Current issues in the management of necrotizing enterocolitis

Cannabidiol decreases histological intestinal injury in a neonatal experimental model of necrotizing enterocolitis

BACKGROUND

Necrotizing enterocolitis (NEC) is a severe inflammatory bowel disease in neonates. Our group has developed an experimental model of NEC, with an effectiveness of 73%. Cannabidiol (CBD) is an innovative treatment for neonatal cerebral hypoxic-ischemic pathologies due to its neuroprotective effect, as a potent anti-inflammatory and reducing oxidative stress substance. Our aim was to evaluate the effect of CBD on intestinal lesions in an experimental model of NEC.

RESULTS

Mortality and intestinal histological damage was significantly lower in the CBD group compared to the rest (p<0.05), establishing CBD as a protective factor against the development of NEC (OR=0.0255; 95% CI=0.0015-0.4460). At IHQ level (TUNEL technique), a lower cell death rate was also observed in the CBD group compared to the VEH group (p<0.05).

CONCLUSIONS

In our experimental model, intraperitoneal CBD acts as a protective factor against NEC, resulting in less histological damage and a lower rate of intestinal cell death.

Extended-spectrum beta-lactamase (ESBL) producing Enterobacterales in stool surveillance cultures of preterm infants are no risk factor for necrotizing enterocolitis: a retrospective case-control study over 12 years

Purpose

Microbial dysbiosis has been found preceding necrotizing enterocolitis (NEC) in preterm infants; thus, we aimed to investigate whether there is evidence that neonates with extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E) positive stool cultures are at higher risk for NEC at the NICU.

Methods

We included very preterm inborn infants of ≤ 32 weeks of gestational age being fecal carriers of ESBL-E and compared them with 1:1 matched (gestational age, birth weight, gender and year) controls tested negative for ESBL-E in the stool between 2005 and 2016. An association with NEC was defined as the first detection of ESBL-E before or at the time of definite diagnosis of NEC.

Results

During the study period, we diagnosed 217 infants with a total of 270 ESBL-E. We identified ten different species with ESBL-producing Klebsiella oxytoca being the most common one (46%) followed by Klebsiella pneumoniae (19%), and Citrobacter freundii (17%). Ten out of 217 infants had any kind of NEC in the case group compared to two of the controls (p < 0.01), but only four cases with predefined criteria were associated with NEC ≥ stage IIa (1.8 vs. 0.5%, p = 0.089, OR 4.1, CI95% 0.45–36.6). NEC mortality rate was 2/8 (25%).

Conclusions

We observed a threefold increase of ESBL-E in stool surveillance cultures during study time and germs were dominated by ESBL-producing Klebsiella spp. There was no evidence that preterm infants colonized with ESBL-E in the stool were at higher risk for definite NEC.

Application of abdominal sonography in diagnosis of infants with necrotizing enterocolitis

The purpose of this study was to explore the diagnostic significance of abdominal sonography (AUS) in infants with Necrotizing enterocolitis (NEC) admitted to a neonatal intensive care unit to better evaluate the ability of AUS to differentiate necrotizing enterocolitis from other intestinal diseases.All patients diagnosed with NEC at the Department of General Surgery and Neonatal Surgery, Qilu Children's Hospital between 1st, Jun, 2010 and 30th, Dec, 2015. The logistic regression analysis and the area under receiver operating characteristic (ROC) curve (AUCs) were also used to identify the sonographic factors for diagnosing NEC.For the entire cohort of 91 patients, we divided these patients into suspected NEC (n = 35) group and definite NEC (n = 56) group. After adjusting for competing sonographic factors, we identified that thick bowel wall (more than 2.5 mm) (P = .013, OR: 1.246), intramural gas (pneumatosis intestinalis) (P = .002, OR:1.983), portal venous gas (P = .022, OR:1.655) and reduced peristalsis (P = .011, OR:1.667) were independent diagnostic factors associated with NEC. We built a logistic model to diagnose NEC according to the results of multivariable logistic regression analysis. We found the AUROC for thick bowel wall (more than 2.5 mm), intramural gas (pneumatosis intestinalis), portal venous gas and reduced peristalsis were significantly lower than the AUROC for the logistic model was 0.841 (95% CI: 0.669 to 0.946).We found that thick bowel wall (more than 2.5 mm), intramural gas (pneumatosis intestinalis), portal venous gas and reduced peristalsis were independent diagnostic factors associated with NEC. The logistic model was significantly superior to the single sonographic parameter for diagnosing NEC.

Interleukin-6 serum levels predict surgical intervention in infants with necrotizing enterocolitis

BACKGROUND

Symptoms at suspicion of necrotizing enterocolitis (NEC) are often nonspecific and several biomarkers have been evaluated for their discriminative power to both diagnose and predict the course from NEC suspicion to complicated disease requiring surgical intervention. Thus, we aimed to assess the utility of interleukin-6 (IL-6) to predict surgical intervention in infants suffering from NEC and, furthermore, to discriminate infants with starting NEC or late-onset sepsis (LOS).

METHODS

IL-6 serum levels at disease onset were retrospectively analyzed in 24 infants suffering from NEC as well as 16 neonates with LOS.

RESULTS

IL-6 serum levels at disease onset were significantly higher in infants suffering from NEC necessitating surgical intervention in the disease course compared to infants with medical NEC (5000 [785-5000] vs. 370 [78-4716] pg/ml, p = 0.0008) as well as gram-positive LOS (5000 [785-5000] vs. 84 [12-269] pg/ml, p = 0.0001). Infants suffering from gram-negative LOS exhibited elevated IL-6 serum levels at disease onset comparable to infants with surgical NEC (5000 [1919-5000] vs. 5000 [785-5000] pg/ml, p = 1.00).

CONCLUSION

The proinflammatory cytokine IL-6 appears to be a promising marker to distinguish surgical NEC from medical NEC at the onset of disease but cannot discriminate between surgical NEC and gram-negative LOS.

LEVEL OF EVIDENCE

II.

Management of NEC: Surgical Treatment and Role of Traditional X-ray Versus Ultrasound Imaging, Experience of a Single Centre

INTRODUCTION

Necrotizing enterocolitis is the most common cause of the postnatal critical conditions and remains one of the dominant causes of newborns' death in Neonatal Intensive Care. The morbidity and mortality associated with necrotizing enterocolitis remains largely unchanged and the incidence of necrotizing enterocolitis continues to increase. There is no general agreement regarding the surgical treatment of the necrotizing enterocolitis.

METHODS

In this paper, we want to evaluate the results obtained in our centre from different types of necrotizing enterocolitis's surgical treatment and to analyse the role of traditional X-ray versus ultrasound doppler imaging in the evolutionary phases of necrotizing enterocolitis. The study was conducted in the Department of Emergency-Urgency NICU, A.O.R.N. Santobono-Pausilipon in Naples from January 2010 to December 2016. Patients were monitored by hematochemical examinations and radiological orthostatic exams every 12 hours, so that they had a surgical opportunity before intestinal perforation occurred. Ultrasonography was performed to monitor preterm infants who were hospitalized in NICU and that showed NEC symptomatology in phase I Bell staging.

RESULTS

They were recruited 75 premature infants with NEC symptomatology in phase I-III of Bell staging, who underwent surgical or medical treatment. In infants with a birth weight >1500 g (N=30), laparotomy and necrotic bowel resection has generally been our preferred approach. In 46 patients we practiced a primary anastomosis after resection of an isolated necrotic intestinal segment. In patients with multiple areas of necrosis and dubious intestinal vitality, were performed a 'second-look' scheduled after 24 to 48 hours to re-evaluate the intestine. In the initial phase of necrotizing enterocolitis, when the radiographic examination shows only a specific dilation of the loops, ultrasonography shows more and more specific signs, as wall thickening, alteration of parietal echogenicity, increase in wall perfusion, single or sporadic airborne microbubbles in the thickness of wall sections.

CONCLUSIONS

Optimal surgical therapy for NEC begins with adequate antibiotic therapy, reintegration of liquids but above all with timely diagnosis, aimed to discover early prodromic phases of wall damage by US, a fundamental tool. Abdomen radiography shows specificity frameworks only when barrier damage is detected while US provides real-time imaging of abdominal structures, highlighting some elements that are completely excluded by radiograph.

Comparison of abdominal radiographs and sonography in prognostic prediction of infants with necrotizing enterocolitis

PURPOSE

The purpose of this study was to investigate the comparison of AR and AUS in predicting prognosis in infants with necrotizing enterocolitis.

METHODS

All patients were diagnosed as NEC at the department of general surgery and neonatal surgery, Qilu children's hospital between 1st, Jun, 2010 and 30th, Dec, 2016. The logistic regression analysis and the area under ROC curve (AUC)s were also used to compare the prognostic values of radiograph and sonograph for NEC.

RESULTS

Throughout the study period, 86 preterm neonates were hospitalized with diagnosis of definite NEC. Among these patients, 39 infants (45.3%) required surgical treatment. After adjusting for competing sonographic factors, we identified that thick bowel wall (more than 2.5 mm) (p = 0.001, HR: 1.849), intramural gas (pneumatosis intestinalis) (p = 0.017, HR: 1.265), portal venous gas (p = 0.002, HR: 1.824), and reduced peristalsis (p = 0.021, HR: 1.544) were independent prognostic factors associated with NEC. After adjusting for competing radiographic factors, we identified that free peritoneal gas (p = 0.007, HR: 1.472), portal venous gas (p = 0.012, HR: 1.649), and dilatation and elongation (p = 0.025, HR: 1.327). Moreover, we found that the AUROC for AR logistic model was 0.745 (95% CI 0.629-0.812), which was significant lower than the AUS logistic model (AUROC: 0.857, 95% CI 0.802-0.946) for predicting prognosis of NEC.

CONCLUSIONS

In conclusion, we found that several radiographic and sonographic parameters were associated with the prognosis of patients with NEC. The AUS model based on the logistic regression analysis was significant superior to the AR model in the prognostic prediction of NEC.

Stem cells and necrotizing enterocolitis: A direct comparison of the efficacy of multiple types of stem cells

PURPOSE

Necrotizing enterocolitis (NEC) is a leading cause of gastrointestinal morbidity and mortality in premature infants. While studies have shown potential for stem cell (SC) therapy in experimental NEC, no study has compared different SC side-by-side. Our purpose was to determine whether one type of SC may more effectively treat NEC than others.

METHODS

Four SC were compared: (1) amniotic fluid-derived mesenchymal SC (AF-MSC); (2) amniotic fluid-derived neural SC (AF-NSC); (3) bone marrow-derived mesenchymal SC (BM-MSC); and (4) neonatal enteric neural SC (E-NSC). Using an established rat model of NEC, pups delivered prematurely received an intraperitoneal injection of SC. Control pups were injected with PBS. Additional controls were breast-fed by surrogates and not subjected to experimental NEC. Intestinal tissue was graded histologically.

RESULTS

NEC incidence was: PBS, 61.3%; breast-fed unstressed, 0%; AF-MSC, 19.1%; BM-MSC, 22.9%; AF-NSC, 18.9%; E-NSC 22.2%. All groups demonstrated statistical significance (p<0.05) compared to controls, and there was no difference between SC groups.

CONCLUSION

All four SC groups reduced the incidence and severity of experimental NEC equivalently. AF-MSC may be preferable because of availability of AF at delivery and ease of expansion, increasing potential for clinical translation.

LEVEL OF EVIDENCE

V (Animal study).

Evaluating the efficacy of different types of stem cells in preserving gut barrier function in necrotizing enterocolitis

BACKGROUND

Necrotizing enterocolitis (NEC) is a leading cause of morbidity and mortality in premature infants. Increased intestinal permeability is central to NEC development. We have shown that stem cells (SCs) can reduce the incidence and severity of NEC. Our current goal was to investigate the efficacy of four different types of SC in preservation of gut barrier function during NEC.

MATERIALS AND METHODS

We compared (1) amniotic fluid-derived mesenchymal SC, (2) bone marrow-derived mesenchymal SC, (3) amniotic fluid-derived neural SC, and (4) enteric neural SC. Premature rat pups received an intraperitoneal injection of 2 × 10⁶ SC or phosphate-buffered saline only and were then subjected to experimental NEC. Control pups were breastfed and not subjected to NEC. After 48 h, animals received a single enteral dose of fluorescein isothiocyanate -labeled dextran (FD70), were sacrificed 4 h later, and serum FD70 concentrations determined.

RESULTS

Compared to breastfed, unstressed pups with intact gut barrier function and normal intestinal permeability (serum FD70 concentration 2.22 ± 0.271 μg/mL), untreated pups exposed to NEC had impaired barrier function with significantly increased permeability (18.6 ± 4.25 μg/mL, P = 0.047). Pups exposed to NEC but treated with SC had significantly reduced intestinal permeability: Amniotic fluid-derived mesenchymal SC (9.45 ± 1.36 μg/mL, P = 0.017), bone marrow-derived mesenchymal SC (6.73 ± 2.74 μg/mL, P = 0.049), amniotic fluid-derived neural SC (8.052 ± 1.31 μg/mL, P = 0.0496), and enteric neural SC (6.60 ± 1.46 μg/mL, P = 0.033).

CONCLUSIONS

SCs improve gut barrier function in experimental NEC. Although all four types of SC reduce permeability equivalently, SC derived from amniotic fluid may be preferable due to availability at delivery and ease of culture, potentially enhancing clinical translation.

A Novel Neonatal Feeding Intolerance and Necrotizing Enterocolitis Risk-Scoring Tool Is Easy to Use and Valued by Nursing Staff

BACKGROUND

Preterm infants are at increased risk of developing feeding intolerance and necrotizing enterocolitis. Comprehensive, targeted nursing assessments can evaluate the risk for and identify early signs of these conditions in an effort to prevent their destructive sequela.

PURPOSE

While the long-term goal is to develop a validated risk-scoring tool for the prediction of feeding intolerance and necrotizing enterocolitis, the objective of the preliminary phase presented here is to assess the ease of use and nurses' attitudes toward a novel feeding intolerance and necrotizing enterocolitis risk-scoring tool.

METHODS

A novel risk-scoring nursing tool was implemented in a University of Illinois-affiliated 48-bed level III neonatal intensive care unit. Data were collected from the electronic medical record of all preterm infants with parental consent during the initial 6-month study period. Scoring accuracy (accuracy of selection of risk factors based on electronic medical record data), ease of use, and nurses' attitudes toward the tool were assessed at the study site and by evaluators at a national neonatal nursing conference.

RESULTS

Fourteen nurses scored 166 tools on the 63 enrolled infants. Sixteen tools (9.6%) contained errors. Mean study site tool ease of use was 8.1 (SD: 2.2) on a 10-point scale. Ninety percent of conference evaluators agreed/strongly agreed that the tool addressed important knowledge gaps.

IMPLICATIONS FOR PRACTICE

The tool is easy to use and valued by nurses. Following validation, widespread implementation is expected to be a clinically feasible means to improve infant clinical outcomes for minimal time and financial cost.

IMPLICATIONS FOR RESEARCH

Tool validation and refinement based on nursing feedback will improve its broad applicability and predictive utility.

Infants Operated on for Necrotizing Enterocolitis: Towards Evidence-Based Pain Guidelines

BACKGROUND

Necrotizing enterocolitis (NEC) is known as an extremely painful childhood condition.

OBJECTIVES

The objective of this study was to explore pain management around NEC-related surgery in our neonatal intensive care unit (NICU) from a chart review of prospectively collected data on 60 operated NEC patients admitted between 2008 and 2013 with a median (IQR) gestational age of 28.3 (25.5-31.6) weeks.

METHODS

Pain medication data and pain scores (i.e. COMFORTneo and Numerical Rating Scale pain and distress scores) from 72 h before until 72 h after surgery were collected.

RESULTS

Preoperatively, 95% of the patients received morphine versus 100% postoperatively, with a median dosage of 10.0 (IQR 9.7-14.5) and 16.9 (IQR 10.1-20.0) μg/kg/h, respectively. Postoperatively, 28 patients (46.7%) received additional fentanyl intermittently and 14 (23.3%) received midazolam, which was part of palliative treatment for 6 patients (42.9%). In patients receiving pain medication, median COMFORTneo scores were 10 (IQR 10-11) preoperatively and 11 (10-12) postoperatively. The pain scores were comparable with those of other patients admitted to the NICU in the same time period.

CONCLUSIONS

Continuous morphine of 10 μg/kg/h preoperatively, with an increase to 15 μg/kg/h postoperatively, seems to constitute a good starting dose for further individualized pain management guided by pain scores.

Intestinal fatty acid-binding protein levels in Necrotizing Enterocolitis correlate with extent of necrotic bowel: results from a multicenter study

BACKGROUND

Intestinal fatty acid-binding protein (I-FABP) is considered as a specific marker for enterocyte damage in necrotizing enterocolitis (NEC).

OBJECTIVE

The purpose of this study was to evaluate the association of plasma and urinary I-FABP levels with the extent of macroscopic intestinal necrosis in surgical NEC.

METHODS

We combined data from prospective trials from two large academic pediatric surgical centers. Nine and 10 infants with surgical NEC were included, respectively. Plasma and urinary of I-FABP at disease onset were correlated with the length of intestinal resection during laparotomy.

RESULTS

Median length of bowel resection was 10cm (range 2.5-50) and 17cm (range 0-51), respectively. Median I-FABP levels were 53ng/mL (range 6.3-370) and 4.2ng/mL (range 1.1-15.4) in plasma in cohort 1 respectively cohort 2 and 611ng/mL (range 3-23,336) in urine. The length of bowel resection significantly correlated with I-FABP levels in plasma (Rho 0.68; p=0.04 and Rho 0.66;p=0.04) and in urine (Rho 0.92; p=0.001).

CONCLUSION

This 'proof of concept' study demonstrates that plasma and urine I-FABP levels at disease onset was strongly associated with the length of intestinal resection in surgical NEC. This offers further evidence that I-FABP levels are a promising biomarker for assessing intestinal necrosis in infants with advanced NEC.

Intra-abdominal sepsis--epidemiology, aetiology and management

Peritonitis is a progressive disease leading inexorably from local peritoneal irritation to overwhelming sepsis and death unless this trajectory is interrupted by timely and effective therapy. In children peritonitis is usually secondary to intraperitoneal disease, the nature of which varies around the world. In rich countries, appendicitis is the principal cause whilst in poor countries diseases such as typhoid must be considered in the differential diagnosis. Where resources are limited, the clinical diagnosis of peritonitis mandates laparotomy for diagnosis and source control. In regions with unlimited resources, radiological investigation, ultrasound, CT scan or MRI may be used to select patients for non-operative management. For patients with appendicitis, laparoscopic surgery has achieved results comparable to open operation; however, in many centres open operation remains the standard. In complicated peritonitis "damage control surgery" may be appropriate wherein source control is undertaken as an emergency with definitive repair or reconstruction awaiting improvement in the patient's general condition. Awareness of abdominal compartment syndrome is essential. Primary peritonitis in rich countries is seen in high-risk groups, such as steroid-dependent nephrotic syndrome patients, whilst in poor countries the at-risk population is less well defined and the diagnosis is often made at surgery.

Serum levels of interleukin-8 and gut-associated biomarkers in diagnosing necrotizing enterocolitis in preterm infants

BACKGROUND

In recent years several potential biochemical markers have been evaluated to facilitate a reliable diagnosis of necrotizing enterocolitis (NEC), but none have made progress to clinical routine. We performed a comparative assessment in premature infants to evaluate the diagnostic value of the routinely available cytokine interleukin (IL)-8, and two promising experimental biomarkers, the gut barrier proteins liver fatty acid binding protein (L-FABP) and intestinal fatty acid binding protein (I-FABP), respectively, for the diagnosis of NEC.

METHODS

IL-8, L-FABP, and I-FABP concentrations were analyzed in the serum of 15 infants with NEC and compared with 14 gestational age-matched infants serving as a control group.

RESULTS

Serum concentrations of I-FABP, L-FABP and IL-8 were significantly higher in infants with NEC compared with controls. IL-8 showed the highest diagnostic value with an area under the curve of 0.99, followed by L-FABP and I-FABP. In addition we found a significant correlation between IL-8 and both FABPs in infants with NEC.

CONCLUSION

Our results further advocate the possible role of IL-8 as a specific marker for NEC. The diagnostic value of IL-8 seems to be superior to I-FABP, and similar to L-FABP. The routinely availability facilitates IL-8 as a possible candidate for further clinical investigations.

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.

Concurrent bloodstream infections in infants with necrotizing enterocolitis

OBJECTIVE

To determine the incidence, microbiology, risk factors, and outcomes related to bloodstream infections (BSIs) concurrent with the onset of necrotizing enterocolitis (NEC).

STUDY DESIGN

We performed a retrospective review of all cases of NEC in a single center over 20 years. BSI was categorized as "NEC-associated" if it occurred within 72 hours of the diagnosis of NEC and "post-NEC" if it occurred >72 hours afterwards. Demographics, hospital course data, microbiologic data, and outcomes were compared via univariate and multivariate analyses.

RESULTS

NEC occurred in 410 infants with mean gestational age and birth weight of 29 weeks and 1290 g, respectively; 158 infants were diagnosed with at least one BSI; 69 (43.7%) with NEC-associated BSI, and 89 (56.3%) with post-NEC BSI. Two-thirds of NEC-associated BSI were due to gram-negative bacilli compared with 31.9% of post-NEC BSI (OR: 4.27; 95% CI: 2.02, 9.03) and 28.5% of all BSI in infants without NEC (OR: 5.02; 95% CI: 2.82, 8.96). Infants with NEC-associated BSI had higher odds of requiring surgical intervention (aOR: 3.51; 95% CI: 1.98, 6.24) and death (aOR: 2.88; 95% CI: 1.39, 5.97) compared with those without BSI.

CONCLUSIONS

BSI is a common, underappreciated complication of NEC occurring concurrent with the onset of disease and afterwards. The microbiologic etiology of NEC-associated BSI is different from post-NEC and late-onset BSI in infants without NEC with a predominance of gram-negative bacilli. Infants with NEC-associated BSI are significantly more likely to die than those with post-NEC BSI and NEC without BSI.

Mortality and intestinal failure in surgical necrotizing enterocolitis

BACKGROUND/PURPOSE

To examine whether as initial surgical intervention for necrotizing enterocolitis, primary peritoneal drainage as compared to primary laparotomy is associated with increased mortality or intestinal failure.

METHODS

Retrospective observational study of 240 infants with surgical necrotizing enterocolitis.

RESULTS

There was no difference concerning the composite outcome of mortality before discharge or survival with intestinal failure after adjusting for known covariates (Odds Ratio 1.73, 95% CI 0.88, 3.40). More surviving infants in the peritoneal drainage with subsequent salvage or secondary laparotomy had intestinal failure compared to those who received a peritoneal drain without subsequent laparotomy and survived (12% vs. 14% vs. 1%, p=0.015).

CONCLUSIONS

There is no difference between peritoneal drainage and laparotomy in infants with surgical necrotizing enterocolitis concerning the combined outcome of mortality or survival with intestinal failure. There is increased intestinal failure in surviving infants treated with peritoneal drain with either subsequent salvage or secondary laparotomy compared to peritoneal drainage alone.

Cellular strain amplifies LPS-induced stress signaling in immature enterocytes: potential implications for preterm infant NCPAP

BACKGROUND

Recent clinical observations of increased necrotizing enterocolitis (NEC) incidence in some nasal continuous positive airway pressure (NCPAP) patients raise concerns about whether the related abdominal distension is benign or contributes to NEC. We tested the hypothesis that mechanical strain causes an exaggerated enterocyte inflammatory response and decreased enterocyte growth and proliferation in the absence and presence of lipopolysaccharide (LPS).

METHODS

First we used a confluent enterocyte (IEC-6) monolayer to investigate effects of strain on inflammatory cytokine production and Toll-like receptor 4 (TLR-4) gene expression. Then we used a low seeding density to measure cell growth and proliferation. Ten percent mechanical strain was applied.

RESULTS

Significant increases in interleukin (IL)-8 and in IL-6 were observed after 8 and 24 h of cellular strain, respectively, and maintained throughout the study. TLR-4 expression was increased at 48 h. Mechanical strain led to slower proliferation and division whereas LPS alone had minimal effects. The responses of LPS and strain were supra-additive, suggesting synergistic cellular effects.

CONCLUSION

We speculate intestinal distension associated with the use of NCPAP, especially in the presence of abnormal gut colonization, may result in increased inflammatory cytokine production and be a contributing factor to neonatal intestinal morbidities.

Could clinical scores guide the surgical treatment of necrotizing enterocolitis?

PURPOSE

Test the diagnostic reliability of the score for neonatal acute physiology-perinatal extension-II (SNAPPE-II) and the metabolic derangement acuity score (MDAS) as predictors of surgery in patients with necrotizing enterocolitis (NEC).

METHODS

The SNAPPE-II and the MDAS were applied to 99 patients with NEC. Both the scores were calculated at the moment of diagnosis (T(0)) and when surgical assessment was required (T(1)). The main outcome was the need of surgical revision. Comparison between models was made through their receiver operator characteristics (ROC) curves.

RESULTS

Thirty-five patients required surgical treatment (group A) and 64 responded to medical therapy (group B). Median SNAPPE-II was 22 versus 5 for group A (U test 621, p = 0.002) at T(0); and 22 versus 10 for group A (U test 487, p = 0.01) at T(1). Measuring the value of the SNAPPE-II as a predictor of surgery, the ROC curve was 0.69 (CI 95%, 0.57-0.80) at T(0) and 0.67 (CI 95%, 0.55-0.80) at T(1). Median MDAS were 2 for both groups A and B at T(0) (U test 890.5, p = 0.113) and 2 versus 1.5 for group A at T(1) (U test 570, p = 0.043). The ROC curve for MDAS was 0.59 (CI 95%, 0.47-0.71) at T(0) and 0.64 (CI 95%, 0.52-0.77) at T(1).

CONCLUSIONS

The diagnostic performance of the SNAPPE-II offers mild results in the moment of the diagnosis of NEC, and at T(1). The MDAS is non significant at T(0) and obtains moderate results at T(1). These results do not encourage using the SNAPPE-II and the MDAS as definite tools to decide for surgical treatment of the patients affected by NEC.

Antibiotic exposure in the newborn intensive care unit and the risk of necrotizing enterocolitis

OBJECTIVE

To determine whether duration of antibiotic exposure is an independent risk factor for necrotizing enterocolitis (NEC).

STUDY DESIGN

A retrospective, 2:1 control-case analysis was conducted comparing neonates with NEC to those without from 2000 through 2008. Control subjects were matched on gestational age, birth weight, and birth year. In each matched triad, demographic and risk factor data were collected from birth until the diagnosis of NEC in the case subject. Bivariate and multivariate analyses were used to assess associations between risk factors and NEC.

RESULTS

One hundred twenty-four cases of NEC were matched with 248 control subjects. Cases were less likely to have respiratory distress syndrome (P = .018) and more likely to reach full enteral feeding (P = .028) than control subjects. Cases were more likely to have culture-proven sepsis (P < .0001). Given the association between sepsis and antibiotic use, we tested for and found a significant interaction between the two variables (P = .001). When neonates with sepsis were removed from the cohort, the risk of NEC increased significantly with duration of antibiotic exposure. Exposure for >10 days resulted in a nearly threefold increase in the risk of developing NEC.

CONCLUSIONS

Duration of antibiotic exposure is associated with an increased risk of NEC among neonates without prior sepsis.

Heparin-binding epidermal growth factor-like growth factor overexpression in transgenic mice increases resistance to necrotizing enterocolitis

BACKGROUND

Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency and the leading surgical cause of death in premature infants. We have shown that administration of exogenous heparin-binding epidermal growth factor-like growth factor (HB-EGF) in mice protects the intestines from experimental NEC. The aim of the current study was to evaluate the effect of gain-of-function of endogenous HB-EGF on susceptibility to NEC.

METHODS

Neonatal HB-EGF transgenic (TG) mice and their wild-type (WT) counterparts were exposed to experimental NEC. An additional group of HB-EGF TG pups were also exposed to NEC, but received the HB-EGF antagonist cross-reacting material 197 (CRM197) injected subcutaneously immediately after birth. To examine gut barrier function, HB-EGF TG and WT pups received intragastric fluorescein isothiocyanate-labeled dextran under basal and stressed conditions, and serum fluorescein isothiocyanate-labeled dextran levels were measured.

RESULTS

Wild-type mice had an incidence of NEC of 54.2%, whereas HB-EGF TG mice had a significantly decreased incidence of NEC of 22.7% (P = .03). Importantly, administration of CRM197 to HB-EGF TG pups significantly increased the incidence of NEC to 65% (P = .004). HB-EGF TG mice had significantly decreased intestinal permeability compared to WT mice both under basal and stressed conditions.

CONCLUSIONS

Our results provide evidence that overexpression of the HB-EGF gene decreases susceptibility to NEC and that administration of the HB-EGF antagonist CRM197 reverses this protective effect.

The Duke Abdominal Assessment Scale: initial experience

Plain abdominal radiographs are the current standard imaging modality of choice in the evaluation of patients with clinically suspected necrotizing enterocolitis. The time interval between radiographic exams varies with the severity of disease and may range from every 6 h to every 24 h. Radiographs are often also obtained at any point of acute clinical deterioration. Evaluation of the abdominal radiographic series is critical as the findings may alter patient management and can be an indication for surgical intervention. For these reasons, it is essential that the radiographic findings are communicated to the referring neonatologist in a clear and consistent manner. Inherent variability and lack of consistency in radiology reporting makes it difficult for the referring clinician to incorporate radiographic reports into his/her treatment algorithm. Assigning abdominal radiographic findings in necrotizing enterocolitis to a numerical scale that increases as the disease progresses provides objective terminology in lieu of subjective descriptors and may facilitate communication to our clinical colleagues. With this task in mind, the Duke Abdominal Assessment Scale was created as a 10-point numerical scale of plain film bowel gas pattern findings designed to reflect progressive disease and increased certainty of the diagnosis of necrotizing enterocolitis.

Deletion of the heparin-binding epidermal growth factor-like growth factor gene increases susceptibility to necrotizing enterocolitis

BACKGROUND

Necrotizing enterocolitis (NEC) is the leading surgical cause of death in premature infants. We have accumulated evidence supporting a role for heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF) in protection of the intestines from NEC. The aim of the current study was to evaluate the effect of loss-of-function of endogenous HB-EGF on susceptibility to NEC.

METHODS

Neonatal HB-EGF((-/-)) knockout (KO) mice and their HB-EGF((+/+)) wild-type (WT) counterparts were exposed to experimental NEC. An additional group of HB-EGF KO pups were also exposed to NEC but had HB-EGF added to their formula. To examine gut barrier function, HB-EGF KO and WT pups received intragastric fluorescein isothiocyanate-labeled dextran (FITC dextran) under basal and stressed conditions, and serum FITC dextran levels were measured.

RESULTS

The WT mice had an incidence of NEC of 53%, whereas HB-EGF KO mice had a significantly increased incidence of NEC of 80% (P = .04). Importantly, administration of exogenous HB-EGF to HB-EGF KO pups significantly reduced the incidence of NEC to 45% (P = .04). Heparin-binding EGF KO mice had significantly increased intestinal permeability compared to WT mice under basal and stressed conditions.

CONCLUSIONS

Our results provide evidence that loss of the HB-EGF gene increases susceptibility to NEC and that administration of exogenous HB-EGF reverses this susceptibility.

Early enteral feeding in conservatively managed stage II necrotizing enterocolitis is associated with a reduced risk of catheter-related sepsis

AIMS

To compare the effect of fasting period duration on complication rates in neonates managed conservatively for necrotizing enterocolitis (NEC) Bell stage II.

METHODS

We conducted a multicenter study to analyze retrospectively multiple data collected by standardized questionnaire on all admissions for NEC between January 2000 and December 2006. NEC was staged using modified Bell criteria. We divided the conservatively managed neonates with NEC Bell stage II into two groups (those fasted for <5 days and those fasted for >5 days) and compared the complication rates.

RESULTS

Of the 47 conservatively managed neonates Bell stage II, 30 (64%) fasted for <5 days (range 1-4 days) and 17 (36%) for >5 days (range 6-16 days). There were no significant differences for any of the patient characteristics analyzed. One (3%) and four (24%) neonates, respectively, developed post-NEC bowel stricture. One (3%) and two neonates (12%) suffered NEC relapse. None and five (29%) neonates developed catheter-related sepsis.

CONCLUSION

Shorter fasting after NEC appears to lower morbidity after the acute phase of the disease. In particular, shorter-fasted neonates have significantly less catheter-related sepsis. We found no benefit in longer fasting.

Necrotizing enterocolitis in 20,822 infants: analysis of medical and surgical treatments

Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency of the neonate. Previous information about this disease has largely been gathered from limited series. We analyzed 13 years of the National Inpatient Sample (NIS) and 3 years of the Kids' Inpatient Database (KID; 1997, 2000, 2003) to generate the most comprehensive profile of outcomes to date of medically versus surgically treated NEC. We identified 20 822 infants with NEC, of whom 15,419 (74.1%) and 5403 (25.9%) were undergoing medical and surgical management, respectively. Overall, surgical patients had greater length of stay, total hospital charges, and mortality. Among infants dying during admission, there was no significant difference in length of stay or charges between the medical and surgical groups. These findings highlight the need for developing a clinically relevant risk stratification tool to identify NEC patients at high risk for death.

Timing of surgical intervention in necrotizing enterocolitis can be determined by trajectory of metabolic derangement

PURPOSE

Seven metrics of metabolic derangement were evaluated as contributors to clinical decision support for operative intervention in infants with suspected necrotizing enterocolitis (NEC).

METHODS

Records of infants with suspected NEC without radiologic evidence of free air were queried for presence of 7 components of metabolic derangement (CMD), consisting of positive blood culture, acidosis, bandemia, thrombocytopenia, hyponatremia, hypotension, or neutropenia. Cases were stratified by clinical decision after each surgical evaluation as observation (OBS) or intervention (INT). Good outcome was defined as full enteric feeding by discharge and bad outcome as death or ongoing parenteral alimentation. Eleven infants undergoing operative intervention after an initial decision to observe were evaluated as matched pairs. Components of metabolic derangement/case and frequency of each CMD were determined for OBS and INT. Mann-Whitney U test was used to compare proportions of CMD in each group. Outcome was compared using chi(2). Observation was then stratified by outcome to determine whether 3 or more metabolic derangements warranting operative intervention would have changed initial clinical decision. The 11 matched cases were similarly analyzed using Wilcoxon-matched pairs.

RESULTS

Between March 2005 and July 2008, 35 infants with NEC received 53 surgical evaluations. A median of 1 CMD/case was defined in 32 instances of OBS. Surgical intervention was carried out in 19 infants with a median of 3 CMD/case. Mann-Whitney U test indicated significant difference in the frequencies of each CMD component in OBS vs INT (P = .04). Good outcome was achieved in 75% of OBS and 63% of INT (non-significant, NS). Analysis of OBS by outcome demonstrated a median 1 CMD/case of 25 with good outcome and 3 CMD/case in infants with bad outcome. Frequency of CMD was significantly higher in infants with bad outcome (P = .02). Wilcoxon-matched pair analysis of the 11 infants with paired evaluations demonstrated a similar distribution and frequency of CMD.

CONCLUSION

Progressive metabolic derangement of infants with NEC can be clinically tracked. The appearance of any 3 of these 7 metrics indicates timely operative intervention. Application of CMD trajectory to timing of surgical intervention may improve outcome and define the relationship between specific CMD and operative risk.

Necrotizing enterocolitis

Necrotizing enterocolitis (NEC) remains a major cause of neonatal morbidity and death. The pathophysiology is poorly understood. Prevailing evidence suggests that NEC is due to an inappropriate inflammatory response of the immature gut to some undefined insult. The mortality rate (15%-25%) for affected infants has not changed appreciably in 30 years. Many infants with NEC recover uneventfully with medical therapy and have long-term outcomes similar to unaffected infants of matched gestational age. Infants with progressive disease requiring surgical intervention suffer almost all of the mortality and morbidity. Of these, approximately 30%-40% will die of their disease and most of the remainder will develop long-term neurodevelopmental and gastrointestinal morbidity. Recent randomized trials suggest that the choice of operation does not influence patient outcome. Current work is focusing on developing a better understanding of the pathogenesis and improving means to identify which infants are at greatest risk of disease progression.

Current concepts regarding the pathogenesis of necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a devastating disease that predominantly affects premature neonates. The mortality associated with NEC has not changed appreciably over the past several decades. The underlying etiology of NEC remains elusive, although bacterial colonization of the gut, formula feeding, and perinatal stress have been implicated as putative risk factors. The disease is characterized by massive epithelial destruction, which results in gut barrier failure. The exact molecular and cellular mechanisms involved in this complex disease are poorly understood. Recent studies have provided significant insight into our understanding of the pathogenesis of NEC. Endogenous mediators such as prostanoids, cyclooxygenases, and nitric oxide may play a role in the development of gut barrier failure. Understanding the structural architecture of the gut barrier and the cellular mechanisms that are responsible for gut epithelial damage could lead to the development of novel diagnostic, prophylactic and therapeutic strategies in NEC.

Necrotizing enterocolitis in newborns: pathogenesis, prevention and management

Necrotizing enterocolitis (NEC) is primarily a disease process of the gastrointestinal (GI) tract of premature neonates that results in inflammation and bacterial invasion of the bowel wall. Despite advances in the care of premature infants, NEC remains one of the leading causes of morbidity and mortality in this population. It occurs in 1-5% of all neonatal intensive care admissions and 5-10% of all very low birthweight (<1500 g) infants. Although research has presented an interesting array of potential contributing factors, the precise aetiology of this multifactorial disease process remains elusive. Historically, it was believed that NEC arose predominantly from ischaemic injury to the immature GI tract, yet alternate plausible hypotheses indicate that many factors are likely to be involved. These may include issues related to the introduction and advancement of enteric feeding, alterations in the normal bacterial colonization of the GI tract, bacterial translocation and activation of the cytokine cascade, decreased epidermal growth factor, increased platelet activating factor, and mucosal damage from free radical production. Clinical manifestations of NEC may be vague, including increased episodes of apnoea, desaturations, bradycardia, lethargy and temperature instability. There may also be GI-specific symptoms such as feeding intolerance, emesis, bloody stools, abdominal distention and tenderness, and abdominal wall discolouration. Laboratory values may be indicative of infection, coagulation abnormalities and fluid retention. Radiographic signs may include ileus, dilated or fixed intestinal loops, air in the intestinal wall or free air in the abdomen. Medical treatment typically consists of bowel rest and decompression, antibacterial therapy, and management of other haematological or electrolyte imbalances. Increased respiratory and cardiovascular support is sometimes needed. In neonates who do not respond adequately to medical management, or if pneumoperitoneum is present, surgical intervention may occur with either use of a peritoneal drain or laparotomy. Advances in antenatal and neonatal care have resulted in increased survival of extremely preterm neonates. As this at-risk population continues to increase, an effective preventative strategy for NEC is needed. One preventative strategy is the use of antenatal corticosteroids to enhance maturation of the fetus if preterm delivery is likely. Recommendation of use of breast milk, early initiation of trophic feeds and judicoius advancement of enteric feeds are current postnatal strategies. Other preventative strategies that have been investigated include the use of oral antibacterials, antioxidants, supplementation of arginine and epidermal growth factor, none of which have changed clinical practice. Recent promising data indicate that prophylactic use of probiotics may play a role in preventing the onset of NEC. However, more large-scale, definitive studies are needed.

The use of the score for neonatal acute physiology-perinatal extension (SNAPPE II) in perforated necrotizing enterocolitis: could it guide therapy in newborns less than 1500 g?

BACKGROUND

Only a handful of clinical parameters other than body weight are used in managing LBW newborns with perforated necrotizing enterocolitis (NEC). Here, we determined clinical use of score for neonatal acute physiology-perinatal extension (SNAPPE II) score in the surgical decision, peritoneal drain (PD) vs PD + laparotomy in low birth weight (LBW) newborns with perforated NEC.

PATIENTS AND METHOD

A retrospective study of all neonates weighing less than 1500 g with the diagnosis of perforated NEC between 2000 and 2006 was performed. Patients were categorized in 2 groups--PD alone vs PD + laparotomy. The SNAPPE score was calculated at various days of clinical evolution. The primary outcome of mortality was used, and comparisons using univariate and multivariate analyses were performed.

RESULTS

Of 39 patients identified, 20 were treated with PD alone, whereas 19 had PD and laparotomy. The mean gestational age (25.6 vs 26.6 weeks) and the mean birth weight (795 vs 910 g) were comparable (P > .05). There were no differences between PD group and LAP group with regard to SNAPPE scores calculated on the day of admission (P = .057), the day before the drain insertion (P = .167) and the day after the drain insertion (P = .66). When considering survival as the dependent variable while controlling for the treatment assignment, the modified SNAPPE score after PD drain insertion in group PD was significantly higher than in the PD + laparotomy group (21.4 vs 9.47; P = .009).

CONCLUSION

The modified SNAPPE score is a good predictor of mortality after the PD insertion. A post-PD insertion, high SNAPPE value was correlated with increased mortality regardless of an additional laparotomy. External validation of the modified SNAPPE score in a large patient population is required before its use in guiding treatment decisions.

Uso de fatores de crescimento epidérmico e estimulador de colônias de granulócitos na prevenção e tratamento da enterocolite necrosante no recém-nascido

OBJETIVO: Revisar os conhecimentos existentes em relação ao uso de fatores de crescimento epidérmico e estimulador de colônias de granulócitos na prevenção e/ou no tratamento da enterocolite necrosante (ECN) durante o período neonatal. FONTES DE DADOS: Revisão da literatura, nas bases de dados Medline, Lilacs, SciELO e PubMed, utilizando os unitermos "recém-nascidos", "enterocolite" e "fatores de crescimento", no período de 2003 a 2007. Nesta busca, 49 artigos foram encontrados, sendo 17 pertinentes ao tema. Também foram utilizados outros artigos, independente do ano de publicação, relacionados a aspectos definidores da ECN no recém-nascido. SÍNTESE DOS DADOS: A ECN continua sendo responsável por uma elevada morbimortalidade neonatal. Os mecanismos fisiopatológicos vêm sendo elucidados e, a partir deles, são discutidas novas terapias, como o uso de fatores de crescimento, destacando-se o fator de crescimento epidérmico e o fator estimulador de colônias de granulócitos. CONCLUSÕES: O uso de fatores de crescimento no tratamento e prevenção da ECN neonatal parece promissor. É necessário maior número de ensaios clínicos para comprovar sua eficácia e segurança. Enquanto isso, a melhor prática médica continua sendo a prevenção da doença.

Evidence vs experience in the surgical management of necrotizing enterocolitis and focal intestinal perforation

INTRODUCTION

Necrotizing enterocolitis (NEC) and focal intestinal perforation (FIP) are neonatal intestinal emergencies that affect premature infants. Although most cases of early NEC can be successfully managed with medical therapy, prompt surgical intervention is often required for advanced or perforated NEC and FIP.

METHODS

The surgical management and treatment of FIP and NEC are discussed on the basis of literature review and our personal experience.

RESULTS

Surgical options are diverse, and include peritoneal drainage, laparotomy with diverting ostomy alone, laparotomy with intestinal resection and primary anastomosis or stoma creation, with or without second-look procedures.

CONCLUSIONS

The optimal surgical therapy for FIP and NEC begins with prompt diagnosis and adequate fluid resuscitation. It appears that there is no significant difference in patient outcome based on surgical management alone. However, the infant's weight, comorbidities, surgeon preference and timing of intervention should be taken into account before operative intervention.

Dynamic change of fecal calprotectin in very low birth weight infants during the first month of life

BACKGROUND

Calprotectin is a cytosolic component of neutrophils. Fecal calprotectin (FC) level is a useful marker for exacerbation of inflammatory bowel disease in children. FC may be a useful marker for necrotizing enterocolitis (NEC).

OBJECTIVE

To determine normal baseline levels of FC and observe dynamic changes of FC levels over the first postnatal month in very low birth weight (VLBW) infants.

METHODS

FC levels of 14 VLBW infants (gestational age 23-30 weeks, birth weight <or=1,500 g) were serially measured in the first postnatal month. Demographics, feeding regimens, antibiotic use, laboratory and x-ray results, and maternal information were recorded. We assessed how FC levels changed over time, varied with nutritional source and differed between sick versus well infants.

RESULTS

FC levels were not related to gestational age or feedings regimen. FC levels tended to decrease with increasing age (p = 0.121) and feeding volumes (p = 0.179). FC levels differed between 'well' and 'sick' infants (122.8 +/- 98.9 vs. 380.4 +/- 246.3 microg/g stool, p < 0.001). FC >350 microg/g stool was noted with signs of gastrointestinal injury, such as bloody stool and bowel perforation. FC levels decreased after initiation of treatments in sick infants who recovered.

CONCLUSIONS

FC levels may be a marker for early diagnosis and resolution of gastrointestinal illnesses in VLBW infants. Its utility for early diagnosis and assessment of resolution of NEC should be studied in a larger cohort of VLBW infants.

A new method to close an intestinal wall defect using fibrin glue and polyglycolic acid felt sealant

PURPOSE

This study aimed to propose an alternative method of suture closure for an intestinal wall defect using 2 absorbable materials.

METHODS

An oval intestinal wall defect was created in the duodenum, ileum, or colon of rabbits. The defect was first covered by polyglycolic felt, which was then completely covered by fibrin glue to make a fibrin glue and polyglycolic acid felt (FGPAF) sealant without any suture procedures. The rabbits with a simple suture closure for the defect were used as controls. The bursting pressure of the treated intestine was measured, and macro- and microscopic observations were carried out for 6 months.

RESULTS

Seven rabbits treated with the FGPAF sealant used in each of the 3 operated regions survived without any signs of peritonitis or intestinal obstruction, similar to the controls. The mean bursting pressure of the segment with wall defect closed by single layer sutures and the segment with FGPAF sealant was 69.7 mm Hg (n = 6) and 70.6 mm Hg (n = 7), respectively. A histologic study at 1 week after operation revealed that the FGPAF circumferentially adhered to the edge of the defect with fibrous tissue extension into the sealant; whereas when performing a laparotomy at 1 month after operation, a round mass consisting of the remnant FGPAF mixed with plant residues of daily chows was found loosely attached to the serousal surface.

CONCLUSION

These results suggest that the present technique may be useful for the new technique of intestinal wall closure.

Treatment Outcomes of Necrotizing Enterocolitis for Preterm Infants

Necrotizing enterocolitis (NEC) is one of the most common life-threatening gastrointestinal emergencies for the preterm infant. The survival rate for preterm infants after NEC has improved over the past two decades, but complications arising from medical and surgical intervention have produced many long term problems. Documented consequences of NEC include feeding intolerance and physical, developmental and cognitive problems. Bedside nurses are well positioned to detect early changes in the infant that may enable early treatment and reduce long-term complications.

Interferon-gamma inhibits intestinal restitution by preventing gap junction communication between enterocytes

BACKGROUND & AIMS

Necrotizing enterocolitis (NEC) is characterized by interferon-gamma (IFN-gamma) release and inadequate intestinal restitution. Because enterocytes migrate together, mucosal healing may require interenterocyte communication via connexin 43-mediated gap junctions. We hypothesize that enterocyte migration requires interenterocyte communication, that IFN impairs migration by impairing connexin 43, and that impaired healing during NEC is associated with reduced gap junctions.

METHODS

NEC was induced in Swiss-Webster or IFN(-/-) mice, and restitution was determined in the presence of the gap junction inhibitor oleamide, or via time-lapse microscopy of IEC-6 cells. Connexin 43 expression, trafficking, and localization were detected in cultured or primary enterocytes or mouse or human intestine by confocal microscopy and (35)S-labeling, and gap junction communication was assessed using live microscopy with oleamide or connexin 43 siRNA.

RESULTS

Enterocytes expressed connexin 43 in vitro and in vivo, and exchanged fluorescent dye via gap junctions. Gap junction inhibition significantly reduced enterocyte migration in vitro and in vivo. NEC was associated with IFN release and loss of enterocyte connexin 43 expression. IFN inhibited enterocyte migration by reducing gap junction communication through the dephosphorylation and internalization of connexin 43. Gap junction inhibition significantly increased NEC severity, whereas reversal of the inhibitory effects of IFN on gap junction communication restored enterocyte migration after IFN exposure. Strikingly, IFN(-/-) mice were protected from the development of NEC, and showed restored connexin 43 expression and intestinal restitution.

CONCLUSIONS

IFN inhibits enterocyte migration by preventing interenterocyte gap junction communication. Connexin 43 loss may provide insights into the development of NEC, in which restitution is impaired.

Paneth cells, defensins, and the commensal microbiota: A hypothesis on intimate interplay at the intestinal mucosa

Mucosal surfaces are colonized by a diverse and dynamic microbiota. Much investigation has focused on bacterial colonization of the intestine, home to the vast majority of this microbiota. Experimental evidence has highlighted that these colonizing microbes are essential to host development and homeostasis, but less is known about host factors that may regulate the composition of this ecosystem. While evidence shows that IgA has a role in shaping this microbiota, it is likely that effector molecules of the innate immune system are also involved. One hypothesis is that gene-encoded antimicrobial peptides, key elements of innate immunity throughout nature, have an essential role in this regulation. These effector molecules characteristically have activity against a broad spectrum of bacteria and other microbes. At mucosal surfaces, antimicrobial peptides may affect the numbers and/or composition of the colonizing microbiota. In humans and other mammals, defensins are a predominant class of antimicrobial peptides. In the small intestine, Paneth cells (specialized secretory epithelial cells) produce high quantities of defensins and several other antibiotic peptides and proteins. Data from murine models indicate that Paneth cell defensins play a pivotal role in defense from food and water-borne pathogens in the intestinal lumen. Recent studies in humans provide evidence that reduced Paneth cell defensin expression may be a key pathogenic factor in ileal Crohn's disease, a subgroup of inflammatory bowel disease (IBD), and changes in the colonizing microbiota may mediate this pathogenic mechanism. It is also possible that low levels of Paneth cell defensins, characteristic of normal intestinal development, may predispose premature neonates to necrotizing enterocolitis (NEC) through similar close links with the composition of the intestinal microbiota. Future studies to further define mechanisms by which defensins and other host factors regulate the composition of the intestinal microbiota will likely provide new insights into intestinal homeostasis and new therapeutic strategies for inflammatory and infectious diseases of the bowel.

Exploratory laparotomy or peritoneal drain? Management of bowel perforation in the neonatal intensive care unit

Premature infants in the neonatal intensive care unit are at risk for necrotizing enterocolitis (NEC) and bowel perforation. Unfortunately the mortality and morbidity for intestinal perforation in neonates, especially extremely low-birth-weight infants (VLBW), is high. The criterion standard traditional management for bowel perforation has been exploratory laparotomy (LAP). Another less invasive alternative treatment modality for selected intestinal perforation is primary peritoneal drainage (PPD). The role and efficacy of PPD as a definitive treatment instead of laparotomy remains to be determined. To better appreciate the emergence and evolving role of PPD in the management of intestinal perforation in NEC or isolated intestinal perforation, 8 selected research articles will be reviewed. Findings from these studies will be summarized to address the original purpose of PPD as a rescue and stabilizing measure for VLBW infants with complicated NEC, the expanded and superior role of PPD when it is used for VLBW infants with isolated ileal perforation, and PPD not as a sole surgical management but as an adjunct therapy to LAP in perforated NEC for the VLBW infants.

Enteral water for hypernatremia and intestinal morbidity in infants less than or equal to 1000 g birth weight

OBJECTIVE

To evaluate the relationship between enteral water infusion for hypernatremia and significant intestinal morbidity in infants <or=1000 grams.

STUDY DESIGN

This is a retrospective study of 321 infants <or=1000 g birth weight. Infants were grouped by the highest serum sodium (mmol/l) during the first 14 days of life as follows: <150 (normal control), >or=150 (high sodium control), >or=150 and treated with sterile water (study group). Significant intestinal morbidity was defined as probable or proven necrotizing enterocolitis or spontaneous intestinal perforation. Statistical analysis included Student's t test for continuous variables and chi(2) with Yeats correction for frequency variables. Multivariate logistic regression analysis was then performed to evaluate confounding variables among groups.

RESULTS

The incidence of intestinal morbidity was significantly higher in the high sodium-water treated group compared to each of the other groups (13/33 (38%) for high sodium-water versus 16/100 (16%) for high sodium control and 18/188 (10%) for normal sodium control, P<0.01 chi(2)). Logistic regression analysis indicated that enteral water and hydrocortisone were risk factors for significant intestinal morbidity.

CONCLUSIONS

Enteral sterile water for hypernatremia appears to be associated with significant intestinal morbidity in infants <or=1000 g. Hydrocortisone is also a risk factor.

Necrotising enterocolitis hospitalisations among neonates in the United States

The objective of this study was to estimate the rate and describe the epidemiology of necrotising enterocolitis (NEC) among neonates (infants <1 month of age) hospitalised in the United States. Hospital discharge records for neonates with an NEC diagnosis and an in-hospital death or routine discharge were selected for analysis from the 2000 Kids' Inpatient Database. An estimated 4463 (SE = 219) hospitalisations associated with NEC occurred among neonates in the United States during the year 2000, resulting in a hospitalisation rate of 109.9 [95% CI 97.2, 122.6] per 100 000 livebirths. The rate of NEC hospitalisations was highest among non-Hispanic Black neonates. The median hospital length of stay was 49 days. The in-hospital fatality rate was 15.2% (SE = 1.0%). Neonates who underwent a surgical procedure during hospitalisation were more likely to have a longer length of stay and to die than were those who did not have surgical intervention. Low-birthweight (LBW) neonates with NEC were more likely than LBW neonates hospitalised with other diagnoses to be very LBW (VLBW), non-Hispanic Black and male. In addition, compared with LBW neonates hospitalised with other diagnoses, LBW neonates with NEC had higher hospital charges and longer lengths of stay, and were more likely to die during hospitalisation. This study provides the first national estimate of the rate of hospitalisation for NEC among neonates in the United States. During 2000, there was one NEC hospitalisation per 1000 livebirths, with approximately 1 in 7 NEC hospitalisations ending in death. NEC accounts for substantial morbidity; thus, the development of prevention strategies and effective therapies continues to be an important issue.

Pain assessment and pharmacologic management for infants with NEC: a retrospective chart audit

Purpose: To examine (1) the frequency and types of painful procedures, (2) the frequency and types of analgesic/sedative use, and (3) the frequency of documented pain assessments that infants experience during the five days following a diagnosis of necrotizing enterocolitis (NEC).

Design: A retrospective descriptive cohort design.

Sample: Thirty-nine infants from one tertiary care unit diagnosed with stage II NEC.

Main Outcome Variable: Painful procedure data were classified into highly invasive procedures and moderately invasive procedures and were collected for five days following the diagnosis of NEC. Frequency and types of analgesic/sedative administration and frequency of documented pain assessments during each of the five days following the NEC diagnosis were collected.

Results: The average number of painful procedures was 16.3 per day, with documented PIPP scores performed on 30–60 percent of the infants during each of the days following the diagnosis of NEC. At no time were more than two PIPP scores per infant documented in a 24-hour period. Analgesics were used in 52–76 percent of infants during the first three days following the diagnosis of NEC, but use decreased gradually on the fourth and fifth days. No correlation between painful procedures and analgesic/sedative administration on any day was found. Similarly, no correlation between documented PIPP scores and analgesic/sedative use on any day was found.

Multi-modal approach to prophylaxis of necrotizing enterocolitis: clinical report and review of literature

For the first time a multimodal approach to NEC prophylaxis is reported, consisting of early trophic feeding with human breast milk, and enteral administration of an antibiotic, an antifungal agent, and probiotics. A retrospective analysis of local protocol of NEC prophylaxis is presented. Included were all VLBWI admitted to the NICU, including transfers within the first 28 days of life. These infants were divided into two groups, an "inborn group" (infants admitted within the first 24 h of life) and an "outborn group" (infants admitted after the onset of their second day of life). Prophylaxis of NEC according to protocol was started at the day of admission, and was continued until discharge. Between 1998 and 2004, 405 VLBWI were admitted, including all transfers within the first 28 days of life. A total of 334 (82%) infants were admitted within the first 24 h of life (inborn group), and 71 (18%) were admitted after 24 h of life (outborn group). Five infants developed clinical features of necrotizing enterocolitis. The inborn group showed a NEC incidence of 0.7% (two infants), whereas the outborn group showed a NEC incidence of 4.5% (three infants), respectively. This difference was significant (P=0.049, Fisher's exact test). A surgical treatment with bowel resection was performed in two infants (both from the outborn group). The present study used a combination of different strategies, all having shown to have some beneficial effect, but not having brought a clinical breakthrough in single administration studies. Combinated were the beneficial effects of human breast milk feeding, oral antiobiotics, oral antifungal agents, and the administration of probiotics. In a homogenous group of preterm infants, using this protocol of multimodal NEC prophylaxis, there was a very low incidence of NEC, when started within the first 24 h of life.

Familial and genetic susceptibility to major neonatal morbidities in preterm twins

BACKGROUND

Intraventricular hemorrhage, necrotizing enterocolitis, and bronchopulmonary dysplasia remain significant causes of morbidity and mortality in preterm newborns.

OBJECTIVES

Our goal was to assess the familial and genetic susceptibility to intraventricular hemorrhage, necrotizing enterocolitis, and bronchopulmonary dysplasia.

METHODS

Mixed-effects logistic-regression and latent variable probit model analysis were used to assess the contribution of several covariates in a multicenter retrospective study of 450 twin pairs born at < or =32 weeks of gestation. To determine the genetic contribution, concordance rates in a subset of 252 monozygotic and dizygotic twin pairs were compared.

RESULTS

The study population had a mean gestational age of 29 weeks and birth weight of 1286 g. After controlling for effects of covariates, the twin data showed that 41.3%, 51.9%, and 65.2%, respectively, of the variances in liability for intraventricular hemorrhage, necrotizing enterocolitis, and bronchopulmonary dysplasia could be accounted for by genetic and shared environmental factors. Among the 63 monozygotic twin pairs, the observed concordance for bronchopulmonary dysplasia was significantly higher than the expected concordance; 12 of 18 monozygotic twin pairs with > or =1 affected member had both members affected versus 3.69 expected. After controlling for covariates, genetic factors accounted for 53% of the variance in liability for bronchopulmonary dysplasia.

CONCLUSIONS

Twin analyses show that intraventricular hemorrhage, necrotizing enterocolitis, and bronchopulmonary dysplasia are familial in origin. These data demonstrate, for the first time, the significant genetic susceptibility for bronchopulmonary dysplasia in preterm infants.

Laparotomy versus peritoneal drainage for necrotizing enterocolitis and perforation

BACKGROUND

Perforated necrotizing enterocolitis is a major cause of morbidity and mortality in premature infants, and the optimal treatment is uncertain. We designed this multicenter randomized trial to compare outcomes of primary peritoneal drainage with laparotomy and bowel resection in preterm infants with perforated necrotizing enterocolitis.

METHODS

We randomly assigned 117 preterm infants (delivered before 34 weeks of gestation) with birth weights less than 1500 g and perforated necrotizing enterocolitis at 15 pediatric centers to undergo primary peritoneal drainage or laparotomy with bowel resection. Postoperative care was standardized. The primary outcome was survival at 90 days postoperatively. Secondary outcomes included dependence on parenteral nutrition 90 days postoperatively and length of hospital stay.

RESULTS

At 90 days postoperatively, 19 of 55 infants assigned to primary peritoneal drainage had died (34.5 percent), as compared with 22 of 62 infants assigned to laparotomy (35.5 percent, P=0.92). The percentages of infants who depended on total parenteral nutrition were 17 of 36 (47.2 percent) in the peritoneal-drainage group and 16 of 40 (40.0 percent) in the laparotomy group (P=0.53). The mean (+/-SD) length of hospitalization for the 76 infants who were alive 90 days after operation was similar in the primary peritoneal-drainage and laparotomy groups (126+/-58 days and 116+/-56 days, respectively; P=0.43). Subgroup analyses stratified according to the presence or absence of radiographic evidence of extensive necrotizing enterocolitis (pneumatosis intestinalis), gestational age of less than 25 weeks, and serum pH less than 7.30 at presentation showed no significant advantage of either treatment in any group.

CONCLUSIONS

The type of operation performed for perforated necrotizing enterocolitis does not influence survival or other clinically important early outcomes in preterm infants. (ClinicalTrials.gov number, NCT00252681.).

Short bowel syndrome and intestinal transplantation in children

PURPOSE OF REVIEW

This review summarizes recent knowledge and clinical practice for pediatric patients suffering extensive intestinal resection causing short bowel syndrome. This condition requires the use of parenteral nutrition, as long as intestinal failure persists, and may be, in some selected cases, an indication for intestinal transplantation.

RECENT FINDINGS

Biological evaluation of intestinal failure is becoming possible with the use of plasma citrulline as a marker of intestinal mass. Few epidemiological data are available; some indicate an increased incidence of short bowel syndrome-related gastroschisis and persistent high incidence of necrotizing enterocolitis. Morbidity and mortality data in pediatric patients with short bowel syndrome are limited, while long-term outcome is better documented from recently reported cohorts. Non-transplant surgery is one of the best options for patients with unadapted short bowel syndrome. Isolated liver transplantation may be avoided. The use of trophic factors for enhancing mucosal hyperplasia still remains disappointing.

SUMMARY

The management should include therapies adapted to each stage of intestinal failure, based on a multidisciplinary approach in centers involving pediatric surgery, pediatric gastroenterology, parenteral nutrition expertise, home-parenteral nutrition program, and liver-intestinal transplantation experience. If managed appropriately, the prognosis of short bowel syndrome is excellent, with limited indications for intestinal and/or liver transplantation. Timing for patient referral in specialized centers remains an issue.

Heparin-binding epidermal growth factor-like growth factor reduces intestinal apoptosis in neonatal rats with necrotizing enterocolitis

PURPOSE

We have previously demonstrated that enterally administered heparin-binding epidermal growth factor-like growth factor (HB-EGF) decreases the incidence and severity of necrotizing enterocolitis (NEC) in a neonatal rat model. Because apoptosis contributes to gut barrier failure in this model, the aim of this study was to investigate the effect of HB-EGF on apoptosis during the development of NEC.

METHODS

NEC was induced in neonatal rats by exposure to hypoxia, hypothermia, hypertonic formula feeding (HHHTF) plus enteral administration of lipopolysaccharide (LPS). Fifty-one neonatal rats were randomly divided into the following groups: (1) breast-fed (BF), (2) HHHTF + LPS, and (3) HHHTF + LPS with HB-EGF (600 microg/kg) added to the formula. NEC was evaluated using a standard histological scoring system. Apoptotic cells in intestinal tissues were detected by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) and by active caspase 3 immunohistochemical staining.

RESULTS

The incidence of NEC in the HHHTF + LPS group was higher than that in the BF group (65% vs 0%, P < .05). With administration of HB-EGF, the incidence of NEC significantly decreased to 23.8% (P < .05). The median TUNEL and active caspase 3 scores in the HHHTF + LPS group were higher than those in the BF group (1.9 vs 0.9 and 1.75 vs 0.6, respectively, P < .05). The median TUNEL and active caspase 3 scores were significantly decreased in the HHHTF + LPS + HB-EGF group compared with the HHHTF + LPS group (1.24 vs 1.9 and 1.0 vs 1.75, respectively, P < .05).

CONCLUSION

HB-EGF reduces the incidence of NEC in a neonatal rat model in part by decreasing apoptosis. These results support the use of HB-EGF-based clinical regimens for the treatment of NEC.

Coming full circle: an evidence-based definition of the timing and type of surgical management of very low-birth-weight (<1000 g) infants with signs of acute intestinal perforation

OBJECTIVE

Gut disruption in very low birth weight follows 1 of 3 clinical pathways: isolated perforation with sudden free air, metabolic derangement (MD) complicated by appearance of free air, or progressive metabolic deterioration without evidence of free air. To refine evidence-based indications for peritoneal drainage (PD) vs laparotomy (LAP), we hypothesized that MD acuity is the determinant of outcome and should dictate choice of PD or LAP.

METHODS

Very low-birth-weight infants referred for surgical care because of free intraperitoneal air or MD associated with signs of enteritis were evaluated by univariate or multivariate logistic regression to investigate the effect on mortality of MD and initial surgical care (LAP vs PD). Metabolic derangement was scaled by assigning 1 point each for thrombocytopenia, metabolic acidosis, neutropenia, left shift of segmented neutrophils, hyponatremia, bacteremia, or hypotension. Laparotomy and PD were stratified by MD acuity, and odds of mortality were calculated for each surgical option.

RESULTS

From October 1991 to December 2003, 65 very low-birth-weight infants with suspected gut disruption were referred for surgical care. Peritoneal drainage and LAP infants had similar birth weight and gastrointestinal age, neither of which predicted mortality. Despite a higher incidence of isolated perforation with sudden free air in PD infants, the incidence of MD and overall mortality were similar for PD and LAP. Multivariate logistic regression demonstrated MD to be the best predictor of mortality (odds ratio [OR], 4.76; confidence interval [CI], 1.41-16.13, P = .012), which significantly increased with interval between diagnosis to surgical intervention (P < .05). Infants with MD receiving PD had a 4-fold increase in mortality (OR, 4.43; CI, 1.37-14.29; P = .0126). Conversely, those without MD and sudden free air who underwent LAP had a 3-fold increase in mortality (OR, 2.915; CI, 1.107-7.692; P = .03.) Of 5, 3 failed PD were "rescued" by LAP.

CONCLUSIONS

The dramatic difference in mortality odds based on surgical option in the presence of MD defines the critical importance of a thorough assessment of physiological status to exclude MD. Absence of MD warrants consideration for PD, especially for sudden intraperitoneal free air. Overwhelming MD may limit options to PD; however, salvage of 3 of 5 infants with failed PD demonstrates the value of LAP, whenever possible, for infants with MD.