Nitrogen retention in critically ill patients is proportional to the branched chain amino acid load.

The nitrogen retention effect of branched chain enriched parenteral nutrition (BcAA) during surgical stress and polytrauma was evaluated in a prospective, randomized, double blind study in 32 patients. The doses of BcAA were 0.16, 0.3, 0.5, and 0.7 g/kg·day with a total amino acid load of 1 or 1.3 g