Glutamine, as a fuel for enterocytes has received much attention, with several recent clinical trials. In severe stress, such as bone marrow transplant, a beneficial effect of glutamine in decreasing hospital stay, increasing nitrogen balance and decreasing infection rates has been demonstrated. These effects have been attributed to improved gut barrier function, but improved gut and hepatic protein synthesis are equally possible.

Nutritive solutions enriched with argnine, RNA and omega–3 fatty acids are also important fuels that influence positively the post–operative recovery of many plasma parameters which reflect patient’s recovery from surgery. These “Enriched solutions” are a better choice than standard diets in improving parameters such as pre–albumin concentration, retinol binding protein concentration, delayed hypersensivity responses, phagocytic ability of monocytes and concentration of IL–2 receptors. People who receive the enriched solution have the same risk of developing post–operative infections if compared with people who receive the standard diet, but the infections in the latter group tend to be much more severe and difficult to treat.

It is also important to say that all the other nutrients must be remembered. Vitamins and minerals are necessary and must be administrated within the nutritional support plan.

Causes of Inadequate Nutrition or Increased Protein Loss
Lack of food is a cause of malnutrition in urban poor populations, especially in alcoholics. However, the most common causes of in–hospital malnutrition are poor food unappetizingly serve, with timing for the benefit of personnel rather than the patients. Patients are given nothing by mouth for the most trivial reasons (chest or abdominal films, other radiological exams). Diets are not advanced rapidly after trivial operations.

There is rapid adaptation to resting starvation, and proteolysis is minimal after as little as four days. The metabolic tragedy of sepsis is that this adaptation to starvation does not occur, and breakdown of protein continues, to supply amino acids either for hepatic protein synthesis for host defenses or for gluconeogenesis for the energy needs of the organism.

Methods of Assessment of Nutritional Status
Accumulation of lean body mass is the principal objective of nutritional support, thus determination of lean body mass is the most appropriate means of nutritional assessment. The methods used are:

• History and Physical Examination: Weight loss, anorexia or a disease process that interferes with intake (such as esophageal carcinoma) should alert the examiner to the possibility of malnutrition. On physical examination, muscle wasting, loss of thinner eminence muscles, loose flabby skin, edema of hypoproteinemia, weakness, loss of body fat and pallor are the key signs that confirm the malnutrition.
• Nitrogen Balance.
• Indirect Calorimetry.
• Delayed Cutaneous Hypersensivity or Anergy.
• Functional Studies of Muscles Function.
• Displacement of Water Volume.
• Neuron Activation Analysis.
• Magnetic Resonance Imaging.

In 1996, Butters et. al. proposed that only simple and inexpensive anamnestic and anthropometric measurements (as weight development abdominal complaints and fat tissue measurements) are necessary for the evaluation of nutritional status. After, from these data, body mass index and ideal body weight can be calculated. Concentrations of albumin, prealbumin, retinol binding protein and creatinine height index can be obtained by simple biochemical laboratory tests. The author defines these parameters to be enough to determine a patient’s nutritional status.

The Patient at Predicted Risk for Surgery can be recognized as follows:

1. Recent weight loss of greater than 10% body weight and/or body weight of 80 to 85% ideal body weight.
2. Serum albumin in a stable, hydrated patient of less than 3g/100 ml.
3. Anergy to injected skin recall antigens.
4. True transferrin of less than 200 mg/100 ml.
5. A history of functional impairment.
6. Significant deficits in hand dynamometry or muscle response to nerve stimulation.

The Indications for nutritional support Should consider the following

1. The premorbid state (healthy or otherwise).
2. The current nutritional status.
3. Age of the patient.
4. Duration of starvation.
5. Degree of the anticipated insult.
6. The likelihood of resuming normal intake soon.
7. Weight loss of 15%.
8. A serum albumin value less than 3g/100 ml.