Screening and Assessment of nutritional status

Screening and assessment of an individual’s nutritional status can be performed using a number of measures ranging from tools such as the Subjective Global Assessment (Detsky et al 1987) to relatively simple measures of height and weight (combined as Body Mass Index). However some measurements (height, laboratory tests, skin fold thickness) may not be readily available in all care settings. Undesired weight loss (>10% of normal body weight in the past six months, or >5% in the past month) may provide an indication of malnutrition although where possible reasons for this unintentional weight loss should be explored with the individual patient.

Accurate measurement of body weight and height, and hence Body Mass Index, may be problematical in many settings through lack of available equipment or challenges in measuring body length among some patient groups. BMI measures have also been found to be less valid within some patient groups, such as children and the very elderly, due to their altered/different fat/lean body mass ratio.

Recording patient weight should follow a specified protocol, where the individual is weighed ideally at the same time of day using the same scales with an appropriate weight range (up to 350kg). Before weighing, any outdoor clothes and shoes should be removed. If possible all weight measurements should be made by a single recorder. In addition to weight measurement, waist circumference is a reliable marker for intra-abdominal fat mass. The waist measurement should be carried out at a specific location half-way between the superior iliac crest and the rib cage, in the mid-axillary line.
Nutritional assessment may also include nutritional intake over the past one, three or seven days; this information may be gathered using 24-hour recall, self or carer reported food intake records or through the involvement of a dietician, where available. It is important to consider why the intake of food and fluids is at the reported level.
Biochemical measurements such as serum albumin, hemoglobin and potassium may be helpful when considering the nutritional status of the ill although these indicators may provide more information upon chronic, rather than acute depletion of specific nutrients. In general it is unlikely that biochemical measurements will provide more information than other indicators such as undesired weight loss although a number of studies cite an association between albumin and pressure ulcers.
The use of nutritional screening or assessment tools appears to be becoming more prevalent in managing patients at risk of/with pressure ulcers. These tools require to be validated and reliable, and like general risk assessment tools should not replace clinical judgement. However, the use of validated nutritional assessment tools may help to foster attention upon the need to consider nutrition when assessing vulnerability to pressure ulcer development.

Nutritional status should be re-assessed regularly following an individualized assessment plan which includes an evaluation date. The frequency of assessment should be based upon the condition of the individual and should occur following specific events such as surgery and any development of infections or other catabolic processes likely to stress the nutritional status of the individual.

While looking at the individual patient the clinical judgement of appropriately trained health professionals may provide sound evaluations of probable nutritional status, it should be acknowledged that excess of body weight may mask nutritional deficiencies – for example morbidly obese individuals may still be malnourished.

Nutritional intervention

Where an assessment or screening of nutritional status indicates that malnutrition may be present, nutritional intervention should be considered. The primary goal of nutritional intervention is generally to correct protein-energy malnutrition ideally through oral feeding. When considering any limitations on normal food and fluid intake, consider the local environment such as ease of access to food, social and functional issues along with the texture of the diet. Changes in these aspects may encourage or facilitate increased oral intake. Overall the goal should be to consider the quality and energy-density of the food intake rather than its quantity. Considering fluid intake quantity is equally important as quality.

Where enhanced normal feeding is not possible, protein-energy rich oral supplements may be considered (Recommendation 1B; Benati et al 2001, Bourdel-Marchasson et al 2000, Breslow et al 1993, Chernoff et al 1990, Delmi et al 1990). The value of vitamin and trace element supplementation in pressure ulcer prevention is unclear (Recommendation 1B; Taylor et al 1974, ter Riet et al 1995).

Where normal feeding and oral supplementation fail to resolve apparent malnutrition then other routes (for example tube-feeding) may be undertaken although the risks associated with these interventions should be considered.
While the amount of supplementation required by individuals will vary, general guidance can be offered where an individual may require a minimum of 30–35 kcal per kg body weight per day, with 1 to 1.5 g/kg/day protein required and 1ml per kcal per day of fluid intake.

Specific guidance on energy expenditure may be provided through the use of standard equations such as the Harris-Benedict or Schofield formulae although it is recommended that advice on their use and interpretation be sought from a dietician (where available) or the multidisciplinary care team.

The success of nutritional intervention should be reviewed within the on-going regular nutritional assessments and may be indicated by outcomes such as increased weight or improved functional ability and/or enhanced health-related quality of life. Successful nutritional intervention may also be marked by a reduced incidence of new pressure ulcers and the healing of established pressure ulcers.

Regular evaluation of the effects of nutritional interventions is required but it should be borne in mind that where individuals are malnourished the effects of feeding and/or supplementation may not be immediately apparent, probably because there first needs to be a restoration of already depleted reserves.

Where patients have established pressure ulcers then a similar strategy of nutritional intervention should normally be considered (normal feeding, then oral supplements and finally tube-feeding) although the demands may be greater. There are a number of observations upon the role of nutritional deficiencies and pressure ulcer healing that can be extracted from controlled trials – protein and calorie supplementation, along with the use of arginine, vitamins and trace elements with antioxidant effects appear to have a positive effect on healing (Recommendation 1B; Benati et al 2001, Bourdel-Marchasson et al 2000, Breslow et al 1993, Chernoff et al 1990, Delmi et al 1990). The evidence for the value of ascorbic acid supplementation is equivocal (Recommendation 1B; Taylor et al 1974, ter Riet et al 1995) and the evidence for zinc supplementation is weak (Recommendation 1B; Norris 1971).

Specific issues may need to be resolved if normal feeding is to be enhanced – for example control of wound odour, altered body image, pain associated with the pressure ulcer and loss of self-esteem because these issues can reduce nutritional intake.

Where individuals present with severe pressure ulcers (Grades 3 and 4) then the multidisciplinary team should consider their basal energy expenditure and pay particular attention to the increased fluid loss through such wounds.
The nutritional requirements of specific groups may be different from those outlined in these guidelines, for example the spinal cord injured.

Nutritional assessment and intervention should of course be combined with all other appropriate interventions including pressure management.

These guidelines have not addressed several specific issues – nutritional assessment and intervention in neonates and paediatrics, the role of parenteral nutrition and specific needs of individual patient groups such as the immuno-suppressed, those with cancers, orthopaedic, trauma and surgical patients and those who have experienced burns. Pharmacological interventions such as the use of anabolic steroids also are not included.

In all of the preceding recommendations regarding nutritional assessment and supplementation all decisions should be taken with regard to patient choice and in light of the overall goals of treatment.

EDUCATION

There is a requirement for all staff (including but not limited to health professionals, untrained staff, catering and porters) to be aware of the importance of nutrition and to understand their role in improving the nutritional status of patients. This education will range from the performance of nutritional screening and assessment, the preparation of attractive, appetizing meals and the delivery and presentation of meals dependent upon the needs of individual staff members. There is a need to establish a nutritional culture within healthcare prompting the appropriate availability and presentation of meals through to continuity of nutritional care across departments and care settings.