Effect of deep surgical sepsis on protein-sparing therapies and nitrogen balance

Four patients from a larger group of 18 patients receiving dextrose-free isotonic (3%) amino acid solution as nutritional support, form the basis of this report. An additional seven patients received intravenous isotonic (5%) dextrose as their sole support in the postoperative period following major elective surgery (average nitrogen balance = -12.3 +/- 2.7 g). All patients were well-nourished as determined by anthropometric measurements. The nonseptic patients receiving infusions of isotonic amino acids demonstrated an improvement in nitrogen balance (= delta 8.5 +2, P less than 0.001) when compared to the postoperative use of 100 to 150 g of glucose. However, sepsis produced a decreased net utilization of the infused crystalline amino acids such that nitrogen balance was similar to the intravenous glucose group (- 10.6 +/- 2.1). This septic response was associated with decreased plasma free fatty acid concentrations and the absence of starvation ketosis and ketonuria. While the nitrogen balance was not different in the septic and the dextrose control groups, deficiencies in plasma amino acid concentrations were observed in the group receiving intravenous infusion of glucose.