Safety and efficacy of early amino acids in preterm <28 weeks gestation: prospective observational comparison

Early versus late administration of amino acids in preterm infants receiving parenteral nutrition

BACKGROUND

Observational studies in preterm newborns suggest that delay in administering amino acids (AA) could result in a protein catabolic state and impact on growth and development.

OBJECTIVES

The objective of this review was to compare the efficacy and safety of early versus late administration of intravenous AA in neonates born at < 37 weeks of gestation.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and trial registries in March 2023. We checked the reference lists of included studies and studies/systematic reviews where subject matter related to the intervention or population examined in this review.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing early administration of AA with late administration in premature newborn infants. We defined early administration of AA solution as the administration of AA in isolation or with total parenteral nutrition within the first 24 hours of birth, and late administration as the administration of AA in isolation or with total parenteral nutrition after the first 24 hours of birth.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. We used the GRADE approach to assess the certainty of the evidence.

MAIN RESULTS

Nine studies (383 participants) were eligible for inclusion in the review. All study participants were born at < 37 weeks of gestation and were inpatients in neonatal intensive care units. No studies reported growth during the first months of life as assessed by difference in weight. Early administration of AA may have little or no effect on growth in the first month of life as measured by length (mean difference (MD) 0.00, 95% confidence interval (CI) -0.41 to 0.41; 1 study; 21 participants; low-certainty evidence) and head circumference (MD 0.05, 95% CI -0.03 to 0.14; 2 studies; 87 participants; low-certainty evidence). No studies reported the discharge weight outcome. Early administration of AA may result in little to no difference in neurodevelopmental outcome assessed by Mental Developmental Index (MDI) of < 70 at two years of age (odds ratio 0.83, 95% CI 0.21 to 3.28; 1 study; 111 participants; low-certainty evidence). No studies reported all-cause mortality at 28 days and before discharge. Early administration of AA may result in a large increase in positive nitrogen balance in the first three days of life (MD 250.42, 95% CI 224.91 to 275.93; 4 studies; 93 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

Low-certainty evidence suggests that there may be little to no difference between early and late administration of AA in growth (measured by length and head circumference during the first month after birth) and neurodevelopmental outcome (assessed by MDI of < 70). No RCTs reported on weight in the first month of life, mortality (all-cause mortality at 28 days and before discharge), or discharge weight. Low-certainty evidence suggests a large increase in positive nitrogen balance in preterm infants who received AA within 24 hours of birth. The clinical relevance of this observation is unknown. The number of infants in the RCTs included in the review was small, and there was clinical heterogeneity amongst trials. Adequately powered trials in infants < 37 weeks' gestation are required to determine optimal timing of initiation of AA. We identified two ongoing studies. Both studies will be recruiting infants ≥ 34 weeks of gestation and may or may not add to the outcome data for this review.

Increased risk of refeeding syndrome-like hypophosphatemia with high initial amino acid intake in small-for-gestational-age, extremely-low-birthweight infants

BACKGROUND

Recent nutrition guidelines for extremely-low-birth-weight infants (ELBWIs) recommend implementation of high initial amino acid (AA) supplementation in parenteral nutrition.

OBJECTIVE

We sought to evaluate the influence of AA intake on refeeding syndrome-like electrolyte disturbances including hypophosphatemia in ELBWIs.

STUDY DESIGN

Medical records of 142 ELBWIs were reviewed. Demographic, nutritional, outcome, and electrolyte data were compared between ELBWIs with initial low (1.5 g/kg/day) and high (3 g/kg/day) AA intake. Multivariate analysis was conducted to determine the odds ratio of hypophosphatemia with high AA intake and small-for-gestational-age (SGA) ELBWIs.

RESULTS

The incidence of hypophosphatemia and severe hypophosphatemia increased from 51% and 8% in period I to 59% and 20% in period II, respectively (p = 0.36 and < 0.01). Specifically, SGA ELBWIs showed higher incidence of hypophosphatemia than appropriate-for-gestational age (AGA) ELBWIs in period II, whereas there was no difference in period I. For severe hypophosphatemia, SGA ELBWIs presented a 27% incidence versus a 2% incidence in AGA ELBWIs, even with low initial AA intake. Despite no difference in phosphate intake between infants with and without hypophosphatemia, serum phosphate level reached a nadir at the sixth postnatal day and gradually recovered over the second week in infants with hypophosphatemia. In multivariate analyses, the odds ratios for severe hypophosphatemia were 3.6 and 6.6 with high AA intake and SGA status, respectively, with the highest being 18.0 with combined high AA intake and SGA status.

CONCLUSIONS

In summary, high initial AA intake significantly increased the risk of refeeding syndrome-like electrolyte dysregulations including severe hypophosphatemia in ELBWIs. In SGA ELBWIs, the risk of electrolyte disturbance was significantly higher, even with low initial AA intake. Therefore, new tailored parenteral nutrition protocols starting with lower energy intake and a gradual increase over the first week may be warranted for application in high-risk SGA ELBWIs.

Paediatric parenteral nutrition: current issues

Parenteral nutrition transformed the prognosis for infants and children with intestinal failure. Soon after its introduction into clinical care 50 years ago, parenteral nutrition was also rapidly adopted for use in the preterm infant, where immaturity of gastrointestinal motor function precluded enteral feeding. Preterm infants subsequently became the single largest group of patients to be fed in this way. Although the development of scientific knowledge and the lessons of clinical experience have reduced the risk of complications, some of the problems and difficulties associated with this form of nutritional support remain challenging. These include central venous catheter-related sepsis, thrombosis, liver disease, bone disease and metabolic disturbance. In an initiative to promote best practice, guidelines on parenteral nutrition were first published by the European Society for Paediatric Gastroenterology, Hepatology and Nutrition and collaborating organisations in 2005. These were constructed following a thorough review of the scientific literature, allowing a series of evidence-based recommendations to be made. The exercise was repeated just over 10 years later and updated guidelines published in 2018. This review summarises key elements from the new guideline, with a focus on what has changed since 2005.

Does High Protein Intake During First Week of Life Improve Growth and Neurodevelopmental Outcome at 18 months Corrected Age in Extremely Preterm Infants?

OBJECTIVE

To examine whether high protein intake during the first week of life alters the growth and neurodevelopmental outcomes at 18 mo corrected age (CA) in preterm infants born < 29 wk.

METHODS

This was a retrospective cohort study of preterm infants (<29 wk) before and after introduction of nutritional policy targeting higher protein intake during the first week of life. The authors compared the growth and neurodevelopmental outcomes at 18 mo CA between infants born before (epoch 1) and after (epoch 2) the introduction of nutrition policy.

RESULTS

Of 171 eligible infants who completed follow-up at 18 mo CA, 87 (51 %) were in post intervention group (epoch 2). The mean (± SD) gestational age (26.3 ± 1.49 wk vs. 26.2 ± 1.48 wk) and birth weight (947 ± 220 g vs. 924 ± 225 g) were similar between the two groups. At 18 mo CA, there were no significant differences in the growth and neurodevelopmental impairment rates between the two groups. Logistic regression analysis revealed that high protein intake (>3.5 g/kg/d) was not associated with improved neurodevelopmental outcome (OR 1.49, 95 % CI 0.52-4.26).

CONCLUSIONS

High protein intake during the first week of age was not associated with better growth or neurodevelopmental outcome at 18 mo CA in preterm infants.

Interventions To Prevent Retinopathy of Prematurity: A Meta-analysis

CONTEXT

The effectiveness of many interventions aimed at reducing the risk of retinopathy has not been well established.

OBJECTIVE

To estimate the effectiveness of nutritional interventions, oxygen saturation targeting, blood transfusion management, and infection prevention on the incidence of retinopathy of prematurity (ROP).

DATA SOURCES

A comprehensive search of several databases was conducted, including Medline, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus through March 2014.

STUDY SELECTION

We included studies that evaluated nutritional interventions, management of supplemental oxygen, blood transfusions, or infection reduction and reported the incidence of ROP and mortality in neonates born at <32 weeks.

DATA EXTRACTION

We extracted patient characteristics, interventions, and risk of bias indicators. Outcomes of interest were any stage ROP, severe ROP or ROP requiring treatment, and mortality.

RESULTS

We identified 67 studies enrolling 21 819 infants. Lower oxygen saturation targets reduced the risk of developing any stage ROP (relative risk [RR] 0.86, 95% confidence interval [CI], 0.77-0.97) and severe ROP or ROP requiring intervention (RR 0.58, 95% CI, 0.45-0.74) but increased mortality (RR 1.15, 95% CI, 1.04-1.29). Aggressive parenteral nutrition reduced the risk of any stage ROP but not severe ROP. Supplementation of vitamin A, E, or inositol and breast milk feeding were beneficial but only in observational studies. Use of transfusion guidelines, erythropoietin, and antifungal agents were not beneficial.

LIMITATIONS

Results of observational studies were not replicated in randomized trials. Interventions were heterogeneous across studies.

CONCLUSIONS

At the present time, there are no safe interventions supported with high quality evidence to prevent severe ROP.

Impact of renal function and protein intake on blood urea nitrogen in preterm infants in the first 3 weeks of life

OBJECTIVE

To examine the relationship between blood urea nitrogen (BUN) during the first 3 weeks of life and protein intake and creatinine (Cr) and to quantify the effect of protein intake on postnatal growth in preterm infants.

STUDY DESIGN

This is a 4-year, single-center, retrospective cohort study. We used multivariable linear regression models to examine the relationships between mean weekly BUN and protein intake adjusted for mean weekly Cr and potential confounders. We used additional regression models to examine the effect of protein intake on growth during this period.

RESULT

Overall, 249 infants met study criteria. As protein intake increased over the first 3 weeks of life, both BUN and Cr decreased significantly. Linear regression models showed protein intake and Cr were each significantly associated with mean BUN for each study week.

CONCLUSION

Protein intake and Cr were each significantly associated with BUN. Significant amelioration of growth failure was seen with higher protein intake.

Practical preterm parenteral nutrition: systematic literature review and recommendations for practice

Current practice in relation to the prescribing, compounding and administration of parenteral nutrition for extremely preterm infants is inconsistent and based on largely historical evidence. Increasingly there are calls for more 'aggressive' nutritional interventions to prevent 'postnatal growth failure'. However the evidence base for these recommendations is weak, and there are no long-term studies examining the impact of such practices. Here we summarise the evidence for preterm parenteral nutrition interventions. We suggest principles to guide practice based on evidence from a systematic search and review of evidence to date, and recommend actions necessary to advance the understanding of this important aspect of preterm care.

The International Network for Evaluating Outcomes of very low birth weight, very preterm neonates (iNeo): a protocol for collaborative comparisons of international health services for quality improvement in neonatal care

BACKGROUND

The International Network for Evaluating Outcomes in Neonates (iNeo) is a collaboration of population-based national neonatal networks including Australia and New Zealand, Canada, Israel, Japan, Spain, Sweden, Switzerland, and the UK. The aim of iNeo is to provide a platform for comparative evaluation of outcomes of very preterm and very low birth weight neonates at the national, site, and individual level to generate evidence for improvement of outcomes in these infants.

METHODS/DESIGN

Individual-level data from each iNeo network will be used for comparative analysis of neonatal outcomes between networks. Variations in outcomes will be identified and disseminated to generate hypotheses regarding factors impacting outcome variation. Detailed information on physical and environmental factors, human and resource factors, and processes of care will be collected from network sites, and tested for association with neonatal outcomes. Subsequently, changes in identified practices that may influence the variations in outcomes will be implemented and evaluated using quality improvement methods.

DISCUSSION

The evidence obtained using the iNeo platform will enable clinical teams from member networks to identify, implement, and evaluate practice and service provision changes aimed at improving the care and outcomes of very low birth weight and very preterm infants within their respective countries. The knowledge generated will be available worldwide with a likely global impact.

Review of macronutrients in parenteral nutrition for neonatal intensive care population

Parenteral nutrition (PN) has become essential in the management of sick and growing newborn populations in the NICU. In the past few decades, PN has become fundamental in the nutritional management of the very low birth weight infant (<1,500 g).1 Although the components in PN are commonly determined and ordered by the physician or neonatal nurse practitioner provider, the NICU nurse is responsible for confirming the components in the daily PN prior to infusion and is responsible for maintaining the infusion of PN. Nurses should understand the nutritional components of PN as well as the indications, side effects, and infusion limitations of each component. The purpose of this article is to review the macronutrients in PN, including carbohydrates, protein, and fat. A subsequent article will review the micronutrients in PN, including electrolytes, minerals, and vitamins.

Targeting 2.5 versus 4 g/kg/day of amino acids for extremely low birth weight infants: a randomized clinical trial

OBJECTIVE

To compare the effect of 2.5 vs 4 g/kg/d of amino acid (AA) in parenteral nutrition of extremely low birth weight infants on metabolic tolerance, short-term growth, and neurodevelopment.

STUDY DESIGN

One hundred thirty-one infants with birth weight between 500 and 1249 g were randomized to 2.5 (standard AA [SAA] group) or 4 (high AA [HAA] group) g/kg/d AA intake, with equal nonprotein energy. The primary outcome was body size at 36 weeks.

RESULTS

One hundred thirty-one patients were randomized and 114 analyzed (58 SAA group and 56 HAA group). Study groups had similar demographics and clinical characteristics. Elevated blood urea (BU >70 mg/dL = BU nitrogen >32.6 mg/dL) occurred in 24% vs 59% (P = .000) and hyperglycemia (>175 mg/dL) in 34% vs 11% (P = .003) of the SAA and HAA patients, respectively. Body weight, length, and head circumference at 36 weeks and 2 years were similar between groups. Bayley Scales of Infant and Toddler Development, Third Edition score was 94 ± 13 in the SAA group and 97 ± 15 in the HAA group (P = .35).

CONCLUSIONS

The HAA group had higher BU levels and better glucose control. An extra 8 g/kg of AA over the first 10 days of life did not improve growth and neurodevelopment.

Early versus late administration of amino acids in preterm infants receiving parenteral nutrition

BACKGROUND

Observational studies in preterm newborns suggest that delay in administering amino acids could result in a protein catabolic state and could impact on growth and development.

OBJECTIVES

To determine the effect of early administration of amino acids in premature newborns on growth, neurodevelopmental outcome, mortality and clinically important side effects.

SEARCH METHODS

The standard search strategy of the Neonatal Review Group as outlined in The Cochrane Library was used. Relevant randomised controlled trials were identified by searching the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library 2012 I ssue 9 ), MEDLINE, EMBASE and CINAHL from their earliest dates to September 2012. The trial registry portal of the World Health Organization's International Cilinical Trial Registry Platform and ClinicalTrials.gov (US National Institute of Health) was searched to identify ongoing and completed but unpublished studies.

SELECTION CRITERIA

Randomised controlled trials comparing early administration of amino acids with late administration in premature newborn infants were included. Early administration of amino acid solution was defined as the administration of amino acids in isolation or with total parenteral nutrition within the first 24 hours of birth; late initiation was defined as the administration of amino acids in isolation or with total parenteral nutrition after the first 24 hours of birth. The primary outcome measures were growth, neurodevelopmental outcome and mortality at 28 days. The secondary outcomes were biochemical abnormalities, sepsis and mortality.

DATA COLLECTION AND ANALYSIS

Both review authors independently selected trials, assessed trial quality and extracted data from the included studies. We contacted authors for further information. Fixed-effect analyses were performed. The treatment effect was expressed as mean difference for continuous variables and as risk difference and risk ratio for dichotomous variables. All results included 95% confidence intervals (CIs).

MAIN RESULTS

Seven randomised controlled trials were included in this review. One randomised controlled trial reported no difference in crown-heel length and occipitofrontal head circumference by day 10. Four trials that enrolled 93 premature infants showed positive nitrogen balance (The mean difference with 95% CI was 250.42 (224.91 to 275.93 P value < 0.00001). Four trials showed a significant difference in the level of blood urea nitrogen (BUN) in the first 48 hours (P value < 0.00001). Early administration of amino acids did not result in metabolic acidosis in the first 24 hours.

AUTHORS' CONCLUSIONS

There is no available evidence of the benefits of early administration of amino acids on mortality, early and late growth and neurodevelopment. There is evidence from four randomised controlled trials included in this review that early administration of amino acids is associated with a positive nitrogen balance. The clinical relevance of this finding is not known. Acid-base status and ammonia levels were normal in the infants who received amino acids early. Given the small number of infants in the randomised controlled trials included in this review, the clinical heterogeneity among them, and the lack of data on important clinical outcomes, there is insufficient evidence to guide practice regarding the early versus late administration of amino acids to infants less than 37 weeks gestation.

Validating the weight gain of preterm infants between the reference growth curve of the fetus and the term infant

BACKGROUND

Current fetal-infant growth references have an obvious growth disjuncture around 40 week gestation overlapping where the fetal and infant growth references are combined. Graphical smoothening of the disjuncture to connect the matching percentile curves has never been validated. This study was designed to compare weight gain patterns of contemporary preterm infants with a fetal-infant growth reference (derived from a meta-analysis) to validate the previous smoothening assumptions and inform the revision of the Fenton chart.

METHODS

Growth and descriptive data of preterm infants (23 to 31 weeks) from birth through 10 weeks post term age were collected in three cities in Canada and the USA between 2001 and 2010 (n = 977). Preterm infants were grouped by gestational age into 23-25, 26-28, and 29-31 weeks. Comparisons were made between the weight data of the preterm cohort and the fetal-infant growth reference.

RESULTS

Median weight gain curves of the three preterm gestational age groups were almost identical and remained between the 3rd and the 50th percentiles of the fetal-infant-growth-reference from birth through 10 weeks post term. The growth velocity of the preterm infants decreased in a pattern similar to the decreased velocity of the fetus and term infant estimates, from a high of 17-18 g/kg/day between 31-34 weeks to rates of 4-5 g/kg/day by 50 weeks in each gestational age group. The greatest discrepancy in weight gain velocity between the preterm infants and the fetal estimate was between 37 and 40 weeks; preterm infants grew more rapidly than the fetus. The infants in this study regained their birthweight earlier compared to those in the 1999 National Institute of Child Health and Human Development report.

CONCLUSION

The weight gain velocity of preterm infants through the period of growth data disjuncture between 37 and 50 weeks gestation is consistent with and thus validates the smoothening assumptions made between preterm and post-term growth references.

Early amino acid administration in very preterm infants: Too little, too late or too much, too soon?

Early postnatal growth failure is well described in very preterm infants. It reflects the nutritional deficits in protein and energy intake that accumulate in the first few weeks after birth. This coincides with the period of maximum parenteral nutrition (PN) dependency, so that protein intake is largely determined by intravenous amino acid (AA) administration. The contribution of PN manufacture, supply, formulation, prescribing and administration to the early postnatal nutritional deficit is discussed, focusing on total AA intake. The implications of postnatal deficits in AA and energy intake for growth are reviewed, with particular emphasis on early head/brain growth and long-term neurodevelopmental outcome. The rationale for maximising AA acid intake as soon as possible after birth is explained. This includes the benefits for very early postnatal nutritional intake and metabolic adaptation after birth. These benefits relate to total AA intake and so have to be interpreted with some caution, given the very limited evidence base surrounding the balance of individual AAs in neonatal PN formulations. This work mostly predates current nutritional recommendations and therefore may not provide a true reflection of individual AA utilisation in current clinical practice.

Early parenteral nutrition and growth outcomes in preterm infants: a systematic review and meta-analysis

BACKGROUND

The achievement of adequate nutritional intakes in preterm infants is challenging and may explain the poor growth often seen in this group. The use of early parenteral nutrition (PN) is one potential strategy to address this problem, although the benefits and harms are unknown.

OBJECTIVE

We determined whether earlier administration of PN benefits growth outcomes in preterm infants.

DESIGN

We conducted a systematic review of randomized controlled trials (RCTs) and observational studies.

RESULTS

Eight RCTs and 13 observational studies met the inclusion criteria (n = 553 and 1796 infants). The meta-analysis was limited by disparate growth-outcome measures. An assessment of bias was difficult because of inadequate reporting. Results are given as mean differences (95% CIs). Early PN reduced the time to regain birth weight by 2.2 d (1.1, 3.2 d) for RCTs and 3.2 d (2.0, 4.4 d) in observational studies. The maximum percentage weight loss with early PN was lower by 3.1 percentage points (1.7, 4.5 percentage points) for RCTs and by 3.5 percentage points (2.6, 4.3 percentage points) for observational studies. Early PN improved weight at discharge or 36 wk postmenstrual age by 14.9 g (5.3, 24.5 g) (observational studies only), but no benefit was shown for length or head circumference. There was no evidence that early PN significantly affects risk of mortality, necrotizing enterocolitis, sepsis, chronic lung disease, intraventricular hemorrhage, or cholestasis.

CONCLUSIONS

The results of this review, although subject to some limitations, show that early PN provides a benefit for some short-term growth outcomes. No evidence that early PN increases morbidity or mortality was found. Neonatal research would benefit from the development of a set of core growth outcome measures.

Four-week nutritional audit of preterm infants born <33 weeks gestation

AIM

Preterm nutritional audits have previously been conducted using assumed milk composition. We audited protein and energy intakes in the first 28 days of preterm life using both assumed milk composition and milk analysis to assess their effect on weight gain and to determine if the recommended reasonable range of intakes were met.

METHODS

Parenteral and enteral intakes and weight gain were recorded daily for infants (n = 63) born <33 weeks gestation, using assumed milk composition. Macronutrient composition was determined by milk analysis for a subset of infants (n = 36). Linear mixed models analysis was used to assess the influence of energy and protein intakes on weight gain.

RESULTS

(Data median (range)): Infants (n = 63) gestation and birth weight were 30 (24-32) weeks and 1400 (540-2580) g, respectively. Macronutrient milk composition was variable: protein 16.6 (13.4-27.6) g/L, fat 46.1 (35.0-62.4) g/L, lactose 68.0 (50.9-74.8) g/L, energy 3074 (2631-3761) kJ/L. Intakes based on measured composition differed from assumed. Protein intake was significantly associated with weight gain. Compared to infants with longer gestations, those born <28 weeks gestation were fed lower volumes, were more reliant on parenteral nutrition, took an additional seven days to transition to fortified feeds and median weight gain velocity took a fortnight longer to reach targets.

CONCLUSION

Preterm milk composition is variable and routine fortification using assumed composition may result in inappropriate nutrition. Fortification regimens stratified by birth gestation may be necessary to achieve preterm nutrition and growth targets. Milk analysis is required for accurate nutritional audit.

[Does early parenteral protein intake improve extrauterine growth in low birth weight preterms?]

INTRODUCTION

Extrauterine growth restriction affects most premature newborns. Early and higher parenteral protein intake seems to improve postnatal growth and associated comorbidities. We evaluate the impact of a new parenteral nutrition protocol based on early amino acid administration on postnatal growth in premature infants with a birth weight < 1,500 grams.

MATERIAL AND METHODS

A case-control study in 58 premature newborns with a birth weight < 1,500 grams. In the case group we included 29 preterm neonates who received at least 1.5 g/kg/day parenteral amino acid during the first 24 hours after birth, reaching a maximum dose of 3.5 g/kg/day on the 3(rd)-4(th) day after birth. The control group was formed by 29 preterm neonates for whom protein support began on the 2(nd-)3(rd) day after birth with a dose of 1g/kg/day with lower daily increases than the case group. Growth rates and complications were followed until 28 days of life or discharge from NICU.

RESULTS

There were no differences between groups in baseline characteristics. Premature newborns who received higher and earlier doses of proteins had a greater weight gain than the control group, and this difference was statistically significant (423 ± 138 g vs. 315 ± 142 g; P=.005). In addition, they had a higher daily weight gain rate (19.4 ± 3.3 vs. 16.5 ± 4.8; P=.010) and they regained birth weight earlier (11.5 ± 3.3 days vs. 14.5 ± 4.5 days; P=.045). A higher incidence of complications was not observed.

CONCLUSIONS

Early and higher amino acid administration improves growth rate in premature neonates with no apparent increase in risks for the patient.

Blood urea nitrogen and serum bicarbonate in extremely low birth weight infants receiving higher protein intake in the first week after birth

OBJECTIVE

To determine correlation between early protein administration and serum blood urea nitrogen (BUN) or bicarbonate (HCO(3)(-)) in extremely low birth weight (ELBW) infants during the first week of life.

STUDY DESIGN

A retrospective review of 154 ELBWs was conducted. Laboratory and nutritional data from postnatal days 1, 4 and 7 were collected. Repeated measures models estimated the relationship of protein intake with BUN and HCO(3)(-) in the first week of life.

RESULT

In total, 359 separate BUN and HCO(3)(-) values were analyzed. Each gram per kilogram of protein administered was associated with an increase in mean BUN of 3.3 mg/dl. This effect decreased daily by 2.1 mg/dl. Each gram per kilogram of protein administered was associated with a decrease in mean HCO(3)(-) by 0.9 mmol/l.

CONCLUSION

The association between protein load and BUN is positive but decreasing over time. Protein is associated with a clinically insignificant decrease in HCO(3)(-). Concerns regarding metabolic derangement from early protein administration in ELBWs are unwarranted.

SCAMP: standardised, concentrated, additional macronutrients, parenteral nutrition in very preterm infants: a phase IV randomised, controlled exploratory study of macronutrient intake, growth and other aspects of neonatal care

Background

Infants born <29 weeks gestation are at high risk of neurocognitive disability. Early postnatal growth failure, particularly head growth, is an important and potentially reversible risk factor for impaired neurodevelopmental outcome. Inadequate nutrition is a major factor in this postnatal growth failure, optimal protein and calorie (macronutrient) intakes are rarely achieved, especially in the first week. Infants <29 weeks are dependent on parenteral nutrition for the bulk of their nutrient needs for the first 2-3 weeks of life to allow gut adaptation to milk digestion. The prescription, formulation and administration of neonatal parenteral nutrition is critical to achieving optimal protein and calorie intake but has received little scientific evaluation. Current neonatal parenteral nutrition regimens often rely on individualised prescription to manage the labile, unpredictable biochemical and metabolic control characteristic of the early neonatal period. Individualised prescription frequently fails to translate into optimal macronutrient delivery. We have previously shown that a standardised, concentrated neonatal parenteral nutrition regimen can optimise macronutrient intake.

Methods

We propose a single centre, randomised controlled exploratory trial of two standardised, concentrated neonatal parenteral nutrition regimens comparing a standard macronutrient content (maximum protein 2.8 g/kg/day; lipid 2.8 g/kg/day, dextrose 10%) with a higher macronutrient content (maximum protein 3.8 g/kg/day; lipid 3.8 g/kg/day, dextrose 12%) over the first 28 days of life. 150 infants 24-28 completed weeks gestation and birthweight <1200 g will be recruited. The primary outcome will be head growth velocity in the first 28 days of life. Secondary outcomes will include a) auxological data between birth and 36 weeks corrected gestational age b) actual macronutrient intake in first 28 days c) biomarkers of biochemical and metabolic tolerance d) infection biomarkers and other intravascular line complications e) incidence of major complications of prematurity including mortality f) neurodevelopmental outcome at 2 years corrected gestational age

Trial registration

Current controlled trials: ISRCTN76597892; EudraCT Number: 2008-008899-14

Outcomes of early parenteral nutrition for premature infants

OBJECTIVE

The objective of this study was to evaluate the safety and efficacy of early amino acid (early AA) administration in very low birth weight (VLBW) infants.

STUDY DESIGN

A pre- and post-intervention study was conducted after initiating an early AA administration protocol. Clinical outcomes were collected for all VLBW infants admitted on the first day of life for 9 months before protocol initiation (standard parenteral nutrition (PN)), and 10 months after initiation of early AA.

RESULT

In all, 88 infants met study criteria for standard PN, and 85 infants for early AA administration. The patient characteristics were similar between the groups. There were no differences in mortality, the day birth weight was regained, the day enteral feeds started, the duration of PN, the day full feeds achieved and weight at 32 weeks post-menstrual age. No differences were found for late sepsis, direct hyperbilirubinemia and chronic lung disease. Necrotizing enterocolitis (NEC) occurred more frequently in the early AA administration group (12 vs 1%, P=0.012).

CONCLUSION

Early AA administration for VLBW infants was as efficacious as standard therapy, although increased NEC in the early AA period may have negatively affected growth and nutrition in that period.

Nutritional support for extremely low-birth weight infants: abandoning catabolism in the neonatal intensive care unit

PURPOSE OF REVIEW

Obviously, the ultimate goal in neonatology is to achieve a functional outcome in premature infants that is comparable to healthy term-born infants. As nutrition is one of the key factors for normal cell growth, providing the right amount and quality of nutrients could prove pivotal for normal development. However, many premature infants are catabolic during the first week of life, which has directly been linked to growth failure, disease, and suboptimal long-term outcome. This review describes the progress in research on parenteral nutrition for premature infants with a focus on amino acids and the influence of nutrition on later outcome.

RECENT FINDINGS

Although randomized clinical trials on early nutrition for premature infants remain relatively sparse, evidence is accumulating on its beneficial effects both on the short-term and long-term. However, some research also warns for adverse effects.

SUMMARY

Despite the fact that substantially improved nutritional therapies for preterm neonates have been implemented, still, some reluctance exists when it comes to providing high amounts of nutrition to the most immature infants. Pros and cons are outlined, as well as deficits in knowledge, when it comes to providing the optimal nutrient strategy in the first postnatal phase.

Initial nutritional management of the preterm infant

Postnatal nutrition has a large impact on long-term outcome of preterm infants. Evidence is accumulating showing even a relationship between nutrient supply in the first week of life and later cognitive development in extremely low birth weight infants. Since enteral nutrition is often not tolerated following birth, parenteral nutrition is necessary. Yet, optimal parenteral intakes of both energy and amino acids are not well established. Subsequently, many preterm infants fail to grow well, with long-term consequences. Early and high dose amino acid administration has been shown to be effective and safe in very low birth weight infants, but the effect of additional lipid administration needs to be defined.

Optimizing growth in the preterm infant

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

Improved growth and decreased morbidities in <1000 g neonates after early management changes

OBJECTIVE

To test the hypothesis that three changes in the early management of extremely low birth weight (ELBW) neonates would decrease the incidence of extra-uterine growth restriction (EUGR) by 25%. The three early management practice changes (EMPC) included surfactant at delivery followed by immediate extubation to nasal continuous positive airway pressure (CPAP), decreased oxygen exposure and early parenteral amino acids.

STUDY DESIGN

Historical cohort study of preterm infants<or=1000 g birth weight (BW) born at the University of Texas Medical Branch between January 2001 and June 2002 (pre-EMPC, before changes, n=87) and July 2004 to December 2005 (post-EMPC, after changes, n=76). Outcomes measured included feeding and growth parameters, morbidities and interventions. Statistical analysis included chi2-analysis, Student's t-test, and analysis of variance.

RESULT

Infants in the post-EMPC cohort regained BW more quickly, maintained appropriate size for weight at 36 weeks and had less morbidity associated with poor long-term outcome. Predictors of EUGR included BW<750 g and surgical necrotizing enterocolitis.

CONCLUSION

The introduction of surfactant at delivery followed by immediate extubation to CPAP, decreased oxygen exposure and early parenteral amino acids in ELBW infants is possible, safe and associated with improvements in growth and morbidity.

Demographic and nutritional factors associated with prolonged cholestatic jaundice in the premature infant

OBJECTIVE

The primary aim of this study was to determine if an association exists between amino-acid levels and development of cholestasis. The secondary aim of our amino-acid dose comparison trial was to identify factors associated with the development of prolonged cholestatic jaundice.

STUDY DESIGN

We compared demographic characteristics and amino-acid levels in neonates who developed cholestasis with those who did not. Parenteral-associated cholestatic liver disease was defined as a direct serum bilirubin above 5 mg per 100 ml any time during the first 28 days after birth in neonates with no history of biliary atresia or viral hepatitis. We obtained filter paper blood spots for amino acid and acylcarnitine measurements on the day of randomization and days 7 and 28 of age to identify a profile of values that could be used to identify neonates with evidence of abnormal liver function.

RESULT

We enrolled 122 neonates in our study; 13 (10.7%) developed cholestasis. Neonates who developed cholestasis were more immature, had lower birth weight, were exposed to parenteral nutrition for a longer period, had a higher cumulative dose of amino acids, were less often on enteral nutrition by day 7 of age, more often had a patent ductus arteriosus and severe intraventricular hemorrhage and were more commonly treated with steroids by 28 days of age. Amino acid and acylcarnitine values were not different for the two groups on the day of randomization. On day 7 (parenteral phase of nutrition), blood urea nitrogen, citrulline, histidine, methionine and succinyl carnitine were higher, and serine, glutamate and thyroxine levels were lower in the neonates who developed cholestasis than in who did not.

CONCLUSION

Cholestasis remains an important complication of parenteral nutrition, and several clinical and biochemical factors may be helpful in identifying high-risk patients.

Evidence supporting early nutritional support with parenteral amino acid infusion

Postnatal growth of extremely low birth weight (ELBW) infants remains poor and does not come close to approximating rates of in utero growth. There is good evidence that early deficiencies in protein may be an important contributor to the poor growth outcomes observed in this population. Protein losses are inversely related to gestational age, and ELBW infants lose 1% to 2% of their total endogenous body protein stores each day that they receive glucose alone. It is now abundantly clear from a variety of studies that providing intravenous amino acids to sick premature infants in early postnatal life can improve protein balance and can increase protein accretion, even at low caloric intakes. Provision of approximately 1 g/kg/day of amino acids will result in a net protein balance close to zero, whereas delivery of 3 g/kg/day will accomplish protein accretion. Although data from metabolic studies, observational studies, and even a few randomized clinical trials overwhelmingly support the short-term safety and efficacy of early amino acids in reversing protein loss, there is much less known about the effects of early amino acid administration on longer-term outcomes such as growth and neurodevelopment in extremely premature infants. Based on the sum of currently available evidence presented, providing ELBW infants with 2.5 to 3.5 g/kg/day of intravenous amino acids as soon as possible after birth is a reasonable recommendation. Future studies are required to determine whether provision of 3 to 3.5 g/kg/day of amino acids is "aggressive" enough for optimal growth and neurodevelopmental outcome of ELBW infants.

Early, aggressive nutritional management for very low birth weight infants: what is the evidence?

The American Academy of Pediatrics Committee on Nutrition goal of providing nutrient intakes that permit the rate of postnatal growth and the composition of weight gain to approximate that of a normal fetus of the same postmenstrual age is rarely met by extremely low gestational age neonates. Therefore, postnatal growth failure or growth restriction continues to be a problem experienced by many of these infants, and they are often less than the 10th percentile of reference intrauterine curves at the time of hospital discharge. Variation in nutritional practices, especially those practices concerned with the initiation and advancement of parenteral and enteral nutrition, largely explain the difference in growth observed at different newborn intensive care units. Although limited, the evidence supports recommendations to administer early parenteral and enteral nutrition, specifically initiation of an amino acid infusion providing about 3 g protein/kg/d within hours of birth, initiation of a lipid emulsion of 0.5 to 1.0 g lipids/kg/d within 24 to 30 hours of birth, and the initiation of minimal enteral feedings within the first 5 days of life. It is important that neonatal clinicians recognize the barriers and obstacles to the implementation of these recommendations.