Disease Specific Feeding by Bharesh Dedhia

Bharesh Dedhia

Immune-enhancing
One recent advance in enteral nutrition has been the use of so-called "immune-enhancing" formulas that include arginine, glutamine, nucleotides, and/or omega-3 fatty acids (fish oil) in septic and catabolic patients. In a multicenter trial, trauma patients receiving such a formula experienced significantly fewer intra-abdominal abscesses and less multiple organ failure.

Pulmonary
Pulmonary formulas are designed to be high in fat (50%) and low in carbohydrates to reduce CO2 production, thereby reducing ventilatory demand. In preclinical studies, a tailored pulmonary formula reduced pulmonary neutrophil accumulation and inflammatory cytokines and improved cardiopulmonary hemodynamics and gas exchange. This disease-specific pulmonary formulation contains eicosapentaenoic acid and -linolenic acid (which modify production of proinflammatory cytokines) and antioxidants (vitamin E, vitamin C, and beta-carotene), and is a calorically dense formula, suitable in particular for fluid-restricted patients with ARDS.

Hepatic
Hepatic enteral formulas contain relative large amounts of the BCAAs valine, leucine, and isoleucine, with low quantities of aromatic amino acids. These products are tailored for patients with hepatic encephalopathy.The rationale is that infusion of BCAA corrects the imbalance between aromatic amino acids and BCAAs in plasma and the CNS that might contribute to the mental disturbances that are common. The use of BCAA-enriched formulas for short periods may be beneficial because they improve nitrogen balance and lessen encephalopathy, but their use for longer periods becomes expensive and may limit protein synthesis, resulting in an inadequate nitrogen balance.

Renal
Specific renal formulas are usually low in protein or contain variable proportions of BCAA. The solutions are usually calorically dense and contain up to 2 kcal/mL. To achieve this density, some formulas may contain significant amounts of fat, the ingestion of which may result in bloating and delayed gastric emptying. Potassium, phosphorus, and magnesium are present in substantially lower amounts than is the case for typical enteral feeds. Renal patients are also at increased risk of certain micronutrient toxicities. However, it is important to feed patients adequately to avoid body cell mass catabolism and malnutrition. For critically ill patients, it is best to use dialysis to clear nitrogen and fluid and to feed them an adequate protein diet than to underfeed protein.Bharesh Dedhia