Hypercatabolism in acute renal failure--mechanisms and therapeutical approaches.

Despite intensive efforts in the nutritional treatment of hypercatabolic acute renal failure (ARF), its prognosis is still deleterious. The most important factor determining the outcome of ARF is the extent of catabolism which is caused by alterations of the hormonal milieu, enhanced proteolytic activity, the hemodialysis process and the patient's underlying or superimposed illness like surgical or nonsurgical trauma, rhabdomyolysis and septicemia. Up to now, in randomly assigned studies, hyperalimentation with protein- and nonprotein-derived calories has failed significantly to improve the nutritional status of the patient, although maximal doses of amino acids have been administered. Since there is some evidence from animal experiments that high doses of amino acids might act nephrotoxic, perhaps rather than further increasing the quantity of amino acids, in the future antiproteolytically acting substances may help in the management of hypercatabolic ARF. Possibly the use of amino acid solutions, enriched with branched chain amino acids, might represent a new approach in the management of negative nitrogen balance in ARF.