<qa>  What is the name of the infusion of stable isotopes labeled aminoIn this protocol, we will investigate fibrinogen metabolism in burn and trauma patients, using an 8h infusion of stable isotopes labeled amino acids 1-13C-phenylalanine, 2H5-phenylalanine, and 2H3-ketoisocaporate. The increase of the labeled amino acids incorporating into fibrinogen during the infusion and the decay of labeled fibrinogen after stopping the isotopes infusion as measured by GC-MS will be used to calculate fibrinogen synthesis and degradation. Stable isotopes are non-radioactive. 