[The effect of enriched branched chain amino acid solution on amino acid metabolism during perioperative total parenteral nutrition support].

A prospective, randomized clinical study was performed in patients underwent subtotal gastrectomy or hemicolectomy. Patients were randomly divided into two groups receiving standard amino acid solution (23% BCAA) or a solution enriched with branched chain amino acid (41% BCAA). Preoperative postprandial plasma amino acid levels were used as base line. The amino acid concentrations in plasma between control group (A) and study group (B) were compared during perioperative period. The dynamics of postoperative plasma amino acid profile of the two groups were similar except that plasma BCAA concentrations were very high in group B. In both groups, the levels of plasma glutamine, alanine, tyrosine, lysine, threonine, arginine, asparagine, and cystine decreased, whereas the levels of plasma methionine, phenylalanine, and tryptophan increased. The solution of 41% BCAA was not found to be superior to standard 23% BCAA in normalizing the disorder of plasma amino acid spectrum during the period of TPN support. The differences of urinary amino acid excretion including 3-MHIS and nitrogen balance between the two groups were not statistically significant. Also the results showed more severe disorder of plasma amino acid profile caused by 41% BCAA solution than by standard solution of 23% BCAA.