Nutritional management of acute renal failure

Acute renal failure (ARF) is associated with fundamental alterations of metabolism and immunocompetence with the induction of a pro-oxidative and proinflammatory state. Thus, the objectives of nutritional therapy include not only conventional goals such as maintaining lean body mass and stimulating immunocompetence and repair functions, but also mitigating the inflammatory state and improving the oxygen radical scavenging system and endothelial functions. Moreover, pre-existing and/or hospital-acquired malnutrition has been identified as an important factor contributing to the persistent high mortality in acutely ill patients with ARF. A nutritional program for a patient with ARF must consider not only the specific metabolic consequences associated with renal failure and with the underlying disease process, but also the profound alterations in nutrient balances induced by replacement therapy. Nutrient requirements thus may differ widely between individual patients and during the course of disease, and nutrition therapy must be coordinated with renal replacement therapy. Whenever possible, enteral nutrition should be provided in patients with ARF because even small amounts of luminal nutrients will help to maintain intestinal function. Nevertheless, in many patients parenteral nutrition, at least supplementary and/or temporarily, will become necessary. Because of the complex alterations in the use of various nutrients and the impaired tolerance to electrolytes and volume load, metabolic complications of nutritional support frequently occur in patients with ARF. Therefore, nutrition therapy must be more closely monitored in patients with ARF than with other diseases.