Malnutrition in the acutely ill patient: is it more than just protein and energy?

Abstract

Malnutrition has traditionally been thought to involve deficiencies in protein and energy (macronutrients); however, we know that specific key nutrients, when deficient. can also lead to significant morbidity and mortality. Large studies performed with replacement of single nutrients, such as zinc, in malnourished populations in Africa and other developing countries has led to reductions in respiratory infections and diarrhoeal diseases. In this regard, It is being increasingly that acutely ill hospitalized patients may not only be malnourished from a macronutrient standpoint, but that such patients may also be deficient in a number of key functional pharmaconutrients. This new knowledge creates a new era in nutritional support, where nutritional therapy is presenting the surgical and critical care community with a “unique opportunity” to improve patient outcomes with a safe, relatively inexpensive and effective intervention. Our vision for the future of nutritional pharmacology in surgery and critical care is one where there will be initiation of early (< 24-48 hours post-surgery or ICU admission) nutrient delivery, preferentially via the enteral route. This should be supplemented by parenteral nutrition in “at risk” patients, when adequate energy cannot be provided enterally. Pharmaconutrients to target therapy to specific disease states in such should be administered as separate components, in a manner similar to that of administering an antibiotic or drug.