Gastric emptying in pre-term infants: the effect of breast milk fortifier

Time intervals between pumping did not affect breastmilk protein produced by mothers of preterm infants

AIM

Few studies investigate factors that might influence the content of expressed breastmilk. This study aims to investigate the influence of the intervals between breastmilk pumping and the time of the day on protein and fat concentration in breastmilk.

METHODS

Mothers of very preterm infants in a neonatal ward who expressed more than 400 mL per day were included. Expressed breastmilk was obtained from each mother over 30 h who were pumping at strictly planned and varying intervals: 2, 3, 4 and 6 h. All samples were analysed using infrared transmission spectroscopy.

RESULTS

Ten mothers participated at a median of 22 days postpartum. A total of 176 milk samples were analysed, and the average protein and fat concentrations in g/100 mL were 1.1 ± 0.23 and 4.2 ± 1.3, respectively. The time intervals between breast pumping sessions did not impact protein content, but fat content decreased by longer intervals (p < 0.01). The time of the day for milk pumping did not influence the protein or fat content.

CONCLUSION

A single milk sample collected after any 2-6 h interval, at any time during the day, represents the protein content in the breastmilk, but not the fat content which decreased with longer intervals.

What to consider for successful administration of oral liquids via enteral feeding tubes? a case study with paediatric ibuprofen suspensions

Administration of medications via enteral feeding tubes (EFTs) is a common practice for children who cannot swallow properly. Although liquid formulations are the preferred dosage forms for this route of administration, little attention has been paid to the amount of drug that reaches the site of absorption after administration via an EFT. This systematic in vitro study aimed to identify formulation parameters and administration approaches that are critical for successful dose delivery via EFTs. For this purpose, drug recovery after administration of three different paediatric ibuprofen suspensions via different types of EFTs was studied using derivative UV spectrophotometry for quantification. Study results indicate that in addition to formulation parameters, feeding tube characteristics and the administration process can have a significant impact on the administered dose. The ratio between the total administered fluid volume (TAV), represented by the sum of dose- and flushing volume, and the feeding tube volume (FTV) proved to be a valuable indicator for assessing successful administration. Incorrect dosing and complications could be avoided if the TAV/FTV ratio was greater than 4. This and other knowledge gained in the study will help to make the administration of liquid paediatric medicines via EFTs both more effective and safer.

A Randomized, Controlled Study to Investigate How Bovine Colostrum Fortification of Human Milk Affects Bowel Habits in Preterm Infants (FortiColos Study)

Background: Human milk does not meet the nutritional needs to support optimal growth of very preterm infants during the first weeks of life. Nutrient fortifiers are therefore added to human milk, though these products are suspected to increase gut dysmotility. The objective was to evaluate whether fortification with bovine colostrum (BC) improves bowel habits compared to a conventional fortifier (CF) in very preterm infants. Methods: In an unblinded, randomized study, 242 preterm infants (26−31 weeks of gestation) were randomized to receive BC (BC, Biofiber Damino, Gesten, Denmark) or CF (FM85 PreNAN, Nestlé, Vevey, Switzerland) as a fortifier. Stools (Amsterdam Stool Scale), bowel gas restlessness, stomach appearance score, volume, and frequency of gastric residuals were recorded before each meal until 35 weeks post-menstrual age. Results: As intake of fortifiers increased, stools became harder in both groups (p < 0.01) though less in BC infants (p < 0.05). The incidence of bowel gas restlessness increased with laxative treatments and days of fortification in both groups (p < 0.01), but laxatives were prescribed later in BC infants (p < 0.01). With advancing age, stomach appearance scores improved, but more so in BC infants (p < 0.01). Conclusions: Although there are limitations, a minimally processed, bioactive milk product such as BC induced similar or slightly improved bowel habits in preterm infants.

Review of paediatric gastrointestinal physiology relevant to the absorption of orally administered medicines

Despite much progress in regulations to improve paediatric drug development, there remains a significant need to develop better medications for children. For the design of oral dosage forms, a detailed understanding of the specific gastrointestinal (GI) conditions in children of different age categories and how they differ from GI conditions in adults is essential. Several review articles have been published addressing the ontogeny of GI characteristics, including luminal conditions in the GI tract of children. However, the data reported in most of these reviews are of limited quality because (1) information was cited from very old publications and sometimes low quality sources, (2) data gaps in the original data were filled with textbook knowledge, (3) data obtained on healthy and sick children were mixed, (4) average data obtained on groups of patients were mixed with data obtained on individual patients, and (5) results obtained using investigative techniques that may have altered the outcome of the respective studies were considered. Consequently, many of these reviews draw conclusions that may be incorrect. The aim of the present review was to provide a comprehensive and updated overview of the available original data on the ontogeny of GI luminal conditions relevant to oral drug absorption in the paediatric population. To this end, the PubMed and Web of Science metadatabases were searched for appropriate studies that examined age-related conditions in the oral cavity, esophagus, stomach, small intestine, and colon. Maturation was observed for several GI parameters, and corresponding data sets were identified for each paediatric age group. However, it also became clear that the ontogeny of several GI traits in the paediatric population is not yet known. The review article provides a robust and valuable data set for the development of paediatric in vitro and in silico biopharmaceutical tools to support the development of age-appropriate dosage forms. In addition, it provides important information on existing data gaps and should provide impetus for further systematic and well-designed in vivo studies on GI physiology in children of specific age groups in order to close existing knowledge gaps and to sustainably improve oral drug therapy in children.

Pre-operative fasting in children: A guideline from the European Society of Anaesthesiology and Intensive Care

Current paediatric anaesthetic fasting guidelines have recommended conservative fasting regimes for many years and have not altered much in the last decades. Recent publications have employed more liberal fasting regimes with no evidence of increased aspiration or regurgitation rates. In this first solely paediatric European Society of Anaesthesiology and Intensive Care (ESAIC) pre-operative fasting guideline, we aim to present aggregated and evidence-based summary recommendations to assist clinicians, healthcare providers, patients and parents. We identified six main topics for the literature search: studies comparing liberal with conservative regimens; impact of food composition; impact of comorbidity; the use of gastric ultrasound as a clinical tool; validation of gastric ultrasound for gastric content and gastric emptying studies; and early postoperative feeding. The literature search was performed by a professional librarian in collaboration with the ESAIC task force. Recommendations for reducing clear fluid fasting to 1 h, reducing breast milk fasting to 3 h, and allowing early postoperative feeding were the main results, with GRADE 1C or 1B evidence. The available evidence suggests that gastric ultrasound may be useful for clinical decision-making, and that allowing a 'light breakfast' may be well tolerated if the intake is well controlled. More research is needed in these areas as well as evaluation of how specific patient or treatment-related factors influence gastric emptying.

Human milk-based fortifier is associated with less alteration of milk fat globule size than cow milk-based fortifier

We aimed to evaluate if human milk-based fortifier (HMBF) affects human milk fat globule (MFG) size less than cow milk-based fortifier (CMBF), which may impact overall infant feeding tolerance. Measurements of donated human milk were performed before fortification as well as at 1 hour, 24 hours, and 48 hours after fortification with CMBF or HMBF. MFG size in each sample of fortified milk was measured by laser light scattering. MFG size in the fortified milks increased gradually over time. At 24 and 48 hours after fortification, MFG size in the milk with CMBF was larger than that in the milk with HMBF (4.8 ± 0.5 vs 4.3 ± 0.3 μm, p<0.01, 5.1 ± 0.7 vs 4.5 ± 0.4 μm, p = 0.03, respectively). HMBF is associated with less alteration of MFG size than CMBF. This may have an impact on feeding tolerance of very preterm infants.

Effect of different positions on gastric residuals in preterm infants initiating full enteral feeding

BACKGROUND

This study was conducted to determine the effect of feeding in different positions on the gastric residual volume after feeding in preterm infants who initiated full enteral feeding.

METHODS

This quasi-experimental study was conducted with the hypothesis that testing the right lateral position leads to less gastric residual than left lateral position and the prone position leads to less gastric residual than the supine position. The data were collected in four stages from 35 preterm infants. Initially, the infants were positioned in supine position and were fed. After feeding, the infant rested in the supine position for 3 h. The stomach content was aspirated, and the volume of gastric residual was measured at the 60th, 120th, and 180th min after feeding. These steps are repeated in order of in the right lateral, left lateral, and prone position. Total gastric residual volume and type of enteral feeding were evaluated.

RESULTS

There was no significant difference among the positions in terms of the volume of gastric residuals in the measurements made at 60th (P = 9.552), 120th (P = .505), and 180th min (P = .430). When the amount of decrease in the gastric residual volumes was a significant difference between all measurement times in right lateral and prone positions (P < .001).

CONCLUSION

Although no significant difference was determined between the positions, the smallest residual volumes were determined in the right lateral and prone positions. The amount of decrease in residual volume was significant in right lateral and prone positions.

25 Years of Research in Human Lactation: From Discovery to Translation

Researchers have recently called for human lactation research to be conceptualized as a biological framework where maternal and infant factors impacting human milk, in terms of composition, volume and energy content are studied along with relationships to infant growth, development and health. This approach allows for the development of evidence-based interventions that are more likely to support breastfeeding and lactation in pursuit of global breastfeeding goals. Here we summarize the seminal findings of our research programme using a biological systems approach traversing breast anatomy, milk secretion, physiology of milk removal with respect to breastfeeding and expression, milk composition and infant intake, and infant gastric emptying, culminating in the exploration of relationships with infant growth, development of body composition, and health. This approach has allowed the translation of the findings with respect to education, and clinical practice. It also sets a foundation for improved study design for future investigations in human lactation.

Multi-nutrient fortification of human milk for preterm infants

BACKGROUND

Human breast milk-fed preterm infants can accumulate nutrient deficits leading to extrauterine growth restriction. Feeding preterm infants with multi-nutrient fortified human milk could increase nutrient accretion and growth rates and improve neurodevelopmental outcomes. Concern exists, however, that multi-nutrient fortifiers are associated with adverse events such as feed intolerance and necrotising enterocolitis.

OBJECTIVES

To determine whether multi-nutrient fortified human milk, compared with unfortified human milk, affects important outcomes (including growth rate and neurodevelopment) of preterm infants without increasing the risk of adverse effects (such as feed intolerance and necrotising enterocolitis).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 9), MEDLINE via PubMed (1966 to 26 September 2019), Embase (1980 to 26 September 2019), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to 26 September 2019). We searched clinical trials databases, conference proceedings, and reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials that compared feeding preterm infants with multi-nutrient (protein and energy plus minerals, vitamins, or other nutrients) fortified human breast milk versus unfortified (no added protein or energy) breast milk.

DATA COLLECTION AND ANALYSIS

We used the standard methods of Cochrane Neonatal. Two review authors separately evaluated trial quality, extracted data, and synthesised effect estimates using risk ratios (RRs), risk differences, and mean differences (MDs). We assessed the certainty of the body of evidence at the outcome level using "Grading of Recommendations Assessment, Development and Evaluation" (GRADE) methods.

MAIN RESULTS

We identified 18 trials in which a total of 1456 preterm infants participated. These trials were generally small and methodologically weak. Meta-analyses provided low- to moderate-certainty evidence showing that multi-nutrient fortification of human milk increases in-hospital rate of weight gain (MD 1.76 g/kg/d, 95% confidence interval (CI) 1.30 to 2.22), body length (MD 0.11 cm/week, 95% CI 0.08 to 0.15), or head circumference (MD 0.06 cm/week, 95% CI 0.03 to 0.08) among preterm infants. Few data on growth and developmental outcomes assessed beyond infancy are available, and these do not show effects of multi-nutrient fortification. The data do not suggest other benefits or harms and provide low-certainty evidence suggesting effects of multi-nutrient fortification on the risk of necrotising enterocolitis in preterm infants (typical RR 1.37, 95% CI 0.72 to 2.63; 13 studies, 1110 infants).

AUTHORS' CONCLUSIONS

Feeding preterm infants with multi-nutrient fortified human breast milk compared with unfortified human breast milk is associated with modest increases in in-hospital growth rates. Evidence is insufficient to show whether multi-nutrient fortification has any effect on long-term growth or neurodevelopment.

Early versus Delayed Fortification of Human Milk in Preterm Infants: A Systematic Review

Expressed breast milk (EBM) is commonly supplemented with commercially prepared human milk fortifier to meet the additional nutritional needs of preterm infants. The optimal milk intake at which to introduce fortification is unknown. The objective of this systematic review was to compare the effect of early fortification (EF) versus that of delayed introduction of human milk fortifier (DF) on short-term outcomes including growth, feeding intolerance, length of hospital stay, and maturity at discharge in very-low-birth-weight infants. The search was carried out until March 2019 using 5 electronic databases (PubMed, Ovid Medline, Web of Science, Ovid Embase, and the Cochrane Library). The search was supplemented with a search of the clinical trial registry and reference lists. Eligible studies involved randomized controlled trials that had been designed to compare EF against DF using multi-nutrient fortifier for infants of a birth weight of <1,500 g who were fed exclusively or predominantly EBM. Four authors independently screened the studies for eligibility. A total of 1,972 articles were screened; 2 studies met the inclusion criteria and were included with a total number of participants of 171. The definition of EF and DF was not consistent between the 2 studies. There was no significant impact of EF versus DF on all outcomes. In conclusion, current data are limited and do not provide evidence on the optimal time to start fortification. The definition of EF and DF needs to be agreed upon and further larger randomized controlled trials are required.

A national survey of the enteral feeding practices in Canadian neonatal intensive care units

Aim

Nutrition affects the growth and neurodevelopmental outcomes of preterm infants, yet controversies exist about the optimal enteral feeding regime. The objective of this study was to compare enteral feeding guidelines in Canadian neonatal intensive care units (NICUs).

Method

The research team identified key enteral feeding practices of interest. Canadian Neonatal Network site investigators at 30 Level 3 NICUs were contacted to obtain a copy of their 2016 to 2017 feeding guidelines for infants who weighed less than 1,500 g at birth. Each guideline was reviewed to compare recommendations around the selected feeding practices.

Results

Five of the 30 NICUs did not have a feeding guideline. The other 25 NICUs used 22 different enteral feeding guidelines. The guidelines in 40% of those NICUs recommend commencing minimal enteral nutrition (MEN) within 24 hours of birth and maintaining that same feeding volume for 24 to 96 hours. In 40% of NICUs, the guideline recommended that MEN be initiated at a volume of 5 to 10 mL/kg/day for infants born at <1,000 g. Guidelines in all 25 NICUs recommend the use of bovine-based human milk fortifier (HMF), and in 56% of NICUs, it is recommended that HMF be initiated at a total fluid intake of 100 mL/kg/day. Guidelines in only 16% of NICUs recommended routine gastric residual checks. Donor milk and probiotics are used in 76% and 72% of the 25 NICUs, respectively.

Conclusion

This study revealed substantial variability in recommended feeding practices for very low birth weight infants, underscoring the need to establish a national feeding guideline for this vulnerable group.

Hydrogen peroxide promotes gastric motility in the newborn rat

BACKGROUND

When compared with infant formula, human milk enhances gastric emptying in preterm infants. Hydrogen peroxide (H₂O₂) is present in large quantities in human milk that has an antimicrobial role for the mother and infant. In vitro adult rat studies suggest that H₂O₂ facilitates gastric motor contraction. Hypothesizing that H₂O₂ enhances gastric motility, we investigated its effects on the newborn rat stomach tissue.

METHODS

Rat newborn and adult gastric fundic segments, or their smooth muscle cells, were used to evaluate the muscle response to H₂O₂ exposure. Tissue expression of Rho kinase 2 (ROCK-2; Western blot), its catalase activity, and H₂O₂ content (Amplex Red) were measured. H₂O₂ gastric mucosal diffusion was evaluated with Ussing chambers.

RESULTS

In both newborn and adult rats, H₂O₂ induced gastric muscle contraction and this response was attenuated by pre-incubation with the antioxidant melatonin. H₂O₂ passively diffused across the gastric mucosa. Its effect on the muscle was modulated via ROCK-2 activation and inhibited by melatonin.

CONCLUSION

H₂O₂, at a concentration similar to that of human milk, promotes gastric motility in the rat. To the extent that the present findings can be clinically extrapolated, the human milk H₂O₂ content may enhance gastric emptying in neonates.

Gastric emptying of different meal volumes of identical composition in preterm infants: a time series analysis

BackgroundPreterm infants' meals typically progress to higher volumes over time. Knowledge of gastric emptying (GE) responses to differing meal volumes may inform enteral feeding management. We examined the effect of meal volume and composition on preterm GE.MethodsForty infants were studied at 33.3±1.4 (29.7-35.6) weeks postmenstrual age when fully enteral fed (target 150 ml/kg/day). Intraindividual comparisons of GE were made for paired meals of 100% and 75% prescribed volume and identical composition of mother's own milk (n=21) and pasteurized donor human milk (n=19). Serial stomach ultrasound images were used to calculate gastric residual volumes (GRVs) and remaining meal proportions (% meal).ResultsGE was faster in the early postprandial period and slowed over time (P<0.001). Reduced volume meals had slower GE rates and lower GRV (P<0.001). Serial postprandial % meal was similar between reduced and full volume meals (P=0.41). Higher milk casein concentration was associated with slower GE (P=0.04). Complete gastric emptying (GRV=0 ml) was more common in infants fed at 3 h intervals compared with those fed every 2 h (P=0.002).ConclusionEarly postprandial GE is more rapid for larger meal volumes. Stable preterm infants may tolerate feeding of a 3 h meal volume at shorter intervals.

Optimizing Nutrition in Preterm Low Birth Weight Infants-Consensus Summary

Preterm birth survivors are at a higher risk of growth and developmental disabilities compared to their term counterparts. Development of strategies to lower the complications of preterm birth forms the rising need of the hour. Appropriate nutrition is essential for the growth and development of preterm infants. Early administration of optimal nutrition to preterm birth survivors lowers the risk of adverse health outcomes and improves cognition in adulthood. A group of neonatologists, pediatricians, and nutrition experts convened to discuss and frame evidence-based recommendations for optimizing nutrition in preterm low birth weight (LBW) infants. The following were the primary recommendations of the panel: (1) enteral feeding is safe and may be preferred to parenteral nutrition due to the complications associated with the latter; however, parenteral nutrition may be a useful adjunct to enteral feeding in some critical cases; (2) early, fast, or continuous enteral feeding yields better outcomes compared to late, slow, or intermittent feeding, respectively; (3) routine use of nasogastric tubes is not advisable; (4) preterm infants can be fed while on ventilator or continuous positive airway pressure; (5) routine evaluation of gastric residuals and abdominal girth should be avoided; (6) expressed breast milk (EBM) is the first choice for feeding preterm infants due to its beneficial effects on cardiovascular, neurological, bone health, and growth outcomes; the second choice is donor pasteurized human milk; (7) EBM or donor milk may be fortified with human milk fortifiers, without increasing the osmolality of the milk, to meet the high protein requirements of preterm infants; (8) standard fortification is effective and safe but does not fulfill the high protein needs; (9) use of targeted and adjustable fortification, where possible, helps provide optimal nutrition; (10) optimizing weight gain in preterm infants prevents long-term cardiovascular complications; (11) checking for optimal weight and sucking/swallowing ability is essential prior to discharge of preterm infants; and (12) appropriate counseling and regular follow-up and monitoring after discharge will help achieve better long-term health outcomes. This consensus summary serves as a useful guide to clinicians in addressing the challenges and providing optimal nutrition to preterm LBW infants.

Trend of Nutritional Support in Preterm Infants

Without appropriate nutritional support, preterm infants fail to grow after birth and have malnutrition. The main reason for delayed feeding is fear of immaturity of gastrointestinal function. The principles of nutritional practice should be as follows: (1) minimal early initiation of enteral feeding with breast milk (0.5-1 mL/h) to start on Day 1 if possible and gradual increase as tolerated; (2) early aggressive parenteral nutrition as soon as possible; (3) provision of lipids at rates that will meet the additional energy needs of about 2-3 g/kg/d; and (4) attempt to increase enteral feeding rather than parenteral nutrition.

Multi-nutrient fortification of human milk for preterm infants

BACKGROUND

Exclusively breast milk-fed preterm infants may accumulate nutrient deficits leading to extrauterine growth restriction. Feeding preterm infants with multi-nutrient fortified human breast milk rather than unfortified breast milk may increase nutrient accretion and growth rates and may improve neurodevelopmental outcomes.

OBJECTIVES

To determine whether multi-nutrient fortified human breast milk improves important outcomes (including growth and development) over unfortified breast milk for preterm infants without increasing the risk of adverse effects (such as feed intolerance and necrotising enterocolitis).

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; 2016, Issue 2), MEDLINE, EMBASE and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (until February 2016), as well as conference proceedings and previous reviews.

SELECTION CRITERIA

Randomised and quasi-randomised controlled trials that compared feeding preterm infants with multi-nutrient (protein and energy plus minerals, vitamins or other nutrients) fortified human breast milk versus unfortified (no added protein or energy) breast milk.

DATA COLLECTION AND ANALYSIS

We extracted data using the standard methods of the Cochrane Neonatal Review Group. We separately evaluated trial quality, data extracted by two review authors and data synthesised using risk ratios (RRs), risk differences and mean differences (MDs). We assessed the quality of evidence at the outcome level using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We identified 14 trials in which a total of 1071 infants participated. The trials were generally small and weak methodologically. Meta-analyses provided low-quality evidence that multi-nutrient fortification of breast milk increases in-hospital rates of growth (MD 1.81 g/kg/d, 95% confidence interval (CI) 1.23 to 2.40); length (MD 0.12 cm/wk, 95% CI 0.07 to 0.17); and head circumference (MD 0.08 cm/wk, 95% CI 0.04 to 0.12). Only very limited data are available for growth and developmental outcomes assessed beyond infancy, and these show no effects of fortification. The data did not indicate other potential benefits or harms and provided low-quality evidence that fortification does not increase the risk of necrotising enterocolitis in preterm infants (typical RR 1.57, 95% CI 0.76 to 3.23; 11 studies, 882 infants).

AUTHORS' CONCLUSIONS

Limited available data do not provide strong evidence that feeding preterm infants with multi-nutrient fortified breast milk compared with unfortified breast milk affects important outcomes, except that it leads to slightly increased in-hospital growth rates.

Gastric Emptying and Curding of Pasteurized Donor Human Milk and Mother's Own Milk in Preterm Infants

We evaluated the effects of fortification and composition on gastric emptying and curding in un/fortified pairs of mother's own milk (MOM, n = 17) and pasteurized donor human milk (PDHM, n = 15) in preterm infants. Retained meal proportions (%) and curding were determined from sonography. Immediate and subsequent postprandial % were higher for PDHM (23%, P = 0.026; 15%, P = 0.006) and fortified meals (31.5%; 8.8%, both P < 0.001), whereas higher casein, whey, and lactose concentrations were associated with lower immediate postprandial % (all P < 0.006). Curding did not affect emptying. Influences of fortification, pasteurization, and differing breast milk compositions are small and unlikely implicated in preterm feeding intolerance.

Influences of breast milk composition on gastric emptying in preterm infants

OBJECTIVES

The aim of the present study was to determine whether specific biochemical and energy concentrations influence gastric emptying of unfortified and fortified mother's own milk (MOM) in stable preterm infants, and whether gastric emptying differs between feeds of unfortified MOM and feeds fortified with S-26 or FM 85 human milk fortifier (HMF) when infants are fed the same volume under similar conditions. Influences of infant gestation, age, and weight, and feed characteristics were also explored.

METHODS

Stomach volumes of 25 paired unfortified and fortified MOM feeds were monitored prefeed and postfeed delivery and at 30-minute intervals thereafter. For each feed, MOM samples were analyzed to determine concentrations of total protein, casein, whey, carbohydrate, lactose, fat, and energy. Fortified feed compositions were calculated by adding fortifier biochemical and energy concentrations to unfortified MOM concentrations. Ultrasound images were used to calculate infant stomach volumes. Statistical comparisons were made of paired stomach volume measurements.

RESULTS

Higher feed concentrations of casein were associated with faster gastric emptying during feed delivery (P = 0.007). When compared with unfortified MOM, S-26 fortified feeds emptied similarly, whereas FM 85 fortified feeds emptied more slowly both during feed delivery and during the postprandial period (P = 0.002, <0.001, respectively). Gastric emptying was slower for 2-hourly feeds compared with that for 3-hourly feeds (P = 0.003) and in supine position compared with that in prone (P = 0.001).

CONCLUSIONS

Breast milk composition influences gastric emptying in stable preterm infants, with feeds of higher casein concentration emptying faster during feeding than otherwise equivalent feeds, and FM 85 fortified MOM emptying more slowly than unfortified MOM.

Bacteriological, biochemical, and immunological properties of colostrum and mature milk from mothers of extremely preterm infants

OBJECTIVES

The objective of this work was to elucidate the influence of extremely premature birth (gestational age 24-27 weeks) on the microbiological, biochemical, and immunological composition of colostrum and mature milk.

METHODS

A total of 17 colostrum and 34 mature milk samples were provided by the 22 mothers of extremely preterms who participated in this study. Bacterial diversity was assessed by culture-based methods, whereas the concentration of lactose, glucose, and myo-inositol was determined by a gas chromatography procedure. Finally, the concentrations of a wide spectrum of cytokines, chemokines, growth factors, and immunoglobulins were measured using a multiplex system.

RESULTS

Bacteria were present in a small percentage of the colostrum and milk samples. Staphylococci, streptococci, and lactobacilli were the main bacterial groups isolated from colostrum, and they could be also isolated, together with enterococci and enterobacteria, from some mature milk samples. The colostrum concentrations of lactose and glucose were significantly lower than those found in mature milk, whereas the contrary was observed in relation to myo-inositol. The concentrations of most cytokines and immunoglobulins in colostrum were higher than in mature milk, and the differences were significant for immunoglobulin G₃, immunoglobulin G₄, interleukin (IL)-6, interferon-γ, interleukin-4 (IL-4), IL-13, IL-17, macrophage-monocyte chemoattractant protein-1 and macrophage inflammatory protein-1β.

CONCLUSIONS

The bacteriological, biochemical, and immunological content of colostrum and mature milk from mothers of extremely preterm infants is particularly valuable for such infants. Efforts have to be made to try that preterm neonates receive milk from their own mothers or from donors matching, as much as possible, the gestational age of the preterm.

Gastric residual evaluation in preterm neonates: a useful monitoring technique or a hindrance?

It is routine practice in most neonatal intensive care units to measure the volume and color of gastric residuals (GRs) prior to enteral bolus feedings in preterm very low birth weight infants. However, there is paucity of evidence supporting the routine use of this technique. Moreover, owing to the lack of uniform standards in the management of GRs, wide variations exist as to what constitutes significant GR volume, the importance of GR color and frequency of GR evaluation, and the color or volume standards that dictate discarding or returning GRs. The presence of large GR volumes or green-colored residuals prior to feeding often prompts subsequent feedings to be withheld or reduced because of possible necrotizing enterocolitis resulting in delays in enteral feeding. Cessation or delays in enteral feeding may result in extrauterine growth restriction, a known risk factor for poor neurodevelopmental and growth outcomes in preterm very low birth weight infants. Although some neonatal intensive care units are abandoning the practice of routine GR evaluation, little evidence exists to support the discontinuation or continuation of this practice. This review summarizes the current state of GR evaluation and underlines the need for a scientific basis to either support or refute the routine evaluation of GRs.

Repeatability of gastric volume measurements and intragastric content using ultrasound in preterm infants

OBJECTIVES

The aim of the present study was to determine whether serial gastric volumes and intragastric curding are repeatable within individual preterm infants when given sequential feeds of the same volume and composition. Infant and feeding characteristics that may influence differences in measured gastric volumes, echogenicity, and intragastric curding were also explored.

METHODS

Ultrasound images were used to calculate gastric volumes and to rate echogenicity and intragastric curding for 20 infants. A total of 29 paired feeds of the same volume and composition were monitored prefeed and postfeed and at 30-minute intervals thereafter. Statistical comparisons of paired gastric volume measurements and agreement between echogenicity and curding ratings were made for each time point. Analyses of factors that influence discrepancies between volume measurements and between curding ratings were performed.

RESULTS

Paired gastric volume measurements were repeatable (intraclass correlation coefficient [ICC] = 0.971, 0.938 < ICC < 0.987). Most (75%) discrepancies were <2 mL and increased over time, although volume differences were small. Overall moderate levels of consistency were observed for ratings of echogenicity (κ = 0.44), and curd presence (κ ≤ 0.65), density (κ = 0.41), and volume (κ = 0.47). Gastric emptying during feed delivery is influenced with infant positioning, fortification of breast milk, and feeding frequency.

CONCLUSIONS

For preterm infants serial gastric volumes are repeatable and ratings of intragastric echogenicity and curding are moderately consistent when fed milk of the same volume and composition. Ultrasound has the potential to further explore factors that influence gastric emptying in the preterm infant.

Preterm dietary study: meal frequency, regurgitation and the surprisingly high use of laxatives among formula-fed infants following discharge

AIM

To describe eating habits and possible feeding intolerance among preterm infants based on type of nutrition.

METHODS

The parents of infants born below 32 weeks filled in questionnaires, before and after discharge, about type of nutrition, number of meals, regurgitation, number of stools and laxative use.

RESULTS

A total of 769 questionnaires based on 286 very preterm infants were completed, and 753 were included. At 40 weeks of corrected age, infants fed both fortified and unfortified human milk received more daily meals (mean 7.37 and 7.57) than preterm formula-fed infants (mean 6.79) (p < 0.05). Fortification of human milk did not seem to increase the incidence of regurgitation. Between 38.7 and 42.9% of the preterm infants were treated with laxatives from discharge to 6 months of corrected age. Infants fed preterm formula prior to discharge, at term, at 2 and 4 months of corrected age received laxatives more often than infants fed human milk, with odds ratios of 13.7, 137.5, 49.7 and 40.5, respectively (p ≤ 0.001).

CONCLUSION

Constipation seems to be frequent among very preterm infants. Laxative use averaged 40% across all the different feeding groups and was as high as 70-85% in formula-fed preterm infants over the course of the study.

Donor human milk bank data collection in north america: an assessment of current status and future needs

BACKGROUND

The Human Milk Banking Association of North America (HMBANA) is a nonprofit association that standardizes and facilitates the establishment and operation of donor human milk (DHM) banks in North America. Each HMBANA milk bank in the network collects data on the DHM it receives and distributes, but a centralized data repository does not yet exist. In 2010, the Food and Drug Administration recognized the need to collect and disseminate systematic, standardized DHM bank data and suggested that HMBANA develop a DHM data repository.

OBJECTIVES

This study aimed to describe data currently collected by HMBANA DHM banks and evaluate feasibility and interest in participating in a centralized data repository.

METHODS

We conducted phone interviews with individuals in different HMBANA milk banks and summarized descriptive statistics.

RESULTS

Eight of 13 (61.5%) sites consented to participate. All respondents collected donor demographics, and half (50%; n = 4) rescreened donors after 6 months of continued donation. The definition of preterm milk varied between DHM banks (≤ 32 to ≤ 40 weeks). The specific computer program used to house the data also differed. Half (50%; n = 4) indicated that they would consider participation in a centralized repository.

CONCLUSIONS

Without standardized data across all HMBANA sites, the creation of a centralized data repository is not yet feasible. Lack of standardization and transparency may deter implementation of donor milk programs in the neonatal intensive care unit setting and hinder benchmarking, research, and quality improvement initiatives.

Validation of ultrasound methods to monitor gastric volume changes in preterm infants

OBJECTIVES

The aim of this study was to validate 4 sonographic methods of estimating stomach volume for the purpose of monitoring changes in gastric volume over time and to describe the echogenic characteristics of milk feeds.

METHODS

Twenty-four infants were monitored during a single intragastric tube feed, with 2 ultrasound images of the entire stomach and an image of the antral cross-sectional area (ACSA) before, during, and after the feed. Raw measurements, 3 stomach volume calculations, and ACSA were tested for intra- and interrater agreement. Calculated stomach volumes and ACSA were compared with delivered feed volumes, and characteristics of stomach image echogenicity graded at each time point.

RESULTS

Spheroid calculation of stomach volume was the most reliable and valid measure of stomach volume. Fortified breast milk feeds were more echogenic than unfortified breast milk feeds. Residual stomach volumes (median 2.12 mL, range 0.59-9.27 mL) were identified in 18 of 24 infants.

CONCLUSIONS

Direct ultrasound stomach measurement (spheroid) will provide a useful research tool and a potential clinical tool for assessing gastric emptying and feeding intolerance in preterm infants.

Australasian neonatal intensive care enteral nutrition survey: implications for practice

AIM

This survey investigated standardised feeding guidelines and nutrition policy in Australasian neonatal intensive care units and compared these with previously published surveys and international consensus nutrition recommendations.

METHODS

An electronic survey on enteral nutrition comprising a wide range of questions about clinical practice was e-mailed to all 25 Australasian neonatal intensive care unit directors of tertiary perinatal centres.

RESULTS

Twenty-five surveys were distributed; 24 (96%) were completed. All respondents preferred breast milk as the first feed. For infants <1000 g, 58% started feeds at 1 mL every 4 hours and 83% started enteral feeds on day 0-2 in the absence of contraindications. The identification of bile-stained gastric aspirates significant enough to withhold feeds varied. Multicomponent breast milk fortifiers were added by 58% when enteral feeds reached 150 mL/kg day, while 21% added these earlier at 120 mL/kg day or less. Iron supplementation was started at 4 weeks by 63% and at 6 weeks by 27%. Only 42% of units had a neonatal dietitian. Of the 24 units who responded, 58% had no written enteral feeding guidelines.

CONCLUSION

Enteral nutrition was initiated earlier than in the past. Great variation remains in clinical practices. Nutritional implications are discussed. Standardisation of feeding guidelines and enteral nutrition policy based on current evidence and international consensus nutrition recommendations may be beneficial and should be encouraged.

Multinutrient fortification of human breast milk for preterm infants following hospital discharge

BACKGROUND

Preterm infants are usually growth restricted at hospital discharge. Feeding preterm infants after hospital discharge with multinutrient fortified breast milk rather than unfortified breast milk may facilitate more rapid catch-up growth and improve neurodevelopmental outcomes.

OBJECTIVES

To determine the effect of feeding preterm infants following hospital discharge with multinutrient fortified human breast milk versus unfortified breast milk on growth and development.

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 Register (CENTRAL, The Cochrane Library, 2012, Issue 3), MEDLINE, EMBASE and CINAHL (until August 2012), conference proceedings, and previous reviews.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials that compared feeding preterm infants following hospital discharge with multinutrient fortified breast milk compared with unfortified human breast milk.

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 review authors and synthesis of data using risk ratio, risk difference and mean difference.

MAIN RESULTS

We identified two small trials involving a total of 246 infants. These did not provide evidence that multinutrient fortification of breast milk for three to four months after hospital discharge affected rates of growth during infancy. One trial assessed infants at 18 months corrected age and did not find any statistically significant effects on neurodevelopmental outcomes.

AUTHORS' CONCLUSIONS

The limited available data do not provide convincing evidence that feeding preterm infants with multinutrient fortified breast milk compared with unfortified breast milk following hospital discharge affects important outcomes including growth rates during infancy. There are no data on long-term growth. Since fortifying breast milk for infants fed directly from the breast is logistically difficult and has the potential to interfere with breast feeding, it is important to determine if mothers would support further trials of this intervention.

A quality improvement project to increase breast milk use in very low birth weight infants

OBJECTIVE

To evaluate a multihospital collaborative designed to increase breast milk feeding in premature infants.

METHODS

Eleven NICUs in the California Perinatal Quality of Care Collaborative participated in an Institute for Healthcare Improvement-style collaborative to increase NICU breast milk feeding rates. Multiple interventions were recommended with participating sites implementing a self-selected combination of these interventions. Breast milk feeding rates were compared between baseline (October 2008-September 2009), implementation (October 2009-September 2010), and sustainability periods (October 2010-March 2011). Secondary outcome measures included necrotizing enterocolitis (NEC) rates and lengths of stay. California Perinatal Quality of Care Collaborative hospitals not participating in the project served as a control population.

RESULTS

The breast milk feeding rate in the intervention sites improved from baseline (54.6%) to intervention period (61.7%; P = .005) with sustained improvement over 6 months postintervention (64.0%; P = .003). NEC rates decreased from baseline (7.0%) to intervention period (4.3%; P = .022) to sustainability period (2.4%; P < .0001). Length of stay increased during the intervention but returned to baseline levels in the sustainability period. Control hospitals had higher rates of breast milk feeding at baseline (64.2% control vs 54.6% participants, P < .0001), but over the course of the implementation (65.7% vs 61.7%, P = .049) and sustainability periods (67.7% vs 64.0%, P = .199), participants improved to similar rates as the control group.

CONCLUSIONS

Implementation of a breast milk/nutrition change package by an 11-site collaborative resulted in an increase in breast milk feeding and decrease in NEC that was sustained over an 18-month period.

Multinutrient fortification of human breast milk for preterm infants following hospital discharge

BACKGROUND

Preterm infants are usually growth restricted at hospital discharge. Feeding preterm infants after hospital discharge with multinutrient fortified breast milk rather than unfortified breast milk may facilitate more rapid catch-up growth and improve neurodevelopmental outcomes.

OBJECTIVES

To determine the effect of feeding with multinutrient fortified human breast milk versus unfortified breast milk on growth and development in preterm or low birth weight infants following hospital discharge.

SEARCH STRATEGY

The standard search strategy of the Cochrane Neonatal Review Group was used. This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 4, 2010), MEDLINE (1966 to April 2010), EMBASE (1980 to April 2010), CINAHL (1982 to April 2010), conference proceedings, and previous reviews.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials that compared feeding preterm infants following hospital discharge with multinutrient fortified breast milk compared with unfortified human breast milk.

DATA COLLECTION AND ANALYSIS

The standard methods of the Cochrane Neonatal Review Group were used, with separate evaluation of trial quality and data extraction by two review authors.

MAIN RESULTS

One small trial (N = 39) was identified. Multinutrient fortification of breast milk for 12 weeks after hospital discharge resulted in higher rates of growth during infancy. At 12 months corrected age, weight (mean difference 1187g, 95% confidence interval (CI) 259, 2115 g), length (3.8 cm, 95%CI 1.2, 6.4 cm) and head circumference (1.0 cm, 95%CI 0.1, 1.9 cm) were statistically significantly greater in the intervention group. No evidence of an effect on neurodevelopmental assessments at 18 months corrected age was found.

AUTHORS' CONCLUSIONS

The limited available data suggest that feeding preterm infants following hospital discharge with multinutrient fortified breast milk compared with unfortified breast milk increases growth rates during infancy. The importance of these effects on long-term growth and development is unclear and deserves further assessment in randomised controlled trials. Since fortifying breast milk for infants fed directly from the breast is logistically difficult and has the potential to interfere with breast feeding, it is important to determine if mothers would support further trials of this intervention.

Protein content and fortification of human milk influence gastroesophageal reflux in preterm infants

OBJECTIVES

: Preterm human milk (HM) may provide insufficient energy and nutrients and thus may need to be fortified. Our aim was to determine whether fat content, protein content, and osmolality of HM before and after fortification may affect gastroesophageal reflux (GER) in symptomatic preterm infants.

METHODS

: Gastroesophageal reflux was evaluated in 17 symptomatic preterm newborns fed naïve and fortified HM by combined pH/intraluminal-impedance monitoring (pH-MII). Human milk fat and protein content was analysed by a near-infrared reflectance analysis. Human milk osmolality was tested before and after fortification. Gastroesophageal reflux indexes measured before and after fortification were compared and were also related to HM fat and protein content and osmolality before and after fortification.

RESULTS

: An inverse correlation was found between naïve HM protein content and acid reflux index (RIpH: P = 0.041, rho =-0.501). After fortification, osmolality often exceeded the values recommended for infant feeds; furthermore, a statistically significant (P < 0.05) increase in nonacid reflux indexes was observed.

CONCLUSIONS

: Protein content of naïve HM may influence acid GER in preterm infants. A standard fortification of HM may worsen nonacid GER indexes and, due to the extreme variability in HM composition, may overcome both recommended protein intake and HM osmolality. Thus, an individualised fortification, based on the analysis of the composition of naïve HM, could optimise both nutrient intake and feeding tolerance.

Human milk fortifiers in very low birth weight infants

The use of HMF remains an important option and has become common practice in all neonatal intensive care units. However, optimal composition of fortifiers is still undefined and more data are needed on safety and long-term benefits. Further research should be directed toward comparisons between different proprietary preparations, evaluating both short-term and long-term outcomes and adverse effects, in search of the best method of fortification.

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.

Hindmilk: a head start in preterm nutrition

BACKGROUND

During the neonatal period, nutrition has a crucial impact on preterm infants' survival, growth and development. Current nutritional practices for preterm infants often fail to meet their nutritional needs and thus have potential adverse consequences for their growth and development. Hindmilk represents a promising avenue to manage this nutritional challenge.

METHOD

The scientific literature was reviewed to determine the current state of knowledge about hindmilk and its effects on the growth and development of preterm infants.

RESULTS

Four studies evaluating the effects of hindmilk on the growth of preterm infants were found and included in this review. These studies report contradictory findings and present serious methodological shortcomings, limiting the evidence on the potential benefits of hindmilk in preterm infants.

CONCLUSIONS

A body of knowledge on the effects of hindmilk on the growth and development of preterm infants is accumulating but there is still a striking need for further investigation.

Human milk fortification and gastric emptying in the preterm neonate

Fortification of expressed breast milk (EBM) is widely recommended for preterm feeding. Fortification of EBM results in increased caloric density and osmolarity, both of which may retard gastric emptying. As gastric emptying is a major determinant of feed tolerance, we investigated the effect of fortification (with Lactodex HMF) of EBM on gastric emptying in preterm neonates. The half gastric emptying time was measured using real time ultrasonography in 25 consecutive preterm neonates first on EBM alone, then on EBM + Lactodex HMF. Each baby served as its own control. The students t-test was used for statistical analysis. The mean gestation age was 34.48 +/- 0.77 weeks. The mean birth weight was 1.92 +/- 0.14 kg. The mean half gastric emptying time at an age of 5.4 +/- 0.86 days on EBM was 24.00 +/- 5.00 min and 24.40 +/- 5.06 min on EBM + human milk fortifier (HMF). The same at 2nd assessment (15.2 +/- 1.79 days), with EBM was 22.80 +/- 4.58 min vs. 23.60 +/- 4.89 min when given EBM + HMF. These differences were not statistically significant. Fortification of EBM with Lactodex HMF does not affect the gastric emptying in preterm neonates and therefore is unlikely to affect feed tolerance in them.

Multicomponent fortification of human breast milk for preterm infants following hospital discharge

BACKGROUND

Preterm infants are usually growth restricted at hospital discharge. Feeding preterm infants after hospital discharge with nutrient-fortified breast milk (rather than unfortified breast milk) may facilitate more rapid catch-up growth and improve neurodevelopmental outcomes.

OBJECTIVES

To determine the effect of feeding with multicomponent fortified human breast milk versus unfortified breast milk on growth and development on preterm or low birth weight infants following hospital discharge.

SEARCH STRATEGY

The standard search strategy of the Cochrane Neonatal Review Group was used. This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 2, 2007), MEDLINE (1966 - May 2007), EMBASE (1980 - May 2007), CINAHL (1982 - May 2007), conference proceedings, and previous reviews.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials that compared feeding preterm infants following hospital discharge with multicomponent fortified breast milk compared with unfortified human breast milk.

DATA COLLECTION AND ANALYSIS

The standard methods of the Cochrane Neonatal Review Group were used, with separate evaluation of trial quality and data extraction by two review authors.

MAIN RESULTS

No eligible trials were identified.

AUTHORS' CONCLUSIONS

There are no data from randomised controlled trials to determine whether feeding preterm infants following hospital discharge with multicomponent-fortified breast milk compared with unfortified breast milk affects growth and development. Given the potential for nutrient fortification to affect growth and development, this intervention may merit further assessment. Since fortifying breast milk for infants fed directly from the breast is logistically difficult (and has the potential to interfere with breast-feeding), it would be important to determine if mothers would support a trial of this intervention. It may be that a trial should first focus on infants who are not able to consume ad libitum quantities of breast milk directly from the breast, who have poor growth or nutritional status, or who have on-going additional metabolic requirements.

Effect of Erythromycin on Gastric Emptying Time of Low Birth Weight Babies

BACKGROUND

To study the promotility effects of low dose erythromycin on gastric emptying time in a population of normal low birth weight (LBW) neonates on breast feeds with or without nutritional supplements and human milk fortifier (HMF).

METHOD

A randomised control trial involving 50 neonates was undertaken and they were given 6mg/kg/day of oral erythromycin or placebo in three divided doses for four consecutive days in the first two weeks of life. The gastric emptying time (GET) was assessed ultrasonographically by measuring the decrease in the antral cross sectional area (ACSA). The time taken for the ACSA to become half the prefeed value, was taken as t/2 or half GET. The babies were also assessed for pre and post intervention side effects of the drug. The results were analysed using SPSS ver 11.5.

RESULTS

The test group showed a significant decrease in GET after the intervention. This effect was mainly seen in the preterm babies as compared to term Small for Gestational Age (SGA) babies. The decrease in GET was more in babies born after 34 weeks of gestation as compared to smaller babies. The reduction in GET was seen in babies on breast milk alone and nutritional supplements with breast milk but not when HMF was added. No side effects of the drug were noted.

CONCLUSION

Low dose erythromycin is a safe way of decreasing gastric emptying in preterm babies born after 34 weeks of gestation in the first two weeks of life.

Reliability of the ICRP'S dose coefficients for members of the public: IV. basis of the human alimentary tract model and uncertainties in model predictions

The biokinetic and dosimetric model of the gastrointestinal (GI) tract applied in current documents of the International Commission on Radiological Protection (ICRP) was developed in the mid-1960s. The model was based on features of a reference adult male and was first used by the ICRP in Publication 30, Limits for Intakes of Radionuclides by Workers (Part 1, 1979). In the late 1990s an ICRP task group was appointed to develop a biokinetic and dosimetric model of the alimentary tract that reflects updated information and addresses current needs in radiation protection. The new age-specific and gender-specific model, called the Human Alimentary Tract Model (HATM), has been completed and will replace the GI model of Publication 30 in upcoming ICRP documents. This paper discusses the basis for the structure and parameter values of the HATM, summarises the uncertainties associated with selected features and types of predictions of the HATM and examines the sensitivity of dose estimates to these uncertainties for selected radionuclides. Emphasis is on generic biokinetic features of the HATM, particularly transit times through the lumen of the alimentary tract, but key dosimetric features of the model are outlined, and the sensitivity of tissue dose estimates to uncertainties in dosimetric as well as biokinetic features of the HATM are examined for selected radionuclides.

Strategies for prevention of feed intolerance in preterm neonates: a systematic review

Postnatal growth restriction and failure to thrive have been recently identified as a major issue in preterm, especially extremely-low-birth-weight neonates. An increased length of time to reach full enteral feedings is also significantly associated with a poorer mental outcome in preterm neonates at 24 months corrected age. Optimization of enteral nutrition without increasing the risk of necrotizing enterocolitis (NEC) has thus become a priority in preterm neonates. A range of feeding strategies currently exists for preventing/minimizing feed intolerance in preterm neonates reflecting the dilemma surrounding the definition and significance of signs of feed intolerance due to ileus of prematurity and the fear of NEC. The results of a systematic review of current strategies for preventing/minimizing feed intolerance in preterm neonates are discussed. The need for clinical research in the area of signs of feed intolerance is emphasized to develop a scientific basis to feeding strategies. Only large pragmatic trials based on such strategies will reveal whether the benefits (improved growth and long term neurodevelopmental outcomes) of aggressive enteral nutrition can outweigh the risks of a potentially devastating illness like NEC, and of prolonged parenteral nutrition in preterm neonates.

Gastric emptying in infants: epigastric impedance versus scintigraphy

AIM

To compare epigastric impedance versus scintigraphy in monitoring the gastric emptying of the same adapted milk formula in infants.

METHODS

Seven infants with clinical symptoms of gastric motility disease underwent scintigraphy with 99mTc sulphur colloid for the 90 min following the ingestion of the same adapted milk formula, in order to evaluate gastric emptying. A bio-impedance device, connected to a PC, was prepared for this purpose with four standard electrodes placed anteriorly on the upper part of the body. The obtained graphs were compared to those of the scintigraphic method. Statistical analysis was performed using Pearson correlation. The confidence limits were set at 95%. Parental consent was obtained before each analysis.

RESULTS

The gastric emptying patterns obtained with epigastric impedance were closely correlated to those shown by the scintigraphy (r = 0.86 +/- 0.08; p < 0.05). A significant correlation between the gastric emptying velocity measured by the two techniques was found (r = 0.94; p = 0.002).

CONCLUSIONS

Epigastric impedance in infants provided estimates of gastric emptying that were closely correlated with scintigraphy. However, the limits derived from the epigastric impedance suggest that, at the moment, the two methods should not be used interchangeably.

Multicomponent fortified human milk for promoting growth in preterm infants

BACKGROUND

For term infants, human milk provides adequate nutrition to facilitate growth, as well as potential beneficial effects on immunity and the maternal-infant emotional state. However, the role of human milk in premature infants is less well defined as it contains insufficient quantities of some nutrients to meet the estimated needs of the infant. Observational studies have suggested that infants fed formula have a higher rate of growth than infants who are breast fed. However, there are potential short term and long term benefits from human milk. Commercially-produced multicomponent fortifiers provide additional nutrients to supplement human milk (in the form of protein, calcium, phosphate, and carbohydrate, as well as vitamins and trace minerals).

OBJECTIVES

The main objective was to determine if addition of multicomponent nutritional supplements to human milk leads to improved growth, bone metabolism and neurodevelopmental outcomes without significant adverse effects in premature infants.

SEARCH STRATEGY

Searches were made of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 2, 3003), MEDLINE (searched August 29, 2003), previous reviews including cross references, abstracts, conferences and symposia proceedings, expert informants, journal handsearching mainly in the English language.

SELECTION CRITERIA

All trials utilising random or quasi-random allocation to supplementation of human milk with multiple nutrients or no supplementation in premature infants within a nursery setting were eligible.

DATA COLLECTION AND ANALYSIS

Data were extracted using the standard methods of the Cochrane Collaboration and its Neonatal Review Group, with separate evaluation of trial quality and data extraction by each author and synthesis of data using relative risk and weighted mean difference.

MAIN RESULTS

Supplementation of human milk with multicomponent fortifiers is associated with short term increases in weight gain, linear and head growth. There is no effect on serum alkaline phosphatase levels; it is not clear if there is an effect on bone mineral content. Nitrogen retention and blood urea levels appear to be increased. There are insufficient data to evaluate long term neurodevelopmental and growth outcomes, although there appears to be no effect on growth beyond one year of life. Use of multicomponent fortifiers does not appear to be associated with adverse effects, although the total number of infants studied and the large amount of missing data reduces confidence in this conclusion. Blood urea levels are increased and blood pH levels minimally decreased, but the clinical significance of this is uncertain.

REVIEWER'S CONCLUSIONS

Multicomponent fortification of human milk is associated with short-term improvements in weight gain, linear and head growth. Despite the absence of evidence of long-term benefit and insufficient evidence to be reassured that there are no deleterious effects, it is unlikely that further studies evaluating fortification of human milk versus no supplementation will be performed. Further research should be directed toward comparisons between different proprietary preparations and evaluating both short-term and long-term outcomes in search of the "optimal" composition of fortifiers.

The use of human milk for premature infants

Various methods have been reported and used clinically to augment the nutrient supply for human milk-fed premature infants. These methods include specialized maltinutrient powdered mixtures (fortifiers), complete liquid formulas designed to be mixed with human milk, complete powdered formulas to be mixed with human milk, and alternate feeding of human milk and preterm formula. Although the optimum nutrition of premature infants is unknown, data are accumulating to suggest that human milk, fortified with additional nutrients, is appropriate for tube-fed infants. The use of fortified human milk typically provides premature infants adequate growth, nutrient retention, and biochemical indices of nutritional status when fed at approximately 180 mL/kg/d compared with unfortified human milk. Data are needed to determine the precise quantity of nutrients to be added as supplements. Nutrient interactions have not been explored in detail. Although large quantities of calcium seem to be needed, the exogenous calcium may affect fat absorption adversely. Manipulation of milk may affect the intrinsic host-defense properties of the milk. Compared with preterm formula, the feeding of fortified human milk may provide significant protection from infection and NEC. Lastly, the potential stimulation of an enteromammary pathway through skin-to-skin contact provides species-specific antimicrobial protection for premature infants. Several of these areas require additional exploration. Thus, for premature infants, neonatal centers should encourage the feeding of fortified human milk, together with skin-to-skin contact, as reasonable methods to enhance milk production while potentially facilitating the development of an enteromammary response.

Feeding tolerance in premature infants fed fortified human milk

BACKGROUND

To evaluate feeding tolerance in premature infants immediately after the addition of human milk fortifier (HMF) to their expressed human milk diet.

METHODS

Data on milk intake, feeding tolerance, and related assessments and growth milestones from a prospective study of feeding strategies in premature infants were analyzed. The database was searched for the first day HMF was added to the feeding of infants receiving human milk exclusively. The following assessments were tabulated for the 5 days before and the 5 days after the addition of HMF: milk intake, the number of episodes of abdominal distension, gastric residual volume (GRV) more than 2 ml/kg and more than 50% of the volume fed in the prior 3 hours. bile-stained gastric residual, emesis or regurgitation, blood in the stool, the number of abdominal radiographs, the number of episodes of apnea and bradycardia, changes in findings in the clinical examination, and the number of hours feeding was withheld. The time to achieve full tube feeding, complete oral feeding, and hospital discharge were recorded.

RESULTS

Seventy-six exclusively human milk-fed premature infants (birth weight, 1065+/-18 g; gestational age, 27+/-0.1 weeks; mean +/- SEM) who received HMF beginning 22+/-0.8 days of age were evaluated. There were significant increases in milk intake and in the number of episodes of GRV more than 2 ml/kg and emesis after the addition of HMF. There were no differences in the number of hours feeding was withheld or any other assessment after the addition of HMF. Infants with increases in GRV more than 2 ml/kg and/or emesis after the addition of HMF were not more likely to be delayed in the time to achieve full tube feeding, complete oral feeding, or hospital discharge than infants who did not experience these events.

CONCLUSION

These data suggest that, when all feeding and related assessments and the time to achieve important growth milestones are considered, the addition of HMF does not adversely affect the outcome of the premature infant.

Enteral feeding in the preterm infant

In planning enteral feeding in the preterm infant, decisions need to be made regarding the feeding schedule, choice of milk, and the route of administration. Feeds should be commenced within a week after birth beginning with subnutritional quantities. Preterm human milk from the infant's own mother is the milk of choice. When full enteral feeding is established, supplementation with human milk fortifier is recommended. Donor human milk and preterm formula are alternatives. Early establishment of enteral nutrition and maintenance of optimal nutrition during infancy are important as dietary manipulations in preterm infants have potential long-term influences on their health, growth and neurodevelopment.

Reproducibility of the 13C-octanoic acid breath test for assessment of gastric emptying in healthy preterm infants

BACKGROUND

The 13C-octanoic acid breath test has been used to measure gastric emptying in preterm infants, but the reproducibility of the test has not been evaluated in this population.

METHODS

Fifty-six paired breath test analyses were performed on 28 healthy preterm infants 1 to 5 days apart using the same food type, volume, and energy content for each paired sample. Breath samples were taken before the feeding, at 5-minute intervals after feeding for 30 minutes, then each 15 minutes for 4 hours. Samples were analyzed using an isotope-ratio mass spectrometer, and 3C recovery was used to calculate values for gastric-emptying coefficient and gastric half-emptying time.

RESULTS

There was no significant difference between test results on different days in the paired samples studied. gastric-emptying coefficients for the first and subsequent samples were 2.6+/-0.1 (mean+/-SEM) and 2.7+/-0.1, respectively, and half-emptying times were 44.5+/-3.7 minutes and 41.4+/-3.2 minutes.

CONCLUSION

The 13C-octanoic acid breath test is a reliable, noninvasive, and reproducible measure of gastric emptying in preterm infants that should have wide application for use in this population.

Gastric emptying in formula-fed and breast-fed infants measured with the 13C-octanoic acid breath test

BACKGROUND

The 13C-octanoic acid breath test, a noninvasive method for measuring gastric emptying, was used to compare the gastric-emptying rate of formula-fed and breast-fed infants. Octanoic acid, a medium-chain fatty acid marked with the stable isotope 13C is immediately absorbed in the duodenum. Because gastric emptying is the rate-limiting step for the absorption of medium-chain fatty acids, the fraction of 13C expired in the breath indicates the rate of gastric emptying.

METHODS

Twenty-nine newborn infants (16 boys, 13 girls) were investigated, with parental consent. The infants had a mean gestational age at birth of 34.5 weeks (range, 27-41 weeks) and a birth weight of 2148 g (range, 960-4100 g). Their mean weight on the day of the test was 2496 g (range, 1998-4140 g), and their mean age was 23 days (range, 7-74 days). Each infant received a test meal after a maximum fasting period of 3 hours. Fourteen infants were fed formula milk (Nutrilon Premium, NV Nutricia, Zoetermeer, The Netherlands) with 13C-octanoic acid and 15 infants received expressed mother's milk mixed with 13C-octanoic acid. After obtaining two basal breath samples and the feeding, breath samples were collected using a nasal prong, every 5 minutes during the first half hour and every 15 minutes during the next 3.5 hours. Analysis of the expired 13C fraction in the breath samples was performed using isotope-ratio mass spectrometry, and the gastric emptying curve and gastric emptying parameters were determined.

RESULTS

The mean half-emptying time determined by the 13C-octanoic acid breath test was 65 minutes (range, 27-98 minutes) for the formula fed infants and 47 minutes (range, 16-86 minutes) for the breast-fed infants. The difference between the half-emptying times is significant (t-test, p < 0.05).

CONCLUSIONS

The results of the 13C-octanoic acid breath test indicated faster gastric emptying of human milk than formula. Our findings are in accordance with those in earlier studies, using the invasive-dilution technique; noninvasive and detailed ultrasonography, which is not easily used because it is operator dependent and the observation time is short; or cineesophago-gastroscintigraphy, which is less suitable for infants (because of the radiation involved). The 13C-octanoic acid breath test is a safe and noninvasive method for measuring gastric emptying in small infants and allows comparison of various feeding methods.

Effects of nutrients in human milk on the recipient premature infant

As the rate of survival of premature infants is increasing, more attention is necessarily focused on improving the quality of survival through optimal nutritional management. The nutritional needs of the premature infant are greater than at any other time in the life cycle. The benefits of human milk for term infants are well known. Emerging data suggest that human milk may especially benefit the premature infant. The human milk-fed premature infant may experience improved health (such as lower rates of infection and necrotizing enterocolitis), gastrointestinal function, and neurodevelopment. These factors may outweigh the concerns about adequate growth, nutrient accretion, and biochemical indices of nutritional status attributed to the lower nutrient content of human milk compared with preterm formula. Some of the nutritional concerns may be met by the use of multinutrient supplements during the time infants receive tube-feeding, generally the time prior to attaining complete oral feeding in-hospital. The available data suggest that the quality of survival of premature infants can be improved, both in the short-term and long-term, through the feeding of human milk.