Higher versus lower protein intake in formula-fed low birth weight infants.

BACKGROUND: The ideal quantity of dietary protein for formula-fed low birth weight infants < 2.5 kilograms is still a matter of controversy and debate. In premature infants, the protein intake must be sufficient to achieve normal growth without negative effects such as acidosis, uremia, and elevated levels of circulating amino acids (e.g. phenylalanine levels). This systematic review evaluates the benefits and risks of higher (>= 3.0 g/kg/day) versus lower (< 3.0 g/kg/day) protein intakes during the initial hospital stay of formula-fed preterm infants < 2.5 kilograms. OBJECTIVES: To determine whether higher (>= 3.0 g/kg/day) versus lower (< 3.0 g/kg/day) protein intakes during the initial hospital stay of formula-fed preterm infants < 2.5 kilograms result in improved growth and neurodevelopmental outcomes without evidence of short and long-term morbidity. SEARCH STRATEGY: Two review authors searched MEDLINE (1966 - May 2005), CINAHL (1982 - May 2005), PubMed (1966 - May 2005), EMBASE (1980 - May 2005), the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 2, 2005), abstracts, conferences and symposia proceedings from Society of Pediatric Research, and American Academy of Pediatrics. Cross references were reviewed independently for additional relevant titles and abstracts for articles up to fifty years old. SELECTION CRITERIA: Randomized controlled trials contrasting levels of formula protein intakes as low (< 3.0 g/kg/day), high (=> 3.0 g/kg/day but < 4.0 g/kg/day), or very high protein intake (=> 4.0 g/kg/day) during hospitalization of neonates less than 2.5 kilograms at birth who were formula-fed. Studies were not included if infants received partial parenteral nutrition during the study period or were fed formula as a supplement to human milk. Given the small number of studies that met all inclusion criteria, studies in which nutrients other than protein also varied (> 10% relative difference) were added in a post-facto analysis. DATA COLLECTION AND ANALYSIS: Two review authors used standard methods of the Cochrane Collaboration and of the Cochrane Neonatal Review Group to independently assess trial eligibility and quality, and extracted data. In a 3-arm trial where two groups fell within the same predesignated protein intake group, weighted means and pooled standard deviations were calculated. MAIN RESULTS: The literature search identified 37 studies, of which five met all the inclusion criteria. All five studies compared low (< 3.0 g/kg/day) to high protein intakes (=> 3.0 g/kg/day but < 4.0 g/kg/day). The overall analysis revealed an improved weight gain (WMD 2.36 g/kg/day, 95% CI 1.31, 3.40) and higher nitrogen accretion (WMD 143.7 mg/kg/day, 95% CI 128.7, 158.8) in infants receiving formula with higher protein content while other nutrients were kept constant. None of the studies reported IQ or Bayley scores at 18 months or later. No significant differences were seen in rates of necrotizing enterocolitis, sepsis or diarrhea. Of three studies included in the post-facto analysis, only one could be included in the meta-analysis. The post-facto analysis revealed further improvement in all growth parameters in infants receiving formula with higher protein content (weight gain: WMD 2.53 g/kg/day, 95% CI 1.62, 3.45, linear growth: WMD 0.16 cm/week, 95% CI 0.03, 0.30, and head growth: WMD 0.23, 95% CI 0.12, 0.35). There was no significant difference (WMD 0.25, 95% CI -0.20, 0.70) in the concentration of plasma phenylalanine between the high and low protein intake groups. One study (Goldman 1969) in the post-facto analysis documented a significantly increased incidence of low IQ scores, below 90, in infants of birth weight less than 1300 grams who received a very high protein intake (6 to 7.2 g/kg/day). AUTHORS' CONCLUSIONS: This systematic review suggests that higher protein intake (=> 3.0 g/kg/day but < 4.0 g/kg/day) from formula accelerates weight gain. Based on increased nitrogen accretion rates, this most likely indicates an increase in lean body mass. Although accelerated weight gain is considered to be a positive effect, increase in other outcome measures examined may represent a negative or ambivalent effect. These include elevated blood urea nitrogen levels and increased metabolic acidosis. Limited information was available regarding the impact of higher formula protein intakes on long term outcomes such as neurodevelopmental abnormalities. As determined in this review, existing research literature on this topic is not adequate to make specific recommendations regarding the provision of very high protein intake (> 4.0 g/kg/day) from formula.

Gastrointestinal function and growth in premature infants: is non-nutritive sucking vital?

OBJECTIVE: To determine the importance of non-nutritive sucking (NNS) in the development of gastrointestinal function and growth in premature infants. DATA SOURCES: A systematic computerized search of MEDLINE, the Cumulative Index of Nursing in Allied Health Literature, Health, Best Evidence, and the Cochrane Library was performed. STUDY SELECTION: The search yielded eight randomized controlled studies relative to the outcomes of interest: sucking response, gastric emptying, weight gain, and time to discharge from hospital. DATA EXTRACTION: Relevant articles were selected using published criteria for detecting clinically sound studies and evidence-based information. DATA SYNTHESIS: NNS reduces length of hospitalization; however, its effect on the other variables was inconclusive. CONCLUSION: There is a lack of agreement concerning the outcomes of interest, apart from the positive contribution of early hospital discharge. The studies were methodologically flawed, which compromised validity and estimation of the treatment effect. NNS cannot be currently recommended as a beneficial intervention.

Cisapride: the problem of the heart.

Cisapride has been used in the neonatal population as a first-line gastrointestinal prokinetic agent for managing feeding intolerance secondary to decreased gastrointestinal motility. Cisapride acts specifically at many levels of the gastrointestinal tract and has no central nervous system side effects. Recently, prolonged QT interval has been reported secondary to high-dose cisapride, and concerns regarding its use in premature infants have been raised. In response, Janssen-Ortho Inc. and Janssen Pharmaceutica, the manufacturers of cisapride in Canada and the U.S., have released safety information prohibiting the use of cisapride in premature infants. In light of the present evidence, it is imperative that NICUs that continue to prescribe cisapride for the management of feeding intolerance exercise vigilance in cardiac monitoring and recognize the importance of drug interactions that lead to elevated cisapride levels.

Ontogeny of the gastrointestinal system and its impact on feeding the preterm infant.

The nutritional management of premature infants is a challenging area for neonatal clinicians for a number of reasons. These include lack of knowledge about when, what, and how to feed; limited clinical experience; and wide variations in practice. New practices in the nutritional management of premature infants must take into consideration the structural and functional maturity of the gastrointestinal system and environmental influences on this system. This article presents current knowledge of embryology and ontogeny of the premature infant's gastrointestinal system and explains how this knowledge may be applied to clinical practice.

Cisapride: a review of the evidence supporting its use in premature infants with feeding intolerance.

A systematic computerized search of all databases was performed to review the scientific evidence in support of the efficacy of cisapride in reducing feeding intolerance in premature infants. Reference lists from these articles were used to identify relevant scientific literature to address important aspects of the use of cisapride. Three open prospective, uncontrolled studies were found. All studies reported improved clinical outcomes as evidenced by decreased gastric residuals, decreased incidence of vomiting, increased feeding volume, decrease in all reflux parameters measured, and increased weight gain. These observational studies reflect the current state of knowledge and have important research and clinical implications because of the profound effects of feeding intolerance on infant growth and development and on length of stay within NICUs.

Impressions from a public health group visit to China.

During my trip to China, I saw how many factors interact to influence maternal and child health. These factors cover a broad scope of biologic, behavioral, environmental, and socioeconomic issues. The experience proved to be invaluable. It has helped me to understand how these factors differ--and how they are alike--in China, Canada, and other cultures.

Nurses' experience with implementing developmental care in NICUs.

The aim of this study was to gain insight into nurses' (N = 8) experience of working in a neonatal intensive-care unit (NICU) that incorporated the developmental-care approach. Although Als's model is family centered, the basic social process identified by nurses was putting the baby first. The process of putting the baby first was uncovered using grounded-theory methodology. The process included three phases: learning, reacting, and advocating/nonadvocating. In each of the phases, four main concepts--encountering, appraising, supporting, and gaining sensitivity--emerged from the data. Nurses appraised the advantages and disadvantages of this therapeutic approach not only to the infant but also to themselves.