Basic nitrogen requirements for intravenous feeding
Lee, H.A.
South African Medical Journal 50(42): 1642-1645
1976
ISSN/ISBN: 0256-9574 PMID: 825968 Document Number: 108606
Amino acids infused are not metabolized in the same way as those given by mouth, and can have greater toxic effects; effects are mentioned briefly. Composition of solutions for infusion, and calculation of basal N requirements, are discussed. A check-list is given, for use in deciding which amino acid solution to use. The 12 items listed are: amino acids should be in L form; all essential amino acids should be present, perhaps with more emphasis on branched-chain ones. There is no ideal amino acid solution available for treating hepatic coma. Essential amino acid content should be at least 30% for adults, 40% for children. Non-essential amino acids must be balanced; use of, e.g., glycine as filler may lead to complications. Sometimes non-essentials such as histidine, cysteine with cystine, or tyrosine may become more important and must be added to solution for, e.g., premature infants. There must be a balance between those that are cationic (lysine, histidine and arginine) and anionic (glutamic and aspartic acids). Biological value should be at least 90%. It is necessary to be aware of concentrations of solvents, so that excessive volumes are not needed when high-N intravenous feeding is planned. Electrolyte content of solution should be remembered; additions might be made. It would be preferable if the solutions had N substrate only, without energy substrate, to allow choice of energy substrate and decrease osmolar load of the amino acid solution. The most expensive amino acid solution may not be the best.