Necrotizing Enterocolitis: Enhancing Awareness for the General Practitioner

[Predictive value of hemoglobin decrease for necrotizing enterocolitis in preterm infants with late-onset sepsis]

OBJECTIVES

To study the predictive value of hemoglobin (Hb) decrease for the occurrence of necrotizing enterocolitis (NEC) in preterm infants with late-onset sepsis (LOS) .

METHODS

Clinical data of 93 LOS preterm infants were collected for retrospective analysis, among which 16 infants developed NEC while 77 infants did not. Based on the decrease in Hb levels from the most recent Hb measurement before LOS occurrence to the initial Hb levels during LOS, the infants were divided into three groups: no Hb decrease (n=15), mild Hb decrease (Hb decrease <15 g/L; n=35), and severe Hb decrease (Hb decrease ≥15 g/L; n=43). Multivariate logistic regression analysis was conducted to explore the predictive factors for NEC secondary to LOS, and the value of Hb decrease in predicting NEC secondary to LOS was evaluated through receiver operating characteristic curve analysis.

RESULTS

The incidence of NEC in the severe Hb decrease group, mild Hb decrease group, and no Hb decrease group were 26%, 14%, and 0% (P<0.05), respectively. Multivariate logistic regression analysis revealed that a larger Hb decrease was an independent predictive factor for NEC in LOS preterm infants (OR=1.141, 95%CI: 1.061-1.277, P<0.001). Receiver operating characteristic curve analysis showed that the area under the curve for predicting NEC in preterm infants with LOS using Hb decrease (with a cut-off value of 20 g/L) was 0.803, with sensitivity and specificity of 0.69 and 0.78, respectively.

CONCLUSIONS

Hb decrease can serve as an indicator for prediction of NEC in preterm infants with LOS.

Reduction in regulatory T cells in preterm newborns is associated with necrotizing enterocolitis

BACKGROUND

Despite multifactorial pathogenesis, dysregulation of inflammatory immune response may play a crucial role in necrotizing enterocolitis (NEC). Regulatory T cells (Tregs) are involved in immune tolerance early in life. We aimed to investigate the predicting role of Tregs in developing NEC in neonates at high risk.

METHODS

We studied six newborns with a diagnosis of NEC (cases) in comparison with 52 controls (without NEC). We further classified controls as neonates with feeding intolerance (FI) and neonates without it (FeedTol). The rate of female and male neonates (sex defined as a biological attribute) was similar. We analyzed the blood frequency of Tregs (not overall numbers) at three time points: 0-3 (T0), 7-10 (T1), and 27-30 (T2) days after birth by flow cytometry. Neonates' sex was defined based on the inspection of external genitalia at birth.

RESULTS

We observed, at T0, a significantly lower frequency of Tregs in NEC cases (p < 0.001) compared with both FI (p < 0.01) and FeedTol controls (p < 0.01). Multivariate analysis reported that the occurrence of NEC was independently influenced by Treg frequency at birth (ß 2.98; p = 0.039).

CONCLUSION

Tregs frequency and features in the peripheral blood of preterm neonates, early in life, may contribute to identifying neonates at high risk of developing NEC.

IMPACT

Regulatory T cells may play a pivotal role in regulating the immune response in early life. Reduction of Tregs in early life could predispose preterm newborns to necrotizing enterocolitis. Early markers of necrotizing enterocolitis are still lacking. We demonstrated a predicting role of assessment of regulatory T cells in the diagnosis of this gastrointestinal emergency. Early identification of newborns at high risk of necrotizing enterocolitis through measurement of regulatory T cells may guide clinicians in the management of preterm newborns in order to reduce the development of this severe condition.

A Retrospective Case Control Study Examining Procalcitonin as a Biomarker for Necrotizing Enterocolitis

Abstract Background: Procalcitonin (PCT) is a biomarker for sepsis, but its utility has not been investigated in necrotizing enterocolitis (NEC). Necrotizing enterocolitis is a devastating multisystem disease of infants that in severe cases requires surgical intervention. We hypothesize that an elevated PCT will be associated with surgical NEC. Patients and Methods: After obtaining Institutional Review Board (IRB) approval (#12655), we performed a single institution retrospective case control study between 2010 and 2021 of infants up to three months of age. Inclusion criteria was PCT drawn within 72 hours of NEC or sepsis diagnosis. Control infants had a PCT drawn in the absence of infectious symptoms. Recursive partitioning (RP) identified PCT cutoffs. Categorical variable associations were tested using Fisher exact or χ² tests. Continuous variables were tested using Wilcoxon rank sum test, Student t-test, and Kruskal-Wallis test. Adjusted associations of PCT and other covariables with NEC or sepsis versus controls were obtained via multinomial logistic regression analysis. Results: We identified 49 patients with NEC, 71 with sepsis, and 523 control patients. Based on RP, we selected two PCT cutoffs: 1.4 ng/mL and 3.19 ng/ml. A PCT of ≥1.4 ng/mL was associated with surgical (n = 16) compared with medical (n = 33) NEC (87.5% vs. 39.4%; p = 0.0015). A PCT of ≥1.4 ng/mL was associated with NEC versus control (p < 0.0001) even when adjusting for prematurity and excluding stage IA/IB NEC (odds ratio [OR], 28.46; 95% confidence interval [CI], 11.27-71.88). A PCT of 1.4-3.19 ng/mL was associated with both NEC (adjusted odds ratio [aOR], 11.43; 95% CI, 2.57-50.78) and sepsis (aOR, 6.63; 95% CI, 2.66-16.55) compared with controls. Conclusions: A PCT of ≥1.4 ng/mL is associated with surgical NEC and may be a potential indicator for risk of disease progression.

Racial Disparities in Breastmilk Receipt and Extremely Low Gestational Age Neonatal Morbidities in an Asian Pacific Islander Population

BACKGROUND

Racial disparities in breastmilk provision and neonatal morbidities of extreme prematurity have been documented in previous studies but are not as well-documented in Asian and Pacific Islander (API) infants. The objectives of this study were to evaluate a predominantly API neonatal intensive care unit (NICU) population for racial disparities in (1) the receipt of breastmilk within 24 h of admission and at discharge and (2) neonatal morbidities among infants ≤ 28 weeks gestational age.

METHODS

A retrospective chart review of 2528 infants from 2018 to 2020 born at the largest level 3 NICU in Honolulu, Hawai'i, was conducted. Multivariable logistic regression analysis was performed on NICU outcomes to calculate adjusted odds ratios (aOR) and confidence intervals (CI).

RESULTS

Native Hawaiian (NH) (aOR 0.73 [0.54, 0.98]), Pacific Islander (PI) (aOR 0.57 [0.41, 0.79]), and Filipino infants (aOR 0.66 [0.49, 0.89]) were less likely to receive breastmilk at discharge compared to Asian infants. PI infants were also more likely to experience necrotizing enterocolitis (aOR 7.89 [1.07, 58.10]) and intraventricular hemorrhage (aOR 3.86 [1.15, 13.02]) compared to Asian infants.

CONCLUSION

In a predominantly API population, disparities in breastmilk receipt and neonatal morbidities exist among NH, PI, and Filipino infants in the NICU. Our findings call for better understanding of the underlying inequities to guide directed efforts, including standardization of care through staff trainings on implicit biases and trauma-informed care, as well as provision of culturally sensitive education and lactation support for these patients.

Necrotizing enterocolitis, gut microbes, and sepsis

Necrotizing enterocolitis (NEC) is a devastating disease in premature infants and the leading cause of death and disability from gastrointestinal disease in this vulnerable population. Although the pathophysiology of NEC remains incompletely understood, current thinking indicates that the disease develops in response to dietary and bacterial factors in the setting of a vulnerable host. As NEC progresses, intestinal perforation can result in serious infection with the development of overwhelming sepsis. In seeking to understand the mechanisms by which bacterial signaling on the intestinal epithelium can lead to NEC, we have shown that the gram-negative bacterial receptor toll-like receptor 4 is a critical regulator of NEC development, a finding that has been confirmed by many other groups. This review article provides recent findings on the interaction of microbial signaling, the immature immune system, intestinal ischemia, and systemic inflammation in the pathogenesis of NEC and the development of sepsis. We will also review promising therapeutic approaches that show efficacy in pre-clinical studies.

Bubbles in the belly: How well do radiology trainees recognize pneumatosis in pediatric patients on plain film?

OBJECTIVES

Pneumatosis intestinalis is a radiographic finding that refers to the presence of gas within the walls of the small or large bowel. This sign is diagnostic in the setting of premature infants with suspected necrotizing enterocolitis. Earlier detection of NEC on X-ray is vital to improve the overall management in these infants. The identification of pneumatosis intestinalis concerning for necrotizing enterocolitis by the "on-call" trainee is critical in the care of the preterm infant. Our objective was to study trainees' ability to identify pneumatosis on an emergent overnight film.

METHODS

The Emergent/Critical Care Imaging SIMulation (WIDI SIM) is a strategically designed computer-aided simulation of an emergency imaging experience that has been rigorously tested and proven to be a reliable means for assessing radiology trainee preparedness to competently and independently cover radiology call. One test case each year included requires the trainee to accurately identify pneumatosis on a plain radiograph of the abdomen in a neonate.

RESULTS

A total of 463 radiology trainees from 32 distinct training programs across the country were given a case of pneumatosis using the WIDI simulation web-based testing platform. On average only 28% of radiology trainees were able to correctly identify pneumatosis intestinalis on plain film. Although the sample sizes in the upper-level trainees were smaller, those with greater number years of training performed better.

CONCLUSIONS

Further training must be given to radiology trainees to accurately recognize pneumatosis and report concerns for necrotizing enterocolitis.

ADVANCES IN KNOWLEDGE

This paper is the first to describe and assess the ability of the "on-call" radiology trainee to accurately recognize pneumatosis and report concerns for necrotizing enterocolitis. Our paper includes the largest cohort of radiology trainees evaluated to this date.

The role of ultrasound in necrotizing enterocolitis

Ultrasound has proved to be a useful modality for enhancing the diagnostic accuracy of necrotizing enterocolitis and associated complications. The standard imaging algorithm for evaluating necrotizing enterocolitis includes radiographs and clinical symptoms, the combination of which constitutes the Bell criteria. Major limitations of using the Bell criteria for diagnosing and clinically managing necrotizing enterocolitis include low diagnostic accuracy of radiographs and nonspecific symptomatology of preterm infants. In this regard, US can offer additional insights into bowel health by helping to characterize bowel motility, echogenicity, thickness, pneumatosis and perfusion. Extramural findings such as portal venous gas, nature and extent of ascites, and pneumoperitoneum can also be assessed. Recently, contrast-enhanced US was explored in a case series of preterm bowel disease and its diagnostic utility warrants further investigation. This article reviews the US features of necrotizing enterocolitis and highlights the role of US as a complement to radiographs, as well as the emerging use of contrast-enhanced US in necrotizing enterocolitis.

Neonatal Gastrointestinal Emergencies: A Radiological Review

BACKGROUND

Abdominal emergencies in neonates require surgical management in almost all cases and complications may include bowel perforation, sepsis, shock, and even death. Radiological imaging has become a very important aid in the clinical setting as it shortens time to diagnosis.

OBJECTIVE

The objective of this review is to discuss the more prevalent neonatal gastrointestinal emergencies, review appropriate imaging options, and illustrate common radiological presentations of these entities.

CONCLUSION

Despite advancements in imaging techniques, it is important to keep in mind that neonates have a higher susceptibility to the adverse effects of ionizing radiation, and therefore radiography and ultrasonography remain the main diagnostic modalities for ruling out the diseases with the worst prognosis. Other modalities (fluoroscopy, computed tomography, and magnetic resonance imaging) may have limited use in very specific conditions. All providers in an emergency department should be familiar with the basic radiological findings that may indicate a gastrointestinal emergency, especially in health institutions that do not have 24-h radiologist coverage.

Recommendations for Diagnosis and Prevention of Cytomegalovirus-Associated Necrotizing Enterocolitis in Breast-Fed Preterm Infants

We present the case of a breast-fed preterm infant with postnatally acquired cytomegalovirus (CMV) and severe necrotizing enterocolitis (NEC) associated with CMV. The infant had persistent severe thrombocytopenia with clinical deterioration despite multiple platelet transfusions and maximal medical treatment. Surgical intervention was not feasible owing to the instability of the infant's condition. Upon identification of CMV in urine, intravenous ganciclovir was initiated with significant clinical improvement. We also present a literature review of cases of CMV-related NEC or other gastrointestinal complications in preterm and term infants.

The glucose infusion rate of parenteral nutrition in the first week of life in preterm infants: an observational study

Background

Most preterm infants require a continuous glucose infusion in the early postnatal period due to the interruption of the transplacental glucose supply after birth to promote better neurodevelopmental outcomes.

Aims

To investigate the glucose infusion rate (GIR) on parenteral nutrition (PN) in the first week of life administered in preterm infants and its effect on neonatal morbidity and mortality.

Methods

This study included 97 infants aged < 37 gestational weeks and weighed < 2500 g at birth. Infants recruited in this study were classified into 3 groups based on the GIR usage in parenteral nutrition as follows: GIR usage of 5- < 7 g/kg/day (Group I), GIR usage of 7–13 g/kg/day (Group II), and GIR usage of > 13–15 g/kg/day (Group III). Univariate and multivariate logistic regression analyzes were carried out to investigate whether the GIR usage in the three groups was associated with selected neonatal morbidities and mortality. Neonatal morbidities analyzed included respiratory distress syndrome (RDS), necrotizing enterocolitis, sepsis, retinopathy of prematurity, pulmonary hypertension, hypoglycemia, and hyperglycemia.

Result

Of 97 preterm infants included, 51.5% infants had a gestational age of 34- < 37 weeks, and 54.6% infants had a birth weight of 1500- < 2500 g. The multivariate logistic regression analysis showed that the GIR usage of 5- < 7 g/kg/day was an independent variable that significantly increased the risk of hypoglycemia (Adjusted Odds Ratio [AOR] = 4.000, 95% Confidence Interval [CI] = 1.384–11.565, P = 0.010) and reduced the risk of sepsis (AOR = 0.096, 95% CI = 0.012–0.757, P = 0.026). The GIR usage in all three groups did not increase the risk of mortality. For neonatal morbidity analyzed in this study, RDS (AOR = 5.404, 95%CI = 1.421–20.548, P = 0.013) was an independent risk factor of mortality.

Conclusion

The GIR usage of < 7 g/kg/day in PN in the first week of life administered to preterm infants was an independent variable in increasing hypoglycemia, but in contrast, reducing the risk of sepsis.

The effects of IGF-1 and erythropoietin on apoptosis and telomerase activity in necrotizing enterocolitis model

BACKGROUND

Apoptosis that occurs after hypoxia/reoxygenation (H/R) has an important role in the pathogenesis of necrotizing enterocolitis (NEC). Telomerase activity, showing the regeneration capacity, may also be important in the recovery process. Therefore, we aimed to investigate the effects of insulin-like growth factor-1 (IGF-1) and erythropoietin (EPO) on apoptosis and telomerase activity in an H/R model.

METHODS

Young mice were divided into four groups each containing ten Balb/c mice. Group 1 (H/R) were exposed to H/R; group 2 and group 3 were pretreated with IGF-1 and EPO, respectively, for 7 days before H/R. Group 4 served as control. Intestinal injury was evaluated by histological scoring and assessment of apoptosis was performed by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) test. Proapoptotic and antiapoptotic gene expressions and telomerase activity were analyzed by real-time PCR.

RESULTS

IGF-1- and EPO-treated animals had decreased histological damage and apoptosis, confirmed by TUNEL test and caspase activity. Telomerase activity was increased in these animals in addition to increased expression of antiapoptotic genes. However, proapoptotic gene expressions were not statistically different.

CONCLUSIONS

The protective effects of IGF-1 and EPO in H/R damage may be through increased expression of antiapoptotic genes and increased telomerase activity, especially for IGF-1.

IMPACT

This is a comprehensive study measuring various variables, namely IGF-1, EPO, apoptosis, apoptotic and antiapoptotic genes, and telomerase activity in the NEC model. The intestinal protective effects of IGF-1 and EPO in H/R damage may occur through increased expression of antiapoptotic genes and increased telomerase activity. To the best of our knowledge, telomerase activity has not been investigated in the NEC model before. Regarding our results, novel strategies may be implemented for the early definitive diagnosis, robust preventive measures, and effective treatment modalities for NEC.

Case report: necrotizing enterocolitis with a transverse colonic perforation in a 2-day old term neonate and literature review

BACKGROUND

Necrotizing enterocolitis (NEC), while classically discussed in preterm and low birth weight neonates, also occurs in the term infant and accounts for 10% of all NEC cases. Despite there being fewer reported cases of NEC in term infants, these presentations demonstrate differences in the onset, severity and risk factors from the classic presentation observed in premature infants. We present a novel case of term NEC that contravenes the reported literature making departures from clinical presentation, risk factors and location of perforation in an otherwise healthy term two-day old infant born after an uncomplicated pregnancy who presented with hematochezia.

CASE PRESENTATION

A healthy term baby born after an uneventful pregnancy presented with bloody stool at 2 days of life who was otherwise well. Investigations revealed pneumoperitoneum from a large proximal transverse colonic perforation secondary to NEC. No typical risk factors for NEC were found.

CONCLUSION

Given the life-threatening potential of an unrecognized perforation we recommend the inclusion of NEC on the differential for neonatal hematochezia.

Gestational Age-Specific Complete Blood Count Signatures in Necrotizing Enterocolitis

Objective: Necrotizing enterocolitis (NEC) is characterized by peripheral cell abnormalities, yet few studies have analyzed the complete blood count (CBC) specifically by gestational age (GA). Our objective was to describe GA-specific immune abnormalities in NEC through a comprehensive analysis of the CBC differential. Methods: Using a cohort of 246 infants (177 cases, 69 controls) admitted to neonatal intensive care units at a single institution, we retrospectively analyzed CBCs around illness onset in NEC cases compared with controls. Cases included surgical NEC (S-NEC, 34.5%) and medical NEC (M-NEC, 65.5%). Infants were divided into those born at GA <33 and ≥33 weeks. Differences in CBC values were described as absolute and percent changes at NEC onset from baseline and at antibiotic completion after NEC. We used machine learning algorithms based on the CBC at NEC to generate predictive models for diagnosis. Results: At NEC onset, there was an acute drop in monocytes and lymphocytes along with a rise in bands in S-NEC infants born <33 weeks compared with M-NEC. In comparison, both M-NEC and S-NEC ≥33 weeks had a percent drop in neutrophils at diagnosis compared with controls. At antibiotic completion, monocytes in S-NEC <33 weeks significantly rose compared with M-NEC, yet for S-NEC ≥33 weeks, bands significantly dropped compared with M-NEC. Predictive modeling was able to accurately predict S-NEC from M-NEC and controls. Conclusion: There are discrete leukocyte patterns in NEC based on GA. The CBC at diagnosis may be useful in identifying patients who will require surgery.

Fecal High-Mobility Group Box 1 as a Marker of Early Stage of Necrotizing Enterocolitis in Preterm Neonates

Introduction: An early diagnosis of necrotizing enterocolitis (NEC), a major gastrointestinal emergency in preterm newborns, is crucial to improve diagnostic approach and prognosis. We evaluated whether fecal high-mobility group box protein 1 (HMGB1) may early identify preterms at risk of developing NEC. Materials and Methods: A case-control study including neonates admitted at the Neonatal Intensive Care Unit (NICU) of the Sapienza University Hospital "Umberto I" in Rome, from July 2015 to December 2016. Stool samples obtained from cases (preterm newborns with NEC) and controls (newborns without NEC) were collected at the enrolment (T0) and within 7-14 days after the first sample collection (T1). HMGB1, extracted and measured with western blot, was reported as densitometry units (DUS). Results: HMGB1 levels in 30 cases (n = 28-Bell stage 1, n = 2 Bell stage 2) were higher [T0: 21,462 DUS (95% CI, 16,370-26,553 DUS)-T1: 17,533 DUS (95% CI, 13,052-22,014 DUS)] than in 30 preterm controls [T0: 9,446 DUS (95% CI, 6,147-12,746 DUS)-T1: 9,261 DUS (95% CI, 5,126-13,396 DUS), p < 0.001). Preterm newborns showed significant higher levels of HMGB1 (15,690 DUS (95% CI, 11,929-19,451 DUS)] in comparison with 30 full-term neonates with birth weight >2,500 g [6,599 DUS (95% CI, 3,141-10,058 DUS), p = 0.003]. Multivariate analysis showed that the risk of NEC was significantly (p = 0.012) related to the HMGB1 fecal levels at T0. Conclusions: We suggest fecal HMGB1 as a reliable marker of early NEC in preterm neonates. This study supports further investigation on the role of fecal HMGB1 assessment in managing preterm newborns at risk of NEC. Further studies are advocated to evaluate diagnostic accuracy of this marker in more severe forms of the disease.

A significant decrease in hemoglobin concentrations may predict occurrence of necrotizing enterocolitis in preterm infants with late-onset sepsis

OBJECTIVE

This study aimed to examine the clinical value of a decrease in hemoglobin concentration (HC) after the onset of sepsis for predicting occurrence of necrotizing enterocolitis (NEC) in preterm infants with late-onset sepsis.

METHODS

We performed a retrospective cohort study between January 2015 and January 2020. Premature neonates (gestational age <37 weeks) with late-onset sepsis (age >3 days) were enrolled. According to the degree of reduction in HC, neonates were divided into the non-decrease group, mild decrease group, and severe decrease group. Demographic data, perinatal conditions, blood cell count analysis, blood culture, and treatment measures were compared.

RESULTS

Eighty premature infants with sepsis were studied. The mortality rate and incidence of NEC were significantly higher in the severe decrease group than in the non-decrease and mild decrease groups. Significant differences were observed in the decrease in HC, red blood cell transfusion, and ventilator application between the NEC and non-NEC groups. A significant decrease in HC was an independent risk factor for NEC in preterm infants with sepsis.

CONCLUSION

A significant decrease in HC is an independent risk factor for NEC and may predict the occurrence of NEC in preterm infants with sepsis.

Abdominal Distention and Emesis in a Term Neonate

BACKGROUND

Necrotizing enterocolitis (NEC) is a gastrointestinal emergency characterized by ischemic necrosis of the intestinal mucosa, leading to bacterial translocation and pneumatosis of the bowel wall. Although there are numerous studies on clinical presentations of preterm NEC, approximately 10-15% of cases occur in full-term neonates. Nearly 10% of all infants with NEC will develop a rapidly progressive and fatal form of the disease called NEC totalis.

CASE REPORT

A 24-day-old term male infant presented to the Emergency Department (ED) with emesis. The infant was ill-appearing with a tense abdomen and had significant tachycardia and hypotension. The patient was immediately volume resuscitated and started on empiric antibiotics. Initial radiographs revealed no evidence of bowel obstruction or pneumatosis. Pediatric Surgery was consulted, and upper gastrointestinal and abdominal computed tomography scans were obtained, which were nondiagnostic. The patient was taken to the operating room for an exploratory laparotomy after continued clinical deterioration and was diagnosed with NEC totalis and passed away within 6 days. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case demonstrates an uncommon presentation of NEC in an otherwise healthy term neonate without any known risk factors. The diagnosis of NEC is challenging because imaging studies may be inconclusive, particularly early in the clinical course. Regardless of the etiology, all infants who present to the ED with signs and symptoms of severe gastrointestinal distress should be treated with basic emergency care, including rapid fluid resuscitation, empiric antibiotics, bowel decompression, and early surgical consultation.