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

Methods

Medline search, Pub-Med search.
Timeframe: publications from 2004 to 2016 were used to update the previous recommendations from 2005.
Type of publications: original papers, meta-analyses, experts’ recommendations, overviews.
Key words: Energy expenditure, total parenteral nutrition,
intensive care, critical care, prematurity, equations.
Language: English

Introduction

Energy supply needs to meet the nutritional needs of the patient which include basal metabolic rate, physical activity, growth, diet induced thermogenesis and correction of pre-existing malnutrition. Excess energy intake may increase the risk of complications both in the short and longer term, such as hyperglycaemia which may increase the risks of complications such as infection, impaired liver function due to steatosis, or abnormal metabolic programming. Inadequate energy supply may result in impaired growth, loss of body tissue including lean mass, sub-optimal motor, cognitive and behavioural development, and impaired immunity, and may also increase the risks of serious morbidity and mortality in infants and children.

Protein intake recommendations aim to meet needs for lean mass accretion and not to provide energy for metabolic functioning, however energy intake recommendations presented include energy intake from all sources including proteins, lipids and carbohydrates. Inadequate energy provision may therefore limit growth (or other outcomes) because protein is used as an energy source (through carbon metabolism) and no longer available for accretion into body tissue. Because splanchnic metabolism contributes significantly to whole body energy and protein turnover, and because some nutrients are excreted in the stool, energy requirements are generally 10e20% higher when fed primarily via the enteral compared to the parenteral route.

An adaptation of Atwater factors (energy content of protein, carbohydrate and lipid correspond to 4, 4 and 9 kcal/g respectively) is useful in clinical practice to calculate metabolisable nutritional energy intake. However, the energy available from macronutrients differs between parenteral and enteral sources. The gross energy content of 1 g of amino acid (AA, 4.8 kcal/g) is about 10% lower than that of 1 g of protein (5.4 kcal/g). In addition, the energy provided after oxidation of 1 g of AA into urea is 3.75 kcal whereas the energy of 1 g AA stored in protein is 4.75 kcal, a value identical to gross energy [3e5]. Gross and metabolisable energy content of glucose (3.75 kcal/g) is less than that of more complex carbohydrate (4.2 kcal/g). Lipid metabolisable energy content of intravenous lipid emulsions (ILE) is similar to gross energy (9.3 kcal/g) but could be lower when ILE contain medium chain triglycerides (MCT) and higher for long chain fatty acids (LC-FAs) [3,4]. When glycerol energy content is added to lipid content, energy content of ILE is around 10 kcal/g. These differences are not easy to incorporate into clinical practice. This explains why energy requirements in parenteral nutrition (PN) are close to that in enteral nutrition and Atwater factors are frequently used to calculate energy intakes (4 kcal/g for protein and carbohydrate and 9 kcal/g for lipid).

It is not possible to determine precise individual energy needs in clinical practice, because the outcomes of interest are multiple (growth, repair and support for functional outcomes) and cannot be determined in the short term. In clinical practice, it is impossible to determine whether energy intakes may be, for example, 10e20% above or below actual needs.

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Xuất bản bởi European Society for Clinical Nutrition and Metabolism.