Necrotizing enterocolitis

Insulin-like growth factor-1 effects on kidney development in preterm piglets

BACKGROUND

Preterm birth disrupts fetal kidney development, potentially leading to postnatal acute kidney injury. Preterm infants are deficient in insulin-like growth factor 1 (IGF-1), a growth factor that stimulates organ development. By utilizing a preterm pig model, this study investigated whether IGF-1 supplementation enhances preterm kidney maturation.

METHODS

Cesarean-delivered preterm pigs were treated systemically IGF-1 or vehicle control for 5, 9 or 19 days after birth. Blood, urine, and kidney tissue were collected for biochemical, histological and gene expression analyses. Age-matched term-born pigs were sacrificed at similar postnatal ages and served as the reference group.

RESULTS

Compared with term pigs, preterm pigs exhibited impaired kidney maturation, as indicated by analyses of renal morphology, histopathology, and inflammatory and injury markers. Supplementation with IGF-1 reduced signs of kidney immaturity, particularly in the first week of life, as indicated by improved morphology, upregulated expression of key developmental genes, reduced severity and incidence of microscopic lesions, and decreased levels of inflammatory and injury markers. No association was seen between the symptoms of necrotizing enterocolitis and kidney defects.

CONCLUSION

Preterm birth in pigs impairs kidney maturation and exogenous IGF-1 treatment partially reverses this impairment. Early IGF-1 supplementation could support the development of preterm kidneys.

IMPACT

Preterm birth may disrupt kidney development in newborns, potentially leading to morphological changes, injury, and inflammation. Preterm pigs have previously been used as models for preterm infants, but not for kidney development. IGF-1 supplementation promotes kidney maturation and alleviates renal impairments in the first week of life in preterm pigs. IGF-1 may hold potential as a supportive therapy for preterm infants sensitive to acute kidney injury.

Racial disparities in the development of comorbid conditions after preterm birth: A narrative review

Despite recognition and attempts to reduce racial disparities in perinatal outcomes, Black infants are still disproportionately represented among those who are born preterm. Postnatal investigations of racial disparities in comorbidities and outcomes after preterm birth are increasing, although their results and interpretations are conflicting. In the present review, we 1.) identify important methodological limitations of that literature 2.) summarize the conflicting literature investigating racial disparities, specifically Black-white differences, in postnatal comorbidities and outcomes after preterm birth 3.) describe mechanisms by which racism operates to contextualize our understanding to inform future work to actively reduce disparities in preterm birth and subsequently, its complications.

Do more mature preterm babies with surgical necrotizing enterocolitis predominantly develop the colonic disease?

Background

The primary aim was to scrutinize our hypothesis: “Do more mature preterm (MMP) babies with surgical necrotizing enterocolitis (NEC) predominantly develop the colonic disease and are different in their response and behaviour in comparison to exceedingly preterm (EP) babies?” Secondary outcomes were to define time taken in developing NEC, time from diagnosis to laparotomy, requirement of parenteral nutrition (PN), and ventilatory support.

Methods

We defined MMP babies as ≥30 weeks of gestation and EP babies as ≤29 weeks+6 days of gestation. Inclusion criteria were all babies <37 weeks with NEC requiring surgery (called surgical NEC group). Data were collected retrospectively and analyzed using QuickCalcs.

Results

Of the total, 41% (97/234) of babies underwent laparotomy between 2010 and 2019. Totally, 81% were EP and 19% were MMP babies. Pure colonic involvement was seen in 9% of EP babies in comparison to 56% in the MMP babies (p=0.0001). Involvement of only the small bowel was seen in two-thirds of EP babies in comparison to only one-third in MMP babies (p=0.01). EP cohort required PN for 82 days (median) in comparison to 17 days (median) in the MMP cohort (p=0.001). Ventilation requirement in the EP group versus the MMP group was 24 vs 9 days (median), respectively (p=0.0006).

Conclusions

MMP babies predominantly developed colonic disease, whereas EP babies predominantly developed small bowel disease. EP babies required a longer duration of PN and ventilation support. This study opens a new area of research to differentiate pathogenesis and maturation patterns of the small and large bowels in babies with NEC.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Radiological findings associated with the death of newborns with necrotizing enterocolitis

Objective

The aim of this study was to identify radiological and clinical risk factors for death in newborns with necrotizing enterocolitis.

Materials and Methods

This was a retrospective cohort study, based on radiological examinations and medical charts of 66 infants with necrotizing enterocolitis, as confirmed by a finding of intestinal pneumatosis (stage IIA, according to modified Bell’s staging criteria). Radiological and clinical variables were evaluated.

Results

Of the 66 infants evaluated, 14 (21.2%) presented pneumatosis in the large and small bowel; 7 (10.6%) presented air in the portal system; and 12 (18.2%) died. Bivariate analysis revealed that the following variables were associated with death: bowel perforation; pneumatosis in the large and small bowel; air in the portal system; earlier gestational age; longer time on mechanical ventilation before the identification of pneumatosis; and longer time on mechanical ventilation before discharge or death. In the multivariate regression, the following variables remained as predictors of death: pneumatosis in the large and small intestines (odds ratio [OR] = 12.4; 95% confidence interval [95% CI] = 1.2-127.4; p = 0.035), perforation (OR = 23.2; 95% CI = 2.2-246.7; p = 0.009), and air in the portal system (OR = 69.7; 95% CI = 4.3-[not calculated]; p = 0.003).

Conclusion

The set of factors most strongly associated with death in infants with necrotizing enterocolitis comprised extensive pneumatosis, pneumoperitoneum, and air in the portal system. Our findings confirm the importance of radiological imaging in the diagnosis and monitoring of necrotizing enterocolitis.

Vital signs analysis algorithm detects inflammatory response in premature infants with late onset sepsis and necrotizing enterocolitis

BACKGROUND

Nonspecific clinical signs and suboptimal diagnostic tests limit accurate identification of late onset sepsis (LOS) and necrotizing enterocolitis (NEC) in premature infants, resulting in significant morbidity and antibiotic overuse. An infant's systemic inflammatory response may be identified earlier than clinical suspicion through analysis of multiple vital signs by a computerized algorithm (RALIS).

AIM

To evaluate the revised RALIS algorithm for detection of LOS and NEC in preterm infants.

METHODS

In this nested case-control study, VS data (heart rate, respiratory rate, temperature, desaturations, bradycardias) were extracted from medical records of infants 23-32 weeks gestation. RALIS generated an output, with score ≥ 5 triggering an alert. Patient episodes were classified based on culture, radiograph, and antibiotic data into categories: LOS, expanded LOS, NEC, and controls. Paired t-tests, linear regression and cross-validation analyses were used to evaluate the relationship between RALIS alert and LOS/NEC.

RESULTS

Among 155 infants with 161 episodes, there were 41 expanded LOS (+blood, CSF, urine, respiratory culture), 31 LOS (+blood, CSF, urine), 9 NEC, and 93 controls. RALIS alert was 43.1 ± 79 h before culture in LOS (p = .012). There was a significant association between RALIS alert and LOS/NEC (β = 0.72, p < .0001). Sensitivity and specificity for LOS/NEC were 84% and 80%, (PPV = 63%; NPV = 93%). The regression model demonstrated an AUC of 89.9%.

CONCLUSIONS

For infants ≤32 weeks, RALIS detects systemic inflammatory responses in LOS and NEC in the first month of life. The algorithm can identify infection earlier than clinical suspicion, even for NEC with negative cultures. RALIS has high NPV to rule-out LOS and NEC, and may, after prospective validation, aid in antibiotic treatment decisions.

FLLL32, a curcumin analog, ameliorates intestinal injury in necrotizing enterocolitis

BACKGROUND

Necrotizing enterocolitis (NEC) is a devastating gastrointestinal disease that primarily affects premature infants. It is characterized by inflammation and leukocyte infiltration that can progress to intestinal necrosis, perforation, systemic inflammatory response, and death. In this study, we examined the effect of FLLL32, a curcumin analog, on an NEC-like neonatal intestinal injury model.

METHODS

NEC was induced in CD-1 mice pups using the Paneth cell ablation and Klebsiella infection model. Pups were divided into sham, NEC, and NEC + FLLL32 groups. At the end of the experiment, pups were euthanized; whole blood and small intestines were harvested. Intestinal inflammatory cytokine profile, in vivo intestinal permeability using serum fluorescein isothiocyanate-dextran, and histological injury scores were compared between the groups.

RESULTS AND CONCLUSION

FLLL32-treated pups had lower intestinal injury, improved intestinal permeability, and lower proinflammatory cytokine profiles compared to those in untreated pups with NEC. These results suggest that FLLL32 plays a protective role in NEC.

Agreement and reproducibility of radiological signs in NEC using The Duke Abdominal Assessment Scale (DAAS)

PURPOSE

Necrotizing enterocolitis (NEC) is associated with high morbidity and mortality. Abdominal radiography is currently an imaging modality of choice in NEC. Recently, a numeric scale of radiological signs in NEC-The Duke Abdominal Assessment (DAAS) was introduced. The aim of this study was to measure the intra- and inter-observer agreement on the radiological signs of NEC according to DAAS to access the feasibility of this scale.

MATERIALS AND METHODS

We have retrospectively analyzed 87 radiographs performed in a group of 43 high-risk neonates with suspected NEC. Radiographs were assessed by 6 independent observers: two pediatric radiologists, two radiology residents, and two neonatologists. Data were analyzed using κ statistics as a measure of intra- and inter-observer agreement.

RESULTS

Fair-to-good intra-observer agreement was noted for all but one of observers. However, with the wide range in κ values, we found only fair inter-observer agreement detecting signs of NEC according to DAAS. There was a higher intra-group agreement in radiology practitioners, with the highest among experienced pediatric radiologists.

CONCLUSION

However, with high observer variability in interpretation of all radiologic signs, we did not confirm that Duke Abdominal Assessment Scale could reliable facilitate reporting of abdominal radiographic findings in neonates with suspected NEC.

Umbilical Venous Catheter Malposition Is Associated with Necrotizing Enterocolitis in Premature Infants

OBJECTIVE

The etiology of necrotizing enterocolitis (NEC) remains elusive despite known associations with several factors, including intestinal ischemia related to the effects of umbilical arterial catheterization on the mesenteric circulation. However, the role of the mesenteric venous circulation has yet to be studied as a potential cause of NEC. We examined the association between umbilical venous catheter (UVC) position and the development of NEC in premature infants.

DESIGN

A prospective cohort study was performed to examine the effect of UVC on portosystemic shunting via the ductus venosus (DV) and its potential role in NEC.

RESULTS

We recruited 132 premature infants, 62 of which had a birth weight ≤1,500 g. NEC was noted in 12 (19%) patients. All infants weighing ≤1,500 g underwent an attempt at UVC insertion. The UVC status was classified as appropriate (n = 39), unsuccessful (n = 9), or malpositioned (n = 14). Among the NEC patients, 7 (58%) had a UVC malposition and 3 (25%) had an unsuccessful attempt. These rates were significantly higher than in patients without NEC (14 and 12%, respectively). Multivariable logistic regression analysis confirmed birth weight (OR 2.2, 95% CI 1.2-4.7, p = 0.001) and UVC malpositioning (OR 6.9, 95% CI 1.6-35.4, p = 0.007) as independent risk factors associated with NEC.

CONCLUSIONS

Unrecognized withdrawal of a UVC into the portal vein or DV is associated with an increased incidence of NEC in infants weighing ≤1,500 g. The data support the need for additional studies to examine this effect. Confirmation of a causal relationship will raise the need to reassess UVC insertion criteria and strategies for more closely monitoring the catheter tip position.

Infant and maternal risk factors related to necrotising enterocolitis-associated infant death in the United States

AIM

To evaluate necrotising enterocolitis (NEC)-associated infant death and identify risk factors related to NEC infant death in the United States.

METHODS

The United States Period Linked Birth/Infant Death data for 2010-2013 were utilised to determine risk factors associated with NEC infant death. Infant mortality rates (IMRs) were calculated and a retrospective matched case-control analysis was performed. An infant case was defined as having the International Classification of Diseases, Tenth Revision code for NEC listed on the death record. Controls were matched on birthweight and randomly selected. Conditional multivariable logistic regression models stratified by birthweight were conducted to determine risk factors for NEC infant death.

RESULTS

The average annual NEC IMR was 12.5 deaths per 100 000 live births and was higher among very low birthweight (VLBW) compared to normal birthweight infants and among black compared to white infants. For VLBW infants, the multivariable analysis identified male sex, five-minute Apgar score of less than 7, and white infants born to a mother who is less than or equal to 19 years of age to be related with NEC-associated infant death.

CONCLUSION

Paediatricians should be aware of the factors related to NEC-associated infant death to reduce the number of infants at greatest risk for NEC and focus on racial disparities.

Cluster of late preterm and term neonates with necrotizing enterocolitis symptomatology: descriptive and case-control study

OBJECTIVE

To investigate a necrotizing enterocolitis (NEC) cluster of late preterm and term neonates (gestational age ≥34 weeks).

METHODS

We conducted a descriptive and a case-control study. Medical records of neonates with modified Bell stage ≥ IB NEC and matched controls were reviewed, in addition to microbiological and environmental investigation. Study variables included maternal/delivery and neonatal factors, medications, procedures and feeding practices. Univariable/multivariable logistic regression analyses were performed for all and for stage ≥ II cases.

RESULTS

Out of 1841 late preterm and term neonates, 10 stage IB and 10 stage ≥ II [mean(SD) birthweight 2529.3 (493.04) g, gestational age 36.96 (1.48) weeks] presented with NEC symptomatology at mean 4.6 (range 2-8) days. Nearly all (19/20) resulted from high-risk pregnancies and received postpartum intermediate care. All were exclusively or partly formula fed. Most (14/20) were born by cesarean delivery. Eight underwent surgery, with no fatality. Intermediate care (p = 0.006), transient tachypnea (p = 0.049), not receiving breast milk (p = 0.019) and in addition intrauterine growth restriction (IUGR) (p = 0.017) for stage ≥ II cases were independently associated with NEC.

CONCLUSIONS

Late preterm and term neonates in need of intermediate care, with IUGR and transient tachypnea were susceptible to NEC; feeding with breast milk was an important protective factor.

Packed red blood cell transfusion (PRBC) attenuates intestinal blood flow responses to feedings in pre-term neonates with normalization at 24 hours

OBJECTIVE

To determine whether packed red blood cell (PRBC) transfusion affects post-prandial superior mesenteric artery blood flow velocities (SMA BFVs) in very-low birth weight (VLBW) neonates and if so, at what time point after transfusion restoration of previous SMA BFV patterns occurs.

DESIGN/METHODS

VLBW pre-term neonates, older than 14 days and tolerating bolus enteral feedings administered every 3 h were enrolled in this prospective observational study. Pulsed Doppler ultrasound was used to measure pre- and post-prandial (at 45 min) time-averaged mean, peak and end diastolic velocities (TAMV, PSV, EDV) immediately before and after 15 ml/kg of PRBC transfusion was given over 3 h; patent ductus arteriosus (PDA) status was also evaluated. Subsequent pre- and post-prandial SMA BFVs were recorded 24 and 48 h after the transfusion.

RESULTS

Pre- and post-prandial measurements were obtained for 21 out of 25 enrolled infants. Post-prandial SMA BFVs were attenuated during the feedings immediately after transfusion; at 24 and 48 h after transfusion, changes in post-prandial SMA BFVs were similar to those measured prior to transfusion; the presence of the PDA did not affect results.

CONCLUSIONS

PRBC transfusion blunted SMA BFV responses to feedings immediately after the transfusion with normalization observed 24 h post-transfusion.

Intestinal proteomics in pig models of necrotising enterocolitis, short bowel syndrome and intrauterine growth restriction

Necrotising enterocolitis (NEC), short bowel syndrome (SBS) and intrauterine growth restriction (IUGR) are three conditions associated with intestinal dysfunction in newborn infants, particularly those born preterm. Piglet (Sus scrofa) models have recently been developed for NEC, SBS and IUGR, and tissue proteomic analyses have identified unknown pathways and new prognostic disease markers. Intestinal HSPs, iron metabolism proteins and proteins related to amino acid (e.g. arginine) and glucose metabolism are consistently affected by NEC progression and some of these proteins are also affected by SBS and IUGR. Parallel changes in some plasma and urinary proteins (e.g. haptoglobin, globulins, complement proteins, fatty acid binding proteins) may mirror the intestinal responses and pave the way to biomarker discovery. Explorative non-targeted proteomics provides ideas about the cellular pathways involved in intestinal adaptation during the critical neonatal period. Proteomics, combined with other -omic techniques, helps to get a more holistic picture of intestinal adaptation during NEC, SBS and IUGR. Explorative -omic research methods also have limitations and cannot replace, but only supplement, classical hypothesis-driven research that investigate disease mechanisms using a single or few endpoints.

Interleukin-8 predicts 60-day mortality in premature infants with necrotizing enterocolitis

OBJECTIVE

The purpose of this study was to evaluate the predictiveness of circulating interleukin (IL)-8 for 60-day mortality in premature infants with necrotizing enterocolitis (NEC).

BACKGROUND

NEC affects up to 5% of premature infants and remains a leading cause of mortality among neonates.

METHODS

A total of 113 infants with surgically (n=50) or medically (n=63) treated NEC were retrospectively analyzed. Laboratory parameters including serum IL-8 were assessed at the diagnosis of NEC and during the preoperative workup.

RESULTS

The 60-day mortality was 19% (22/113), 10% (6/63) in medical and 33% (16/50) in surgical NEC. IL-8 levels significantly correlated with 60-day mortality (odds ratio: 1.38; CI 1.14-1.67; p=0.001). Median IL-8 levels at diagnosis were significantly higher in neonates who were later treated surgically (median=2625 pg/ml; range: 27-7500) compared with those treated medically (median=156 pg/ml; range: 5-7500; p<0.001). The AUC to discriminate between medical and surgical NEC was 0.82 (CI, 0.74-0.90), and an exploratory IL-8 cutoff point could be established at 1783 pg/ml (sensitivity of 90.5%; specificity of 59.2%).

CONCLUSIONS

Our findings that serum IL-8 (i) correlates directly with 60-day mortality and (ii) differs significantly between medically and surgically treated infants may change the process of therapeutic decision making in NEC.

The challenges facing training in pediatric surgery worldwide

Like most specialties, pediatric surgery is becoming more complex, and changes to health systems have not always been in the best interests of trainees or their surgical teachers. This paper outlines four of the current challenges faced by training boards in pediatric surgery worldwide, and documents their implications for the future training of pediatric surgeons.

Feasibility of exclusive enteral feeds from birth in VLBW infants >1200 g--an RCT

AIM

To evaluate the feasibility of initiation of exclusive enteral feeds on first day of life in very low birthweight infants >1200 g.

METHODS

Haemodynamically stable infants with birthweights 1200-1500 g irrespective of gestational age were randomized into two groups.

STUDY GROUP

Enteral feeds 80 mL/kg/day started within 1 h of birth and increased by 20 mL/kg/day to 180 mL/kg/day. No intravenous fluids given.

CONTROL GROUP

Intravenous fluids 50 mL/kg/day started along with enteral feeds 30 mL/kg/day within 1 h of birth and increased by 20 mL/kg/day to 180 mL/kg/day. The outcome measures were - primary: time to regain birthweight and secondary: duration of hospital stay, incidence of necrotizing enterocolitis and sepsis.

RESULTS

Twenty three babies randomized in each group. Infants in study group regained birthweight earlier [mean 5.52 days, SD ± 2.94] compared to those in control group [mean 12.7 days, SD ± 2.25] (p < 0.0001). Duration of hospital stay was lower in study group [mean 15.04 days, SD ± 5.26] compared to those in control group [mean 28.04 days, SD ± 6.76] (p < 0.0001). No necrotizing enterocolitis detected.

CONCLUSION

It is feasible to initiate exclusive enteral feeds from first day of life in stable infants with birthweight between 1200 and 1500 g without any parenteral fluid support. It leads to twice as faster regaining of birthweight and halves duration of hospital stay.

Oral L-arginine supplementation and faecal calprotectin levels in very low birth weight neonates

OBJECTIVE

The objective of this study is to determine the potential effect of oral L-arginine supplementation on intestinal inflammation in very low birth weight (VLBW) neonates, as estimated by faecal calprotectin levels.

STUDY DESIGN

The study enrolled 83 VLBW neonates with birth weight ≤1500 g and gestational age ≤34 weeks. In this double-blind study, 40 neonates received daily oral L-arginine supplementation of 1.5 mmol kg(-1) per day between the 3rd and 28th day of life, and 43 neonates placebo. Stool samples were collected on days 3, 14 and 28, and calprotectin was measured by enzyme-linked immunosorbent assay.

RESULT

Calprotectin values significantly decreased over time in both groups (P=0.032). No difference in faecal calprotectin values was recorded between neonates receiving arginine supplementation and neonates receiving placebo at days 3, 14 and 28.

CONCLUSION

Faecal calprotectin values decrease with increasing postnatal age in VLBW infants, but this is not related to arginine supplementation.

Does hospital transfer predict mortality in very low birth weight infants requiring surgery for necrotizing enterocolitis?

BACKGROUND

Necrotizing enterocolitis (NEC) is a leading cause of infant mortality, and the most common reason for emergent surgery in very low birth weight (VLBW, < 1,500 g) infants. We investigated whether transfer for higher level of surgical care affects mortality in this population.

METHODS

VLBW infants who underwent NEC surgery were reviewed retrospectively from the California Patient Discharge Linked Birth Cohort Database (1999-2007). Transfer for emergent operation was defined as surgery ≤2 days after transfer. Mortality was analyzed with multivariate logistic regression.

RESULTS

Overall, 1,272 VLBW infants with surgical NEC were identified, with a 39% mortality. Transfer for operative care occurred in 406 (32%) infants. Unadjusted mortality was not increased for infants who were transferred compared with not transferred (37% vs. 40%; P = .25). Adjusted mortality for infants transferred for operative care did not differ from those who received operative care at their primary neonatal intensive care unit (odds ratio 0.75, 95% confidence interval 0.42-1.32). Lower birth weight, lack of prenatal care, peritoneal drainage as sole surgical intervention, and pulmonary interstitial emphysema/pulmonary hemorrhage were associated with increased odds of mortality (P < .05).

CONCLUSION

VLBW infants with surgical NEC do not demonstrate increased risk of mortality when transferred emergently for operative care. Future efforts must engage health professionals caring for this vulnerable population to maximize resource allocation and safety.

Primary anastomosis in necrotizing enterocolitis: the first option to consider

INTRODUCTION

Necrotizing enterocolitis (NEC) is the most frequent gastrointestinal emergency in preterm newborns. Thirty percent of all cases will require surgical intervention. Following resection of the involved segment, most patients will undergo a diverting enterostomy.

OBJECTIVE

To describe the safety and effectiveness of primary anastomosis in patients with complicated NEC.

METHODS

This study was a retrospective chart review. The study participants were obtained from both public and private health systems between December 2004 and December 2009 in Santiago, Chile. The inclusion criteria were any patient who underwent a laparotomy for necrotizing enterocolitis. The following variables were evaluated: gestational age, birth weight, use of peritoneal drains, macroscopic features of the intestinal segment, number of anastomoses, parenteral nutrition requirements and post-surgical complications.

RESULTS

Seventy patients were identified. Sixty patients (85%) underwent primary anastomosis. The remaining 10 patients underwent a resection with enterostomy. In the primary anastomosis group (n = 60), twelve percent weighed <1,000 g and 22% weighed 1,000-1,500 g. Two anastomoses were required in 18 patients. Post-surgical complications included infection of the surgical wound in three cases and anastomotic dehiscence in only one case. Seven percent developed short bowel syndrome. Overall mortality was 11.6%, all secondary to sepsis.

CONCLUSION

In this series, primary anastomosis was a safe alternative in the management of complicated NEC, with low morbidity and mortality, independent of age, weight, intraperitoneal contamination or extent of disease.

Necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is the most common acquired gastrointestinal disease of premature neonates and is a serious cause of morbidity and mortality. NEC is one of the leading causes of death in neonatal intensive care units. Surgical treatment is necessary in patients whose disease progresses despite medical therapy. Surgical options include peritoneal drainage and laparotomy, with studies showing no difference in outcome related to approach. Survivors, particularly those requiring surgery, face serious sequelae.

P-glycoprotein induction by breast milk attenuates intestinal inflammation in experimental necrotizing enterocolitis

P-glycoprotein (Pgp), a product of the multi-drug resistance gene MDR1a, is a broad specificity efflux ATP cassette transmembrane transporter that is predominantly expressed in epithelial tissues. Because mdr1a(-/-) mice tend to develop spontaneous colitis in bacteria-dependent manner, Pgp is believed to have a role in protection of the intestinal epithelium from luminal bacteria. Here we demonstrate that levels of Pgp in the small intestine of newborn rodents dramatically increase during breastfeeding, but not during formula feeding (FF). In rats and mice, levels of intestinal Pgp peak on days 3-7 and 1-5 of breastfeeding, respectively. The mdr1a(-/-) neonatal mice subjected to FF, hypoxia, and hypothermia have significantly higher incidence and pathology, as well as significantly earlier onset of necrotizing enterocolitis (NEC) than congenic wild type mice. Breast-fed mdr1a(-/-) neonatal mice are also more susceptible to intestinal damage caused by the opportunistic pathogen Cronobacter sakazakii that has been associated with hospital outbreaks of NEC. Breast milk, but not formula, induces Pgp expression in enterocyte cell lines in a dose- and time-dependent manner. High levels of ectopically expressed Pgp protect epithelial cells in vitro from apoptosis induced by C. sakazakii. Taken together, these results show that breast milk-induced expression of Pgp may have a role in the protection of the neonatal intestinal epithelium from injury associated with nascent bacterial colonization.

Antibiotic use for presumed neonatally acquired infections far exceeds that for central line-associated blood stream infections: an exploratory critique

OBJECTIVE

To assess antibiotic use as a complementary neonatal intensive care unit (NICU) infection measure to the central line-associated blood stream infection (CLABSI) rate.

STUDY DESIGN

Patient days (PDs), line days, antibiotic (AB) use, CLABSI and other proven infections were analyzed in consecutive admissions to two NICUs over 3 and 6 months, respectively, from 1 January 2008 until discharge. An antibiotic course (AC) consisted of one or more uninterrupted antibiotic days (AD), classified as perinatal or neonatal, if started ≤3 d or ≥4 d post birth and as rule-out sepsis or presumed infection (PI) if treated ≤4 d or ≥5d, respectively. Events were expressed per 1000 PD and aggregated by conventional treatment categories and by clinical perception of infection certainty: possible, presumed or proven.

RESULT

The cohort included 754 patients, 18,345 PD, 6637 line days, 718 AC and 4553 AD. Of total antibiotic use, neonatal use constituted 39.2% of ACs, and 29.0% of ADs, When analyzed per 1000 PD, antibiotic use to treat PIs vs CLABSIs, was either 14 fold (CI 6.6-30) higher for ACs (5.40 vs 0.38/1000 PD, P<0.0001) or 8.8 fold (CI 7.1-11) higher for ADs (48.3 vs 5.5/1000 PD, P<0.0001).

CONCLUSION

CLABSI rates, present a lower limit of NICU-acquired infections, whereas antibiotic-use measures, about 10-fold higher, may estimate an upper limit of that burden. Antibiotic-use metrics should be evaluated further for their ability to broaden NICU infection assessment and to guide prevention and antibiotic stewardship efforts.

Necrotizing enterocolitis requiring surgery: outcomes by intestinal location of disease in 4371 infants

OBJECTIVE

The objective of this study was to determine whether the outcomes of infants with surgically managed necrotizing enterocolitis (NEC) differ according to whether the location of NEC is in the small bowel, large bowel, or both.

STUDY DESIGN

A retrospective analysis was performed using the Healthcare Cost and Utilization Project Nationwide Inpatient Sample and Kids' Inpatient Database. A total of 5374 infants identified as having undergone surgical management of NEC were stratified by location of bowel affected as small bowel (SB) only, large bowel (LB) only, or both small and large bowel (SB&LB). The type of surgical operation performed was used as a proxy for the location of bowel affected.

RESULTS

Of the 5374 infants with a diagnosis of NEC, 4371 had an operation that allowed for stratification by location. The LB group (n = 963) fared the best in all outcomes. The SB group (n = 2126) had the longest length of stay and highest total hospital charges, and mortality was comparable with that of the SB&LB group (n = 1282).

CONCLUSIONS

Mortality, length of stay, and total hospital charges varied according to location of bowel affected by NEC.

The risk of necrotizing enterocolitis after indomethacin tocolysis

BACKGROUND

Postnatal indomethacin is reportedly associated with an increased incidence of necrotizing enterocolitis (NEC) in preterm infants. Because indomethacin readily crosses the placenta, we hypothesized that antenatal indomethacin (AI) would increase the risk for NEC in preterm infants.

OBJECTIVE

The goal of this study was to explore the association between AI and NEC in preterm infants.

METHODS

Medical records of preterm infants, 23 to 32 weeks' gestational age, without major congenital anomalies, were reviewed. Maternal and neonatal data were abstracted. Association of AI within 15 days before delivery (predictor variable) and classification of NEC according to modified Bell's stage 2a or higher in the first 15 days after delivery (early NEC [primary outcome variable]) was explored by using bivariate analyses, multivariate logistic regression, and propensity score analysis.

RESULTS

Of 628 eligible infants, 63 received AI and 28 developed early NEC. AI exposure was significantly associated with multiple gestation, race, antenatal corticosteroids and magnesium sulfate, lower birth weight and gestational age, umbilical arterial catheter placement, respiratory distress syndrome, postnatal vasopressors and antibiotics, patent ductus arteriosus, sepsis, NEC, intraventricular hemorrhage, and mortality. On multivariate logistic regression controlling for covariates, AI was significantly associated with early NEC (adjusted odds ratio: 7.193 [95% confidence interval: 2.514-20.575]; number needed to harm: 5). The results remained significant when analyses were repeated using AI exposure within 5 days before delivery as a predictor variable; on analyses stratified according to gestational age; and on propensity score analysis.

CONCLUSIONS

AI was associated with NEC in preterm infants in the first 15 days of life in this study, as were multiple other clinical factors.

Red blood cell transfusion, feeding and necrotizing enterocolitis in preterm infants

OBJECTIVE

Preliminary studies suggested an association between red blood cell (RBC) transfusion and necrotizing enterocolitis (NEC) in premature neonates. An advantageous effect of withholding feeds during transfusion has never been studied. We aimed, first, to determine whether preterm infants who developed NEC were more likely to be transfused in the 48 to 72 h before the diagnosis of NEC; second, to test if a strict policy of withholding feeds during transfusion would decrease the incidence of transfusion-associated NEC.

STUDY DESIGN

The study was conducted in two phases. Phase 1: a retrospective case-control study of premature low-birth weight (<32 weeks and <2500 g) infants who developed NEC over a 6-year period. Phase 2: a comparison study of the incidence of NEC during the 18-months preceding, and the 18 months following the change of practice to withholding feeds during RBC transfusion.

RESULT

In the case-control study (25 infants with NEC and 25 controls), more infants in the NEC group received transfusions in the 48 and 72 h preceding diagnosis (56 vs 20% within 48 h, P=0.019; and 64 vs 24% within 72 h, P=0.01). The total number of transfusions and age of RBCs were not different between the two groups. Implementing the policy of withholding feeds during transfusion was associated with a decrease in the incidence of NEC from 5.3 to 1.3% (P=0.047).

CONCLUSION

Infants who developed NEC frequently received RBC transfusions in the 48 and 72 h preceding presentation of NEC. A strict policy of withholding feeds during transfusion may have a protective effect from NEC.

Noninvasive evaluation of splanchnic tissue oxygenation using near-infrared spectroscopy in preterm neonates

BACKGROUND

Diagnosis of necrotizing enterocolitis (NEC) in preterm neonates is challenging. We hypothesized that regional splanchnic oxygen saturation (rsSO₂) measured by near-infrared spectroscopy (NIRS) is a biomarker for mesenteric perfusion.

OBJECTIVE

To evaluate feasibility and safety of continuous rsSO₂ monitoring in preterm infants in the first 14 days of life.

METHODS

Preterm neonates ≤30 weeks' gestation had a NIRS sensor placed in the left paraumbilical region within 48 h of birth. rsSO₂ was recorded every 30 s. Clinical data including pulse oximetry (SaO₂) were recorded. Fractional tissue oxygen extraction (FTOE) was computed as follows: (SaO₂ - rsSO₂) × 100/SaO₂.

RESULTS

Of 21 infants enrolled, 2 were excluded because of skin breakdown and missing data. Daily mean rsSO₂ values decreased over the first 9 days (p < 0.0001) followed by an increase from day 10 (D10) to D14 (p = 0.0061). rsSO(2) was lower and FTOE was higher in infants with feeding intolerance compared to those without feeding intolerance (p = 0.0043). rsSO₂ accounted for ≥99.5% of the variance in FTOE. Two neonates with NEC had persistently low rsSO₂ with loss of variability preceded or followed by very high rsSO₂.

CONCLUSIONS

We have reported feasibility, safety and ranges for rsSO₂ for a small number of preterm infants in the first 2 weeks of life.

An outbreak of necrotizing enterocolitis associated with norovirus genotype GII.3

BACKGROUND

Necrotizing enterocolitis (NEC) is an acute abdominal emergency of unknown etiology predominantly affecting preterm infants. We describe a cluster of NEC in a level III NICU involving 15 infants over a6-month period. Cohorting and stringent infection control measures were associated with termination of the cluster. A case-control study was used to investigate potential risk factors associated with development of NEC.

METHODS

Stool samples were collected from 55 infants (10 of 15 NEC and 45 non-NEC controls). Enteric pathogens were identified by culture and/or molecular diagnostic techniques. For the case-control study, controls were selected from admitted neonates during the same time and in the preceding 6-month period, matched for gestation and birthweight.

RESULTS

Forty percent (4/10) of NEC infants had norovirus RNA detected compared with 9% (4/45) of non-NEC infants (OR: 6.83, 95% CI: 1.3-34.9,P = 0.021). A lower rate of prolonged rupture of membranes and a higher rate of maternal smoking was also observed in NEC infants than in controls. No significant differences in incidences of chorioamnionitis, intrapartum antibiotics,volume of feedings, time of first formula feeding, and rates of patent ductus arteriosus or intrauterine growth retardation were detected.

CONCLUSIONS

Infants who developed NEC had an increased incidence of norovirus detection in their stool following diagnosis. This further strengthens the case for an etiologic role of norovirus in the pathogenesis of NEC.

Decreasing Birth Weight May Predispose Premature Infants to Increased Mortality From Necrotizing Enterocolitis

The objective of this study was to determine if there are any “risk factors” that could assist clinicians in identifying premature infants who are at greater risk for mortality when developing necrotizing enterocolitis (NEC). This was a retrospective study of infants admitted to the neonatal intensive care unit (NICU) at Children’s Hospital of Illinois, Peoria. Seventy-eight patients were diagnosed with NEC and were divided into 2 groups: NEC-survived versus NEC-died. Maternal risk factors, infant demographics, birth weight, incidence of sepsis, histamine-2 (H2) receptor blockers prescribed, temperature, anemia, and day of life when trophic feedings were begun and when enteral feedings were advanced were compared for significant differences. Univariate tests demonstrated that mothers of infants who died from NEC had a higher incidence of premature rupture of membranes. A premature infant’s decreasing birth weight significantly increased the risk for NEC-related mortality. Premature infants who received early trophic feedings had less NEC-related mortality, but this finding was not significant. Other conditions such as maternal risk factors, H2 blockers in total parenteral nutrition, enteral feedings, and temperature were not significant. Logistic regression indicated that a premature infant’s birth weight significantly increased his or her probability of dying from NEC while adjusting for other variables. A premature infant’s birth weight could be used by clinicians as a tool to identify patients at greater risk for NEC-related mortality. Although the true etiology of NEC remains unclear, early initiation of trophic feedings with colostrum may be the best defense for preventing the onset of this devastat- ing disease.

Effects of probiotics, prebiotics, and synbiotics on messenger RNA expression of caveolin-1, NOS, and genes regulating oxidative stress in the terminal ileum of formula-fed neonatal rats

Necrotizing enterocolitis (NEC) afflicts extremely low birth weight neonates, and probiotics reduces its incidence and severity. NO is involved in the pathogenesis of NEC, and caveolin-1 regulates NO signaling. We tested the hypothesis that intestinal caveolin-1 and NOS are deficient in formula-fed neonatal rats and that supplementation with "Florastar Kids" and/or galacto-oligosaccharides and fructo-oligosaccharides preserves caveolin-1 and NOS. At birth (P0), neonatal rat pups were maternally fed or hand-gavaged with or without supplemented formula. Samples from the terminal ileum were analyzed for total NO metabolites, growth factors, and gene expression of caveolin-1, NOS isoforms, and antioxidants. Our data showed that formula feeding with and without supplementation resulted in significant growth restriction. Despite suboptimal nutrition, growth factors involved in intestinal repair and regeneration were increased in the neonatal rat ileum. Caveolin-1, endothelial NOS, and neuronal NOS were simultaneously down-regulated with formula feeding while inducible NOS was up-regulated. Superoxide dismutase and glutathione peroxidase were up-regulated with supplementation. These data provide a probable mechanism for the benefits of supplemented formula for decreasing the severity of NEC by preserving the antioxidant systems.

Early nasal continuous positive airway pressure and necrotizing enterocolitis in preterm infants

BACKGROUND

The use of early nasal continuous positive airway pressure (ENCPAP) as the mode of initial respiratory support for very low birth weight (VLBW) infants has been increasing. The impact of CPAP and oxygen on gut mucosa and perfusion in premature infants is not known. The relation between ENCPAP and necrotizing enterocolitis (NEC) has not been adequately addressed.

OBJECTIVE

To evaluate if the use of an individualized respiratory management strategy encouraging the use of ENCPAP is associated with an increased risk of NEC, and to determine risk factors for NEC in premature infants supported by CPAP.

METHODS

A retrospective analysis was conducted on VLBW infants (birth weight < 1500 g) managed at 2 institutions that use an ENCPAP respiratory management strategy for premature infants. Data on the use of oxygen and mode of ventilatory support were collected during the first 3 days of life. Diagnosis of NEC was used as the dependent variable in a logistic regression model. Birth weight, gender, prenatal steroid use, mode of respiratory support (CPAP versus ventilator) and fraction of inspired oxygen, umbilical artery catheter placement, partial pressure of oxygen, patent ductus arteriosus, early sepsis, hospital, and delivery room management (ENCPAP versus initial intubation) were controlled for in the model.

RESULTS

Data on 343 premature infants were collected for this study. Mean birth weight was 999 +/- 289 g and gestational age was 28 +/- 2.6 weeks. The majority of patients were managed with ENCPAP, with only 13% of patients intubated in the delivery room. The overall incidence of NEC was 7% (n = 24). The exposure to ENCPAP did not increase the risk for NEC compared with the use of a ventilator. CONCLUSIONS. The risk of NEC in VLBW premature infants was not increased by the use of ENCPAP. Initial respiratory support with ENCPAP seems to be a safe alternative to routine intubation and mechanical ventilation in premature infants.

Endotoxin induced chorioamnionitis prevents intestinal development during gestation in fetal sheep

Chorioamnionitis is the most significant source of prenatal inflammation and preterm delivery. Prematurity and prenatal inflammation are associated with compromised postnatal developmental outcomes, of the intestinal immune defence, gut barrier function and the vascular system. We developed a sheep model to study how the antenatal development of the gut was affected by gestation and/or by endotoxin induced chorioamnionitis.

Chorioamnionitis was induced at different gestational ages (GA). Animals were sacrificed at low GA after 2d or 14d exposure to chorioamnionitis. Long term effects of 30d exposure to chorioamnionitis were studied in near term animals after induction of chorioamnionitis. The cellular distribution of tight junction protein ZO-1 was shown to be underdeveloped at low GA whereas endotoxin induced chorioamnionitis prevented the maturation of tight junctions during later gestation. Endotoxin induced chorioamnionitis did not induce an early (2d) inflammatory response in the gut in preterm animals. However, 14d after endotoxin administration preterm animals had increased numbers of T-lymphocytes, myeloperoxidase-positive cells and gammadelta T-cells which lasted till 30d after induction of chorioamnionitis in then near term animals. At early GA, low intestinal TLR-4 and MD-2 mRNA levels were detected which were further down regulated during endotoxin-induced chorioamnionitis. Predisposition to organ injury by ischemia was assessed by the vascular function of third-generation mesenteric arteries. Endotoxin-exposed animals of low GA had increased contractile response to the thromboxane A2 mimetic U46619 and reduced endothelium-dependent relaxation in responses to acetylcholine. The administration of a nitric oxide (NO) donor completely restored endothelial dysfunction suggesting reduced NO bioavailability which was not due to low expression of endothelial nitric oxide synthase.

Our results indicate that the distribution of the tight junctional protein ZO-1, the immune defence and vascular function are immature at low GA and are further compromised by endotoxin-induced chorioamnionitis. This study suggests that both prematurity and inflammation in utero disturb fetal gut development, potentially predisposing to postnatal intestinal pathology.

Necrotizing enterocolitis: etiology, presentation, management, and outcomes

Necrotizing enterocolitis is one of the most common gastrointestinal disease processes affecting infants in the neonatal intensive care unit. Its morbidity and mortality are substantial. This devastating and challenging process results in immediate and long-term morbidities for the affected infant and frustrates the clinician who struggles to prevent the process, recognize it when it does develop, and provide management techniques to enhance the outcome.