Neonates presenting with bloody stools and eosinophilia can progress to two different types of necrotizing enterocolitis

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.

Necrotizing Enterocolitis Complicating Severe RSV Bronchiolitis in PICU Settings

This retrospective study aims to analyze the baseline characteristics and factors associated with poor outcomes in patients with necrotizing enterocolitis (NEC) complicating respiratory syncytial virus (RSV) infection. Using the Virtual Pediatric Systems data registry, patients under 2 years admitted to the pediatric intensive care unit (PICU) were screened. Patients with documented RSV infection and NEC, intestinal perforation, noninfectious gastroenteritis/colitis, or pneumatosis intestinalis occurring around the timing of RSV bronchiolitis diagnosis were included. Out of the screened patients, 41 were analyzed. Most patients (93%) were aged 30 days to 2 years, one-third had baseline anatomical cardiac defects, and 20% history of prematurity. Median PICU length of stay was 11.7 days. Seven patients died before hospital discharge. While not statistically significant, nonsurvivors tended to exhibit higher PRISM-3 scores, more acidemia, and lower systolic blood pressure. These findings emphasize the need for cautious assessment of gastrointestinal symptoms in critically ill patients with RSV infection.

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

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

A murine neonatal model of necrotizing enterocolitis caused by anemia and red blood cell transfusions

Necrotizing enterocolitis (NEC) is an idiopathic, inflammatory bowel necrosis of premature infants. Clinical studies have linked NEC with antecedent red blood cell (RBC) transfusions, but the underlying mechanisms are unclear. Here we report a neonatal murine model to investigate this association. C57BL/6 mouse pups rendered anemic by timed phlebotomy and then given RBC transfusions develop NEC-like intestinal injury with prominent necrosis, inflammation, and submucosal edema/separation of the lamina propria in the ileocecal region and colon within 12-24 h. The anemic intestine is infiltrated by inflammatory macrophages, which are activated in situ by RBC transfusions via a Toll-like receptor (TLR)-4-mediated mechanism and cause bowel injury. Chelation of RBC degradation products with haptoglobin, absence of TLR4, macrophage depletion, and inhibition of macrophage activation is protective. Intestinal injury worsens with increasing severity and the duration of anemia prior to transfusion, indicating a need for the re-evaluation of current transfusion guidelines for premature infants.

Reference intervals for stool calprotectin in preterm neonates and their utility for the diagnosis of necrotizing enterocolitis

OBJECTIVE

Calprotectin is an antimicrobial protein found in stool when released by granulocytes. We sought to create stool calprotectin reference ranges in preterm neonates and to evaluate whether levels exceeding the upper reference interval are diagnostic for necrotizing enterocolitis (NEC).

STUDY DESIGN

Stool calprotectin was measured in premature neonates without gastrointestinal pathology to create reference intervals. For comparison, levels from infants undergoing "rule out NEC" evaluations were plotted on these reference intervals.

RESULTS

Stool calprotectin reference intervals were created according to gestational age at birth and corrected gestational age. Levels during "rule out NEC" evaluations were more often above the upper reference interval with NEC vs. those without NEC.

CONCLUSIONS

Stools from preterm neonates have a higher range of calprotectin than stools from healthy term neonates. In evaluating preterm neonates for NEC with stool calprotectin, a calprotectin upper reference interval that incorporates corrected gestational age best predicts the diagnosis of NEC.

Anemia, red blood cell transfusions, and necrotizing enterocolitis

In the past 15 years, multiple clinical studies have identified a temporal association between red blood cell (RBC) transfusions and necrotizing enterocolitis (NEC). With some variability, most of these studies indicate that up to one-third of all cases of NEC involving very low-birth weight infants may occur within 24-48h after receiving a RBC transfusion. There is also evidence that the risk of such transfusion-associated NEC may be higher in infants transfused with the greatest severity of anemia. In this article, we summarize the clinical evidence pertaining to these issues; specifically, the contribution of RBC transfusions, and the contribution of severity of underlying anemia, to the pathogenesis of a type of NEC potentially termed, "transfusion/anemia-associated NEC."

Changing the paradigm of defining, detecting, and diagnosing NEC: Perspectives on Bell's stages and biomarkers for NEC

Better means to diagnose and define necrotizing enterocolitis are needed to guide clinical practice and research. Adequacy of Bell's staging system for clinical practice and clarity of cases used in NEC clinical datasets has been a topic of controversy for some time. This article provides reasons why a better global definition for NEC is needed and offers a simple alternative bedside definition for preterm NEC called the "Two out of Three" rule. Some argue that biomarkers may fill knowledge gaps and provide greater precision in defining relevant features of a clinical disease like NEC. NEC biomarkers include markers of inflammation, intestinal dysfunction, hematologic changes, and clinical features. Development and reporting of NEC biomarkers should be guided by the FDA's BEST Consensus resource, "Biomarkers, EndpointS, & other Tools" and consistently report metrics so that studies can be compared and results pooled. Current practice in the NICU would be enhanced by clinical tools that effectively inform the clinical team that a baby is at increasing risk of NEC. Ideally, these tools will incorporate both clinical information about the baby as well as molecular signals that are indicative of NEC. While meaningful biomarkers for NEC and clinical tools exist, translation into practice is mediocre.

A critical question for NEC researchers: Can we create a consensus definition of NEC that facilitates research progress?

In the last decades the reported incidence of preterm necrotizing enterocolitis (NEC) has been declining in large part due to implementing comprehensive NEC prevention initiatives, including breast milk feeding, standardized feeding protocols, transfusion guidelines, and antibiotic stewardship and improving the rigor with which non-NEC cases are excluded from NEC data. However, after more than 60 years of NEC research in animal models, the promise of a "magic bullet" to prevent NEC has yet to materialize. There are also serious issues involving clinical NEC research. There is a lack of a common, comprehensive definition of NEC. National datasets have their own unique definition and staging definitions. Even within academia, randomized trials and single center studies have widely disparate definitions. This makes NEC metadata of very limited value. The world of neonatology needs a comprehensive, universal, consensus definition of NEC. It also needs a de-identified, international data warehouse.

The ConNECtion Between Abdominal Signs and Necrotizing Enterocolitis in Infants 501 to 1500 g

BACKGROUND

Necrotizing enterocolitis (NEC) can become severe quickly, making early recognition a priority and understanding the occurrence of abdominal and clinical signs of impending NEC important.

PURPOSE

The purpose of this study was to examine relationships of abdominal signs up to 36 hours before diagnosis of NEC within subgroups treated medically, surgically, or those who died.

METHODS

A 3-site, descriptive correlational case-control design with retrospective data collection was used matching each NEC case to 2 controls (N = 132).

RESULTS

NEC cases were exposed to less human milk and fed later. Among them, 61% (n = 27) had at least 1 abdominal sign 36 hours before diagnosis, with fewer numbers having 2 (18%; n = 8) or 3 (5%; n = 2). At 36 hours before NEC, abdominal distension, duskiness, higher gastric residual, and greater count of abdominal signs were associated with severe NEC. No medical NEC cases had abdominal signs 36 or 24 hours before diagnosis. Highest severity of NEC was related to more abdominal signs at the times leading up to and at diagnosis of NEC. Gastric residuals were largely unrelated to NEC except for the most severe NEC at 36 hours before diagnosis.

IMPLICATIONS FOR PRACTICE

Communicating a count of abdominal signs may support earlier recognition and treatment of NEC.

IMPLICATIONS FOR RESEARCH

More research is needed to explore timing for clinical worsening of status (eg, surgical and NEC leading to death) and to study effective clinical approaches targeting early recognition to support timely action.

The complete blood cell count in a refined cohort of preterm NEC: the importance of gestational age and day of diagnosis when using the CBC to estimate mortality

OBJECTIVE

The value of the white blood cell count (WBC) in necrotizing enterocolitis (NEC) is controversial. One reason for this confusion may be that the various WBC lineages change substantially with increasing gestational age and thereby age of NEC onset. This study postulated that if a data set was large enough and the diagnosis of NEC clean enough, absolute WBC counts would facilitate prediction of NEC mortality. The objective of this study was to determine whether absolute WBC counts enhance the prediction of NEC mortality.

STUDY DESIGN

A de-identified data subset from the Pediatrix national data set specific to the diagnoses of NEC in patients who had a CBC drawn on the day of diagnosis (exclusive of the diagnoses of spontaneous intestinal perforations and congenital anomalies) was the target for analysis. Values of primary interest included: gestation, day of diagnosis, absolute WBC count, platelet count, hematocrit, mortality and the day of diagnosis. Stepwise regression analysis was used to predict mortality.

RESULT

A total of 4059 (79%) survivors and 1107 (21%) infants who died with a diagnosis of medical or surgical NEC were included in the data set. Associations with mortality were found with low gestational age, low platelet count, low hematocrit, high band/segmented neutrophil ratio, earlier day of diagnosis, high birth weight z-score, non-white race, no antenatal steroids in gestations above 24 weeks, absolute lymphocyte count adjusted for gestational age, and absolute monocyte count high and low values. A stepwise regression analysis yielded a receiver-operator curve of 0.819 with a sensitivity of 65% and specificity of 84%.

CONCLUSION

Absolute WBC values enhance prediction of NEC survival when used in combination with readily available data on the day of NEC diagnosis.

Manifestations of Cow's-Milk Protein Intolerance in Preterm Infants

OBJECTIVES

Cow's-milk protein intolerance (CMPI) is poorly recognized in preterm infants. This study examined the clinical events that preceded the diagnosis of CMPI in preterm infants.

METHODS

This was a retrospective study of infants in a level-III neonatal intensive care unit of those who received parenteral nutrition (PN) support during a 12-month period. Parameters assessed included birth weight (g), diagnosis, duration and frequency on PN, type of enteral feeds at initiation, and achievement of enteral autonomy. CMPI was diagnosed based on persistent feeding intolerance that resolved after change of feeds from intact protein to a protein hydrolysate or crystalline amino acid formula.

RESULTS

Three hundred forty-eight infants with birth weight (median/range) 1618 g (425-5110) received PN. Fifty-one (14%) infants required multiple courses of PN, and 19 of 348 (5%) were diagnosed with CMPI. The requirement for multiple courses on PN versus single course was associated with a high likelihood of CMPI: 14 of 51 versus 5 of 297, P < 0.001. Nine of the 14 infants identified with CMPI were initially diagnosed with necrotizing enterocolitis (NEC) after a median duration of 22 days (19-57) on intact protein feeds. After recovery from NEC, they had persistent feeding intolerance including recurrence of "NEC-like illness" (N = 3) that resolved after change of feeds to a protein hydrolysate or crystalline amino acid formula.

CONCLUSIONS

The requirement for multiple courses of PN because of persistent feeding intolerance after recovery from NEC and recurrence of "NEC-like illness" may be a manifestation of CMPI in preterm infants.

Increased monocytes and bands following a red blood cell transfusion

OBJECTIVE

The objective of this study is to analyze the white blood cell changes that occur after a transfusion of red blood cells in order to identify a subclinical inflammatory response in neonates.

STUDY DESIGN

Retrospective analysis of infants who received a red blood cell transfusion in an intensive care nursery. White blood cell results within 24 h pre- to 48 h post-transfusion were collected and analyzed. Statistical analysis included ANOVA, T-test, Mann-Whitney U test, Pearson's correlation and multivariable linear regression.

RESULT

Monocytes (P=0.02) and bands (P=0.035) were increased post-transfusion. There were no differences in monocytes (P=0.46) or bands (P=0.56) between groups who did or did not have blood cultures obtained. There was no difference in monocytes between groups who did or did not have sepsis (P=0.88).

CONCLUSION

We identified an elevation in monocytes and bands in the 48 h following a transfusion in premature infants. Our findings support a possible pro-inflammatory response related to transfusion of red blood cells.

Necrotizing enterocolitis following intensive phototherapy in full-term newborns – is there a possible association?

Background: Necrotizing enterocolitis is rare in full-term infants, and is currently not considered a known complication of phototherapy.

Highlights: Three cases of necrotizing enterocolitis in full-term babies possibly associated to intensive phototherapy for treatment of early neonatal hyperbilirubinemia due to isoimmune hemolytic disease of the newborn.

Conclusions: Although rare, the association between occurrences of necrotizing enterocolitis in full-term newborn infants and intensive phototherapy merits caution and clinical awareness to such possible complication. Presumptive explanation is that intensive phototherapy causes marked vasodilataion in the skin that may result in decreased perfusion of the intestine leading to ischemia and necrotizing enterocolitis. This calls for further studies to investigate the effects of phototherapy on the vascular bed in the gut and other vital organs that could have clinical implications.

Immunologic and Hematological Abnormalities in Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a leading cause of mortality in preterm infants. This article reviews the immunologic and hematological abnormalities typically seen in infants with NEC, such as elevated plasma cytokine levels, thrombocytopenia, increased or decreased neutrophil counts, low monocyte counts, and anemia. Some of these findings may provide important diagnostic and prognostic information.

Early Persistent Blood Eosinophilia in Necrotizing Enterocolitis Is a Predictor of Late Complications

BACKGROUND

Eosinophils infiltrate intestinal tissue during necrotizing enterocolitis (NEC) and adult bowel diseases. We theorized that epithelial damage causes eosinophilic activation and recruitment at NEC onset.

OBJECTIVE

We studied the relationship between persistent blood eosinophilia and medical or surgical complications during NEC.

METHODS

NEC cases and controls at MU Children's Hospital (2008-2013) underwent review. A Likert scale measured NEC severity. We utilized an SPSS database for statistical analyses.

RESULTS

Of 50 NEC cases, infants in group 1 (n = 15) had eosinophilia <2 days after onset and those in group 2 (n = 25) had NEC but no persistent eosinophilia. Group 3 (n = 46) consisted of controls, i.e. infants without NEC matched for birth weight and gestational age and group 4 (n = 4) of preterm infants with infection and ≤5 days of eosinophilia. Hematologic assessment defined persistent eosinophilia as ≥5% eosinophils for ≥5 days after NEC onset. Absolute eosinophil counts were 2 times higher in group 1 than in group 2 (p = 0.002). The mean duration of eosinophilia was 8 days in group 1 versus 1 day in group 2 (p < 0.001). A Likert score of NEC severity was 3-fold higher in group 1 than in group 2 (p < 0.001). Compared to group 2, group 1 infants were 8 times more likely to have hepatic fibrosis or intestinal strictures.

CONCLUSIONS

Early persistent blood eosinophilia is not currently a predictor of complications after the onset of NEC. This biomarker identifies immature infants at a high risk for adverse outcomes during NEC convalescence.

Unique risks of red blood cell transfusions in very-low-birth-weight neonates: associations between early transfusion and intraventricular hemorrhage and between late transfusion and necrotizing enterocolitis

Red blood cell transfusions can be life-saving for neonates with severe anemia or active hemorrhage. However, risks of transfusions exist and should always be weighed against potential benefits. At least two transfusion risks are unique to very low birth weight neonates. The first is an association between transfusions given in the first days after birth and the subsequent occurrence of a grade 3 or 4 intraventricular hemorrhage. The second is an association between "late" RBC transfusions and the subsequent occurrence of necrotizing enterocolitis. Much remains to be discovered about the pathogenesis of these two outcomes. Moreover, work is needed to clearly establish whether transfusions are causatively-associated with these outcomes or are co-variables. This review will provide basic data establishing these associations and propose mechanistic explanations.

Necrotizing enterocolitis: the road to zero

Necrotizing enterocolitis (NEC) continues to be the most severe gastrointestinal emergency facing the preterm neonate. The pathogenesis of NEC is still a complex and poorly understood process, but with increasing understanding of the role of enteral feeding, gut immunity and the altered gut microbiota, new opportunities to reduce overall NEC rates are now possible. Prevention strategies continue to lead as the most suitable approaches to reducing NEC, as early diagnosis and rapid effective treatment of NEC are still not optimal. Programmatic changes are equally important as subscribing to individual prevention strategies. The primary focus of this review is to summarize the best strategies we currently have to eliminate NEC within an institution.

Haematological abnormalities in neonatal necrotizing enterocolitis

OBJECTIVE

Necrotizing enterocolitis (NEC) is a leading cause of morbidity and mortality in preterm infants born prior to 32 weeks gestation or with a birth weight less than 1500 grams. In this article, we review hematological abnormalities associated with NEC.

METHODS

A literature search was performed using the databases PubMed, EMBASE, and Scopus, and the electronic archive of abstracts presented at the annual meetings of the Pediatric Academic Societies.

RESULTS

Thrombocytopenia, disseminated intravascular coagulation, increased or decreased neutrophil counts, and hemolytic anemia are frequent events in NEC.

CONCLUSIONS

NEC is associated with several hematological abnormalities, which may play a direct or indirect role in the pathogenesis of gut mucosal injury, and may also carry important prognostic information.

Associations between "early" red blood cell transfusion and severe intraventricular hemorrhage, and between "late" red blood cell transfusion and necrotizing enterocolitis

Transfusion of banked donor erythrocytes can be life saving for small and ill neonates with severe anemia or active hemorrhage. However, risks of transfusions exist and must be weighed against potential benefits each time a transfusion is considered. The present review seeks to bring together the published data supporting 2 newly postulated risks of transfusions among very low-birth-weight neonates. The first is an association between "early" red blood cell transfusions, those administered in the first few days after birth, and the subsequent occurrence of a grade 3 or 4 intraventricular hemorrhage. The second is an association between "late" RBC transfusions and the subsequent occurrence of necrotizing enterocolitis. Much remains to be discovered about the pathogenetic links between transfusion and these adverse outcomes. Moreover, work is needed to clearly establish whether transfusions are causatively associated with these adverse outcomes or are covariables. The purpose of this chapter is to review the associations between transfusion and intraventricular hemorrhage and between transfusions and necrotizing enterocolitis and to use these associations to hypothesize that evidence-based improvements in transfusion practice have the potential to improve neonatal intensive care unit outcomes.