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Education & Practice Online First, published on December 16, 2014 as 10.1136/archdischild-2014-306516 INTERPRETATIONS
How to use: nutritional assessment in children Anthony E Wiskin,1,2 Mark J Johnson,2 Alison A Leaf,2 Stephen A Wootton,1,2 R Mark Beattie3 1
Faculty of Medicine, University of Southampton, Southampton, Hampshire, UK 2 NIHR Southampton Biomedical Research Centre, Hampshire, UK 3 University Hospital Southampton NHS Foundation Trust, Southampton, Hampshire, UK Correspondence to Dr Anthony E Wiskin, Southampton Centre for Biomedical Research, MP113, Southampton General Hospital, Tremona Road, Southampton, Hampshire SO16 6YD, UK; [email protected] Accepted 23 November 2014
INTRODUCTION One-fifth of children in hospitals are undernourished. Ignorance of undernourishment results in poorer outcomes for those children: longer hospital stays, complications and readmission.1 Nutritional assessment ought, therefore, to be a key feature of any holistic care and form part of routine practice.2 It is only by identifying poor growth and shortfalls in nutrient intake that it is possible to form an appropriate management plan. The purpose of this article is to provide an overview of how clinicians might approach nutritional assessment of children as part of their regular clinical practice. PHYSIOLOGICAL BACKGROUND Growth reference standards
To cite: Wiskin AE, Johnson MJ, Leaf AA, et al. Arch Dis Child Educ Pract Ed Published Online First: [ please include Day Month Year] doi:10.1136/archdischild2014-306516
Measurements of height and weight in children need to be interpreted relative to a reference population. Growth charts used in the UK are a combination of the WHO growth standards (0–4 years) and the UK 1990 (4–18 years). Data for the UK 1990 growth reference charts were collated from seven different sources and include measurements taken between 1978 and 1990 on over 25 000, predominantly white, British children.3 The WHO growth standards were derived from the WHO Multicentre Growth Reference Study (MGRS), which monitored the growth of children in optimum conditions (including exclusive breast feeding for 6 months) in six different countries around the world.4 The MGRS study demonstrated that across the globe children grow in a similar pattern provided optimum conditions are met and is the first data produced as a reference of how children should grow. Recommended nutrient intakes
The UK Department of Health has published recommendations for children and adults for the intakes of most major
macronutrients and micronutrients, in the form of Dietary Reference Values (DRVs).5 DRVs include: ▸ Estimated average requirement (EAR): The average requirement value of a specific nutrient for a specific population, based on given criteria (usually related to amounts required to prevent deficiency of the nutrient); ▸ Reference nutrient intake: The amount a nutrient that will prevent deficiency for 97% of the population, often corresponding to the EAR plus two SDs (previously known as recommended daily amount).
TECHNOLOGICAL BACKGROUND-CARRYING OUT A NUTRITIONAL ASSESSMENT Nutritional assessment contains several components because an individual’s nutritional status cannot be defined by any single measure. Important components to consider include anthropometry, body habitus/composition, dietary intake and gastrointestinal function. The aim is to provide an objective estimate of nutritional status and identify undernutrition and obesity. The WHO and other authors describe malnutrition and obesity in terms of weight for height or weight for age thresholds6–9 (box 1). History Clinical history
It is important to gain an understanding of the child’s current presenting symptom and pre-existing health problems, including pain and mobility. Gastrointestinal function is particularly relevant as it is important to consider how an individual patient will deal with the intake provided. High stool output may represent malabsorption of nutrients or secretory/osmotic diarrhoea, which may have nutritional implications. Similarly, a child who is vomiting profusely is unlikely to maintain their prescribed dietary intake. Children
Wiskin AE, et al. Arch Dis Child Educ Pract Ed 2014;0:1–6. doi:10.1136/archdischild-2014-306516
1
Copyright Article author (or their employer) 2014. Produced by BMJ Publishing Group Ltd under licence.
Downloaded from http://ep.bmj.com/ on January 22, 2015 - Published by group.bmj.com
Interpretations Box 1
Table 1 Clinical features of micronutrient deficiencies
Definitions of malnutrition and obesity
Likely deficient nutrient
Sign/symptom
WHO severe malnutrition children aged 6–60 months ▸ Weight for height more than three SDs below the mean for the population and symmetrical oedema WHO moderate malnutrition children aged 6–60 months ▸ Weight for height between 2 and 3 SDs below the population mean WHO malnutrition older children ▸ Body mass index (BMI) 95th centile
with constipation often have a reduced intake or altered dietary pattern as a consequence. Other gastrointestinal pathology should be considered including malabsorption secondary to primary gut, pancreatic or liver disease. Dietary intake assessment
In clinical practice, physicians should ask questions about intake, appetite and satiety to determine how current intake is different to normal. Physical and/or emotional responses to food are important to an individual’s intake. Appetite is the desire to eat food and differs from hunger, the physical sensation of requiring food. Satiety is the sensation of being satisfied after a meal, that is, no longer hungry. In adults, responses to a simple appetite questionnaire predict weight loss10 demonstrating their use as part of a nutritional assessment. More formal evaluation of dietary intake can be estimated by a variety of techniques including food diary, dietary recall and food frequency questionnaires and should ideally be undertaken by trained dieticians. Such techniques are subject to bias, with patients overestimating or underestimating their intake based on their perceptions of the observers’ opinion. Translating dietary information into quantitative estimates of macronutrient or calorific intake is difficult. Issues arise with the description of portion sizes and quantification of actual food eaten compared with what was offered, the constituents of homemade foods and the nutrition food reference database used. Examination
Clinical examination includes a general assessment of the health of the child and assessment of any comorbidities/illness that may be relevant. Assessment of hydration, muscle bulk and subcutaneous fat can be informative. Examination may reveal evidence of specific nutrient deficiencies. Some single nutrient deficiencies can be identified by examining the hands, face, skin and hair (table 1). 2
Anaemia
Iron Copper Folate B12
Excessive blinking, dry conjunctivae/cornea corneal ulceration, Bitot’s spots
Vitamin A
Angular stomatitis+smooth tongue
Iron B vitamins
Hair loss
Iron Biotin
Joint pain, gum swelling, loose teeth spontaneous haemorrhage
Vitamin C
Anthropometry
Measurements of height and weight need to be obtained using a standard technique and standard equipment to ensure reliable results. The child should stand barefoot with the head positioned so that a line drawn from the ear canal to the lower edge of the eye socket is horizontal (the Frankfurt plane) the back of the head, shoulder blades, buttocks, calves and heels should all touch the vertical board. Observers following a standard protocol can produce measurements with a high degree of precision and accuracy.11 In children aged
Education & Practice Online First, published on December 16, 2014 as 10.1136/archdischild-2014-306516 INTERPRETATIONS
How to use: nutritional assessment in children Anthony E Wiskin,1,2 Mark J Johnson,2 Alison A Leaf,2 Stephen A Wootton,1,2 R Mark Beattie3 1
Faculty of Medicine, University of Southampton, Southampton, Hampshire, UK 2 NIHR Southampton Biomedical Research Centre, Hampshire, UK 3 University Hospital Southampton NHS Foundation Trust, Southampton, Hampshire, UK Correspondence to Dr Anthony E Wiskin, Southampton Centre for Biomedical Research, MP113, Southampton General Hospital, Tremona Road, Southampton, Hampshire SO16 6YD, UK; [email protected] Accepted 23 November 2014
INTRODUCTION One-fifth of children in hospitals are undernourished. Ignorance of undernourishment results in poorer outcomes for those children: longer hospital stays, complications and readmission.1 Nutritional assessment ought, therefore, to be a key feature of any holistic care and form part of routine practice.2 It is only by identifying poor growth and shortfalls in nutrient intake that it is possible to form an appropriate management plan. The purpose of this article is to provide an overview of how clinicians might approach nutritional assessment of children as part of their regular clinical practice. PHYSIOLOGICAL BACKGROUND Growth reference standards
To cite: Wiskin AE, Johnson MJ, Leaf AA, et al. Arch Dis Child Educ Pract Ed Published Online First: [ please include Day Month Year] doi:10.1136/archdischild2014-306516
Measurements of height and weight in children need to be interpreted relative to a reference population. Growth charts used in the UK are a combination of the WHO growth standards (0–4 years) and the UK 1990 (4–18 years). Data for the UK 1990 growth reference charts were collated from seven different sources and include measurements taken between 1978 and 1990 on over 25 000, predominantly white, British children.3 The WHO growth standards were derived from the WHO Multicentre Growth Reference Study (MGRS), which monitored the growth of children in optimum conditions (including exclusive breast feeding for 6 months) in six different countries around the world.4 The MGRS study demonstrated that across the globe children grow in a similar pattern provided optimum conditions are met and is the first data produced as a reference of how children should grow. Recommended nutrient intakes
The UK Department of Health has published recommendations for children and adults for the intakes of most major
macronutrients and micronutrients, in the form of Dietary Reference Values (DRVs).5 DRVs include: ▸ Estimated average requirement (EAR): The average requirement value of a specific nutrient for a specific population, based on given criteria (usually related to amounts required to prevent deficiency of the nutrient); ▸ Reference nutrient intake: The amount a nutrient that will prevent deficiency for 97% of the population, often corresponding to the EAR plus two SDs (previously known as recommended daily amount).
TECHNOLOGICAL BACKGROUND-CARRYING OUT A NUTRITIONAL ASSESSMENT Nutritional assessment contains several components because an individual’s nutritional status cannot be defined by any single measure. Important components to consider include anthropometry, body habitus/composition, dietary intake and gastrointestinal function. The aim is to provide an objective estimate of nutritional status and identify undernutrition and obesity. The WHO and other authors describe malnutrition and obesity in terms of weight for height or weight for age thresholds6–9 (box 1). History Clinical history
It is important to gain an understanding of the child’s current presenting symptom and pre-existing health problems, including pain and mobility. Gastrointestinal function is particularly relevant as it is important to consider how an individual patient will deal with the intake provided. High stool output may represent malabsorption of nutrients or secretory/osmotic diarrhoea, which may have nutritional implications. Similarly, a child who is vomiting profusely is unlikely to maintain their prescribed dietary intake. Children
Wiskin AE, et al. Arch Dis Child Educ Pract Ed 2014;0:1–6. doi:10.1136/archdischild-2014-306516
1
Copyright Article author (or their employer) 2014. Produced by BMJ Publishing Group Ltd under licence.
Downloaded from http://ep.bmj.com/ on January 22, 2015 - Published by group.bmj.com
Interpretations Box 1
Table 1 Clinical features of micronutrient deficiencies
Definitions of malnutrition and obesity
Likely deficient nutrient
Sign/symptom
WHO severe malnutrition children aged 6–60 months ▸ Weight for height more than three SDs below the mean for the population and symmetrical oedema WHO moderate malnutrition children aged 6–60 months ▸ Weight for height between 2 and 3 SDs below the population mean WHO malnutrition older children ▸ Body mass index (BMI) 95th centile
with constipation often have a reduced intake or altered dietary pattern as a consequence. Other gastrointestinal pathology should be considered including malabsorption secondary to primary gut, pancreatic or liver disease. Dietary intake assessment
In clinical practice, physicians should ask questions about intake, appetite and satiety to determine how current intake is different to normal. Physical and/or emotional responses to food are important to an individual’s intake. Appetite is the desire to eat food and differs from hunger, the physical sensation of requiring food. Satiety is the sensation of being satisfied after a meal, that is, no longer hungry. In adults, responses to a simple appetite questionnaire predict weight loss10 demonstrating their use as part of a nutritional assessment. More formal evaluation of dietary intake can be estimated by a variety of techniques including food diary, dietary recall and food frequency questionnaires and should ideally be undertaken by trained dieticians. Such techniques are subject to bias, with patients overestimating or underestimating their intake based on their perceptions of the observers’ opinion. Translating dietary information into quantitative estimates of macronutrient or calorific intake is difficult. Issues arise with the description of portion sizes and quantification of actual food eaten compared with what was offered, the constituents of homemade foods and the nutrition food reference database used. Examination
Clinical examination includes a general assessment of the health of the child and assessment of any comorbidities/illness that may be relevant. Assessment of hydration, muscle bulk and subcutaneous fat can be informative. Examination may reveal evidence of specific nutrient deficiencies. Some single nutrient deficiencies can be identified by examining the hands, face, skin and hair (table 1). 2
Anaemia
Iron Copper Folate B12
Excessive blinking, dry conjunctivae/cornea corneal ulceration, Bitot’s spots
Vitamin A
Angular stomatitis+smooth tongue
Iron B vitamins
Hair loss
Iron Biotin
Joint pain, gum swelling, loose teeth spontaneous haemorrhage
Vitamin C
Anthropometry
Measurements of height and weight need to be obtained using a standard technique and standard equipment to ensure reliable results. The child should stand barefoot with the head positioned so that a line drawn from the ear canal to the lower edge of the eye socket is horizontal (the Frankfurt plane) the back of the head, shoulder blades, buttocks, calves and heels should all touch the vertical board. Observers following a standard protocol can produce measurements with a high degree of precision and accuracy.11 In children aged
