Randomized trial of "slow" versus "fast" feed advancements on the incidence of necrotizing enterocolitis in very low birth weight infants

Association of necrotizing enterocolitis with anemia and packed red blood cell transfusions in preterm infants

OBJECTIVE

To determine association of anemia and red blood cell (RBC) transfusions with necrotizing enterocolitis (NEC) in preterm infants.

STUDY DESIGN

A total of 111 preterm infants with NEC ≥ stage 2a were compared with 222 matched controls. In all, 28 clinical variables, including hematocrit (Hct) and RBC transfusions were recorded. Propensity scores and multivariate logistic regression models were created to examine effects on the risk of NEC.

RESULT

Controlling for other factors, lower Hct was associated with increased odds of NEC (odds ratio (OR)=1.10, P=0.01). RBC transfusion has a temporal relationship with NEC onset. Transfusion within 24 h (OR=7.60, P=0.001) and 48 h (OR=5.55, P=0.001) has a higher odds of developing NEC but this association is not significant by 96 h (OR=2.13, P=0.07), post-transfusion.

CONCLUSION

Anemia may increase the risk of developing NEC in preterm infants. RBC transfusions are temporally related to NEC. Prospective studies are needed to better evaluate the potential influence of transfusions on the development of NEC.

Risk Factors That May Predispose Premature Infants to Increased Incidence of Necrotizing Enterocolitis

The objective of this study was to determine if there are any common “risk factors” that could assist clinicians in identifying premature infants who are at greater risk for developing necrotizing enterocolitis (NEC). This was a retrospective study of infants admitted to the neonatal intensive care unit at Children’s Hospital of Illinois, Peoria. In total, 384 charts were reviewed. Seventy-eight infants diagnosed with NEC were compared to 246 infants who did not have NEC. Maternal risk factors, infant demo-graphics, incidence of sepsis, H2 blockers prescribed, temperature, anemia, and day-of-life gut priming and enteral feedings were compared between the two groups for significant differences. Univariate tests and logistic regression demonstrated that mothers of infants who developed NEC had a higher incidence of premature rupture of membranes. Significantly more males developed NEC than females. African American infants had a higher incidence of developing NEC than white infants. Infants who developed NEC often had a prior diagnosis of sepsis and were prescribed H2 blockers more frequently. Infants who had early initiation of gut priming and earlier initiation of enteral feedings had significantly less incidence of NEC than infants whose gut priming and enteral feedings were delayed. This study supports that risk factors for NEC are multifactorial and could assist clinicians in identifying subgroups, within the neonatal population, that are at greater risk for this disease, leading to the implementation of strategies to reduce the onset of NEC. Unfortunately, the true etiology of NEC remains unclear.

Slow versus rapid enteral feeding advancement in preterm newborn infants 1000-1499 g: a randomized controlled trial

AIM

To evaluate whether preterm neonates weighing 1000-1499 g at birth receiving rapid enteral feeding advancement at 30 mL/kg/day attain full feedings (180 mL/kg/day) earlier than those receiving slow enteral feeding advancement at 20 mL/kg/day without increase in the incidence of feeding intolerance or necrotizing enterocolitis.

METHODS

A total of 100 stable intramural neonates weighing between 1000 and 1499 g and gestational age less than 34 weeks were randomly allocated to enteral feeding (expressed human milk or formula) advancement of 20 mL/kg/day (n = 50) or 30 mL/kg/day (n = 50).

RESULTS

Neonates in the rapid feeding advancement group achieved full volume feedings before the slow advancement group (median 7 days vs. 9 days) (p < 0.001), had significantly fewer days of intravenous fluids (median 2 days vs. 3.4 days) (p < 0.001), shorter length of stay in hospital (median 9.5 days vs. 11 days) (p = 0.003) and regained birth weight earlier (median 16 days vs. 22 days) (p < 0.001). There were no statistical differences in the proportion of infants with apnea, feed interruption or feed intolerance.

CONCLUSION

Rapid enteral feeding advancements of 30 mL/kg/day are well tolerated by stable preterm neonates weighing 1000-1499 g.

ADEPT - Abnormal Doppler Enteral Prescription Trial

BACKGROUND

Pregnancies complicated by abnormal umbilical artery Doppler blood flow patterns often result in the baby being born both preterm and growth-restricted. These babies are at high risk of milk intolerance and necrotising enterocolitis, as well as post-natal growth failure, and there is no clinical consensus about how best to feed them. Policies of both early milk feeding and late milk feeding are widely used. This randomised controlled trial aims to determine whether a policy of early initiation of milk feeds is beneficial compared with late initiation. Optimising neonatal feeding for this group of babies may have long-term health implications and if either of these policies is shown to be beneficial it can be immediately adopted into clinical practice.

METHODS AND DESIGN

Babies with gestational age below 35 weeks, and with birth weight below 10th centile for gestational age, will be randomly allocated to an "early" or "late" enteral feeding regimen, commencing milk feeds on day 2 and day 6 after birth, respectively. Feeds will be gradually increased over 9-13 days (depending on gestational age) using a schedule derived from those used in hospitals in the Eastern and South Western Regions of England, based on surveys of feeding practice. Primary outcome measures are time to establish full enteral feeding and necrotising enterocolitis; secondary outcomes include sepsis and growth. The target sample size is 400 babies. This sample size is large enough to detect a clinically meaningful difference of 3 days in time to establish full enteral feeds between the two feeding policies, with 90% power and a 5% 2-sided significance level. Initial recruitment period was 24 months, subsequently extended to 38 months.

DISCUSSION

There is limited evidence from randomised controlled trials on which to base decisions regarding feeding policy in high risk preterm infants. This multicentre trial will help to guide clinical practice and may also provide pointers for future research.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN: 87351483.

Does the enteral feeding advancement affect short-term outcomes in very low birth weight infants?

BACKGROUND AND OBJECTIVES

Controversy exists regarding the optimal enteral feeding regimen of very low birth weight infants (VLBW). Rapid advancement of enteral feeding has been associated with an increased rate of necrotizing enterocolitis. In contrast, delaying enteral feeding may have unfavorable effects on nutrition, growth, and neurodevelopment. The aim is to compare the short-term outcomes of VLBW infants in tertiary care centers according to their enteral feeding advancement.

PATIENTS AND METHODS

We prospectively studied the influence of center-specific enteral feeding advancement in 1430 VLBW infants recruited from 13 tertiary neonatal intensive care units in Germany on short-term outcome parameters. The centers were post hoc stratified to "rapid advancement to full enteral feeds" (median duration of advancement to full enteral feeds < or =12.5 days; 6 centers), that is, rapid advancement (RA), or "slow advancement to full enteral feeds" (median duration of advancement to full enteral feeds >12.5 days; 7 centers), that is, slow advancement (SA).

RESULTS

VLBW infants born in centers with SA (n = 713) had a significantly higher rate of sepsis compared with VLBW infants born in centers with RA (n = 717), which was particularly evident for late-onset sepsis (14.0% vs 20.4%; P = 0.002). Furthermore, more central venous lines (48.6% vs 31.1%, P < 0.001) and antibiotics (92.4% vs 77.7%, P < 0.001) were used in centers with SA.

CONCLUSIONS

Center differences in enteral feeding advancement occur and may have a significant impact on short-term outcomes such as nosocomial sepsis. Large, multicenter, prospective trials are required to further elucidate the optimal feeding strategy for VLBW infants.

Optimizing growth in the preterm infant

Most very low birth weight preterm infants experience postnatal growth failure in the neonatal ICU. In an attempt to minimize this phenomenon, the nutritional support of these infants has tended to become more aggressive in recent years and has become a focus of much study. Despite this attention, many questions remain unresolved. This article examines several of these issues, including the controversies regarding optimal postnatal growth velocity, early aggressive nutritional support, and the transition to enteral nutrition in preterm infants.

Nutritional practices in the neonatal intensive care unit: analysis of a 2006 neonatal nutrition survey

OBJECTIVE

The goal of this investigation was to determine how current parenteral nutrition and enteral nutrition practice intentions for preterm infants compare with published recommendations and previous feeding practices.

METHODS

A survey of feeding strategies for 3 preterm infant weight groups was sent to NICU directors, neonatal fellowship directors, neonatologists, neonatal nurse practitioners, and neonatal dieticians. A total of 775 surveys were distributed by both electronic and standard mail services.

RESULTS

There were 176 survey responses (23%). The majority of practitioners initiated parenteral nutrition for very preterm infants in the first day of life. Ninety-one percent of respondents increased protein delivery daily. Most respondents increased lipid delivery at a fixed rate, rather than on the basis of triglyceride levels. Insulin was used in 98% of units, but only 12% of the time as a nutritional adjuvant to increase weight gain. Across all birth weight categories, breast milk was prescribed most commonly for the first enteral feeding. Enteral feedings were started earlier and increased faster than in the past, especially for extremely low birth weight infants (<1000 g). The majority of respondents prescribed enteral feedings for infants with indwelling umbilical arterial (75%) and umbilical venous (93%) catheters. Despite data that more rapid feeding advancement is safe, >80% of respondents increased feedings at rates of 10 to 20 mL/kg per day across all weight categories.

CONCLUSIONS

Clinicians reported that they are initiating parenteral and enteral nutrition earlier and in larger volumes than in the past, reflecting increased knowledge about best nutritional practices in very preterm neonates. The data suggest that the persistent extrauterine growth failure of preterm infants is not attributable to a lack of best nutritional practice knowledge and intention.

Clinical parameters do not adequately predict outcome in necrotizing enterocolitis: a multi-institutional study

OBJECTIVE

Necrotizing enterocolitis (NEC) remains a major cause of neonatal morbidity and mortality. Some infants recover uneventfully with medical therapy whereas others develop severe disease (that is, NEC requiring surgery or resulting in death). Repeated attempts to identify clinical parameters that would reliably identify infants with NEC most likely to progress to severe disease have been unsuccessful. We hypothesized that comprehensive prospective data collection at multiple centers would allow us to develop a model which would identify those babies at risk for progressive NEC.

STUDY DESIGN

This prospective, observational study was conducted at six university children's hospitals. Study subjects were neonates with suspected or confirmed NEC. Comprehensive maternal and newborn histories were collected at the time of enrollment, and newborn clinical data were collected prospectively, thereafter. Multivariate logistic regression analysis was used to develop a predictive model of risk factors for progression.

RESULT

Of 455 neonates analyzed, 192 (42%) progressed to severe disease, and 263 (58%) advanced to full feedings without operation. The vast majority of the variables studied proved not to be associated with progression to severe disease. A total of 12 independent predictors for progression were identified, including only 3 not previously described: having a teenaged mother (odds ratio, OR, 3.14; 95% confidence interval, CI, 1.45 to 6.96), receiving cardiac compressions and/or resuscitative drugs at birth (OR, 2.51; 95% CI, 1.17 to 5.48), and having never received enteral feeding before diagnosis (OR, 2.41; 95% CI, 1.08 to 5.52).

CONCLUSION

Our hypothesis proved false. Rigorous prospective data collection of a sufficient number of patients did not allow us to create a model sufficiently predictive of progressive NEC to be clinically useful. It appears increasingly likely that further analysis of clinical parameters alone will not lead to a significant improvement in our understanding of NEC. We believe that future studies must focus on advanced biologic parameters in conjunction with clinical findings.

Bacterial colonization, probiotics, and necrotizing enterocolitis

The intestinal microflora has a significant role in intestinal health and gut function. The neonatal population is unique in that intestinal colonization is not established and is known to be influenced by delivery method, feeding, gestational age, and medical interventions. The preterm infant is particularly sensitive to colonization patterns as inherent intestinal defense mechanisms are immature and immature intestinal epithelial cells are known to have exaggerated inflammatory responses to both commensal and pathogenic bacteria. These responses contribute to the development of neonatal necrotizing enterocolitis in this patient population. As certain bacteria are known to influence intestinal maturation and down-regulate intestinal inflammation, it has been suggested that influencing the intestinal flora of preterm infants may be beneficial. Clinical studies indicate that probiotic therapy may decrease the incidence of necrotizing enterocolitis and studies are ongoing to elucidate the mechanism of action of different probiotic organisms. Although concerns remain and further study is necessary, probiotics are a plausible means of optimizing intestinal colonization and influencing outcome of these vulnerable infants.

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.

The early use of minimal enteral nutrition in extremely low birth weight newborns

OBJECTIVE

To gather information regarding the efficacy of early minimal enteral nutrition on overall feeding tolerance in extremely low birth weight infants.

STUDY DESIGN

Prospective randomized controlled trial comparing the early use of minimal enteral nutrition in extremely low birth weight infants from day 2 to day 7 vs control infants. On day 8, feeding volume in both groups were advanced by 10 ml kg(-1) day(-1) until full enteral feedings were reached. Time to full feeds, number of intolerance episodes, anthropometric measurements, peak total bilirubin levels, incidence of necrotizing enterocolitis and incidence of sepsis were compared between the two groups with t-test and chi (2) test.

RESULT

Eighty-four infants were enrolled in the study but only 61 infants completed the feeding protocol. No statistically significant differences were found between the groups with regards to growth patterns, feeding tolerance, mortality, length of hospital stay and incidence of sepsis and necrotizing enterocolitis.

CONCLUSION

Early minimal enteral nutrition use in extremely low birth weight infants did not improve feeding tolerance.

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.

Prevention and treatment of necrotising enterocolitis in preterm neonates

Prevention and treatment of NEC has become an area of priority for research due to the increasing number of preterm survivors at risk, and the significant mortality and morbidity related to the illness. Probiotic supplementation appears to be a promising option for primary prevention of NEC but further large trials are necessary for documenting their safety in terms of sepsis as well as long-term neurodevelopmental outcomes and immune function. As new frontiers including immunomodulating agents like pentoxifylline continue to be explored, the impact of well-established simple strategies like antenatal glucocorticoid therapy, and early and preferential use of breast milk must not be forgotten. Clinical research on manifestations of ileus of prematurity, and feeding in the presence of common risk factors such as IUGR is needed. Safety of minimal enteral feeds in terms of NEC and benefits of standardised feeding regimens need to be confirmed. Association of common clinical practices such as red cell transfusions, H2 receptor blockade, and thickening of feeds with NEC warrants attention. An approach utilising a package of potentially better practices seems to be the most appropriate strategy for the prevention and treatment of NEC.

Effect of high volume intake of mother's milk with an individualized supplementation of minerals and protein on early growth of preterm infants <28 weeks of gestation

OBJECTIVE

A prospective study was designed to evaluate the effects of high volume intake of mother's milk fortified (FMM) with an individualized supplementation of minerals and protein on tolerance, short-term somatic growth, serum concentrations of calcium, phosphorus, alkaline phosphatase, and total plasma protein in healthy preterm infants below 28 weeks of gestation.

METHODS

Sixty preterm infants were included in the FMM group, for having received >80% or more of the milk volume as their own mother's milk at 3 weeks of postnatal age to 38 weeks of corrected gestational age. This group was compared with 60 preterm infants fed exclusively preterm formula milk (PF). Intended fluid volume of the FMM group was approximately 200 and 150-170 mL/kg/d in the PF group. Mother's milk was supplemented with the goal of a daily protein intake of 3.5-4 g/kg/d. Phosphorus was supplemented from 15.5 to 31 mg per 100mL mother's milk.

RESULTS

Both feeding regimes were well tolerated. At the end of the study, nutritional management in both groups resulted in a body weight between the 25th and 50th percentiles of intrauterine growth expectations. Serum values of electrolytes, alkaline phosphatase, plasma protein, blood urea nitrogen, and urinary mineral excretion did not differ significantly between the two groups at study entry as well as at the end of the investigation.

CONCLUSIONS

Mother's milk fed at higher volumes with an individualized fortification of minerals and protein provides sufficient nutrients to allow adequate growth of preterm infants <28 weeks of gestation.

Dilemmas initiating enteral feedings in high risk infants: how can they be resolved?

In initiating enteral feedings for high-risk infants, clinicians struggle with three fundamental questions: When should enteral feedings be initiated? Should a period of trophic (minimal) feeding be provided? When feedings are advanced, how rapidly should the volume be increased? We present the findings of our systematic reviews of randomized trials addressing each of these questions. These reviews identified various limited short-term benefits of initiating feedings early, providing a period of trophic feedings, and increasing the volume at a relatively rapid rate when feedings are advanced. However, the safety and effectiveness of these approaches are unclear due to limitations in trial design, an inadequate sample size, and the problems inherent in evaluating the effects of initial feeding regimen on necrotizing enterocolitis (NEC) and neurodevelopmental outcome. We provide a detailed description of how a multicenter clinical trial might best be designed to adequately address these questions. In our view, it would be necessary to assess the effect of three feeding regimens on survival without neurodevelopmental impairment (primary outcome) among extremely low birth weight (ELBW) infants. The most daunting obstacle to resolving our current feeding dilemmas is the sample size required to assess all important outcomes. Even in the largest existing research network that achieves a high follow-up rate (the NICHD Neonatal Research Network), it is not feasible to meet conventional (frequentist) sample size requirements. Fortunately, this problem may be addressed using Bayesian methods. (For this reason and because Bayesian methods are likely to be increasingly used in neonatal trials, we provide a brief introduction to these methods.) We show that, with the sample size achievable in the Neonatal Network, Bayesian analyses are likely to provide clear and clinically useful assessments of the probability of benefit for all important clinical outcomes resulting from initial feeding regimens for ELBW infants.

Prevention of necrotizing enterocolitis in preterm infants: a 20-year experience

OBJECTIVE

Diet, indomethacin, and early use of dexamethasone have been implicated as possible causes of necrotizing enterocolitis and intestinal perforation. Because we seldom prescribe indomethacin or early dexamethasone therapy and we follow a special dietary regimen that provides late-onset, slow, continuous drip enteral feeding, we reviewed our 20 years of experience for the incidence of necrotizing enterocolitis and bowel perforation.

METHODS

We reviewed data on all 1239 very low birth weight infants (501-1500 g) admitted to our level III unit over a period of 20 years (1986-2005), for morphologic parameters, necrotizing enterocolitis, bowel perforation, use of the late-onset, slow, continuous drip protocol, and indomethacin therapy. Outcome data were also compared with Vermont Oxford Network data for the last 4 years.

RESULTS

In 20 years, 1158 infants received the late-onset, slow, continuous drip feeding protocol (group I), whereas 81 infants had either a change in dietary regimen, use of indomethacin, or early use of dexamethasone (group II). The rate of necrotizing enterocolitis in group I of 0.4% was significantly lower than that in group II of 6%. Group I, in comparison with the Vermont Oxford Network, had significantly lower rates of necrotizing enterocolitis (0.4% vs 5.9%), surgical necrotizing enterocolitis (0.4% vs 3.1%), and bowel perforation (0.35% vs 2.2%).

CONCLUSIONS

Our 20-year experience with 1239 very low birth weight infants suggests strongly that the late-onset, slow, continuous drip feeding protocol and avoidance of indomethacin and early dexamethasone treatment contribute to the prevention of necrotizing enterocolitis.

The fear of necrotizing enterocolitis versus achieving optimal growth in preterm infants--an opinion

Very-low-birthweight (VLBW) infants suffer marked growth delay despite well-intentioned efforts at combining enteral and parenteral nutrition. Fear of necrotizing enterocolitis (NEC) has traditionally influenced neonatologists toward delaying and progressing slowly with enteral feeding, while supporting the infant with parenteral nutrition. Current evidence suggests significant benefits of enteral feeding that is started early and advanced at rates of 20-35 ml/kg/d.

CONCLUSION

We conclude that fear of inadequate growth should replace the fear of NEC in guiding nutritional strategies for these infants.

Audit of feeding practices in babies<1200 g or 30 weeks gestation during the first month of life

AIM

In 2002, the composition of the breast milk fortifier used in our hospital changed, giving increased protein and energy. We therefore decided to prospectively audit nutritional management in our unit and to compare nutritional intake and growth in our babies with published data.

METHODS

Data were prospectively collected over a 3-month period on infants<1200 g or 30 weeks gestation. Prescribed and delivered volumes of all parenteral and enteral fluids were recorded. Babies were weighed as per unit protocol.

RESULTS

Thirty-four infants met the audit criteria. Data are median (range). After the first week of life, energy and protein intakes were 147 (78-174) kcal/kg/day and 3.9 (2.1-4.8) g/kg/day respectively. Daily weight gain was 17 (-3.2-35.4) g/kg and was significantly associated with both energy and protein intakes (P<0.001). However, standard deviation scores for weight fell from 0.15 (-1.9-2.0) at birth to -1.0 (-2.9-0.8) by 36 weeks corrected age. Time to commencing enteral feeds was 1 (1-3) day and to full enteral feeds was 8 (5-28) days. One infant was diagnosed with necrotising enterocolitis and eight with chronic lung disease. Mean protein intake was significantly lower in babies with chronic lung disease (P=0.005).

CONCLUSION

Overall, nutritional intakes and weight gain in this cohort of babies lie within the recommended ranges, although protein intakes in the smallest babies are at the lower end of the range. Enteral feeds are introduced early and advanced rapidly, but we have a low incidence of necrotising enterocolitis. However, babies still fell across weight centiles, suggesting that actual intakes for these tiny babies may be inadequate.

Outcome following patent ductus arteriosus ligation in premature infants: a retrospective cohort analysis

Background

The patent ductus arteriosus (PDA) is an important problem in premature infants. Surgical PDA ligation is usually only be considered when medical treatment has either failed or was contraindicated. The aims of our study were to determine the mortality and morbidity following patent ductus arteriosus ligation in premature infants, and whether prostaglandin synthetase inhibitor (PSI) use prior to ligation affects outcome.

Methods

A retrospective case note review study to determine the outcome of premature infants undergoing patent ductus arteriosus ligation in one tertiary neonatal intensive care unit and two paediatric cardiothoracic centres.

Results

We had follow-up data on 87 infants. Cumulative mortality rates at 7 days, 30 days and at hospital discharge were 2%, 8% and 20% respectively. The incidence of chronic lung disease, intraventricular haemorrhage, necrotising enterocolitis and retinopathy of prematurity were 77%, 39%, 26% and 28% respectively. There was no difference in mortality, incidence of chronic lung disease or duration of oxygen dependence between those who had and those who had not received a PSI prior to surgical ligation. In those who had received 2 or more courses of PSI prior to surgical ligation, there was a trend to increase in the duration of oxygen therapy and chronic lung disease, but no difference in mortality.

Conclusion

This study shows that patent ductus arteriosus ligation is a relatively safe procedure (30 day survival 92%) but there is substantial late mortality and a high incidence of morbidity in the survivors. 2 or more courses of PSI prior to surgical ligation trends to increased oxygen dependence and chronic lung disease. This high risk population requires careful follow-up. A definitive prospective cohort study is lacking.

Management of preterm infants with intrauterine growth restriction

Preterm intrauterine growth restriction (IUGR) is strongly associated with increased mortality and morbidity. In the management of these infants, complications of preterm birth can be amplified by the effect of suboptimal fetal growth. It is important that pregnancies with IUGR are detected before birth, so that delivery can be arranged in a high-risk maternity unit with the appropriate neonatal staff in attendance. The provision of full support for resuscitation and stabilisation of these infants is crucial to the short-term and long-term health of these infants, who have suffered chronic hypoxia and malnutrition in utero. The long term outcome studies of these infants are retrospective and they include SGA infants. The effects of prematurity affect the outcome of IUGR infants. IUGR is associated with cerebral palsy in those delivered more than 32 weeks gestation. Infants less than 32 weeks of gestation may have poor developmental outcome if the head growth is affected, these infants may have associated cognitive and behavioural problems. Children who fail to grow by 2-4 years are at risk of long term growth problems. This paper outlines the acute and long-term management of these infants.

Prolonged hospital stay for extremely premature infants: risk factors, center differences, and the impact of mortality on selecting a best-performing center

OBJECTIVE

The first objective was to identify factors associated with prolonged hospital stay (PHS: hospitalized >42 weeks postmenstrual age) in extremely premature (EP: born less than or equal to 28 weeks gestation) infants. The second objective was to identify a PHS best-performing benchmark center.

METHODS

This study was a retrospective cohort analysis of infants born < or =28 weeks gestation and admitted to one of 12 tertiary centers between January 1998 and October 2001. Risk-adjusted odds of PHS, defined as hospitalization beyond 42 weeks postmenstrual age, and the competing outcome, mortality, were assessed using logistic regression models.

RESULTS

Among 3892 EP survivors who had complete data for multivariable analysis, 685 (18%) had PHS. Variables contributing to PHS included chronic lung disease (oxygen use at discharge home or 36 week postmenstrual age) (OR 6.75; 95% CI: 5.04 to 9.03), necrotizing enterocolitis requiring surgery (OR 13.83; 95% CI: 8.05 to 23.76), and >two episodes of late-onset sepsis (OR 2.39; 95% CI: 1.66 to 3.44). Centers' risk-adjusted PHS odds differed from the reference center, which had the lowest incidence of PHS and mortality (overall P-value <0.0001). Mortality contributed to PHS, but in an opposite direction compared to other factors. Centers with lowest PHS odds were among those with highest mortality.

CONCLUSIONS

These findings suggest that reduction of CLD, surgical NEC, and late onset sepsis could reduce PHS in EP infants. Risk adjusted odds of PHS and mortality are both crucial for selecting a PHS best-performing center.

Early enteral feeding for the very low birth weight infant: the development and impact of a research-based guideline

Providing optimal nutrition for the very low birth weight (VLBW) infant is critical during the neonatal period. Evidence-based practice guidelines are essential in managing these fragile infants. Putting scientific research into daily clinical practice may be arduous at times, however. A multidisciplinary team of health care providers successfully established a practical feeding guideline for a 52-bed, teaching-affiliated, Level III neonatal intensive care unit in St. Louis. This guideline identifies human milk as the recommended source of nutrition for the VLBW infant, a suggestion that has significantly affected lactation services in the unit. This article describes the process of developing, implementing, and evaluating a feeding guideline based on current research and describes the impact on lactation rates of having such a guideline in place within the unit.

Feeding growth restricted preterm infants with abnormal antenatal Doppler results

Absence or reversal of end diastolic flow (AREDF) in the umbilical artery is associated with poor outcome, and elective premature delivery is common. Feeding these infants is a challenge. They often have poor tolerance of enteral feeding, and necrotising enterocolitis may develop. This review explores current practice to see if there is evidence on which to base guidelines. The incidence of necrotising enterocolitis is increased in infants with fetal AREDF, especially when complicated by fetal growth restriction. Abnormalities of splanchnic blood flow persist postnatally, with some recovery during the first week of life, providing justification for a delayed and careful introduction of enteral feeding. Such a policy exposes babies to the risks of parenteral nutrition, with no trials to date showing any benefit of delayed enteral nutrition. Trials are required to determine the optimum timing for introduction of enteral feeds in growth restricted infants with fetal AREDF.

Enteral administration of a simulated amniotic fluid to very low birth weight neonates

OBJECTIVE

To reduce feeding intolerance among very low birth weight neonates.

STUDY DESIGN

A total of 10 neonates with birth weights of 750 to 1250 g were given oral-gastric boluses (2.5 ml/kg every 3 hours) of a solution patterned after amniotic fluid. When milk feedings were begun the milk was mixed with the test solution. The solution was given at a constant daily dose of 20 ml/kg/day while the volumes of milk feedings were gradually increased. When milk feedings reached 80 ml/kg/day the test solution was discontinued. A comparison group consisted of neonates who met study criteria but were cared for during the period immediately preceding the study. The outcome was the number of calories taken enterally over the first 21 days of life.

RESULTS

The test solution was begun an average of 27 hours after birth (range, 4 to 45). In the test group the first milk feedings were introduced 74 hours after birth (range, 18 to 144), which was similar to the time milk was introduced in the comparison subjects (79 hours; range, 18 to 168). After milk feedings were started, the test patients had a total of four NPO days (0.4 NPO days per patient) during their first 21 days, while the comparison group had 34 NPO days (3.4 NPO days per patient). During the first 14 days of life the test solution recipients had a median of 26.5 enteral cal/kg/day (range, 4.3 to 68.9), while the comparison neonates had 8.5 (range, 0.2 to 25; p < 0.05). During the first 21 days of life the test solution recipients had a median of 56.9 enteral cal/kg/day (range, 11.5 to 89.4), while the comparison neonates had 19.2 (range, 0.9 to 52.8; p < 0.05).

CONCLUSION

In all, 10 VLBW infants tolerated the test solution for periods up to 14 days with no significant adverse effects. A randomized trial to determine whether this solution reduces feeding intolerance among VLBW neonates should be conducted.

Pragmatic approach to in-hospital nutrition in high-risk neonates

Extremely low birth weight infants may experience periods of moderate to severe undernutrition during the acute phase of their respiratory problems. This undernutrition contributes to early growth deficits in these patients and may have long-lasting effects, including poor neurodevelopmental outcome. Early postnatal intravenous amino-acid administration and early enteral feeding strategies will minimize the interruption of nutrient intake that occurs with premature birth. These two strategies will prevent intracellular energy failure, allow the administration of more non-protein energy, as well as enhance overall nutritional health, as evidenced by less postnatal weight loss and earlier return to birth weight, and improved overall postnatal growth and outcome.

Early enteral feeding in newborn surgical patients

OBJECTIVE

We report the results of a multicenter prospective trial of early enteral trophic feeding in a group of 56 neonates who required abdominal surgery for a variety of congenital anomalies.

METHODS

In this clinical study, 33 neonates were fed in the early postoperative period (early enteral nutrition [EEN] group), and the remaining 23 (control [C] group) were fasted until resolution of postoperative ileus. Patients in the EEN group (Kocaeli feeding protocol) received 3 to 5 mL of breast milk every hour through a nasogastric feeding tube, starting a mean of 12 h (8 to 20 h) after surgery. The nasogastric tube was clamped for 40 min after each infusion and then opened for drainage. Groups were further divided into two subgroups according to whether an intestinal anastomosis or laparotomy was performed. The change in daily gastric drainage, time to first stool, day of toleration to full oral feeding, and length of hospital stay were compared. Blood bilirubin levels, white blood cell count, and C-reactive protein levels were monitored.

RESULTS

The time to first stool and day of toleration to full oral feeding occurred significantly sooner, whereas nasogastric tube drainage duration and hospital stay were significantly shorter in the EEN-anastomosis group than in the C-anastomosis group. Time to first stool occurred significantly sooner in the EEN-laparotomy group than in the C-laparotomy group, although other parameters did not differ. Neither anastomotic leakage nor dehiscence was observed in any group. There were two cases of wound infection and two of exitus among patients in the C group.

CONCLUSION

Postoperative, early intragastric, small-volume breast milk feeding is well tolerated by newborns. It is a reliable and feasible approach in neonates even in the presence of an intestinal anastomosis after abdominal surgery.

Randomized, controlled trial of slow versus rapid feeding volume advancement in preterm infants

OBJECTIVES

To determine whether infants who are fed initially and advanced at 30 mL/kg per day (intervention) take fewer days to get to full feedings than those who are fed initially and advanced at 20 mL/kg per day (control), without increasing their incidence of feeding complications and necrotizing enterocolitis (NEC). We also examined whether these infants regain birth weight earlier, have fewer days of intravenous fluids, and a have shorter hospital stay.

METHODS

A randomized, controlled, single-center trial was conducted in a Neonatal Intensive Care Unit of a community-based county hospital in Houston, Texas. Infants between 1000 and 2000 g at birth, gestational age < or =35 weeks, and weight appropriate for gestational age were allocated randomly to feedings of expressed human milk or Enfamil formula starting and advanced at either 30 mL/kg per day or 20 mL/kg per day. Infants remained in the study until discharge or development of stage > or =IIA NEC.

RESULTS

A total of 155 infants were enrolled: 72 infants in the intervention group and 83 in the control group. Infants in the intervention group achieved full-volume feedings sooner (7 vs 10 days, median), regained birth weight faster (11 vs 13 days, median), and had fewer days of intravenous fluids (6 vs 8 days, median). Three infants in the intervention group and 2 control infants developed NEC for an overall incidence of 3.2% (relative risk: 1.73; 95% confidence interval: 0.30-10.06).

CONCLUSION

Among infants between 1000 and 2000 g at birth, starting and advancing feedings at 30 mL/kg per day seems to be a safe practice and results in fewer days to reach full-volume feedings than using 20 mL/kg per day. This intervention also leads to faster weight gain and fewer days of intravenous fluids.

Early enteral feeding and nosocomial sepsis in very low birthweight infants

BACKGROUND

The interrelations between early enteral feeding, necrotising enterocolitis (NEC), and nosocomial sepsis (NS) remain unclear.

OBJECTIVE

To evaluate the effect of age at the introduction of enteral feeding on the incidence of NS and NEC in very low birthweight (VLBW< 1500 g) infants.

METHODS

Data were collected on the pattern of enteral feeding and perinatal and neonatal morbidity on all VLBW infants born in one centre during 1995-2001. Enteral feeding was compared between infants with and without NS and/or NEC.

RESULTS

The study sample included 385 infants. Of these, 163 (42%) developed NS and 35 (9%) developed NEC. Enteral feeding was started at a significantly earlier mean (SD) age in infants who did not develop nosocomial sepsis (2.8 (2.6) v 4.8 (3.7) days, p = 0.0001). Enteral feeding was introduced at the same age in babies who did or did not develop NEC (3.1 (2) v 3.7 (3) days, p = 0.28). Over the study period, the mean annual age at the start of enteral feeding fell consistently, and this correlated with the mean annual incidence of NS (r(2) = 0.891, p = 0.007). Multiple logistic regression analysis showed age at start of enteral feeding, respiratory distress syndrome, and birth weight to be the most significant predictors of risk of NS (p = 0.0005, p = 0.024, p = 0.011).

CONCLUSIONS

Early enteral feeding was associated with a reduced risk of NS but no change in the risk of NEC in VLBW infants. These findings support the use of early enteral feeding in this high risk population, but this needs to be confirmed in a large randomised controlled trial.

Necrotizing enterocolitis: preventative strategies

Necrotizing enterocolitis (NEC) remains a major cause of morbidity and mortality in premature infants. Although the pathogenesis of NEC is unclear, prevention strategies have been developed based on clinical observations and epidemiologic and experimental data. Most current strategies have centered on feeding practices (eg, institution of feeds, advancement of feeds, composition of feeds, and standardization of feeding practices). Emerging strategies include amino acid supplementation, the use of platelet-activating factor(PAF) antagonists or PAF-acetylhydrolase administration, polyunsaturated fatty acid administration, epidermal growth factor administration, and the use of pre- and probiotics.

Gastric residuals and their relationship to necrotizing enterocolitis in very low birth weight infants

OBJECTIVE

To determine the characteristics of gastric residuals in very low birth weight (VLBW; <or=1500 g birth weight) infants with and without necrotizing enterocolitis (NEC).

METHODS

Case-control study compared 51 VLBW infants who had proven NEC (pneumatosis intestinalis, portal venous gas, and/or perforation; excluding spontaneous gastrointestinal perforations) with 102 control subjects (without suspected or proven NEC) who were matched for birth weight, gestational age, race, and sex and were born January 1996 to December 2001. The age in days at diagnosis of NEC was identified in infants with NEC, and feeding characteristics were recorded for the previous 6 days. Feeding characteristics were recorded for control subjects for the corresponding time period.

RESULTS

The median birth weight was 822 g and median gestational age was 26 weeks in both groups. Feeds were started on the fifth day, with a planned increase to full feeds over 10 days (median) in both groups. Median time to full feeds was 13 days in both groups. Median age of onset of NEC was day 24. The total residuals as a percentage of total feed volume (the primary outcome), maximum residual in the previous 6 days, maximum residual as a percentage of the feed, maximum residuals over the 6 days, and the percentage of feeds with residuals were higher in the NEC group. The maximum residual (median [25th-75th centiles]) was as follows: control subjects: 2 mL per feed (0.5-3.5) or 14% of a feed (4-33); NEC group: 4.5 mL per feed (1.5-9.8) or 40% of a feed (24-61). The total residuals as percentage of feeds and the average of maximum residuals increased in the NEC group from the first 3 days to the 3 days before diagnosis of NEC, but a similar increase was not noted for control subjects.

CONCLUSIONS

VLBW infants who developed NEC had more gastric residuals. However, there was overlap with the normal control subjects. Of the gastric residual data, the maximum residual seems to be the best predictor for NEC in the subsequent days.

Treatment and prevention of necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is the most common serious, acquired gastrointestinal disorder in the newborn infant. Although many variables are associated with development of NEC, only prematurity has been consistently identified in case-controlled studies. Traditionally, the diving seal reflex has been invoked as the mechanism responsible for ischaemic injury and necrosis. Intestinal ischaemia is likely to be the final common pathway in NEC; however, it is due to the release of vasoconstricting substances, such as platelet activating factor, rather than perinatal asphyxia. Bacteria and/or bacterial toxins are likely to have a key role in the pathogenesis of NEC by fostering production of inflammatory mediators. The role of feeding practices in the pathogenesis of NEC remains controversial. Treatment of infants with NEC generally includes a regimen of bowel rest, gastric decompression, systemic antibiotics and parenteral nutrition. Infants with perforation are generally operated upon; however, there has been recent interest in primary peritoneal drainage as an alternative. Prevention of NEC still remains elusive. Avoidance of preterm birth, use of antenatal steroids and breast-milk feeding are practices that offer the greatest potential benefits. Use of any other strategy should await further trials.

Early feeding after necrotizing enterocolitis in preterm infants

OBJECTIVE

To report our experience with an early initiation of enteral feedings after necrotizing enterocolitis (NEC).

STUDY DESIGN

Over a 4-year period, all inborn infants with NEC Bell stage II or greater received enteral feedings, increased by 20 mL/kg/d, once no portal vein gas had been detected on ultrasound for 3 consecutive days (group 1). Infants were compared with a historic comparison group (group 2).

RESULTS

Necrotizing enterocolitis rates were 5% (26/523) in the early feeding group and 4% (18/436) in the comparison group. One early feeding infant and two comparison group infants died of NEC, whereas two and one, respectively, had recurrent NEC. Enteral feedings were restarted at a median of 4 days (range, 3-14) versus 10 days (range, 8-22) after onset of NEC. Early feeding was associated with shorter time to reach full enteral feedings (10 days [range, 7-31] vs 19 days [range, 9-76], P<.001), a reduced duration of central venous access (13.5 days [range, 8-24] vs 26.0 days [range, 8-39], P<.01), less catheter-related septicemia (18% vs 29%, P<.01), and a shorter duration of hospital stay (63 days [range, 28-133] vs 69 days [range, 36-150], P<.05).

CONCLUSION

Early enteral feeding after NEC was associated with significant benefits and no apparent adverse effects. This study was underpowered, however, to exclude a higher NEC recurrence risk potentially associated with this change in practice.

Probiotics for preterm infants?

Infants nursed in special care baby units develop an abnormal pattern of microbial colonisation, which may contribute to disease. Enteric feeding of live microbial supplements (probiotics) may provide benefit to such infants and help to prevent diseases such as neonatal necrotising enterocolitis.

Late graft loss after intestinal transplantation in an adult patient as a result of necrotizing enterocolitis

A 50-year-old recipient of an intestinal and coecal graft with sudden onset of abdominal distention and pain, lack of bowel movements, and vomiting after closure of the diagnostic ostomy 7 months after transplantation is reported. A plain abdominal radiograph revealed pneumatosis intestinalis. An angiography excluded obstruction of large vessels, however, with absent microcirculation of the intestine. Upper gastrointestinal endoscopy showed extensive ulcerative enteritis with several spontaneous perforations. The patient underwent exploration demonstrating a nonviable intestine. The entire necrotic intestine was removed. Vascular thrombosis was excluded. Clinical data, and macroscopic and histologic features of the intestinal graft were diagnostic for necrotizing enterocolitis (NEC). Though there has been evidence for the occurrence of NEC not only in premature infants but even in older infants, children and adolescents, the presented case is, to our knowledge, the first report of NEC as etiology of late graft loss after intestinal transplantation in an adult recipient.

Current controversies in the understanding of necrotizing enterocolitis. Part 1

Necrotizing enterocolitis (NEC) has widespread implications for neonates. While mostly affecting preterm neonates, full-term neonates, especially those with congenital heart disease, are also at risk. Although the exact pathogenesis of NEC remains elusive, three major factors, a pathogenic organism, enteral feedings, and bowel compromise, coalesce in at-risk neonates to produce bowel injury. Initiation of the inflammatory cascade likely serves as a common pathway for the disorder. Clinical signs and symptoms range from mild feeding intolerance with abdominal distension to catastrophic disease with bowel perforation, peritonitis, and cardiovascular collapse. Vigilant assessment of at-risk neonates is crucial. When conservative medical management fails to halt injury, surgical intervention is often needed. Strategies to decrease the incidence and ultimately prevent NEC loom on the horizon, such as exclusive use of human breastmilk for enteral feedings and administration of probiotics.

Prolonging small feeding volumes early in life decreases the incidence of necrotizing enterocolitis in very low birth weight infants

OBJECTIVE

Approximately 90% of infants who develop necrotizing enterocolitis (NEC) do so after being fed. Previous prospective studies have shown that infants given small enteral feedings for the first 7 to 10 days of feeding do not have an increased risk for NEC compared with those given no feedings. Although neonatologists now commonly increase feeding volumes, no study has compared the risk for NEC between infants fed these small volumes and those fed volumes that are increased slowly. The purpose of this study was to compare the risks and benefits of small and increasing feeding volume.

METHODS

In a randomized, controlled trial, we randomly assigned 141 preterm infants in the newborn intensive care unit to be fed 10 days using 1 of 2 schedules. One group was fed 20 mL/kg/d for the first 10 study days (minimal). The other group (advancing) was fed 20 mL/kg/d on study day 1; feeding volume was increased by 20 mL/kg/d up to 140 mL/kg/d, which was maintained until study day 10. The main outcome measure was incidence of NEC; secondary outcomes were maturation of intestinal motor patterns, time to reach full enteral feedings, and incidence of late sepsis.

RESULTS

The study was closed early because 7 infants who were assigned to advancing feeding volumes developed NEC, whereas only 1 infant fed minimal feeding volumes did, or 10% versus 1.4%. Although infants who were fed minimal volumes established full enteral feeding volumes later than infants who were fed advancing volumes, maturation of intestinal motor patterns and the incidence of late sepsis and feeding intolerance was similar in the 2 groups.

CONCLUSION

Given that advancing feeding volumes increase the risk of NEC without providing benefits for motor function or feeding tolerance, neonatologists should consider using minimal feeding volumes until future trials assess the safety of advancing feeding volumes.

Hydrolyzed protein accelerates feeding advancement in very low birth weight infants

BACKGROUND

Feeding intolerance is common in very low birth weight (VLBW; <1500 g) infants. Hydrolyzed protein preterm infant formula (HPF) has been shown to accelerate the gastrointestinal transit of formula. The aim of this study was to investigate whether HPF improves early feeding tolerance compared with standard preterm infant formula (SPF). We hypothesized that HPF would accelerate early enteral feeding advancement.

METHODS

Primary outcome was the time from initiation of milk feeds until full feeds (150 mL/kg birth weight/d) were achieved in infants who received <10% human milk (HM) to exclude HM as a confounder. Because the availability of HM was not predictable at the time of enrollment, all eligible VLBW infants (n = 129) were randomly assigned in a randomized, controlled trial to receive HPF or SPF if HM was not available. Infants who received >10% HM (n = 42) were excluded. Milk bolus feeding every 2 to 3 hours was started at the discretion of the attending physician and advanced by 16 mL/kg/d. Preprandial gastric residuals were tolerated up to 5 mL/kg; otherwise, feedings were reduced or withheld. Data are shown as median (5th and 95th percentile).

RESULTS

Forty-six and 41 (HPF vs SPF) infants received <10% HM. There was no significant difference with regard to birth weight, gestational age, and onset of milk feeds (day 3 [1-8] vs 4 [2-6]). The time from initiation of milk feeds to full feeds was significantly shorter with HPF feeding (10 [9-27] vs 12 [9-28] days).

CONCLUSION

HPF improved the feeding tolerance and enabled a more rapid establishment of full enteral feeding in VLBW infants compared with SPF.

Feeding the ill or preterm infant

Illness and immaturity often interfere with a neonate's ability to receive full enteral feedings during the first week of life. The goals of feeding in the NICU are to nourish the preterm infant for appropriate growth and development and to facilitate the earliest possible discharge from the NICU. Early, small-volume feedings, or trophic feedings, have been studied as a method for achieving these goals. The high-risk infant given such trophic feedings not only receives minimum enteral nutrition, but also attains earlier full nutritional feedings and, consequently, is discharged home earlier. Oro- or nasal-gastric gavage feedings are usually indicated for this group of infants because of their physiologic immaturity and the frequent presence of respiratory illness. Recent studies support the use of intermittent bolus feedings, which have long been used for the premature infant. Several authors have noted advantages to continuous infusions as well. Because the infant is unable to pace or refuse gavage feedings, the caretaker must determine the appropriate volume of each feeding. The optimal volume for initiation and advancement of trophic and nutritional feedings is still under investigation, but reports have demonstrated safe volumes for even the extremely premature infant.

Aggressive nutrition of the very low birthweight infant

We propose an approach to nutrition of the VLBW infant that aims at minimizing the interruption of nutrient uptake engendered by premature birth. Our approach is aggressive in that it goes beyond current practice in several key aspects. The gap in nutrient intakes between the proposed aggressive approach and current practice will most likely disappear over the next few years as today's aggressive practice becomes tomorrow's standard practice. As the gap diminishes, so will the threat that nutritional deprivation poses to growth and development of VLBW infants.