pupil dilation.

RESULTS

Five-hundred and twelve infants were included, corresponding to 1033 ocular fundus examinations. No case of death could be ascribed to the use of eye drops. Two cases of necrotizing enterocolitis could be ascribed to the use of tropicamide with a doubtful and plausible intrinsic imputability according to French imputability criteria.

CONCLUSION

The pupillary dilation protocol used in Caen University Hospital for screening of retinopathy of prematurity might be implicated in two cases of necrotizing enterocolitis with an uncertain imputability of tropicamide 0.5% eye drops. No serious side effect could be ascribed to the use of phenylephrine 5% eye drops in this study.