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Published on 24 March 2010

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Malnutrition: one size won’t fit all

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Providing a clear and substantial improvement to the clinical outcome of malnutrition patients can only be achieved if clinicians begin to identify and overcome the current problems associated with nutrition support

Professor
Mohandas
Mallath
MD
Head
Department of digestive
diseases and
clinical nutrition
Dean-Academic
Tata Memorial Centre
Mumbai, India

Malnutrition is the commonest co-morbid disease found in patients at hospitals and in the communities where people dwell. The prevalence of malnutrition among hospitalised patients is known to vary widely between 20% and 80% depending on the criteria used and the nature of the healthcare setting (eg, Intensive Care Unit).[1–2] Nutrition therapy was the most important componentof medical treatment before the discovery of antibiotics. Sadly, malnutrition has continued to remain a major problem in communities and hospitals in all parts of the world, in spite of all the scientific evidence describing its clinical and economical impact and all the guidelines proposed by various governmental agencies and medical societies. Sometimes, malnutrition precedes the onset of a disease (eg, tuberculosis) or it develops along with progression of the disease (eg, cancer of the pancreas). Such situations are generally beyond the purview of prevention and clinical interventions (see Figure 1). What is distressing is the fact that a lot of clinical malnutrition is iatrogenic for it begins or worsens to severe grades after the patient has started his or her hospital visits and this can amount to medical neglect. Malnutrition that develops or worsens during medical treatments or hospital stay is often due to the poor recognition by the medical and paramedical staff and neglect of early interventions.

Numerous studies have shown that clinical malnutrition has serious implications on the recovery process from disease, trauma, surgery and other therapies. Malnutrition suppresses immunity, delays tissue repair and promotes the loss of muscle mass which results in increased morbidity, mortality, hospital stay and costs. Malnutrition is uniformly associated with increased morbidity, mortality, hospital stay, costs as well as delayed rehabilitation and quality of life both in acute and chronic, medical and surgical settings. There is a fair amount of evidence that early detection and appropriate nutritional care can reduce infections, shorten hospital stay, and reduce the cost of care.[3] Nutritional assessment is therefore mandatory in order to recognise malnutrition early and initiate timely nutritional therapy.

It must be stated at the outset that the benefits of nutrition screening and intervention have come in small increments. The results of most randomised clinical trials using intensive and expensive nutrition support during the treatment of different disease states has not been spectacular in terms of reducing the overall mortality that we had aimed for. Furthermore, the end results of nutritional patients have varied considerably among different disease and their treatment settings. Some of the better results were seen in patients undergoing surgery for upper digestive cancer. On the other hand the use of routine nutrition support by total parenteral nutrition during cytotoxic chemotherapy for cancer had resulted in net harm. The problem with clinical nutrition therapy of yesteryears is that it has been driven by simplistic attitudes such as “one size fits all” and “if little is good, lots must be better”. Failure of nutrition support in general and parenteral nutrition to provide clear and substantial improvement in the clinical outcomes of patients and thereby provide value for money can be attributed to several factors listed in Table 1. In general there are three issues that need to be corrected: correct diagnosis of malnutrition; correct route of feeding; and correct amounts of feeding.

Correct diagnosis of malnutrition
Having observed patients in India, United Kingdom and United States of America, I have come to realise that malnutrition has too many faces. For example a newly diagnosed impoverished Indian man with a cancer of buccal mucosa and having a BMI of 18.0 Kg/m2 with no change in food intake and body weight would be classified as being well nourished by Subjective Global Assessment and severely malnourished by any screening tools that uses BMI as one of the components of assessment. We have reported that the use of BMI for malnutrition screening results in over-estimation of severe malnutrition in the Indian population because nearly half of the population has BMI below 18.5Kg/m2 (see Figure 2). As a result, the association of malnutrition (by BMI based tools) and clinical outcomes are not significant in Indian patients.[2,4] On the contrary in countries where a substantial proportion of patients are overweight or obese the threshold for diagnosis of severe malnutrition would be higher. Like any other disease, early and correct diagnosis of malnutrition and appropriate staging of its severity is very important for guiding appropriate treatments. While the well-nourished patients with adequate or excess nutritional reserves may be kept starving for some days without harm, the nutritionally depleted would require early interventions to prevent further deterioration. Conversely providing early nutritional support to well nourished patients could adversely affect the outcomes (eg, hyperglycaemia). It is likely that these issues have been over looked in the early intervention studies conducted in the 1970s and 1980s. Nutritional support should be given to nutritionally depleted patients.

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Correct route of feeding
One turf battle that has been around for a while was between enteral and parenteral nutrition. In health and most illness the gastrointestinal tract is functional and can be used to provide nutrition. Nutrients administered through the gut follow a more physiological route and are less expensive. While oral feeding is the preferred route in health, the desire to take foods and beverages by mouth is diminished during illness. Furthermore the lack of company, and isolation in hospitals and nursing homes further diminish food intakes. I have found that in India where multiple family members share the room and meals both at home and in hospitals result in better intake of foods. For those who can’t eat but have a functioning gut, feeding tubes can be placed at various sites using a variety of techniques. The trouble with the saying “if the gut works, use it” is that we can’t use a working gut unless a proper feeding tube is placed. This is a real problem as feeding tube placement can be challenging and time consuming as a result of which the threshold for the use of parenteral nutrition is low in many places. In the presence of a committed nutrition support group we have been able to place feeding tubes in 96% of our cancer patients and thereby avoid the use of total parenteral nutrition (TPN).[5] The use of TPN can be restricted to a smaller group of patients with severely increased requirements that can’t be meet by enteral feeding, or when the gut is not usable due to various reasons. More often a combination of EN and PN may be necessary to deliver adequate amounts of nutrients. The availability of a nutrition support team helps to improve the delivery of nutrients. It is essential that all medical, paramedical staff and family members of the patient involved in the care of the patients maintain an active interest in clinical nutrition support so as to ensure maximal benefits to the patients. Irrespective of the route, adequate nursing care and periodic monitoring are necessary to reduce complications (eg, infections, aspirations, etc) and improve the cost-effectiveness of nutrition therapy.

Correct amounts of feeds
The type and the amount of nutrients are determined by several factors. The estimation of the nutritional needs in adults are often guided by formulas based on experiments done on healthy volunteers. The validity of these well known formulas used to estimate the energy and other requirements are being tested in different populations and clinical settings.[6] In general there is increasing evidence that the formulas developed in one population can be erroneous in another population (see Figure 3). As a result many use a more common sense approach calculating fixed amounts of calories per kilogram body weight or continue to use formulas that may not be appropriate. More importantly a very recently published multinational survey indicates that nutrition support for critically ill patients continues to be suboptimal.[7] The delivery of the prescribed nutrient requirement is further complicated by the inability to deliver the estimated requirements to the patients or the patients are unable to tolerate the nutrients. They may manifest in the form of delayed gastric emptying or diarrhoea during enteral feeding or hyperglycemia or hypertriglyceridaemia during parenteral feeding. Hyperglycaemia has received a lot of attention in recent years.[8] In reality how much of the intolerance is due to the formulation, how much to delivery and how much to the extent of sickness is difficult to quantify. Frequently for patients who are very sick or unstable, a combination of EN and PN is able to achieve the nutritional goals.

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Nutrition at Home
The provision of nutrition support at home is an integral part of healthcare delivery. The need for home enteral feeding and home TPN has been increasing following the advent of ambulatory therapies. Home enteral feeding helps the patient to be in a familiar environment and enjoy more normal relationships. A great responsibility is placed on the patient and the family during ambulatory nutrition therapy. Homecare givers should be trained adequately. This can be an issue in many parts of the world where people may live alone or have outlived a spouse to a very old age. Irrespective of where the nutrition support is delivered, monitoring of nutritional support at home, nursing home or hospital is recommended.

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Future Research
Malnutrition being the commonest co-morbidity associated with human disease creates a big opportunity for continued research. Understanding the mechanisms involved in the development of anorexia, weight loss and cachexia in patients and identifying suitable targets will be rewarding. Malnutrition broadly is the result of reduced nutrient intake and increased nutrient needs. Recent research suggests that many diseases create a chronic inflammatory state, with loss of taste and smell, malabsorption, prolonged starving for multiple investigations and treatment related sideeffects all contribute to reduced food intake. Anorexia has a central role in cachexia and increased metabolic demands triggered by cytokines. Preferential mobilisation of fat and the sparing of skeletal muscle seen in simple starvation are replaced by an equal mobilisation of fat and skeletal muscle in cancer patients. The increase in basal energy expenditure is triggered by cytokines. Preferential mobilisation of fat and the sparing of skeletal muscle seen in simple starvation  are replaced by an equal mobilisation of fat and skeletal muscle in these patients. The role of nutraceuticals like glutamine, other omega-3 fatty acids and immune boosting nutrients needs to be tested in well designed adequately powered clinical trials where patient related outcomes are needed. Last but not the least the role of genes and epigenetics in clinical nutrition needs to be studied for personalising clinical nutrition.

There are many things that can be done to help our war on malnutrition. First we need to have simpler and cheaper devices to measure accurately the nutritional requirement of sick patients. Second, there is a need to develop devices that would help in accessing the gut for enteral feeding. Availability of easily placeable and comfortable feeding tubes that do not block easily and stay put would definitely help in enteral feeding programmes. Similarly, the research on safe vascular access goes far beyond their use in TPN. Then issues like stability, contamination, loss during storage, and flexibity are important issues for EN and PN formulations.

The compounding of three in one bags (TIO) of various sizes and volumes is necessary to provide optimal nutrient delivery to the patients. This is particularly true in the intensive care setting and paediatric settings where more calories need to be delivered in less volumes. Stability of lipids and micronutrients in the TIO bag is another issue. Availability of small volume bags could facilitate nutrition support in ICU by combining EN with PN to reach the goals.

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Summary

Nutritional therapy must be considered in the treatment plan for all patients. Patients capable of oral intake can be managed by dietary modification and nutrition supplements. Special care should be taken to avoid food and drink borne infections. Some patients need tube feeding to ensure adequate nutrient intake during their treatments and thereafter. TPN is required for a small proportion of patients. In hospitalised patients the primary responsibility of ordering and the supervision of nutritional therapy lies with the attending doctor. The availability of a nutrition support team will increase the cost-effectiveness of nutrition therapy.

References
1. McClave SA, et al. Journal of Parenteral and Enteral Nutrition 2009;33:277-316.
2. Shirodkar M, et al. Indian J Gastroenterol 2005;24:246-50.
3. Clinical Guideline 32 National cost impact report to accompany ‘Nutrition support in adults: oral nutrition support, enteral tube feeding and parenteral nutrition’ Published by the NICE, London 2006.
4. Mohandas KM, et al. Clin Nutrition 2003;22(Supl-1): S92-93.
5. Shastri YM, et al. Aliment Pharmacol Ther 27, 649-658.
6. Walker RN, Heuberger RA. Respiratory Care 2009;54:509-21.
7. Jones NE, et al. Nutrition therapy in the critical care settings: What is best achebvable practice? An international multicentre observational study. CCM 2010;38:1-7.
8. Inzucchi SE, Siegel MD. New Engl J Med 2009;360:1346-49.



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