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Treating malnutrition in primary care

Hazel Rollins CBE
MSc BSc(Hons) RN RM
Nutrition Nurse Specialist
Luton and Dunstable Hospital NHS Trust

Malnutrition is defined as: "A state of nutrition in which a deficiency or excess (or imbalance) of energy, protein and other nutrients causes measurable adverse effects on tissue/body form and function, and clinical outcome."(3)
Approximately 5% of the UK adult population has a body mass index less than 20kg/m(2) (an indication of malnutrition). This figure rises to 16% in residential and nursing homes. It is often associated with chronic illness (such as stroke, cancer, chronic neurological diseases and chronic gastrointestinal disease) and social deprivation (such as poverty and homelessness, social isolation and dependency). One study found that over 10% of patients are malnourished after major surgery, and a high proportion of these are women and younger patients.(4) Another study revealed that patients receiving district nursing care are significantly more likely to be malnourished.(2)

The consequences of malnutrition
Malnourished patients are known to visit their GP more frequently, have higher prescription costs and are more likely to be admitted to hospital and die.(5) Malnutrition affects all body systems. Immunity is reduced and infections more common. There is evidence of delayed wound healing and an increased prevalence of pressure sores. Thermoregulation is adversely affected, which may increase the risk of falls. Muscle strength is reduced. Malnutrition is known to affect mood - individuals may be depressed and apathetic with loss of libido.

Detecting malnutrition
Many attempts have been made to develop screening tools to detect malnutrition. Until recently, none met the criteria generally accepted for guideline development. However, in 2000, the Malnutrition Advisory Group (a standing committee of the British Association for Parenteral and Enteral Nutrition) produced multiprofessional guidelines for the detection and management of malnutrition that meet these stringent criteria.(3) The screening tool has been piloted in both outpatient and general practice settings. Even in inexpert hands the screening tool takes only two minutes to complete.
The screening tool consists of three components: body mass index (BMI), percentage weight loss and a subjective element that allows the use of clinical judgment.
Here BMI (weight/height squared; normal range 20-25kg/m(2)) is used to screen for the risk of chronic protein-energy undernutrition. A BMI less than 18.5kg/m(2) indicates that protein-energy undernutrition is probable.
One argument against the use of BMI in the community is the lack of suitable scales and height meters. Weight and height provide important clinical information, and it is important to be able to take such measurements accurately. Even in hospitals the provision of scales is variable and they are poorly calibrated. Healthcare settings should have access to properly and regularly calibrated clinical (rather than domestic) scales and height meters. Where necessary, weighing hoists should be used.
Height can be difficult to measure in elderly patients. However, if height were measured proactively during patients' visits to the surgery, this would become less of a problem. Surrogate measures of height can also be used, such as demispan or knee-height.(3)
It is generally accepted that an unintentional weight loss of more than 10% in 3-6 months is clinically ­significant. This is a method of screening for risk of acute or recent onset protein-energy undernutrition. It can be calculated from the following formula:
% weight loss = normal weight - measured weight X 100
                                            normal weight

Looking at subjective factors helps to categorise patients when it is not possible to establish the BMI or a weight history. Risk factors include: a history of decreased food intake or loss of appetite; weight loss suggested by loose-fitting clothing and jewellery; and psychological and physical illness that may lead to weight loss.

Management plan
There would be little point in using healthcare-resourced screening for malnutrition if nothing could be done to improve nutritional status. However, for some groups of patients there is much to be gained by ­detecting and treating malnutrition, and it is easy for malnutrition to be overlooked while attention is paid to complex medical and social problems. Looking after the patient's nutritional status as part of their overall ­management falls within our duty of care.
Once malnutrition is detected, a management plan should be agreed, including the following elements:(3)

  • The potential goals of intervention, such as improvement of walking distance and healing of pressure sores.
  • Treatment or alleviation of the underlying ­condition, for example provision of specialist crockery and ­cutlery for patients with arthritis of the hands.
  • Identification and treatment of specific nutrient deficiencies.
  • Improvement of the protein-energy status using food in the first instance.
  • The use of nutritional supplements if indicated - this is more likely to be of benefit in those with a BMI 20kg/m(2).(6)
  • Monitoring at an appropriate interval to ensure that goals are met.
  • Consideration of a dietetic/nutrition support team referral if these simple measures are ineffective.

Conclusion
If 40% of patients enter hospital malnourished, it appears the real problem lies in the community. Health professionals can use a simple tool to screen for malnutrition and then set realistic goals for its ­management. Joint efforts to manage such malnutrition may prove very fruitful.

References

  1. McWhirter JP, Pennington CR. ­­Inci­-dence and recognition of ­malnutrition in hospital. BMJ 1994;308:945-8.
  2. Edington J, Kon P, Martyn CN. Prevalence of malnutrition in patients in general practice. Clin Nutr 1996;15:60-3.
  3. Elia M. Guidelines for detection and management of malnutrition. Maidenhead: BAPEN; 2000.
  4. Edington J, et al. Prevalence of malnutrition after major surgery. J Hum Nutr Dietetics 1997;10:111-6.
  5. Martyn CN, et al. The effect of ­nutritional status on the use of health care resources by patients with chronic disease living in the community. Clin Nutr 1998;17:119-23.
  6. Stratton RJ, Elia M. A critical systematic analysis of the use of oral nutritional supplements in the community. Clin Nutr 1999;18(suppl 2):29-84.

Resources
British Association for Parenteral and Enteral Nutrition
(BAPEN)
T:01527 457850
F:01527 458718
W:www.bapen.org

National Nurses Nutrition Group
Annmarie Daniels
Membership Secretary
Department of Clinical Nutrition
St Mark's Hospital
Level 5
Watford Road
Harrow HA1 3UJ
T:0208 2354000 extn 4120