ReviewPrognostic impact of disease-related malnutrition
Section snippets
Background
Malnutrition remains a significant problem in hospital despite the growing body of evidence describing both its clinical and economical consequences. Depending on the definition used, the prevalence of hospital malnutrition is reported to range between 20% and 50% (see Table 1). In elderly patients1 and in some settings such as in oncology2 this rate is even higher.
Although malnutrition undeniably promotes morbidity and appropriate nutritional therapy is available in the affluent countries,
Definition
Malnutrition has been described as the imbalance between intake and requirement which results in altered metabolism, impaired function and loss of body mass5 or as a state of nutrition in which a deficiency or imbalance of energy, protein, and other nutrients causes measurable adverse effects on tissue and/or body form.6 However, there is still no internationally accepted criterion for diagnosing malnutrition which probably explains part of the reported wide range of malnutrition prevalence in
Causes for malnutrition
In developed countries the main cause of malnutrition is disease. Any disorder, whether chronic or acute, has the potential to result in or aggravate malnutrition in more than one way: response to trauma, infection or inflammation may alter metabolism, appetite, absorption, or assimilation of nutrients.15 Mechanical obstructions in the gastrointestinal tract may lead to reduced food intake by causing nausea or vomiting, pain or discomfort induced by the passage of food. The catabolic effects of
Prevalence of malnutrition in hospital
Table 1 lists studies on the prevalence of hospital malnutrition since 1990. The wide range is probably not only due to the different medical or geographic settings but also to the different patient populations and the differing criteria used to diagnose malnutrition. It is obvious that the general prevalence of malnutrition has not changed during the last 15 years although the treatment of certain diseases has significantly improved resulting in a better nutritional status (e.g. the reduced
Perioperative morbidity
Malnutrition significantly affects convalescence following disease, surgery, or trauma.
Wound healing is impaired in malnourished surgical patients.52, 53 Studies have shown that the inflammatory phase is prolonged, the proliferation of the fibroblasts, the collagen synthesis and the neoangiogenesis are reduced in malnutrition.54
Recent preoperative food intake has been reported to have a greater influence on wound healing response than absolute losses of protein and fat from body stores.55 The
Mortality
A close relationship between malnutrition and increased mortality has been demonstrated in chronic disease such as HIV/AIDS,42 chronic liver disease,38, 103 terminal renal insufficiency,41, 104, 105 cancer,36, 106 and COPD107; but also in acute settings such as stroke and hip fracture89, 91 as well as following lung resection,72 thoracotomy,73 cardiac surgery,66 and lung108 or liver transplantation,39 malnutrition has been shown to increase mortality. Malnourished patients in an intensive care
Economical implications
Due to the longer length of stay in hospital and more intensive treatment of malnourished patients, malnutrition has undeniably also become an economical issue (Figure 2). Robinson et al. demonstrated that patients with an impaired nutritional status on admission to hospital experienced a 30% increase of hospital stay.113 This was associated with a doubling of the costs, even though the patients had the same disease-related group (DRG) and therefore the same reimbursement. A recent study from
Conclusion
Malnutrition is common in sick subjects (especially hospital patients) but is frequently not recognised or underestimated. Malnutrition increases morbidity and mortality in acute and chronic diseases, impairs recovery and convalescence, prolongs treatment duration, and increases treatment costs.
Since it has been demonstrated that proper nutritional care can reduce the prevalence of hospital malnutrition and costs, nutritional assessment should be part of every medical examination in order to
Conflict of interest statement
None declared.
Acknowledgements
We thank Baxter Deutschland GmbH (Erlangen, Germany) and the Foundation Nutrition 2000Plus (Switzerland) for their financial support.
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