Nutritional support of patients with renal disease.

Current concepts in the nutritional support of patients with renal disease are reviewed. In chronic renal failure, alterations in fat, carbohydrate, and glycogen metabolism usually occur and may be worsened by acute illness. Total parenteral nutrient (TPN) therapy is rarely required unless complications occur. In contrast, acute renal failure is generally associated with hypovolemia, sepsis, soft tissue injury, and coagulation defects, all of which influence metabolism and extracellular fluid volume; the gluconeogenesis that often occurs in these patients masks the metabolic effects of uremia. Nutritional support of patients with renal disease aims at providing adequate nutrients while limiting accumulation of nitrogenous waste. Current concepts concerning essential amino acids (EAAs), nonessential amino acids (NEAAs), and urea recycling are reviewed. The caloric needs of patients with renal failure are assumed to be similar to those of other hospitalized patients. There is no clinically important advantage of using an EAA formulation rather than mixed (EAA and NEAA) amino acids. Since fluid restriction is recommended and protein use is improved with diets with a high calorie-to-nitrogen ratio, the use of TPN solutions with dextrose 350 g is recommended. If glucose intolerance is severe, fat should be considered as a calorie source. Recommendations for monitoring the metabolic status of patients with renal failure receiving nutritional support are reviewed. Monitoring the metabolic status of patients with renal disease is crucial to providing safe and effective nutritional therapy. There appears to be no clinically important advantage to amino acid products specially formulated for use in renal disease.