Effect of amino acid infusion on free amino acid spectrum in plasma and nitrogen balance in severe trauma patients

Objective: To investigate the effect of amino acid infusion on free amino acid spectrum in plasma and nitrogen balance in severe trauma patients.Methods: 40 severe trauma patients were randomly divided into two groups: experiment group(amino acid+glucose+fat emulsion) and control group(glucose+fat emulsion).Blood samples were taken for determination of plasma levels of free amino acid and nitrogen balancewas was measured after 4 days.Results: The levels of glycine,cysteine,valine,methionine,isoleucine,leucine,lysine,histidine and arginine in experiment group were significantly higher than those in control group(P0.05).The ratio of phenylalanine and tyrosine(Phe/Tyr)and the ratio of branched-chain amino acids and aromatic amino acids(BCAA/AAA)in two groups were not different and clearly higher or lower than the normal value(P0.05).The nitrogen balance was-(6.6±3.8)g/L in control group and -(0.7±5.0)g/L in experiment group(P0.05).Conclusion: Intravenous infusion of 1.2 g/(kg·d)amino acid can increase the levels of most of free amino acid in severe trauma patients.Supplement of amino acid can improve nitrogen balance,but can not correct the amino acid metabolism disorder.