ISSN:
1432-1238
Keywords:
Injury
;
TPN
;
Nitrogen balance
;
Amino acid profile
;
Nitrogen vs amino acid requirement
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract The metabolic derangements of injury are known to influence nitrogen (N) requirements whilst less is known about individual amino acid (AA) requirements. This study was designed to investigate prospectively N vs AA requirement in 36 injured patients treated with total parenteral nutrition (TPN). The non-protein caloric input was 30 kcal kg-1 day-1 and three AA solutions were assessed containing the same AAs but in different proportion. Overall N intake was set at 0.35 g N kg-1 day-1 for solution A and B and 0.24 g N kg-1 day-1 for solution C. Solution B was similar to A, both being enriched in branched chain AAs (BCAA: 0.69 g kg-1 day-1 in B compared with 0.55 g kg-1 day-1 in A) while decreased in aromatic and sulphurated forms (1.75 times the normal need). Solution C was designed to maintain a daily input of BCAA similar to A (0.52 g kg-1 day-1) but with the supply of aromatic and sulphurated AA between solutions A and B, the supply of other AAs (lysine, theonine, histidine, arginine, glycine) being dependent on the selected N intake. For all the essential AAs the supply was always greater than normal allowances. Increasing BCAA over 0.55 g kg-1 day-1 did not improve N balance when N intake was 0.35 g kg-1 day-1, whilst nutrition with solution C was unable to maintain N balance. Moreover we found indirect evidence that this N intake, 0.52g kg-1 day-1 was more sparing than 0.37 g kg-1 day-1 of BCAA. N balance of the three groups suggests that injured patients need more than 0.24 g N kg-1 day-1 probably for non-essential AA synthesis. The study of plasma AA values support the increased non-essential N need in group C and allows us to suggest the proper AA composition of the overall optimal daily N intake (0.28–0.30 g N kg-1 day-1) in catabolic patients: BCAA about 0.5 g kg-1 day-1, phenylalanine, methionine, tryptophane, threonine and lysine from 2–3 to 5–10 times the normal allowance, the remainding N supply (about 0.14 g kg-1 day-1) should be made up from histidine, arginine, tyrosine, serine, proline, glycine, glutamic and aspartic acid.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00262896
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