Specific muscle protein-sparing postoperative dextrose-free amino acid infusions

The protein-sparing and ketogenic effect of postoperative infusion of maintenance solutions containing either 3.5% amino acids or 5% dextrose in 0.33 normal (N) saline was compared by nitrogen balance and urinary acetone determination in 31 patients. A specific muscle protein sparing effect was determined by quantitation of excretion of 3-methylhistidine in seven patients of the amino acid group and eight patients in the dextrose group. In addition, an extensive hormone and substrate profile was determined. It was found that amino acid infusions not only produce a less negative nitrogen balance but also significantly reduce excretion of 3-methylhistidine indicating specific preservation of the muscle compartment.