Khuyến nghị của ESPGHAN/ESPEN/ESPR về dinh dưỡng qua đường tĩnh mạch cho trẻ em: Axit amin

30/11/2023

Methods

Search: Searches were performed in three stages. First, all the titles with the relevant key words were retrieved by the Cochrane Collaboration Department from Budapest, who also performed the first reduction. Publications published after the previous guidelines [1] (i.e., from 2004eDecember 2014), were considered. Members of the Working Group subsequently read all the titles and abstracts, and selected potentially relevant ones. These were retrieved and full articles were assessed. Some studies published in 2015 or 2016 during the revision process have also been considered. The references cited in the previous guidelines are not repeated here, except for some relevant publications; only the previous guidelines will be cited instead.

Outcome: Recommendations were developed from a standpoint of nutrient adequacy. Depending on age groups, nutrient adequacy was based on intrauterine accretion rate, organ development, factorial estimates of requirements and amino acid interactions. Individual amino acids are discussed. Minimal intakes of specific amino acids are those that meet the specific requirement of children in that age group. Maximal intakes are recommended to prevent excessive and potentially harmful intakes of amino acids.

Introduction

Proteins are the major structural and functional components of all cells in the body. They consist of chains of amino acid subunits joined together by peptide bonds. The chain length ranges from two amino acids to thousands, with molecular weights subsequently ranging from hundreds to hundreds of thousands of Daltons. From a nutritional perspective, an important aspect of a protein is its amino acid composition. Some amino acids are classified as essential (indispensable). These are amino acids that cannot be synthesized by humans and hence must be provided in the diet or parenteral solution (Table 1). Non-essential amino acids can be synthesized from other amino acids or from other precursors. Some amino acids are categorized as semi-essential. These amino acids can be synthesized from other amino acids but their synthesis is limited under certain circumstances.

Ments for assessing adequacy of amino acid intake include anthropometry (weight and length), nitrogen balance, metabolic
indices (e.g. amino acid concentrations, albumin, pre-albumin, total protein concentrations, blood urea nitrogen, metabolic acidosis), whole-body nitrogen kinetics, specific amino acid kinetics and the indicator amino acid method. The intake of each essential amino acid required to maintain nitrogen equilibrium in children and infants has been defined as the amount necessary to obtain adequate growth and nitrogen balance. The amino acid indicator method is an accurate and fast way to determine specific amino acid requirements. It has been developed to measure specific amino acid requirements [2e4] and has been validated in animal models of infancy [5,6]. Such an approach has recently been used in the determination of the requirement of several amino acids in parenterally fed neonates (Table 2) [7e10].

Amino acid Requirement (mg/kg/d)
Tyrosine 74
Methionine þ cysteine 47
Threonine 38
Lysine 105

Most currently used parenteral amino acid mixtures contain amino acid amounts that result in a plasma amino acid pattern resembling the plasma amino acid patterns of normally growing, breast fed infants and children, or cord blood. These paediatric parenteral amino acid mixtures provide more essential and less non-essential amino acids than normally deposited by the infant or child. The utilisation of the amino acid supply depends on a sufficient energy intake, and often an energy supply of 30e40 kcal per 1 g amino acids is recommended.

Xuất bản bởi European Society for Clinical Nutrition and Metabolism.

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