Necrotizing enterocolitis among neonates in the United States

Slow advancement of enteral feed volumes to prevent necrotising enterocolitis in very low birth weight infants

BACKGROUND

The major modifiable risk factors for necrotising enterocolitis (NEC) in very low birth weight (VLBW) infants relate to enteral feeding practices. Observational studies suggest that conservative feeding regimens that include slowly advancing enteral feed volumes reduce the risk of NEC. However, slow feed advancement may delay establishment of full enteral feeding and so be associated with metabolic and infectious morbidities secondary to prolonged exposure to parenteral nutrition.

OBJECTIVES

To determine the effect of slow rates of enteral feed advancement on the incidence of NEC, mortality and other morbidities in VLBW infants.

SEARCH STRATEGY

We used the standard search strategy of the Cochrane Neonatal Group. We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, 2010, Issue 4), MEDLINE (1966 to December 2010), EMBASE (1980 to December 2010), CINAHL (1982 to December 2010), conference proceedings, and previous reviews.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials that assessed the effect of slow (up to 24 ml/kg/day) versus faster rates of advancement of enteral feed volumes upon the incidence of NEC in VLBW infants.

DATA COLLECTION AND ANALYSIS

Data collection and analysis was performed in accordance with the standard methods of the Cochrane Neonatal Review Group.

MAIN RESULTS

We identified four randomised controlled trials in which a total of 496 infants participated. Few participants were extremely low birth weight or growth restricted. The trials defined slow advancement as daily increments of 15 to 20 ml/kg and faster advancement as 30 to 35 ml/kg. Meta-analyses did not detect statistically significant effects on the risk of NEC (typical relative risk 0.91, 95% confidence interval 0.47 to 1.75) or all cause mortality (typical relative risk 1.43, 95% confidence interval 0.78 to 2.61). Infants who had slow rates of feed volume advancement took significantly longer to regain birth weight [reported median difference 2 to 6 days] and to establish full enteral feeding [reported median difference 2 to 5 days].

AUTHORS' CONCLUSIONS

Current data do not provide evidence that slow advancement of enteral feed volumes reduces the risk of NEC in VLBW infants. Increasing the volume of enteral feeds at slow rather than faster rates results in several days delay in regaining birth weight and establishing full enteral feeds but the long term clinical importance of these effects is unclear. Further randomised controlled trials are needed to determine how the rate of daily increment in enteral feed volumes affects clinical outcomes in VLBW infants.

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.

Necrotizing enterocolitis in infants with periventricular hemorrhagic infarction: associations and outcomes

BACKGROUND

Necrotizing enterocolitis (NEC) and periventricular hemorrhagic infarction (PVHI) are complications of prematurity associated with poor neurodevelopmental outcomes.

OBJECTIVES

We characterized temporal and causal associations between NEC and type of PVHI as well as associations with outcomes.

METHODS

This was a multicenter retrospective study of infants with birth weight <1,500 g and diagnosis of PVHI by a pediatric radiologist at 3 neonatal intensive care units in North Carolina, USA, between January 1998 and December 2004. NEC was confirmed using radiological and surgical pathology findings. Infants were assessed by 3 years using the Bayley Scales of Infant Development, second edition.

RESULTS

35 of 112 (31%) of study patients developed NEC. NEC was diagnosed subsequent to PVHI by a median of 16.6 days (95% CI [9.5, 24.9], p < 0.0001). Indomethacin use and the presence of bilateral PVHI were associated with an increased risk of subsequent NEC (OR 2.8, 95% CI [1.1, 7.2] and OR 2.4, 95% CI [1.1, 5.7], respectively). Having bilateral versus unilateral PVHI was associated with a 2.34-fold increased risk of death (95% CI [1.27, 4.33], p = 0.007). NEC was not associated with worse motor outcomes in this population. Overall, the probability of a mental development index >70 was greatest for infants with unilateral PVHI versus bilateral PVHI, although the presence of NEC was associated with worse cognitive outcomes in both groups.

CONCLUSIONS

Premature infants with PVHI often subsequently develop NEC, especially if they have bilateral PVHI and are exposed to indomethacin. While NEC results in worse neurodevelopmental outcomes, PVHI severity appears more important to the outcome of these infants.

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.

Economic evaluation of enhanced staff contact for the promotion of breastfeeding for low birth weight infants

OBJECTIVES

There is evidence that breastmilk feeding reduces mortality and short and long-term morbidity among infants born too soon or too small. The aim of this study was to evaluate the cost-effectiveness of enhanced staff contact for mothers with infants in a neonatal unit with a birth weight of 500-2,500 g from the perspective of the UK National Health Service.

METHODS

A decision-tree model linked clinical outcomes with long-term health outcomes. The study population was divided into three weight bands: 500-999 g, 1000-1,749 g, and 1,750-2,500 g. Clinical and resource use data were obtained from literature reviews. The measure of benefit was quality-adjusted life-years. Uncertainty was evaluated using cost-effectiveness acceptability curves and sensitivity analyses.

RESULTS

The intervention was less costly and more effective than the comparator in the base-case analysis for each birth weight group. The results were quite robust to the sensitivity analyses performed.

CONCLUSIONS

This is the first economic evaluation in this complex field and offers a model to be developed in future research. The results provide preliminary indications that enhanced staff contact may be cost-effective. However, the limited evidence available, and the limited UK data in particular, suggest that further research is required to provide results with confidence.

National prospective surveillance study of necrotizing enterocolitis in neonatal intensive care units

PURPOSE

There is scant epidemiological data on necrotizing enterocolitis (NEC), so we conducted a national study to characterize prevalence, surgical management, and mortality.

METHODS

A prospective cross-sectional survey was performed in the United Kingdom requesting data from 158 level 2 and 3 neonatal intensive care units (NICUs) during 2 winter and 2 summer months in 2005 to 2006; 51% of questionnaires were returned. Results are given as percentage with 95% confidence intervals.

RESULTS

(1) Period prevalence: 211 infants were diagnosed with NEC (45% Bell's stage I, 21% stage II, and 33% stage III) from a total of 10,946 NICU admissions, with a period prevalence of 2% (1.7-2.2). In infants less than 1000 g birth weight, the prevalence was 14% (12-16), and in less than 26 weeks of gestation, 14% (11-17). Prevalence decreased significantly with increasing birth weight (P < .0001) and increasing gestation (P < .0001). (2) SURGERY: 66 infants received surgical procedures; peritoneal drain in 13 (followed by laparotomy in 8) and in 53, laparotomy alone. (3) Mortality: 27 infants died with NEC of a total 283 deaths, thus, accounting for 9.5% of NICU mortality. Eight (30%) infants with NEC died without surgery.

CONCLUSIONS

Prevalence of NEC in the United Kingdom is high and comparable to published series in other countries from the 1990s. There may be a hidden mortality in patients who do not receive surgery.

Interval between clinical presentation of necrotizing enterocolitis and bowel perforation in neonates

OBJECTIVE

To define the interval between clinical presentation of necrotizing enterocolitis (NEC) and bowel perforation in neonates.

METHODS

Charts of neonates with discharge diagnosis of NEC (n = 124) from our NICU during 2004-2008 were retrospectively reviewed. Demographic data were collected. Acute episode of NEC was defined as the interval between clinical presentations to resumption of enteral feeds. Neonates are followed, as a standard of care, clinically and radiologically until resumption of enteral feeds at the discretion of the attending clinician. Abdominal radiograph results were reviewed serially to determine the interval between clinical presentation and bowel perforation using pneumoperitoneum as the surrogate radiological marker. Histological report of resected bowel specimens was reviewed for coagulative necrosis as evidence of NEC and to exclude spontaneous intestinal perforation (SIP). Neonates with stage 1 NEC and SIP were excluded from the results.

RESULTS

105 neonates with stage 2 NEC were included in the study. Forty-six needed surgical treatment (group 2) and 59 did not need surgery (group 1). Twenty-six (26/46, 56%) group 2 neonates had bowel perforation and hence required surgery. Pneumoperitoneum was noted at a median interval of 1 day after presentation of symptoms. Twenty neonates in group 2 needed surgery for clinical indications including worsening clinical examination, thrombocytopenia or persistent metabolic acidosis. Fifty-nine neonates (group 1) were treated with bowel rest, antibiotics and parenteral nutrition. Group 2 neonates were significantly more premature, weighed less and had less radiographs than group 1 neonates. Mortality was significantly higher in group 2 compared to group 1.

CONCLUSION

Bowel perforation occurs at a median interval of 1 day after clinical presentation of NEC. Neonates not needing surgery for their disease are exposed to significantly more radiographs than those needing surgery. Radiological evaluation can be safely minimized or eliminated after 2 days of presentation.

Therapeutic closure of the ductus arteriosus: benefits and limitations

Patency of the ductus arteriosus (PDA), a common complication of preterm birth, has been associated to increased risk for intraventricular cerebral hemorrhage, necrotizing enterocolitis, bronchopulmonary dysplasia and death. Consequently, prophylactic or curative treatment has been advocated before the critical left-to-right shunting occurs. A host of studies has shown that both pharmacological agents and surgical closure are effective in closing the ductus arteriosus in premature infants. Indomethacin has long been the drug of choice. However, renal and cerebral haemodynamic side effects have been frequently reported. Strategies to minimise adverse effects of indomethacin, such as the association with frusemide, dopamine or the use of low-dose prolonged treatment with indomethacin have failed or shown partial benefit. Other NSAIDs have been investigated. But either the profile of adverse effects was unfavourable, as in the case of mefenamic acid, or their efficacy was less than that of indomethacin for PDA closure. More recently, ibuprofen has been proposed for the treatment of PDA as it was shown to induce less adverse effects on cerebral blood flow, intestinal and renal hemodynamics, while retaining similar efficacy to indomethacin. However, since renal perfusion, GFR and diuresis in early neonatal life strongly depend on the vasodilator effects of PGs on the afferent glomerular arterioles, ibuprofen, as other COX-inhibitors may not be exempt of some renal undesirable effects. While numerous studies have shown that PDA is a risk factor associated with immaturity and with increased incidence of complications of preterm birth, including broncho-pulmonary dysplasia, retinopathy of prematurity, necrotizing enterocolitis and death, there is little evidence that such association is causative. Moreover, still little evidence exists from even recent randomized controlled trials that the pharmacological closure of PDA benefits to premature infants in terms of clinically significant short-term or medium-term outcomes, beyond a positive effect on DA patency. The use of COX-inhibitors for the prophylaxis or closure of PDA during the first hours or days of life should thus be cautious and based on an individual evaluation of benefit and risk. There is need of a randomized, placebo-controlled trials designed to assess the benefits in terms of mortality and morbidity outcomes of an early, or even very early pharmacological closure of PDA in extremely low gestational age infants.

Placental vascular obstructive lesions: risk factor for developing necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is a severe neonatal disease affecting particularly preterm infants. Its exact pathogenesis still remains unknown. In this study, we have compared the prevalence of vascular obstructive lesions in placentae of premature newborns which developed NEC and of a control group. We further compared separately the findings of placentae of infants of less than 30 weeks of gestation, the age group in which NEC occurs most frequently. We found signs of fetal vascular obstructive lesions in 65% of the placentae of preterm patients developing NEC, compared to only 17% of the placentae of preterm patients in the control group. In the age groups below 30 weeks of gestation, 58.5% of placentae of later NEC patients presented such lesions compared to 24.5% in the control group. The significant difference between NEC and control group suggests a strong association between fetal vascular obstructive lesions and NEC. Therefore, we propose that fetal vascular obstructive lesions might be considered as a risk factor for the development of NEC in premature infants.

An exclusively human milk-based diet is associated with a lower rate of necrotizing enterocolitis than a diet of human milk and bovine milk-based products

OBJECTIVE

To evaluate the health benefits of an exclusively human milk-based diet compared with a diet of both human milk and bovine milk-based products in extremely premature infants.

STUDY DESIGN

Infants fed their own mothers' milk were randomized to 1 of 3 study groups. Groups HM100 and HM40 received pasteurized donor human milk-based human milk fortifier when the enteral intake was 100 and 40 mL/kg/d, respectively, and both groups received pasteurized donor human milk if no mother's milk was available. Group BOV received bovine milk-based human milk fortifier when the enteral intake was 100 mL/kg/d and preterm formula if no mother's milk was available. Outcomes included duration of parenteral nutrition, morbidity, and growth.

RESULTS

The 3 groups (total n = 207 infants) had similar baseline demographic variables, duration of parenteral nutrition, rates of late-onset sepsis, and growth. The groups receiving an exclusively human milk diet had significantly lower rates of necrotizing enterocolitis (NEC; P = .02) and NEC requiring surgical intervention (P = .007).

CONCLUSIONS

For extremely premature infants, an exclusively human milk-based diet is associated with significantly lower rates of NEC and surgical NEC when compared with a mother's milk-based diet that also includes bovine milk-based products.

The Pediatrix BabySteps Data Warehouse and the Pediatrix QualitySteps improvement project system--tools for "meaningful use" in continuous quality improvement

The Pediatrix BabySteps Clinical Data Warehouse (CDW) is a rich and novel tool allowing unbiased extraction of information from an entire neonatal population care by physicians and advanced practice nurses in Pediatrix Medical Group. Because it represents the practice of newborn medicine ranging from small community intensive care units to some of the largest neonatal intensive care units in the United States, it is highly representative of scope of practice in this country. Its value in defining outcome measures, quality improvement projects, and research continues to grow annually. Now coupled with the BabySteps QualitySteps program for defined clinical quality improvement projects, it represents a robust methodology for meaningful use of an electronic health care record, as designated during this era of health care reform. Continued growth of the CDW should result in continued important observations and improvements in neonatal care.

Cluster of necrotizing enterocolitis in a neonatal intensive care unit: New Mexico, 2007

Background

Although the cause of necrotizing enterocolitis (NEC) is unknown, infection control practices have been shown to play an important role in containing many outbreaks. We investigated the etiology of a cluster of NEC in a level 3 neonatal intensive care unit and monitored for new cases following the implementation of enhanced infection control measures.

Methods

Investigators performed a chart and laboratory review for neonates with a diagnosis of NEC during January 1, 2007, to February 13, 2007, to identify risk factors. Enhanced environmental cleaning, cohorting of infants and nurses, and increased attention to hand hygiene were instituted. Commercial feeding products in the unit were tested for bacterial contamination. Close monitoring for new cases continued for 2 months following the identification of the cluster.

Results

Eleven cases of NEC were identified during the study period. Patients had a median of 5 disease risk factors (range, 3-8). Four distinct pathogens were detected in blood or stool specimens from 4 different patients. One sample of human milk fortifier (HMF) tested contained a colony count of Bacillus cereus at the US Food and Drug Administration's upper microbiologic limit for contamination. Seven (65%) patients received HMF before symptom onset, and 9 (82%) patients received 1 or more types of liquid formula. Only 1 new case was identified during the period of close monitoring.

Conclusion

A microbiologic cause was not identified, and, although the cluster might have resolved spontaneously, enhanced infection control and changing batches of HMF might have played a role in controlling this outbreak.

Antecedents of Bell stage III necrotizing enterocolitis

OBJECTIVE

New biopharmaceuticals hold promise for preventing or treating necrotizing enterocolitis. However, it is unclear whether any such biopharmaceutical that requires enteral administration could be administered using an 'early-treatment' paradigm. This study was undertaken to assess this issue based on data from every case of Bell stage III NEC cared for during the past 7 years at Intermountain Healthcare.

STUDY DESIGN

Patients with Bell stage III NEC were identified from electronic medical record repositories and the diagnosis was validated using operative reports. Electronic and paper records of each patient were then used to identify potential clinical and laboratory antecedents occurring within the 48 h period preceding the diagnosis of NEC.

RESULT

One hundred eighteen patients had Stage III NEC. The earliest recognized antecedents were nonspecific for NEC (apnea/bradycardia, skin mottling and irritability). These were recorded at 2.8+/-2.1, 4.5+/-3.1 and 5.4+/-3.7 (mean+/-s.d.) hours, respectively, before NEC was diagnosed. The most commonly identified gastrointestinal antecedents were blood in the stools, increased abdominal girth and elevated pre-feeding gastric residuals or emesis. These were identified 2.0+/-1.9, 2.8+/-3.1 and 4.9+/-4.0 h before NEC was recognized. Thirty-eight percent had a blood transfusion (18+/-12 h) preceding the NEC. Tachycardia, tachypnea, hypotension and diarrhea were rarely identified as antecedents and no consistent laboratory antecedents were discovered.

CONCLUSION

We judge that an 'early treatment of NEC' paradigm testing any pharmacological agent that must be administered enterally is not feasible. The first recognized antecedents of Bell stage III NEC are nonspecific for gastrointestinal pathology and insufficient time exists for dosing between the first gastrointestinal signs and placement of the gastric decompression tube.

Can we cut the incidence of necrotizing enterocolitis in half--today?

Necrotizing enterocolitis (NEC) is a common gastrointestinal emergency of neonates. Population studies estimate the incidence of NEC at between 0.3 and 2.4 per 1000 live births in the United States, with a predominance of cases among preterm neonates born at the earliest gestational ages. The disease burden of NEC includes an overall disease-specific mortality rate of 15-20%, with yet higher rates in those of earliest gestations. The NEC burden also includes an increase in hospital costs approximating $100,000/case, as well as severe late sequellae including parenteral nutrition-associated liver disease and short bowel syndrome. Differentiating NEC from other forms of acquired neonatal intestinal disease is critical to assessing the success of NEC prevention strategies. Promising new prevention strategies are now being tested; one such is prophylactic heparin-binding epidermal growth factor-like growth factor (HB-EGF) administration. However, two prevention strategies have already been shown in meta-analyses to reduce the incidence of NEC, but we speculate that these are not being fully utilized. They are; 1) implementing a written set of feeding guidelines (also called standardized feeding regimens) for newborn intensive care unit (NICU) patients, and 2) implementing programs to increase the availability of human milk for patients at risk of developing NEC.

Ontogeny of FOXP3(+) regulatory T cells in the postnatal human small intestinal and large intestinal lamina propria

FOXP3(+) regulatory T cells (Treg) suppress innate and adaptive immune responses and are critical for intestinal immune homeostasis. Our objective was to define the postnatal developmental regulation of Treg in relationship to other T cells in the human intestinal tract. We analyzed 41 small and 18 large intestinal paraffin-embedded tissue samples from preterm and term infants with and without necrotizing enterocolitis (NEC) for the presence of CD3(+), CD4(+), CD8(+), and FOXP3(+) cells by immunohistochemistry. We compared labeled cells against age, gestational age (GA), or (corrected) postmenstrual age (PMA). The GA ranged from 23 to 40 weeks, with a mean of 32 (standard deviation, 4.7) weeks. Independent of age, GA, or PMA, the numbers of CD4(+) cells were higher in the small intestine compared to the large intestine (P = 0.046), except in patients with NEC. FOXP3(+) cells could be detected as early as 23 weeks in GA in both large and small bowel, and similar quantities were detected at the highest GA examined (40 weeks). We saw no statistically significant effect of GA, age, or PMA on total number of FOXP3(+) cells or by comparing FOXP3(+) to CD4(+) or FOXP3(+) to CD8(+) ratios, indicating intact ontogeny of Treg in intestinal tissue early in gestation. Human infants exhibit presence of mucosal FOXP3(+) cells in the small and large intestinal mucosa at birth and as early as 23 weeks GA. The frequency of FOXP3(+) cells and the ratios of FOXP3(+) to CD4(+) or CD8(+) cells do not change with increasing intrauterine development or postnatal age.

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.

Epidemiology of necrotizing enterocolitis temporal clustering in two neonatology practices

OBJECTIVE

To develop a statistical method for defining clusters of necrotizing enterocolitis (NEC) cases in the neonatal intensive care unit (NICU).

STUDY DESIGN

The study group included 2782 infants weighing 401 to 1500 g at birth born between 1996 and 2004. NEC was defined as Bell stage II or III. Two statistical methods were used to define "disease clusters": a modified scan test and a comparison of observed and expected incidence density rates (IDRs) of NEC at each NICU.

RESULTS

The proportion of infants with NEC was similar in the 2 NICUs (7.1% vs 7.7%; P = .6), as was the expected IDR of NEC (1.39/1000 patient-days vs 1.32/1000 patient-days; P = .72). Twelve temporal clusters of NEC were identified in the 2 NICUs, representing 18% of 203 total NEC cases during the study period. No seasonal/secular trends were noted for NEC rates or identified clusters. Potential NEC clusters of > or =3 cases at either NICU had a >75% likelihood of being a true NEC cluster.

CONCLUSIONS

No operational definition of NEC cluster exists. This study introduces methods to use in prospective surveillance and to guide studies investigating etiologic relevance. Using the proposed methods, statistically significant clusters (ie, potential outbreaks) of NEC within NICUs can be identified early, providing an opportunity for early implementation of cluster investigation protocols.

Outcomes of the "clip and drop" technique for multifocal necrotizing enterocolitis

BACKGROUND

The "clip and drop" (CD) has been proposed as a useful strategy in the management of severe multifocal necrotizing enterocolitis (NEC). There is little published data on clinical outcomes after this intervention. We report a 2-center experience with this technique.

METHODS

A retrospective review of infants who underwent CD between 1998 and 2006 at 2 tertiary pediatric surgery centers. Data recorded included intestinal resections, interval between laparotomies, anastomoses at subsequent surgery, time to full feeds, and complications including mortality. Data are reported as median with ranges.

RESULTS

Thirteen infants (7 male, 6 female) with a birth weight of 811 (514-2110) g underwent CD of up to 5 bowel segments. In 8 of 9 early survivors, all CD segments were viable. Six patients (46%) were alive at 29 (9-96) months. Survivors underwent 4 (3-4) laparotomies and 4 (2-6) bowel anastomoses and had intestinal continuity restored at 67 (51-162) days.

CONCLUSIONS

With multiple interventions, half the infants in this high-risk group survived and achieved full enteral feeds. The CD is a valuable technique in a selected group of infants with fulminant NEC.

Risk factors for necrotizing enterocolitis in preterm infants: how race, gender, and health status contribute

PURPOSE

To examine 5 infant characteristics and health factors that might be risk factors for necrotizing enterocolitis (NEC) in preterm infants.

SUBJECTS

One hundred thirty-four preterm infants at high risk for NEC because of either having a birth weight of <1500 g or requiring mechanical ventilation at birth.

DESIGN

Descriptive secondary analysis using data from a larger longitudinal study.

METHODS

Weekly review of infants' medical record until discharge; demographic questionnaire completed by mothers at the time of enrollment; and data analysis done with logistic regression, Fischer's exact tests, and correlations.

OUTCOME MEASURES

Total number of days the infant required mechanical ventilation, birth weight in grams, number of infections prior to NEC diagnosis, maternal race (black, white, or Asian), and infant gender were used to predict the development of NEC.

RESULTS

Maximum likelihood estimates indicated that mechanical ventilation had a positive relationship with developing NEC, such that as the number of days of mechanical ventilation increased so did the risk of developing NEC. There was also a very strong positive relationship between the number of nosocomial infections and NEC, indicating that as the number of infections increased, the likelihood of developing NEC increased. Although the relationship between race and NEC was not significant in the logistic regression, the Fisher exact test showed that black preterm infants had increased incidence of NEC as compared with other races. This relationship was not due to correlations between race and mechanical ventilation or infections. No relationship between gender and NEC was noted. Birth weight was not significantly associated with NEC in the logistic regression but was correlated with NEC, probably because of its correlation with mechanical ventilation and number of infections.

CONCLUSIONS

In this sample, number of infections and length of mechanical ventilation were the primary predictors of NEC in preterm infants. In addition, the frequency that black infants are diagnosed with NEC is significantly higher than that of other races. Knowledge of risk factors for NEC can allow healthcare providers to evaluate and adjust care practices for preterm infants who present with higher risk for NEC on the basis of empirical data.

Necrotizing enterocolitis during the first week of life: a multicentered case-control and cohort comparison study

OBJECTIVE

Necrotizing enterocolitis (NEC) is rare during the first week of life; most cases occur after 2 to 4 weeks. We hypothesized that when NEC develops in the first week, certain predisposing factors and feeding practices are identifiable. To test this, we sought to identify every case of NEC diagnosed during the first week within the Intermountain Healthcare system during the most recent 6-year period.

STUDY DESIGN

Data were collected from neonates admitted to any Intermountain Healthcare neonatal intensive care unit (NICU) with a date of birth from 1 January 2001 through 31 December 2006. Electronic and paper records were obtained for all with a diagnosis of NEC (Bell stage >or=II) within the first 168 h. X-rays, physician notes, nursing records, laboratory reports and operative reports were subjected to critical review to reexamine the diagnosis of NEC. Among those with confirmed NEC, we recorded underlying conditions and every feeding given prior to the diagnosis of NEC. Comparisons were made with patients that did not develop NEC, yet were cared for in the same NICUs, during the same period of time, and of the same gestational ages.

RESULT

A total of 28 neonates were identified electronically as having NEC during the first week. Critical review confirmed this in 21, but 5 were determined at laparotomy to have had spontaneous intestinal perforation, and 2 others were found on surgical reports to have had a congenital infarction of the colon. Total 20 of the 21 confirmed cases developed NEC while in a NICU being treated for another condition. The exception was a small-for-gestational-age neonate in a well baby nursery. Compared to 6100 controls, the 21 with early NEC were more likely to have had a meconium-positive test for illicit drug exposure (P<0.005), early onset sepsis (P<0.034) and respiratory distress (P<0.039). They were less likely than case-controls to have been fed human milk (P=0.003) and were more likely to have been fed formula exclusively (P=0.019). None who were fed human milk exclusively developed early NEC. Twelve of the twenty-one were fed (by gavage or bottle) amounts exceeding the upper limit of volumes taken by breastfed neonates.

CONCLUSION

We speculate that the prevalence of NEC during the first week could be reduced by identifying at-risk patients, feeding them human milk exclusively for the first week and using feeding volumes that do not exceed that taken by healthy breastfed neonates.

Radiologists' agreement when using a 10-point scale to report abdominal radiographic findings of necrotizing enterocolitis in neonates and infants

OBJECTIVE

The purpose of this study was to evaluate radiologists' agreement when using a 10-point scale of abnormal findings designed to standardize reporting of abdominal radiographs in neonates or infants with suspected necrotizing enterocolitis.

MATERIALS AND METHODS

A 10-point scale of radiographic findings was devised at our institution and was in use for approximately 18 months before the initiation of this study. After institutional review board approval, 88 abdominal radiographs (anteroposterior and cross-table lateral) were randomly selected for review, allowing for an equal distribution of examinations throughout the scale according to the original examination report. The mean age of the patients in the total study population was 24.9 days (range, 0-56 days); 61 patients (47.3%) were girls and 68 (52.7%) were boys. Four pediatric radiologists having 20, 13, 7, and 5 years of experience scored images twice at least 4 weeks apart according to the scale, which was designed to characterize certainty and severity of disease in neonates and infants with possible necrotizing enterocolitis. Interobserver and intraobserver agreement was assessed by applying weighted kappa statistics. Operative and pathology reports were reviewed.

RESULTS

The average intraobserver weighted kappa value was 0.792 (SD, 0.025; range, 0.635-0.946). The average interobserver weighted kappa value was 0.665 (SD, 0.035, range, 0.574-0.898).

CONCLUSION

Substantial intraobserver and interobserver agreement was found when radiologists used a 10-point scale to report abnormal findings on abdominal radiographs in neonates or infants with suspected necrotizing enterocolitis. This scale warrants further evaluation as a potentially useful clinical tool.

Low mortality in necrotizing enterocolitis associated with coagulase-negative Staphylococcus infection

The aim of this study was to correlate the clinical course of necrotizing enterocolitis (NEC) with infection by coagulase-negative Staphylococcus at the onset of the illness. Records of all newborn infants developing NEC between January 1998 and December 2001 were reviewed. NEC was classified according to the criteria of Bell et al. Numeric variables were described by standard statistical methods. Comparisons between subgroups were performed by parametric statistical tests. Forty-four patients developed NEC stage II (n = 25) or III (n = 19). The incidence was 0.024% of live births in the hospital, and the mortality rate was 9%. The main risk factor was prematurity (84%). Only one-fourth of the patients had gastric residuals. A platelet count of <100,000 cells/mm3 occurred only in grade III NEC. Blood cultures were positive in 34% of the patients. The predominant organism (73%) was coagulase-negative Staphylococcus (CoNS). Neither Clostridium nor Bacteroides species were isolated. Stage II patients were maintained nothing per os (NPO) for 9 +/- 3 days and received antibiotics for 10 +/- 3 days. All of the stage III patients required an operation. In one-third of them, primary peritoneal drainage was initially performed but all required further operative procedures. We report a low incidence and mortality rate of necrotizing enterocolitis. Thrombocytopenia is confirmed as a marker of severity. Positive blood cultures for CoNS may explain, at least in part, the low mortality reported.

Comparison of epidermal growth factor and heparin-binding epidermal growth factor-like growth factor for prevention of experimental necrotizing enterocolitis

BACKGROUND

Necrotizing enterocolitis (NEC) is a devastating gastrointestinal disease of prematurely born infants. Epidermal growth factor (EGF) and heparin-binding EGF-like growth factor (HB-EGF) have protective effects against intestinal injury. The aim of this study was to compare the effect of oral administration of HB-EGF, EGF, or both on the incidence of NEC in a neonatal rat model.

MATERIALS AND METHODS

Premature rats were fed by hand and exposed to asphyxia and cold stress to develop NEC. Four diets were used: formula (NEC), formula supplemented with 500 ng/mL HB-EGF (HB), 500 ng/mL EGF (EGF), or a combination of both (E+HB). Ileal injury, endogenous HB-EGF production, expression of EGF receptors, goblet cell density, and expression of apoptotic proteins were evaluated.

RESULTS

Oral administration of either EGF or HB-EGF significantly reduced the incidence of NEC; however, EGF provided better protection in physiologically relevant doses. Simultaneous administration of both growth factors did not result in any synergistic protective effect against NEC. There were no significant differences between treatment groups in ileal gene expression of EGF receptors or HB-EGF. However, the balance of apoptotic proteins in the ileum was shifted in favor of cell survival in EGF-treated rats. This mechanism may be responsible for the higher efficiency of EGF protection against NEC.

CONCLUSIONS

These data suggest that a physiological dosage of EGF or a pharmacological dosage of HB-EGF could be used for prevention of NEC.

Probiotics for the prevention of necrotizing enterocolitis

Necrotizing enterocolitis (NEC) remains a significant cause of morbidity and mortality for low birth weight premature infants. Prematurity, ischemia, formula feeding, and bacterial colonization are risk factors for the self-perpetuating cycle of damaged intestinal epithelia, inflammation, bacterial entry, sepsis, and shock that characterizes NEC. Probiotics are food supplements containing live bacteria that benefit the recipient by improving the microflora balance within the intestine. Several studies suggest that the administration of probiotics may have a prophylactic effect for NEC and may reduce morbidity and mortality rates for low birth weight infants.

Neonatal necrotizing enterocolitis

Necrotizing enterocolitis (NEC) remains a major cause of morbidity and death in neonates. The 30% to 50% mortality rate for NEC with perforation has not changed appreciably in the past 30 years. The critical relevant outcomes following NEC include survival, gastrointestinal function, and neurodevelopmental status. In each of these areas, initial anecdotal and case-series analysis has been followed by studies using more sophisticated methods of analysis. The single most important predictor of outcome, besides gestational age, is whether or not the disease has progressed to the point requiring surgical intervention. Patients with NEC requiring operation have a high mortality. Moreover, the vast majority of morbidity following NEC occurs in the patients who survive following operation. The purpose of this review is to examine the evolution of evidence regarding outcomes for patients with NEC and to provide an update on our current state of knowledge.

Slow advancement of enteral feed volumes to prevent necrotising enterocolitis in very low birth weight infants

BACKGROUND

The major modifiable risk factors for necrotising enterocolitis in very low birth weight infants relate to enteral feeding regimens. Observational studies suggest that conservative feeding regimens such as delaying the introduction of enteral feeds or slowly advancing feed volumes reduce the risk of necrotising enterocolitis

OBJECTIVES

To determine the effect of slow rates of enteral feed advancement on the incidence of necrotising enterocolitis, mortality and other morbidities in very low birth weight infants.

SEARCH STRATEGY

The standard search strategy of the Cochrane Neonatal Group was used. Searches were made of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 4, 2007), MEDLINE (1966 - December 2007), EMBASE (1980 - December 2007), CINAHL (1982- December 2007), conference proceedings, and previous reviews.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials that assessed the effect of slow (up to 24 ml/kg/day) versus faster rates of advancement of enteral feed volumes upon the incidence of necrotising enterocolitis in very low birth weight infants.

DATA COLLECTION AND ANALYSIS

The standard methods of the Cochrane Neonatal Group were used, with separate evaluation of trial quality and data extraction by two authors. Data were synthesised using a fixed effects model and reported using typical relative risk, typical risk difference and weighted mean difference.

MAIN RESULTS

Three randomised controlled trials in which a total of 396 infants participated were identified. Few participants were extremely low birth weight or growth restricted. The trials were generally of good methodological quality but caregivers and investigators were aware of the allocated interventions. Meta-analyses did not detect statistically significant effects on the risk of necrotising enterocolitis [typical relative risk 0.96 (95% confidence interval 0.48 to 1.92); typical risk difference 0.00 (95% confidence interval -0.05 to 0.05)] or all cause mortality [typical relative risk 1.40 (95% confidence interval 0.71 to 2.80); typical risk difference 0.03 (95% confidence interval -0.03 to 0.10)]. Infants who had slow rates of feed volume advancement took longer to regain birth weight [reported median difference between two and five days] and to establish full enteral feeding [reported median difference between three and five days]. No statistically significant effect on the total duration of hospital stay was detected.

AUTHORS' CONCLUSIONS

The currently available data do not provide evidence that slow advancement of enteral feed volumes reduces the risk of necrotising enterocolitis in very low birth weight infants. Increasing the volume of enteral feeds at slow rather than faster rates results in several days delay in regaining birth weight and establishing full enteral feeds but the long-term clinical importance of these effects is unclear. Further randomised controlled trials are needed to determine how the rate of daily increment in enteral feed volumes affects important clinical outcomes in very low birth weight infants, and particularly in extremely low birth weight or growth restricted infants.

Necrotizing enterocolitis: recent scientific advances in pathophysiology and prevention

Necrotizing enterocolitis (NEC) is a leading cause of morbidity and mortality among infants in the neonatal intensive care unit. Here we review the epidemiology and pathophysiology of NEC, with an emphasis on the latest research findings and potential areas for future research. NEC continues to be one of the most devastating and unpredictable diseases affecting premature infants. Despite decades of research, the pathogenesis of this disease remains unclear, and prevention and treatment strategies are limited. Hopefully, future studies aimed at understanding premature intestinal defenses, commensal or probiotic bacterial influences, and possible genetic predisposition will lead to the improvement of prevention and treatment strategies.

Surgical management of necrotizing enterocolitis and isolated intestinal perforation in premature neonates

Necrotizing enterocolitis (NEC) and isolated intestinal perforation (IP) are two relatively common disease conditions that require neonatal surgical therapy. The early mortality rate approaches 50%, and survivors frequently have growth and neurodevelopmental impairment. Much discussion has occurred regarding whether initial drain placement alone or laparotomy with resection of diseased intestine should be the initial surgical therapy. Several recent prospective studies have shown that the early mortality rate is likely not significantly different after either of these surgical approaches. Major morbidity, especially the likelihood for neurodevelopmental impairment, may be different in the two treatment groups. Further prospective trials are needed to further explore this question and are planned. Studies focusing on prevention of NEC and IP and also on improved medical treatment are needed to allow a major advance in the outcomes of infants with NEC and IP. As these studies are being performed, trials evaluating existing medical and surgical therapies are also needed.

Necrotizing enterocolitis

In necrotizing enterocolitis (NEC) the small (most often distal) and/or large bowel becomes injured, develops intramural air, and may progress to frank necrosis with perforation. Even with early, aggressive treatment, the progression of necrosis, which is highly characteristic of NEC, can lead to sepsis and death. This article reviews the current scientific knowledge related to the etiology and pathogenesis of NEC and discusses some possible preventive measures.

Metaanalysis of the effect of antenatal indomethacin on neonatal outcomes

OBJECTIVE

The objective of the study was to determine whether indomethacin used as a tocolytic agent is associated with adverse neonatal outcomes.

STUDY DESIGN

We used published guidelines of the Metaanalysis of Observational Studies in Epidemiology Group (MOOSE) to perform the metaanalysis. The search strategy used included computerized bibliographic searches of MEDLINE (1966-2005), PubMed (1966-2005), abstracts published in Obstetrics and Gynecology (1991-2005), abstracts published in Pediatric Research (1991-2005), and references of published manuscripts. Study inclusion criteria were publication in English, more than 30 deliveries less than 37 weeks' gestation, and meeting diagnostic criteria for individual neonatal outcomes. Exclusion criteria included case reports, case series, and multiple publications from the same author. Metaanalysis was performed using random effects model if there were more than 2 observational studies for a specific outcome. Eggers test was performed to exclude publication bias. Sensitivity analysis was performed to evaluate the effect of antenatal steroid exposure, gestation, and recent antenatal indomethacin exposure (duration of 48 hours or more between the last dose and delivery).

RESULTS

Fifteen retrospective cohort studies and 6 case-controlled studies met inclusion criteria. Antenatal indomethacin was associated with an increased risk of periventricular leukomalacia (odds ratio [OR], 2.0; 95% confidence interval [CI], 1.3-3.1). Recent exposure to antenatal indomethacin was associated with necrotizing enterocolitis (OR, 2.2; 95% CI; 1.1-4.2). Antenatal indomethacin was not associated with intraventricular hemorrhage, patent ductus arteriosus, respiratory distress syndrome, bronchopulmonary dysplasia, and mortality.

CONCLUSION

Antenatal indomethacin may be associated with an increased risk of periventricular leukomalacia and necrotizing enterocolitis in premature infants and therefore should be used judiciously for tocolysis.

Molecular signaling in necrotizing enterocolitis: regulation of intestinal COX-2 expression

Necrotizing enterocolitis (NEC) is the most common surgical emergency in premature infants. The underlying etiology of NEC remains unknown, although bacterial colonization of the gut, formula feeding, and perinatal stress have been implicated as putative risk factors. The disease is characterized by exuberant gut inflammation leading to ischemia and coagulation necrosis of the intestinal epithelium. The molecular and cellular mechanisms responsible for these pathologic changes are poorly understood. It has been shown that various exogenous and endogenous mediators such as lipopolysaccharide, inflammatory cytokines, platelet activating factor, and nitric oxide may play a role in the pathogenesis of NEC. Recent studies in our laboratory and others have established a link between NEC and activation of cyclooxygenase-2, the enzyme that catalyzes the rate-limiting step in the biosynthesis of prostanoids. The challenge is in defining the molecular signaling pathways leading to accumulation of these mediators early in the disease progression, before the onset of tissue necrosis and systemic sepsis. Identification and characterization of these pathways could lead to the development of novel treatment strategies to alleviate the morbidity and mortality associated with NEC.

Early human milk feeding is associated with a lower risk of necrotizing enterocolitis in very low birth weight infants

BACKGROUND

Necrotizing enterocolitis (NEC) is a frequent cause of mortality and morbidity in very low birth weight (VLBW) infants. Human milk (HM) feeding has been associated with lower risk of NEC. However, mothers of VLBW infants often experience insufficient milk production, resulting in mixed feedings of HM and formula. Moreover, medical complications often limit the volume of feeding they can be given.

OBJECTIVE

To determine if high proportions of (50% or greater) HM enteral feeding within the first 14 days of life are protective against NEC.

METHOD

This was a prospective cohort study of VLBW infants who were grouped according to the HM proportion of enteral feeding in the first 14 days: <50% (low human milk, LHM, n=46) and > or =50% (high human milk, HHM, n=156). The outcome of interest was development of NEC (Bell stage 2 or 3). Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) and to assess potential confounding due to perinatal risk factors.

RESULT

Two hundred and two infants were studied. Confirmed NEC occurred in 5/46 (10.6%) of the LHM group, as compared with 5/156 (3.2%) of the HHM. Gestational age was the only perinatal factor associated with risk of NEC. After adjustment for gestational age, HHM was associated with a lower risk of NEC ((OR=0.17, 95% CI: 0.04 to 0.68), P=0.01).

CONCLUSION

Enteral feeding containing at least 50% HM in the first 14 days of life was associated with a sixfold decrease in the odds of NEC.

Ontogeny of salivary epidermal growth factor and necrotizing enterocolitis

OBJECTIVE

To examine the ontogeny of salivary epidermal growth factor (sEGF) in premature infants and to determine the relation of sEGF to the development of necrotizing enterocolitis (NEC).

STUDY DESIGN

Salivary EGF was prospectively measured in 327 infants with gestational ages from 23 weeks to term. Infants of < or = 32 weeks' gestation (n = 261) were followed with weekly sEGF measurements through 3 weeks of life. Multivariable regression analyses were used to determine variables significantly related to sEGF levels and to identify predictors of NEC.

RESULTS

Over the first 3 weeks of life, sEGF increased across gestational age and postnatal age categories. In multivariable models, gestational age was a significant predictor of sEGF levels (P < .009). In a cohort of 27 infants who had NEC, gestational age, race, and changes in sEGF levels between weeks of life 1 and 2 were predictive of the development of NEC. These infants had lower sEGF at week 1 and greater increases from week 1 to week 2 compared with infants without NEC.

CONCLUSIONS

There is a positive relation between sEGF levels and gestational age. Patterns of sEGF levels over the first 2 weeks of life were significantly related to development of NEC in very low birth weight infants.

Necrotizing enterocolitis: a practical guide to its prevention and management

Neonatal necrotizing enterocolitis is the second most common cause of morbidity in premature infants and requires intensive care over an extended period. Despite advances in medical and surgical techniques, the mortality and long-term morbidity due to necrotizing enterocolitis remain very high. Recent advances have shifted the attention of researchers from the classic triad (ischemia, bacteria, and the introduction of a metabolic substrate into the intestine) of necrotizing enterocolitis, to gut maturation, feeding practices, and inflammation. The focus on inflammation includes proinflammatory cytokines such as tumor necrosis factor-alpha, interleukin (IL)-6, IL-18, and platelet-activating factor. Research related to the etiology of necrotizing enterocolitis has moved quickly from clostridial toxin to bacterial and other infectious agents. More recently, the pattern of bacterial colonization has been given emphasis rather than the particular species or strain of bacteria or their virulence. Gram-negative bacteria that form part of the normal flora are now speculated as important factors in triggering the injury process in a setting where there is a severe paucity of bacterial species and possible lack of protective Gram-positive organisms. Although the incidence of necrotizing enterocolitis has increased because of the survival of low birthweight infants, clinicians are more vigilant in their detection of the early gastrointestinal symptoms of necrotizing enterocolitis; however, radiographic demonstration of pneumatosis intestinalis remains the hallmark of necrotizing enterocolitis. With prompt diagnosis, a large proportion of infants with necrotizing enterocolitis are now able to be managed medically with intravenous fluid and nutrition, nasogastric suction, antibacterials, and close monitoring of physiologic parameters. In the advanced cases that require surgery, clinicians tend to opt for either simple peritoneal drainage (for very small and sick infants) or laparotomy and resection of the affected part. Intestinal transplantation later in life is available as a viable option for those who undergo resection of large segments of the intestine. It is becoming more evident that treatment of this devastating disease is expensive and comes with the toll of significant long-term sequelae. This has resulted in renewed interest in designing alternative strategies to prevent this serious gastrointestinal disease. Simple trophic feeding and the use of L-glutamine and arginine are novel avenues that have been examined. The use of probiotics ('friendly' bacterial flora) has been introduced as a promising tool for establishing healthy bacterial flora in the newborn gut to block the injury process that may ultimately lead to necrotizing enterocolitis.

Observational study to compare the clinical efficacy of the natural surfactants Alveofact and Curosurf in the treatment of respiratory distress syndrome in premature infants

INTRODUCTION

Natural surfactants have been shown to be superior to synthetic surfactants in the treatment of neonatal respiratory distress syndrome (RDS). In Germany, Alveofact (A) and Curosurf (C) are the most frequently used natural surfactant preparations. The aim of this retrospective, observational study was to compare the effects of A and C on gas exchange and outcome in premature infants.

METHODS

During a 5-year period in our neonatal intensive care unit (NICU), 187 premature infants were treated with surfactant, with 82 receiving A and 105 receiving C. We recorded F(I)O(2) and gas exchange (PaO(2)/F(I)O(2) ratio, PaCO(2), SaO(2)) during the first 72h after surfactant application and the incidence of outcome parameters at day 28 (bronchopulmonary dysplasia (BPD), intraventricular hemorrhage (IVH grade III or IV), patent ductus arteriosus (PDA), pneumothorax, necrotizing enterocolites (NEC) and death). The differences between the patient groups were assessed by ANOVA or the calculation of relative risks. Bonferroni correction was used for multiple comparisons.

RESULTS

There were no statistically significant differences between infants treated with A and C in mean gestational age (28.4 vs. 28.4 weeks), birth weight (1210 vs.1258 g) and time of first surfactant application (60 vs. 90 min postnatal). We observed no significant between group differences in course of F(I)O(2) and blood gases, or in incidence at day 28 of BPD (41.7% vs. 42.8%), IVH III/IV (18.3% vs. 14.3%), pneumothorax (9.8% vs. 4.8%), PDA (23.2% vs. 21.9%), PVL (7.3% vs. 9.5%) and death (17% vs. 17.1%). There were also no statistically significant differences in the subgroup of infants <28 weeks. The lower incidence of NEC in A compared with C (1.2% vs. 10.5%, P=0.01) was not statistically significant after Bonferroni correction.

CONCLUSION

Independent of gestational age no significant difference in the clinical efficacy of A and C was observed.

A simple presurgical necrotizing enterocolitis-mortality scoring system

OBJECTIVE

To assess the relationship between early laboratory parameters, disease severity, type of management (surgical or conservative) and outcome in necrotizing enterocolitis (NEC).

STUDY DESIGN

Retrospective collection and analysis of data from infants treated in a single tertiary care center (1980 to 2002). Data were collected on disease severity (Bell stage), birth weight (BW), gestational age (GA) and pre-intervention laboratory parameters (leukocyte and platelet counts, hemoglobin, lactate, C-reactive protein).

RESULTS

Data from 128 infants were sufficient for analysis. Factors significantly associated with survival were Bell stage (P<0.05), lactate (P<0.05), BW and GA (P<0.01, P<0.001, respectively). From receiver operating characteristics curves, the highest predictive value resulted from a score with 0 to 8 points combining BW, Bell stage, lactate and platelet count (P<0.001). At a cutoff level of 4.5 sensitivity and specificity for predicting survival were 0.71 and 0.72, respectively.

CONCLUSION

Some single parameters were associated with poor outcome in NEC. Optimal risk stratification was achieved by combining several parameters in a score.

Necrotising enterocolitis

Necrotising enterocolitis is one of the most common gastrointestinal emergencies in newborn infants. Here we review the epidemiology, clinical presentation, and pathophysiology of the disease, as well as strategies for diagnosis, management, and prevention. Necrotising enterocolitis is one of the most devastating and unpredictable diseases affecting premature infants. Despite decades of research, its pathogenesis remains unclear; diagnosis can be difficult; and treatment is challenging. We will need to improve our understanding of intestinal defences in premature infants, dietary and bacterial factors, and genetic effects that could predispose infants to necrotising enterocolitis before we can develop new strategies for prevention and treatment.

Surgical necrotizing enterocolitis and intraventricular hemorrhage in premature infants below 1000 g

BACKGROUND/PURPOSE

Infants with very low birth weight are at increased risk for both intraventricular hemorrhage (IVH) and necrotizing enterocolitis (NEC). IVH often progresses in severity after initial diagnosis and causes severe neurological morbidity and mortality. The authors examined the role of NEC in the progression of IVH in these infants.

METHODS

The authors conducted a retrospective case-control study using data from the University of Maryland neonatal intensive care unit database between 1991 and 2003. From a cohort of 957 infants with very low birth weight, 53 pairs of infants labeled as IVH progression versus controls were selected and closely matched in respect to their gestational age and birth weight. Charts from these infants were reviewed to identify risk factors contributing to IVH progression.

RESULTS

Infants with IVH progression were significantly more likely to suffer from NEC (odds ratio, 3.6), whereas infants with surgical NEC showed a greater association with IVH progression (odds ratio, 5.33). Association with thrombocytopenia was also seen (odds ratio, 3.33). Sepsis showed trend toward significance (odds ratio, 1.9; P = .095) for progression of IVH.

CONCLUSION

Surgical NEC showed the greatest risk for IVH progression. NEC and thrombocytopenia also appear to be risk factors for IVH progression.

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.

Reported medication use in the neonatal intensive care unit: data from a large national data set

OBJECTIVES

The objectives were (1) to identify the drugs reported most commonly during NICU care, (2) to examine how different methods of documenting drug use could influence prioritization of drugs for future research aimed at evaluating safety and efficacy, (3) to describe the demographic differences in the population samples for some specific medications, (4) to identify which reported medications are used for patient populations with >20% mortality rates, and (5) to examine how reports of drug use change over time.

METHODS

A retrospective review of a large national data set was performed.

RESULTS

The 10 medications reported most commonly for the NICU were ampicillin, gentamicin, ferrous sulfate, multivitamins, cefotaxime, caffeine citrate, furosemide, vancomycin, surfactant, and metoclopramide. Medications used for patient populations with >20% mortality rates included amphotericin, clonazepam, dobutamine, epinephrine, ethacrynic acid, insulin, lidocaine, metolazone, milrinone, inhaled nitric oxide, nitroglycerin, octreotide, pancuronium, phenytoin, sodium nitroprusside, sodium polystyrene sulfonate (Kayexalate), tris-hydroxymethylaminomethane acetate buffer, and tolazoline. Several of these drugs (eg, amphotericin B and bumetanide) were used primarily for extremely premature neonates, and this usage might explain the high mortality rates for the population of neonates treated with these medications. Other medications (clonazepam, milrinone, inhaled nitric oxide, and phenytoin) were used primarily for near-term and term infants. The explanation for the high mortality rates for these neonates is less clear and may be related primarily to the severity of illness for which the medications are used. Utilization rates for several different medications (eg, cisapride, metoclopramide, and dexamethasone) changed by >50% during the past 5 years.

CONCLUSIONS

Data reported here are the first from a large national data set on the use of different medications for neonates admitted for intensive care and should be helpful in establishing priority agendas for future drug studies in this population.

Acute systemic complications in the preterm fetus after asphyxia: role of cardiovascular and blood flow responses

1. Poor perfusion of the kidneys and gut, and associated functional impairment, are major problems in the first days of life in very preterm infants. These complications can be associated with a substantial mortality and further problems such as reduced kidney growth and chronic renal problems in later childhood. 2. There is very little information, and consequently considerable debate, about how or even whether to improve perfusion of the vital organs of this most vulnerable group of babies. Current treatments simply do not consistently improve babies' perfusion generally or kidney and gut perfusion and function in particular. 3. In this review we critically examine clinical and experimental evidence that suggests that exposure to low oxygen levels before and during birth may be a significant contributor to impaired systemic perfusion, and highlight areas requiring further research. 4. This knowledge is essential to develop and refine ways of improving perfusion of the kidneys and other vital organs in premature babies.

New insights into spontaneous intestinal perforation using a national data set: (2) two populations of patients with perforations

BACKGROUND

Spontaneous intestinal perforation (SIP) is increasingly common in the premature infant and has been demonstrated to be associated with early postnatal administration of glucocorticoids and indomethacin. Before survival of the extremely low birth weight (ELBW) infant, SIP was thought to be a rare, congenitally acquired disease sporadically affecting the muscularis of the distal intestine. These disparate views of etiology have not been previously reconciled in the literature.

OBJECTIVES

(1) To establish a cohort of SIP patients in a national data set. (2) To use timing of diagnosis as a unique data element and thereby differentiate between SIP cases which are susceptible to postnatal risk factors versus those occurring at or immediately after birth (and therefore not exposed to postnatal risk factors).

METHODS

A large identified national data set was used to retrospectively look at timing of diagnosis and then the cohort was divided into postnatal treatment groups for further subanalyses. This analysis resulted in the division of the cohort into early and late diagnosis SIP subcohorts. These were then queried retrospectively by univariate analysis to look for differences in demographics between the two (using a P-value < 0.05).

RESULTS

There were 633 patients with SIP evaluated in this data set. The early SIP cohort (0-3 days) was made up of 116 infants with a median BW of 1.401 kg, whereas the late cohort (4-14 days) held 386 infants with a median BW of 775 g. Infants with early SIP were significantly more likely to: be male, have higher Apgar scores, have not received antenatal steroids, surfactant or required mechanical ventilation.

CONCLUSIONS

Two populations of infants acquire SIP: ELBW infants acquire SIP on average between 7 and 10 days of life after exposure to indomethacin and glucocorticoids (either endogenous or exogenous), and infants with early SIP (0-3 days) who are significantly less likely to have been exposed to postnatal risk factors and are less premature.