Feeding strategies for premature infants: randomized trial of gastrointestinal priming and tube-feeding method

Estimating the dietary intake of breastfeeding preterm infants

AIM

To determine how accurately the daily prescribed feed volume (mL/day) estimates the actual intake of breastfeeding preterm infants and to characterise the volume taken during a breastfeed at differing gestational and postmenstrual ages.

METHODS

A cross sectional study was conducted on preterm infants born <37 weeks gestation from two Australian neonatal units. To determine the volume taken in a 24-h period infants were weighed before and after each breastfeed. This volume was added to the charted intake to determine the total intake and then compared to the prescribed feed volume. Bland Altman analyses were used to assess the level of agreement between the two methods.

RESULTS

Fifty six infants were studied on 206 breastfeeding occasions. There was a small bias (27 mLs/day) but large 95% limits of agreement (-76 to 130 mL/day). The volume taken during a single breastfeed ranged from 0 to 101 mL (median 23 mL, IQR 9 to 31 mL) and was greater in more mature infants.

CONCLUSIONS

Using the prescribed feed volume to estimate total intake has limited clinical utility for the individual infant, however the relatively small bias means that it may be useful within a population or for comparison between groups in which population means are compared. There was a large variation in volume taken during a breastfeed across all gestational and postmenstrual ages.

Aspiration and evaluation of gastric residuals in the neonatal intensive care unit: state of the science

The routine aspiration of gastric residuals (GR) is considered standard care for critically ill infants in the neonatal intensive care unit (NICU). Unfortunately, scant information exists regarding the risks and benefits associated with this common procedure. This article provides the state of the science regarding what is known about the routine aspiration and evaluation of GRs in the NICU focusing on the following issues: (1) the use of GRs for verification of feeding tube placement, (2) GRs as an indicator of gastric contents, (3) GRs as an indicator of feeding intolerance or necrotizing enterocolitis, (4) the association between GR volume and ventilator-associated pneumonia, (5) whether GRs should be discarded or refed, (6) the definition of an abnormal GR, and (7) the potential risks associated with aspiration and evaluation of GRs. Recommendations for further research and practice guidelines are also provided.

Cardiorespiratory events with bolus versus continuous enteral feeding in healthy preterm infants

We evaluated the effects of bolus vs continuous tube feeding on cardiorespiratory events, detected by polysomnographic monitoring, in healthy preterm infants. Continuous tube feeding resulted in a significant increase of apneas and apneas-related hypoxic episodes compared with bolus feeding.

Reducing necrotizing enterocolitis in very low birth weight infants using quality-improvement methods

OBJECTIVE

Owing to a rise in necrotizing enterocolitis (NEC, stage ⩾ 2) among very low birth weight (VLBW, birth weight <1500 g) infants from 4% in 2005 to 2006 to 10% in 2007 to 2008, we developed and implemented quality improvement (QI) initiatives. The objective was to evaluate the impact of QI initiatives on NEC incidence in VLBW infants.

STUDY DESIGN

In September 2009, we developed an NEC QI multidisciplinary team that conducted literature reviews and reviewed practices from other institutions to develop a feeding protocol, which was implemented in December 2009. The team tracked intervention compliance and occurrence of NEC stage ⩾ 2. In May 2010, we reviewed our nasogastric tube practice and relevant literature to develop a second intervention that reduced nasogastric tube indwelling time. The infants were divided into three groups: baseline (January 2008 to Novovember 2009, n219), QI phase 1 (December 2009 to May 2010, n62) and QI phase 2 (June 2010 to November 2011, n170).

RESULT

The NEC incidence did not decrease after implementation of the feeding protocol in QI phase 1 (19.4%) but did decline significantly after changing nasogastric tube management in QI phase 2 (2.9%). Multivariable logistic regression analysis demonstrated a significant relationship between QI phase and the incidence of NEC.

CONCLUSION

QI initiatives were effective in decreasing NEC incidence in our high human milk-feeding NICU. Nasogastric tube bacterial contamination may have contributed to our peak in NEC incidence.

Impact of peer counselors on breastfeeding outcomes in a nondelivery NICU setting

PURPOSE

Although the independent effects of lactation consultants and peer counselors have been shown to improve breastfeeding outcomes, the joint effects have yet to be considered, particularly in the neonatal intensive care unit (NICU) in nondelivery hospitals. Therefore, the objective of this study was to assess the effect of lactation staff type on breastfeeding outcomes during hospital stay after the addition of peer counselors to a NICU lactation program.

SUBJECTS

A total of 596 mother-infant pairs admitted to Nationwide Children's Hospital, Columbus, Ohio, pre- and postlactation program expansion.

DESIGN

A descriptive pre-/posttest study as conducted.

MAIN OUTCOME MEASURES

Differences in provision of any maternal breast milk, exclusive breast milk, or direct breastfeeding during NICU stay and at discharge were evaluated pre and postprogram implementation. Logistic regression was used to determine associations between lactation staff type and each outcome during hospital stay.

RESULTS

Infants receiving any breast milk during NICU stay increased from baseline to postprogram year 1 (63% vs 73%; P= 0.03). Direct breastfeeding increased from baseline to postprogram year 4 (42% vs 53%; P= 0.03). Mothers seen by only peer counselors were less likely to provide any breast milk at discharge, provide exclusive breast milk during stay or discharge, to be direct breastfeeding during stay or at discharge compared with mothers seen by both peer counselors and lactation consultants.

CONCLUSIONS

NICU lactation programs should consider including both peer counselors and lactation consultants to improve breastfeeding outcomes during hospital stay.

Bolus vs. continuous feeding: effects on splanchnic and cerebral tissue oxygenation in healthy preterm infants

BACKGROUND

Intermittent and continuous tube feeding modes are commonly used to feed preterm infants. However, there is no clear evidence regarding which method is better tolerated. We investigated the differences between bolus and continuous feeding in terms of cerebral and splanchnic oxygenation in healthy preterm infants.

METHODS

Thirty preterm infants underwent a simultaneous 6-h near-infrared-spectroscopy monitoring of cerebral and splanchnic oxygenation, during which they were fed twice through an orogastric tube: one meal was given as a 10-min bolus, and the other was given continuously over a period of 3 h. Oxygenation trends over time were evaluated and compared between bolus and continuous feeding modes.

RESULTS

Cerebral oxygenation did not change over time and did not differ between the two feeding techniques. Splanchnic oxygenation changed significantly over time and differed between the two feeding techniques, with a significant increase after bolus feeding and a remarkable reduction during continuous feeding.

CONCLUSION

Bolus and continuous feeding modes influence splanchnic oxygenation in healthy preterm infants differently. Further studies are needed to investigate possible underlying mechanisms and potential effects on feeding tolerance.

High-protein formulas: evidence for use in preterm infants

Relatively high amounts of protein are required to achieve normal fractional protein synthetic rates during the late second through early third trimester of fetal growth. Once preterm infants achieve higher protein intakes for sustained periods, growth begins to approximate that of the normally growing fetus and long-term neurodevelopmental outcomes are improved. Preterm formulas have been developed that are enriched in protein. This review discusses several factors when using standard preterm formulas and high-protein preterm formulas in the neonatal intensive care unit, with an emphasis on quantity and quality of enteral protein delivery and risks to insufficient and/or excess protein administration.

Intestinal muscularis propria increases in thickness with corrected gestational age and is focally attenuated in patients with isolated intestinal perforations

PURPOSE

Intestinal perforations are common in premature infants, leading to a diagnostic dilemma between necrotizing enterocolitis and isolated intestinal perforation (IIP). IIP is thought to result from a congenital or acquired absence of the muscularis propria. However, developmental events leading to IIP are not well understood. This study examines the relationship between corrected gestational age (CGA) and intestinal muscle development in controls and patients with IIP.

METHODS

Specimens from stillbirths and infants undergoing intestinal surgery from 8 to 48weeks' CGA were collected from 2005 to 2012. Twelve patients with IIP were identified. Control specimens were collected during 25 fetal autopsies and 39 bowel resections. In each case, three sections of intestine were examined histologically for muscularis mucosa, circular and longitudinal muscle thickness. Comparisons of control and perforated specimens were performed via linear regression and ANOVA.

RESULTS

Controls and adjacent normal segments in IIP showed a linear relationship between thickness of circular and longitudinal muscles with CGA. Circular and longitudinal muscles were thinner in perforated segments than in adjacent normals and CGA-matched controls (p<0.05).

CONCLUSION

Intestinal muscularis propria increases in thickness with CGA. Muscle thickness is focally attenuated in patients with isolated intestinal perforations, while the remaining intestine is normal, suggesting that primary repair is an appropriate treatment.

Feeding intolerance in the preterm infant

Feeding intolerance (FI), defined as the inability to digest enteral feedings associated to increased gastric residuals, abdominal distension and/or emesis, is frequently encountered in the very preterm infant and often leads to a disruption of the feeding plan. In most cases FI represents a benign condition related to the immaturity of gastrointestinal function, however its presentation may largely overlap with that of an impending necrotizing enterocolitis. As a consequence, individual interpretation of signs of FI represents one of the most uncontrollable variables in the early nutritional management of these infants, and may lead to suboptimal nutrition, delayed attainment of full enteral feeding and prolonged intravenous nutrition supply. Strategies aimed at preventing and/or treating FI are diverse, although very few have been validated in large RCT and systematic reviews. The purpose of this paper is to summarize the existing information on this topic, spanning from patho-physiological and clinical aspects to the prevention and treatment strategies tested in clinical studies, with specific attention to practical issues.

Viscera and muscle protein synthesis in neonatal pigs is increased more by intermittent bolus than by continuous feeding

BACKGROUND

Continuous and intermittent bolus orogastric feedings are strategies used in infants unable to tolerate normal feeds.

METHODS

To determine the effects of feeding modality on protein synthesis in different tissues, neonatal pigs received a balanced formula by orogastric tube as an intermittent bolus feed every 4 h or as a continuous infusion, or were fasted overnight.

RESULTS

As compared with fasting, protein synthesis in gastrocnemius, masseter, and soleus muscles; left ventricle; liver; pancreas; jejunum; and kidney increased in bolus- and continuously fed pigs, but the greatest increase occurred after a bolus meal. Tuberous sclerosis complex (TSC2), the proline-rich AKT substrate of 40 kDa (PRAS40), eukaryotic initiation factor (eIF) 4E binding protein (4EBP1), and ribosomal protein S6 kinase 1 (S6K1) phosphorylation in all tissues, and the proportion of ribosomal protein S4 in liver polysomes were enhanced 90 min following the bolus meal but not immediately before the meal or during continuous feeding. Eukaryotic elongation factor 2 (eEF2) and eIF2α phosphorylation were unaffected by feeding.

CONCLUSION

These results suggest that intermittent bolus feeding increases protein synthesis in muscles of different fiber types and visceral tissues to a greater extent than continuous feeding by stimulating translation initiation.

Nutrition Management of the Critically Ill Pediatric Patient

Provision of optimal nutritional support to children in the pediatric intensive care unit (PICU) is important for optimizing nutritional management, yet challenging because of a variety of factors. Previous nutritional status, degree of malnutrition, and variability in disease states differ significantly among PICU patients. Although there are numerous benefits for enteral nutrition (EN) in critically ill children, obstacles exist within the PICU that prevent the initiation and delivery of appropriate EN and parenteral nutritional (PN) support. Evidence-based nutrition care guidelines have been established to promote optimal nutrition support practice in PICU patients, including identification of those at greatest nutritional risk, initiating EN or PN in a timely manner, and providing EN as the preferred nutrition support modality for children with a functioning gastrointestinal tract. Strategies can be implemented to minimize avoidable delays or interruptions to the optimal delivery of PN and EN, including establishing nutrition support guidelines to promote consistency in practice, promoting clear and consistent communication among the PICU team via direct communication, unit rounds, and the medical record. The education of frontline PICU staff by trained professionals such as pediatric registered dietitians board certified in pediatric nutrition or nutrition support practice can also help promote improved nutritional support practice and outcomes. Specific strategies to optimize nutritional support and EN initiation and delivery at the author’s institution are also presented.

Near-infrared spectroscopy measurements of splanchnic tissue oxygenation during continuous versus intermittent feeding method in preterm infants

OBJECTIVES

The aim of the present study was to compare the effects of continuous and intermittent bolus milk feeding on splanchnic regional oxygenation (rSO₂S) in small-for-gestational age (SGA) and appropriate-for-gestational age (AGA) preterm infants.

METHODS

Infants with gestational age <32 weeks were prospectively studied by near-infrared spectroscopy. Each infant was given a milk bolus in ~10 minutes (intermittent feeding) followed after 3 hours by a 3-hour continuous feeding. rO₂S and splanchnic fractional oxygen extraction ratio (FOES [S = splanchnic]) were recorded 30 minutes before (T₀) and 30 minutes after the beginning of bolus feeding (T₁), 30 minutes before (T₂), at the end (T₃), and 30 minutes after the continuous feeding period (T₄).

RESULTS

rSO2S increased at T₁ in both AGA and SGA groups, whereas FOES did not vary during the study period. Moreover, we found that rSO2S was higher and FOES was lower at T₁ and T₃ in the AGA than in the SGA group.

CONCLUSIONS

Bolus milk feeding increases splanchnic oxygenation in both AGA and SGA infants, whereas continuous feeding does not. Splanchnic oxygenation is higher in AGA than in SGA infants both during bolus and continuous feeding. Continuous enteral feeding could help to limit the risk of hypoxic-ischemic gut damage in preterm infants in critical condition, especially in AGA infants.

Early trophic feeding versus enteral fasting for very preterm or very low birth weight infants

BACKGROUND

The introduction of enteral feeds for very preterm (< 32 weeks) or very low birth weight (< 1500 grams) infants is often delayed due to concern that early introduction may not be tolerated and may increase the risk of necrotising enterocolitis. However, prolonged enteral fasting may diminish the functional adaptation of the immature gastrointestinal tract and extend the need for parenteral nutrition with its attendant infectious and metabolic risks. Trophic feeding, giving infants very small volumes of milk to promote intestinal maturation, may enhance feeding tolerance and decrease the time taken to reach full enteral feeding independently of parenteral nutrition.

OBJECTIVES

To determine the effect of early trophic feeding versus enteral fasting on feed tolerance, growth and development, and the incidence of neonatal morbidity (including necrotising enterocolitis and invasive infection) and mortality in very preterm or VLBW infants.

SEARCH METHODS

We used the standard search strategy of the Cochrane Neonatal Review Group. This included electronic searches of the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 12), MEDLINE, EMBASE and CINAHL (1980 until December 2012), conference proceedings and previous reviews.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials that assessed the effects of early trophic feeding (milk volumes up to 24 ml/kg/day introduced before 96 hours postnatal age and continued until at least one week after birth) versus a comparable period of enteral fasting in very preterm or very low birth weight infants.

DATA COLLECTION AND ANALYSIS

We extracted data using the standard methods of the Cochrane Neonatal Review Group with separate evaluation of trial quality and data extraction by two authors and synthesis of data using risk ratio, risk difference and mean difference.

MAIN RESULTS

Nine trials in which a total of 754 very preterm or very low birth weight infants participated were eligible for inclusion. Few participants were extremely preterm (< 28 weeks) or extremely low birth weight (< 1000 grams) or growth restricted. These trials did not provide any evidence that early trophic feeding affected feed tolerance or growth rates. Meta-analysis did not detect a statistically significant effect on the incidence of necrotising enterocolitis: typical risk ratio 1.07 (95% confidence interval 0.67 to 1.70); risk difference 0.01 (-0.03 to 0.05).

AUTHORS' CONCLUSIONS

The available trial data do not provide evidence of important beneficial or harmful effects of early trophic feeding for very preterm or very low birth weight infants. The applicability of these findings to extremely preterm, extremely low birth weight or growth restricted infants is limited. Further randomised controlled trials would be needed to determine how trophic feeding compared with enteral fasting affects important outcomes in this population.

Is there an advantage for preterm infants to feed orally in an upright or sidelying position?

Over the last decade, nursing staff and feeding therapists have promoted the upright and sidelying bottle feeding positions as 'optimal' for preterm infants. To verify such benefits, very low birth weight infants were randomized to being fed in the customary semi-reclined (control), upright, or side-lying position. The primary outcome was days from start to independent oral feeding. Secondary outcomes included infants' oral feeding skill levels monitored when taking 1,2, 3-5, and 6-8 oral feedings per day. Infants fed in the upright and sidelying groups attained independent oral feeding within the same number of days as control counterparts. There was no difference in the maturation of their oral feeding skills.

Early Versus Late Minimal Enteral Feeding in Weeks Preterm Growth-Restricted neonates with Abnormal Antenatal Doppler Studies

Abstract Background: Preterm and growth-restricted babies are at high risk of milk intolerance and necrotising enterocolitis, as well as post-natal growth failure. Objective: To evaluate the effects of an "early" enteral feeding regimen, starting on day 2 after birth compared to late enteral feeding, starting on day 6 after birth in preterm growth restricted babies with abnormal antenatal Doppler studies regarding the incidence of NEC and feeding intolerance. Patients and Methods: Babies with gestational age below 37 weeks, and with birth weight below 10th centile for gestational age, will be randomly allocated to an "early" or "late" enteral feeding regimen. Results: Hundred-thirty three infants enrolled in the study: 66 received early feeding and 67 received delayed feeding. The incidence of NEC and feeding intolerance was not significantly different between the two groups. Conclusion: Early minimal enteral feeding (MEF) of preterm infants with IUGR and abnormal antenatal Doppler results may not have a significant effect on the incidence of NEC or feeding intolerance.

Feed intolerance and necrotizing enterocolitis in preterm small-for-gestational age neonates with normal umbilical artery Doppler flow

This was a prospective observational study conducted in a level III neonatal unit in North India to measure the incidence of feed intolerance and necrotizing enterocolitis (NEC) in preterm small for gestational age (SGA) neonates with normal umbilical artery Doppler flow in comparison with gestation matched appropriate for gestational age (AGA) neonates. Fifty consecutive singleton SGA preterms between 28 and 34 weeks gestation with normal Doppler were enrolled and 50 gestation matched AGA served as controls. There was a trend toward more feed intolerance (22% vs. 12%, p = 0.183), NEC (12% vs. 6%, p = 0.295) and mortality (8% vs. 2%, p = 0.362) in SGA group and these babies also had significantly more hypoglycemia (p = 0.000) and polycythemia (p = 0.032) and longer hospital stay (p = 0.017).

Neonatal short bowel syndrome as a model of intestinal failure: physiological background for enteral feeding

Intestinal failure (IF) is a well identified clinical condition, which is characterised by the reduction of functional gut capacity below the minimum needed for adequate digestion and absorption of nutrients for normal growth in children. Short bowel syndrome (SBS) is the leading cause of IF in neonates, infants and young children usually as a result of extensive intestinal resection during the neonatal period. Simultaneously maintaining optimal nutritional status and achieving intestinal adaptation is a clinical challenge in short bowel patients. Both growth and development of the child as well as gut adaptation should be considered synergistically as primary outcome parameters. Enteral nutrition (EN) can be introduced orally and/or by tube feeding (TF). Several controversies over nutritional treatment of children with SBS related intestinal failure remain. As reported from different centres around the world, most practices are more "experienced based" rather than "evidence based". This is partly due to the small number of patients with this condition. This review (based on a consensus) discusses the physiological principles and nutritional management, including the type of diet and route of delivery. Perspectives in optimizing intestinal adaptation and reducing the consequences of small intestinal bacterial overgrowth are also discussed.

A UK and Irish survey of enteral nutrition practices in paediatric intensive care units

The aim of the present study was to describe the present knowledge of healthcare professionals and the practices surrounding enteral feeding in the UK and Irish paediatric intensive care unit (PICU) and propose recommendations for practice and research. A cross-sectional (thirty-four item) survey was sent to all PICU listed in the Paediatric Intensive Care Audit Network (PICANET) database (http://www.picanet.org.uk) in November 2010. The overall PICU response rate was 90 % (27/30 PICU; 108 individual responses in total). The overall breakdown of the professional groups was 59 % nursing staff (most were children's nurses), 27 % medical staff, 13 % dietitians and 1 % physician assistants. Most units (96 %) had some written guidance (although brief and generic) on enteral nutrition (EN); 85 % of staff, across all professional groups (P= 0.672), thought that guidelines helped to improve energy delivery in the PICU. Factors contributing to reduced energy delivery included: fluid-restrictive policies (60 %), the child just being 'too ill' to feed (17 %), surgical post-operative orders (16 %), nursing staff being too slow in starting feeds (7 %), frequent procedures requiring fasting (7 %) and haemodynamic instability (7 %). What constituted an 'acceptable' level of gastric residual volume (GRV) varied markedly across respondents, but GRV featured prominently in the decision to both stop EN and to determine feed tolerance and was similar for all professional groups. There was considerable variation across respondents about which procedures required fasting and the duration of this fasting. The present survey has highlighted the variability of the present enteral feeding practices across the UK and Ireland, particularly with regard to the use of GRV and fasting for procedures. The present study highlights a number of recommendations for both practice and research.

Oral feeding competences of healthy preterm infants: a review

Background. With increasing sophistication and technology, survival rates hugely improved among preterm infants admitted to the neonatal intensive care unit. Nutrition and feeding remain a challenge and preterm infants are at high risk of encountering oral feeding difficulties. Objective. To determine what facts may impact on oral feeding readiness and competence and which kind of interventions should enhance oral feeding performance in preterm infants. Search Strategy. MEDILINE database was explored and articles relevant to this topic were collected starting from 2009 up to 2011. Main Results. Increasingly robust alertness prior to and during feeding does positively impact the infant's feeding Skills. The review found that oral and non-oral sensorimotor interventions, provided singly or in combination, shortened the transition time to independent oral feeding in preterm infants and that preterm infants who received a combined oral and sensorimotor intervention demonstrated more advanced nutritive sucking, suck-swallow and swallow-respiration coordination than those who received an oral or sensorimotor intervention singly.

Early or delayed enteral feeding for preterm growth-restricted infants: a randomized trial

BACKGROUND

Growth-restricted preterm infants are at increased risk of developing necrotizing enterocolitis (NEC) and initiation of enteral feeding is frequently delayed. There is no evidence that this delay is beneficial and it might further compromise nutrition and growth.

METHODS

Infants with gestation below 35 weeks, birth weight below the 10th centile, and abnormal antenatal umbilical artery Doppler waveforms were randomly allocated to commence enteral feeds "early," on day 2 after birth, or "late," on day 6. Gradual increase in feeds was guided by a "feeding prescription" with rate of increase the same for both groups. Primary outcomes were time to achieve full enteral feeding sustained for 72 hours and NEC.

RESULTS

Four hundred four infants were randomly assigned from 54 hospitals in the United Kingdom and Ireland (202 to each group). Median gestation was 31 weeks. Full, sustained, enteral feeding was achieved at an earlier age in the early group: median age was 18 days compared with 21 days (hazard ratio: 1.36 [95% confidence interval: 1.11-1.67]). There was no evidence of a difference in the incidence of NEC: 18% in the early group and 15% in the late group (relative risk: 1.2 [95% confidence interval: 0.77-1.87]). Early feeding resulted in shorter duration of parenteral nutrition and high-dependency care, lower incidence of cholestatic jaundice, and improved SD score for weight at discharge.

CONCLUSIONS

Early introduction of enteral feeds in growth-restricted preterm infants results in earlier achievement of full enteral feeding and does not appear to increase the risk of NEC.

Maternal dietary DHA supplementation to improve inflammatory outcomes in the preterm infant

Dietary DHA (22:6n-3) is a long-chain PUFA that has provocative effects on inflammatory signal events that could potentially affect preterm infant health. It is well known that the essential fatty acid of the (n-3) series; α-linolenic acid (18:3n:3) can be desaturated and elongated in the liver endoplasmic reticulum and peroxisome to produce the 22-carbon DHA. Nevertheless, concern exists as to the efficiency of this mechanism in providing the preterm infant with adequate DHA. Activity of the δ-6-desaturase and the δ-5-desaturase necessary for DHA synthesis is decreased by protein deprivation. The combined effects of suboptimal intake of both DHA and protein in the preterm infants could have substantial clinical consequences.

Anabolic signaling and protein deposition are enhanced by intermittent compared with continuous feeding in skeletal muscle of neonates

Orogastric tube feeding is indicated for neonates with impaired ability to ingest and can be administered by intermittent bolus or continuous schedule. Our aim was to determine whether feeding modalities affect muscle protein deposition and to identify mechanisms involved. Neonatal pigs were overnight fasted (FAS) or fed the same amount of food continuously (CON) or intermittently (INT; 7 × 4 h meals) for 29 h. For 8 h, between hours 20 and 28, pigs were infused with [(2)H(5)]phenylalanine and [(2)H(2)]tyrosine, and amino acid (AA) net balances were measured across the hindquarters. Insulin, branched-chain AA, phenylalanine, and tyrosine arterial concentrations and whole body phenylalanine and tyrosine fluxes were greater for INT after the meal than for CON or FAS. The activation of signaling proteins leading to initiation of mRNA translation, including eukaryotic initiation factor (eIF)4E·eIF4G complex formation in muscle, was enhanced by INT compared with CON feeding or FAS. Signaling proteins of protein degradation were not affected by feeding modalities except for microtubule-associated protein light chain 3-II, which was highest in the FAS. Across the hindquarters, AA net removal increased for INT but not for CON or FAS, with protein deposition greater for INT. This was because protein synthesis increased following feeding for INT but remained unchanged for CON and FAS, whereas there was no change in protein degradation across any dietary treatment. These results suggest that muscle protein accretion in neonates is enhanced with intermittent bolus to a greater extent than continuous feeding, mainly by increased protein synthesis.

Enteral feeding practices in the NICU: results from a 2009 Neonatal Enteral Feeding Survey

PURPOSE

: The purpose of this study was to examine the current management of the enteral feeding regimens of premature infants cared for in the neonatal intensive care unit (NICU).

SUBJECTS

: The study included responses from 70 neonatal nurses who participated in a 2009 Neonatal Enteral Feeding Survey distributed electronically to the National Association of Neonatal Nurses membership. These respondents were representative of both the United States and Canada, with 29 US states represented. The majority of respondents (95.7%) reported current nursing employment in a level III NICU.

DESIGN

: Survey research was used in this exploratory study. The survey, Enteral Tube Feeding Practices in the Neonatal Intensive Care Unit, was developed in collaboration with expert neonatal nurses and nutritionists, pilot tested, and distributed via electronic means.

METHODS

: Survey research was conducted according to the Dillman methodology. Data analysis included descriptive statistics and univariate analysis of variance assessing for significant differences in specific neonatal feeding practices reported. Thematic analysis was used to analyze the qualitative data reported.

OUTCOME MEASURES

: The outcome measures included the survey responses to the questions asked about the implementation of an enteral feeding protocol and various aspects of enteral feeding practices in the NICU.

RESULTS

: The majority of participants (60.9%) reported that an enteral feeding protocol was implemented in practice, but that it was inconsistently followed because of individual physician or nurse practice patterns, or highly individualized feeding plans required of specific clinical care needs of the patient. Respondents indicated that gestational age was the leading criteria used to initiate feedings, and patent ductus arteriosis treatment was the primary contraindication to enteral feedings. The leading factor reported to delay or alter enteral feedings was the presence of gastric residuals. Survey data indicated that other contraindicating factors to enteral feeding are variable across NICUs and, as reported, are often inconsistent with the current research published to date.

CONCLUSIONS

: Research is needed to provide a foundation on which to develop effective enteral feeding protocols that are appropriate for the diversity of infants cared for in the NICU. Such research findings will culminate in the development and implementation of enteral feeding protocols in the NICU, which will result in improved nutrition, growth, and development outcomes for premature infants.

Intermittent bolus feeding has a greater stimulatory effect on protein synthesis in skeletal muscle than continuous feeding in neonatal pigs

Orogastric tube feeding, using either continuous or intermittent bolus delivery, is common in infants for whom normal feeding is contraindicated. To compare the impact of different feeding strategies on muscle protein synthesis, after withholding food overnight, neonatal pigs received a complete formula orally as a bolus feed every 4 h or were continuously fed. Protein synthesis rate and translational mechanisms in skeletal muscle were examined after 0, 24, and 25.5 h. Plasma amino acid and insulin concentrations increased minimally and remained constant in continuously fed compared to feed-deprived pigs; however, the pulsatile meal feeding pattern was mimicked in bolus-fed pigs. Muscle protein synthesis was stimulated by feeding and the greatest response occurred after a bolus meal. Bolus but not continuous feeds increased polysome aggregation, the phosphorylation of protein kinase B, tuberous sclerosis complex 2, proline-rich Akt substrate of 40 kDa, eukaryotic initiation factor (eIF) 4E binding protein (4EBP1), and rp S6 kinase and enhanced dissociation of the 4EBP1 ·eIF4E complex and formation of the eIF4E ·eIF4G complex compared to feed deprivation (P < 0.05). Activation of insulin receptor substrate-1, regulatory associated protein of mammalian target of rapamycin, AMP-activated protein kinase, eukaryotic elongation factor 2, and eIF2α phosphorylation were unaffected by either feeding modality. These results suggest that in neonates, intermittent bolus feeding enhances muscle protein synthesis to a greater extent than continuous feeding by eliciting a pulsatile pattern of amino acid- and insulin-induced translation initiation.

Continuous nasogastric milk feeding versus intermittent bolus milk feeding for premature infants less than 1500 grams

BACKGROUND

Milk feedings can be given via nasogastric tube either intermittently, typically over 10 to 20 minutes every two or three hours, or continuously, using an infusion pump. Although theoretical benefits and risks of each method have been proposed, effects on clinically important outcomes remain uncertain.

OBJECTIVES

To examine the evidence regarding the effectiveness of continuous versus intermittent bolus nasogastric milk feeding in premature infants less than 1500 grams.

SEARCH METHODS

Searches were performed of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2011), MEDLINE, CINAHL and HealthSTAR up to July 2011.

SELECTION CRITERIA

Randomised and quasi-randomised clinical trials comparing continuous versus intermittent bolus nasogastric milk feeding in premature infants less than 1500 grams.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed all trials for relevance and methodologic quality. The standard methods of the Cochrane Neonatal Review Group were used to extract data.

MAIN RESULTS

Overall, the seven included trials, involving 511 infants, found no differences in time to achieve full enteral feeds between feeding methods (weighted mean difference (WMD) 2 days; 95% CI -0.3 to 3.9) . In the subgroup analysis of those studies comparing continuous nasogastric versus intermittent bolus nasogastric milk feedings the findings remained unchanged (WMD 2 days, 95% CI -0.4 to 4.1). There was no significant difference in somatic growth and incidence of NEC between feeding methods irrespective of tube placement. One study noted a trend toward more apneas during the study period in infants fed by the continuous tube feeding method compared to those fed by intermittent feedings delivered predominantly by orogastric tube placements [mean difference (MD) 14.0 apneas during study period; 95% CI -0.2 to 28.2]. In subgroup analysis based on weight groups, one study suggested that infants less than 1000 grams and 1000 to 1250 grams birth weight gained weight faster when fed by the continuous nasogastric tube feeding method compared to intermittent nasogastric tube feeding method (MD 2.0 g/day; 95% CI 0.5 to 3.5; MD 2.0 g/day; 95% CI 0.2 to 3.8, respectively). A trend toward earlier discharge for infants less than 1000 grams birth weight fed by the continuous tube feeding method compared to intermittent nasogastric tube feeding method (MD -11 days; 95% CI -21.8 to -0.2).

AUTHORS' CONCLUSIONS

Small sample sizes, methodologic limitations, inconsistencies in controlling variables that may affect outcomes, and conflicting results of the studies to date make it difficult to make universal recommendations regarding the best tube feeding method for premature infants less than 1500 grams. The clinical benefits and risks of continuous versus intermittent nasogastric tube milk feeding cannot be reliably discerned from the limited information available from randomised trials to date.

Oral and non-oral sensorimotor interventions enhance oral feeding performance in preterm infants

AIM

The aim of this study was to determine whether oral, tactile/kinaesthetic (T/K), or combined (oral+T/K) interventions enhance oral feeding performance and whether combined interventions have an additive/synergistic effect.

METHOD

Seventy-five preterm infants (mean gestational age 29 wk; standard error of the mean [SEM] 0.3 wk; mean birthweight 1340.3g; SEM 52.5 g; 49 males and 26 females) were randomly assigned to one of three intervention groups or a control group. The oral group received sensorimotor input to the oral structures, the T/K group received sensorimotor input to the trunk and limbs, and the combined group received both. The outcomes were time from introduction of nipple feeding to independent oral feeding (d), proficiency (intake in the first 5 min, %), volume transfer (%), rate of transfer (mL/min), volume loss (%), and length of hospital stay (d).

RESULTS

Infants in the three intervention groups achieved independent oral feeding 9-10 days earlier than those in the control group (p<0.001; effect size 1.9-2.1). Proficiency (p ≤ 0.002; effect size 0.7-1.4) at the time of one to two and three to five oral feedings per day, volume transfer (p ≤ 0.001; effect size 0.8-1.1) at one to two, three to five, and six to eight oral feedings per day, and overall rate of transfer (p ≤ 0.018; effect size 0.8-1.1) were greater, and overall volume losses were less (p ≤ 0.007; effect size 0.9-1.1), than in the control group (p ≤ 0.042). The combined group attained independent oral feeding at a significantly younger postmenstrual age than controls (p=0.020) and had clinically greater proficiency than the T/K group (p=0.020; effect size 0.7) and oral group (p=0.109; effect size 0.5). Length of hospital stay was not significantly different between groups (p=0.792; effect size 0.02-0.3).

INTERPRETATION

Oral and T/K interventions accelerated the transition from introduction to independent oral feeding and enhanced oral feeding skills. T/K has beneficial effects beyond the specific targeted system. The combined sensorimotor intervention led to an additive/synergistic effect for proficiency, further benefiting this population.

Nutrition support in the pediatric surgical patient

This article deals with the nutritional needs of pediatric patients. It begins by discussing the caloric requirements of different pediatric patients and moves on to a breakdown of the specific nutrients required. It then progresses to a detailed description of the enteral and parenteral modalities for delivery of nutrition to pediatric patients. The article concludes with a discussion of specific problems and disorders encountered in pediatric surgical patients.

The impact of feeding interval on feeding outcomes in very low birth-weight infants

OBJECTIVE

Test the hypothesis that very low birth-weight (VLBW) infants fed every 2 h (q2) are able to reach full enteral feedings more quickly than infants fed every 3 h (q3).

STUDY DESIGN

We performed a retrospective cohort study comparing q2 infants (n=103) with q3 infants (n=251). The primary outcome was days from start of a feeding advance to full feedings (120 ml per kg per day). Multivariable regression models were used to control for maternal and perinatal factors that preceded the initiation of the feeding advance.

RESULT

Infants fed q2 reached full feedings 2.7 days sooner than q3 infants (95% confidence interval (CI) 1.5, 3.9). After adjustment for confounders, q2 infants reached full feedings 3.7 (95% CI 1.6, 5.9) days more quickly. Infants fed q3 were more likely to receive >28 days of parenteral nutrition (odds ratio (OR) 4.7; 95% CI 1.5, 14.4), and were more likely to have feeds held for ≥ 7 days (OR 4.7, 95% CI 1.9, 11.7).

CONCLUSION

VLBW infants demonstrate improved feeding tolerance when fed more frequently.

Delayed introduction of progressive enteral feeds to prevent necrotising enterocolitis in very low birth weight infants

BACKGROUND

The introduction of progressive enteral feeds for very low birth weight (VLBW) infants is often delayed for several days or longer after birth due to concern that earlier introduction may not be tolerated and may increase the risk of necrotising enterocolitis (NEC). However, delaying enteral feeding could diminish the functional adaptation of the gastrointestinal tract and prolong the need for parenteral nutrition with its attendant infectious and metabolic risks.

OBJECTIVES

To determine the effect of delayed introduction of progressive enteral feeds on the incidence of NEC, mortality and other morbidities in VLBW infants.

SEARCH STRATEGY

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 delayed (more than four days' postnatal age) versus earlier introduction of progressive enteral feeds on the incidence of NEC, mortality and other morbidities in VLBW infants.

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

We identified five randomised controlled trials (RCT) in which a total of 600 infants participated. The trials defined delayed introduction as later than five to seven days after birth and early introduction as less than four days after birth. Two of the trials, in which a total of 488 infants participated, only recruited growth-restricted infants with Doppler ultrasound evidence of abnormal fetal circulatory distribution or flow. Meta-analyses did not detect statistically significant effects on the risk of NEC [typical relative risk 0.89, 95% confidence interval (CI) 0.58 to 1.37] or all cause mortality (typical relative risk 0.93, 95% CI 0.53 to 1.64). Infants who had delayed introduction of enteral feeds took significantly longer to establish full enteral feeding (reported median difference three days).

AUTHORS' CONCLUSIONS

Current trial data do not provide evidence that delayed introduction of progressive enteral feeds reduces the risk of NEC in VLBW infants. Delaying the introducing of progressive enteral feeds results in several days delay in establishing full enteral feeds but the clinical importance of this effect is unclear. Further RCTs are needed to give more precise estimates of the effect of delaying the introduction of enteral feeds on clinical outcomes in VLBW infants.

An evaluation of enteral feeding practices in critically ill children

BACKGROUND

Establishing and sustaining enteral feeding in critically ill children is challenging and has met with many problems.

AIMS AND OBJECTIVES

The aim of this study was to investigate (a) how actual calorie intake compared with estimated caloric requirements and (b) whether feeding guideline adherence resulted in improved nutritional intake.

DESIGN AND METHODS

A prospective observational study was undertaken over 1 month in a tertiary referral paediatric intensive care unit (PICU) in the northwest of England.

RESULTS

Forty-seven children were studied, with a wide range of diagnoses in a 1-month period. Only 47% of the children had enteral feeds started within our 6 h post-admission target. Over half (55%) of the children received less than half of their estimated calorie requirements, but if feeding guidelines were followed, this resulted in a significantly higher (p = 0.004) delivery of the child's estimated requirements.

CONCLUSIONS

This study found that many children are not receiving adequate nutrition in PICU and that the use of feeding guidelines significantly improves calorie delivery in PICU patients.

RELEVANCE TO CLINICAL PRACTICE

This paper highlights the dearth of research related to enteral feeding in critically ill children. We found that the use of feeding guidelines improved calorie delivery and so units should be encouraged to develop their own guidelines based on the best evidence available.

Evaluation of potential factors predicting attainment of full gavage feedings in preterm infants

BACKGROUND

The clinical measures of gastric residuals and abdominal distention are often used to guide feeding in preterm infants, but there are few data demonstrating their usefulness. Similarly, techniques are now available to investigate gastrointestinal (GI) function noninvasively and safely, but their ability to predict attainment of full gavage feedings and/or feeding volume in preterm infants is unclear.

OBJECTIVE

We sought to determine prospectively the potential relationships of attainment of full gavage feedings and feeding volume with clinical measures and noninvasive GI tests.

METHODS

Fifty preterm infants were followed prospectively. Daily tally was taken of gavage feeding intake, gastric residual volumes (GRVs; milliliters per day, number of GRVs >50% of the previous feeding volume, and number of GRVs >2 ml/kg), and abdominal distention. Infants underwent repeated measurement of lactase activity, GI permeability, fecal calprotectin concentration, and gastric emptying.

RESULTS

The number of GRVs >2 ml/kg tended to decrease with postnatal age (p = 0.06). Lactase activity and feeding volume in milliliters per kilogram per day prior to achieving full feedings were correlated (p = 0.007, β = 0.164). There was no correlation between feeding outcomes and GRV (ml/day), GRV >50%, GRV >2 ml/kg, small bowel, colonic, or whole bowel permeability, fecal calprotectin concentration, gastric emptying, or abdominal distention.

CONCLUSIONS

GRV is unreliable in predicting attainment of full gavage feeding. Lactase activity is related to feeding volume. However, other noninvasive GI tests utilized were not predictive. These data cast doubt upon the utility of GRV in guiding feeding therapy. Randomized trials of different GRV management protocols are needed.

Intestinal absorption of lipid emulsion in premature infants: a pilot study

BACKGROUND

Adequate nutritional intake is essential in the very-low-birth-weight infant, but difficult to achieve in the first few postnatal days. Can lipids be given enterally in the first few days of life in sick preterm infants?

OBJECTIVE

To determine tolerance and absorption of lipid emulsion when fed enterally to very-low-birth-weight infants.

DESIGN/METHODS

Infants had a birth weight <1,500 g, an appropriate weight for gestational age, and were receiving parenteral nutrition. We performed a progressive series of studies, enrolling 5 infants in each group. Group 1 infants were fed enteral lipid emulsion at 1 g/kg/day for 4 days, starting when 60 ml/kg/day of breast milk was tolerated enterally. Simultaneously, a matched control group which received no oral lipid emulsion was enrolled. We then enrolled group 2 infants who were fed 3 g/kg/day with the same protocol as group 1. Group 3 infants were fed enteral lipid emulsion starting in the first 72 h of life. The infants were fed 1, 2 and 3 g/kg/day subsequently for 48 h each. Fat absorption was measured.

RESULTS

Gestational age was 24.6-30.8 weeks and birth weight was 620-1,400 g. One infant (group 1) developed necrotizing enterocolitis 1 week after the study. There were no other adverse clinical findings. On average, enteral lipid emulsion was started on day 8 of life in groups 1 and 2, and on day 2 in group 3. The intestinal lipid absorption was 93.6% (min. = 76%). There was no difference in fat absorption between the 4 groups (p > 0.05).

CONCLUSIONS

Lipid emulsions are an isotonic high-calorie source which can be given safely enterally instead of intravenously in the immediate neonatal period of very-low-birth-weight infants without clinical adverse effects and with almost complete absorption. There are potential advantages to oral administration of a lipid emulsion starting in early life which require further investigation.

Relationship of Neonatal Oral Motor Assessment Scale to Feeding Performance of Premature Infants

OBJECTIVE: Some premature infants require prolonged tube-feeding, beyond term equivalent gestational age. Tools that could prospectively identify such infants from among otherwise healthy patients are needed. We examined how well the Neonatal Oral Motor Assessment Scale (NOMAS) predicts premature infants' transition from tube to oral feeding. DESIGN: Data from a prospective study of sucking behavior as a predictor of feeding skills were used to examine the relationship of NOMAS and other nominal predictors to pre-defined feeding milestones. SETTING: Neonatal intensive Care Unit PATIENTS: 51 tube-fed, premature infants METHODS: NOMAS was administered soon (<72 hours) after oral feeding was initiated, and weekly thereafter, until infants reached full oral feeding. A timed measure of feeding efficiency was also done as oral feeding was initiated. A standardized, permissive protocol for feeding advance was used. Nonparametric rank sum tests and ANOVA were used to relate NOMAS, feeding efficiency, and other baseline variables to feeding milestones. RESULTS: Gestational age at birth, birth weight, and initial feeding efficiency predicted shorter transition and earlier acquisition to full oral feeding; NOMAS scores did not predict feeding outcomes. CONCLUSIONS: NOMAS was a poor predictor, while feeding efficiency and other baseline traits were better predictors of feeding skills in premature infants.

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

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

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.

Early trophic feeding for very low birth weight infants

BACKGROUND

The introduction of enteral feeds for very low birth weight (VLBW) infants is often delayed due to concern that early introduction may not be tolerated and may increase the risk of necrotising enterocolitis. However, enteral fasting may diminish the functional adaptation of the immature gastrointestinal tract and prolong the need for parenteral nutrition with its attendant infectious and metabolic risks. Early trophic feeding, giving infants very small volumes of milk during the first week after birth, may promote intestinal maturation, enhance feeding tolerance and decrease time to reach full enteral feeding independently of parenteral nutrition.

OBJECTIVES

To determine the effect of early trophic feeding versus enteral fasting on feed tolerance, growth, and the incidence of necrotising enterocolitis, mortality and other morbidities in VLBW 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 1, 2009), MEDLINE (1966 - February 2009), EMBASE (1980 - February 2009), CINAHL (1982 - February 2009), conference proceedings, and previous reviews.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials that assessed the effects of early trophic feeding (milk volumes up to 24 ml/kg/day introduced before 96 hours postnatal age and continued until at least one week after birth) versus a comparable period of enteral fasting in VLBW 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 review authors. Data were synthesised using a fixed effects model and reported using typical relative risk, typical risk difference and weighted mean difference.

MAIN RESULTS

Nine trials, in which a total of 754 VLBW infants participated, were eligible for inclusion. These trials did not provide any evidence that early trophic feeding affected feed tolerance or growth rates in VLBW infants. Meta-analysis did not detect a statistically significant effect on the incidence of necrotising enterocolitis: typical relative risk 1.07 (95% confidence interval 0.67, 1.70); typical risk difference 0.01 (95% confidence interval -0.04, 0.05).

AUTHORS' CONCLUSIONS

The available data cannot exclude important beneficial or harmful effects and are insufficient to inform clinical practice. Further large pragmatic randomised controlled trials are needed to determine how early trophic feeding compared with enteral fasting affects important clinical outcomes in VLBW infants.

The effects of formula feeding on physiological and immunological parameters in the gut of neonatal rats

A unique model of formula feeding in the neonatal rat was utilized to investigate the effects of an enterally delivered artificial milk formula on clinically relevant immunological and biological characteristics in the gut, compared to naturally reared pups. Hooded Wistar rat pups were randomly allocated to two treatment groups: formula-fed (FF) or naturally suckled (NS). A flexible silastic intra-gastric cannula was surgically implanted into the FF pups, through which an artificial rat milk supplement was continuously delivered from day 4 to day 10 of life. Rat pups were sacrificed at 10 days of age. Body weight, small intestinal weight, mucosal CD8(+) cell numbers, and ileal lactase activity in FF animals were significantly decreased compared to their NS counterparts (P < 0.05). Numbers of eosinophils, mucosal mast cells, CD4(+) T-cells, ileal villus height and gastric emptying times were significantly increased in FF pups (P < 0.05). We have developed a new rat model of artificial feeding which possesses important immunological and biological similarities to the premature human infant.

Early amino-acid administration improves preterm infant weight

OBJECTIVE

Premature infants, especially those born less than 1500 g, often exhibit slow overall growth after birth and lack of early nutritional support may be an important element. We tested the hypothesis that early administration of amino acids (within the first few hours of life) to infants born at less than 1500 g would be associated with fewer infants that were less than the 10th percentile at 36 weeks post-conceptual age than infants that received amino acids after the first 24 h of life.

STUDY DESIGN

A prospective intervention of early amino-acid (EAA) supplementation, began before 24 h of life, in preterm infants, <1500 g, was compared to a retrospective cohort of preterm infants receiving late amino-acid (LAA) supplementation, began after 24 h of life. The primary outcome variable was the proportion of infants at less than the 10th percentile at 36 weeks post-conceptual age.

RESULT

Fewer infants fell below the 10th percentile (P<0.001) in the EAA group. Furthermore, infants in the EAA groups had significantly greater weight gains than did the LAA group (P<0.003) after adjusting for gestational age and time from birth to discharge. In addition, shorter duration of parenteral nutrition was associated with EAA supplementation (P<0.001).

CONCLUSION

A prospective strategy of EAA in preterm infants <1500 g was associated with an improved weight gain, suggesting that nutrition that included amino acids may be critical during the first 24 h of life.

Prevention and Treatment of Tube Dependency in Infancy and Early Childhood

Tube dependency is recognized as an unintended result of long-term tube feeding in infants and young children. The condition involves disturbing side effects such as vomiting, gagging, and active food refusal. It prevents infants from making the transition from tube to oral feeding and from starting to learn to eat in the absence of any medical indication for continuation of enteral feeding. Tube dependency can have a destructive impact on the child's development, even in cases when the nutritional influence might be beneficial. The authors set up recommendations for the prevention of tube dependency and suggest guidelines for weaning tube-dependent children based on the results of the Graz program and satellite programs using a similar model. A sample of 221 tube-dependent patients aged 4 months to 15 years of age provided the clinical study group on which this article is based. Begun in 1987, a comprehensive tube-weaning program was developed on the basis of clinical experience and encounters with more than 430 tube-dependent children in 20 years, resulting in a success rate of 78/81 (96% for 2007) and 79/84 (94% for 2008). Placement must be preceded by clear criteria and a decision as to the indicated nutritional goal and time of use. The placement of a temporary tube must generate a plan covering maintenance issues, including time, method, and team for weaning. Aspects of tube feeding that go beyond purely medical and nutritional issues need to be considered to minimize the frequency and severity of unintended tube dependency in early childhood.

The relationship between feeding and necrotizing enterocolitis in very low birth weight infants

Necrotizing enterocolitis (NEC) is the most common gastrointestinal emergency in the NICU, with often devastating consequences. The etiology of NEC is probably multifactorial, with preterm infants at the highest risk. The relationship between feeding and NEC was identified in the 1970s, leading to delayed feeding becoming standard treatment in NICUs. More recent research suggests that early feedings not only are safe, but reduce other morbidities associated with prematurity. Standardized feeding guidelines seem to confer some benefits in decreasing NEC, despite a wide variability in feeding practices within the published guidelines. A standardized approach to the management of feeding problems may be the key. This article briefly reviews the pathogenesis of NEC and examines studies of various feeding practices for their relationship to the development of NEC. It also highlights the potential benefits of breast milk in NEC prevention.

Neonatal nutrition: a brief review

BACKGROUND

With increasing survival of extremely premature infants, emphasis is now focused on the quality of these survivors' lives. Possibly the most important factor in the premature's ability to survive in the NICU and thrive is the ability to replicate in utero growth through enteral and parenteral nutrition.

DATA SOURCES

Current literature and review articles were retrieved from PubMed and personal files of the authors.

RESULTS

The use and complications of the various components of total parenteral nutrition (TPN) were reviewed. The composition of appropriate enteral feeds for the premature was reviewed as was the difficulties associated with the establishment of adequate enteral feeds in the premature infants.

CONCLUSIONS

Early initiation of amino acids in TPN and timely increases in the components of TPN can improve the caloric intake of prematures. Enteral feeds, particularly of breast milk, may be started within the first few days of life in all but hemodynamically unstable prematures. Newer lipid preparations show promise in reversing the hepatic damage of TPN associated cholestatic jaundice.

A controlled-flow vacuum-free bottle system enhances preterm infants' nutritive sucking skills

We have shown that a controlled-flow vacuum-free bottle system (CFVFB) vs. a standard bottle (SB) facilitates overall transfer and rate of milk transfer, and shortens oral feeding duration in very-low-birth-weight (VLBW) infants. We aimed to understand the basis by which this occurs. Thirty infants (19 males; 27 +/- 1 weeks gestation) were randomized to a CFVFB or SB. Outcomes monitored at 1-2 and 6-8 oral feedings/day when infants were around 34 and 36 weeks postmenstrual age, respectively, included: overall transfer (% volume taken/volume prescribed), rate of milk transfer (ml/min), sucking stage, frequency of suction (#S/s) and expression (#E/s), suction amplitude (mmHg), and sucking burst duration (s). At both periods we confirmed that infants using a CFVFB vs. SB demonstrated greater overall transfer and rate of milk transfer, along with more mature sucking stages. Suction and expression frequencies were decreased with CFVFB vs. SB at 1-2 oral feeding/day; only that of suction was reduced at 6-8 oral feedings/day. No group differences in suction amplitude and burst duration were observed. We speculate that oral feeding performance improves without significant change in sucking effort with a CFVFB vs. SB. In addition, we have shown that VLBW infants can tolerate faster milk flow than currently presumed. Finally, the use of a CFVFB may reduce energy expenditure as it enhances feeding performance without increasing sucking effort.

Strategies for feeding the preterm infant

According to many experts in neonatal nutrition, the goal for nutrition of the preterm infant should be to achieve a postnatal growth rate approximating that of the normal fetus of the same gestational age. Unfortunately, most preterm infants, especially those born very preterm with extremely low birth weight, are not fed sufficient amounts of nutrients to produce normal fetal rates of growth and, as a result, end up growth-restricted during their hospital period after birth. Growth restriction is a significant problem, as numerous studies have shown definitively that undernutrition, especially of protein, at critical stages of development produces long-term short stature, organ growth failure, and both neuronal deficits of number and dendritic connections as well as later behavioral and cognitive outcomes. Furthermore, clinical follow-up studies have shown that among infants fed formulas, the nutrient content of the formula is directly and positively related to mental and motor outcomes later in life. Nutritional requirements do not stop at birth. Thus, delaying nutrition after birth 'until the infant is stable' ignores the fundamental point that without nutrition starting immediately after birth, the infant enters a catabolic condition, and catabolism does not contribute to normal development and growth. Oxygen is necessary for all metabolic processes. Recent trends to limit oxygen supply to prevent oxygen toxicity have the potential, particularly when the blood hemoglobin concentration falls to less than 8 g/dl, to develop growth failure. Glucose should be provided at 6-8 mg/min/kg as soon after birth as possible and adjusted according to frequent measurements of plasma glucose to achieve and maintain concentrations >45 mg/dl but <120 mg/dl to avoid the frequent problems of hyperglycemia and hypoglycemia. Similarly, lipid is required to provide at least 0.5 g/kg/day to prevent essential fatty acid deficiency. However, the high rate of carbohydrate and lipid supply that preterm infants often get, based on the incomplete assumption that this is necessary to promote protein growth, tends to produce increased fat in organs like the liver and heart as well as adipose tissue. More and better essential fatty acid nutrition is valuable, but more organ and adipose fat has no known benefit and many problems. Amino acids and protein are essential not only for body growth but for metabolic signaling, protein synthesis, and protein accretion. 3.5-4.0 g/kg/day are necessary to produce normal protein balance and growth in very preterm infants. Attempts to promote protein growth with insulin has many problems - it is ineffective while contributing to even further organ and adipose tissue fat deposition. Enteral feeding always is indicated and to date nearly all studies have shown that minimal enteral feeding approaches (e.g., 'trophic feeds') promote the capacity to feed enterally. Milk has distinct advantages over formulas in avoiding necrotizing enterocolitis (NEC), and while feeding is associated with NEC, minimal enteral feeding regimens produce less NEC than those geared towards more aggressive introduction of enteral feeding. Finally, overfeeding has the definite potential to produce adipose tissue, or obesity, which then leads to insulin resistance, glucose intolerance, and diabetes. This scenario occurs more commonly as infants are fed more and gain weight more rapidly after birth, regardless of their birth weight. Infants with IUGR and postnatal growth failure may be uniquely 'set up' for this outcome, while infants with in utero obesity, such as infants of diabetic mothers, already are well along this adverse outcome pathway.

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.

Clinical predictors of necrotizing enterocolitis in premature infants

BACKGROUND

Necrotizing enterocolitis (NEC) has emerged as the most common neonatal gastrointestinal emergency, is the most common cause of death in neonates undergoing surgery, and accounts for yearly additional hospital charges in excess of $6.5 million. Prematurity is the only common variable identified in case-controlled studies exploring this disease.

OBJECTIVES

To improve the understanding of the relationship between factors related to intestinal inflammation and ischemia and the enteral feeding regimen in the context of the premature gut, thereby identifying antecedents of NEC.

METHODS

Data were collected from the medical records of 247 premature infants for this retrospective case-controlled study. Diagnosis of NEC, as defined by Bell Stages IIA-IIIB, was required for study group assignment (n = 84). Multivariate analysis techniques were used to predict the relationships between selected variables on the outcome of NEC.

RESULTS

Premature infants were 13 times more likely to develop NEC if the infant required increased respiratory support to maintain oxygenation during the early neonatal period and 6.4 times more likely to develop NEC if the infant did not receive nutritionally fortified enteral feedings of breast milk. When both factors were present, the odds of NEC increased 28.6 times when compared with infants without these factors.

DISCUSSION

The study findings extend knowledge of antecedents to NEC beyond prematurity, highlighting the role that respiratory support and nutritional fortification of enteral feedings play in the pathogenesis of this disease. Early identification of antecedents to NEC will improve critical care management of the neonate and, in turn, decrease the incidence of this devastating gastrointestinal disease. The study findings will guide further inquiry in neonatal nutrition, physiologic and metabolic functioning, and acute clinical management of the neonate.