Increased Nitrogen Retention after Trans-Operative Intravenous Amino Acid and Glucose Infusion, without Changes in Urinary Amino Acid, Adrenaline and Plasma Urea or Glucose

Abstract

Objective: Nutritional deficiencies are associated with increased morbidity and mortality during and after surgery. The present study evaluated nitrogen retention after transoperative intravenous infusion of amino acids and glucose. Design: Prospective study. Setting: Large community hospital. Patients: 18 randomly chosen patients undergoing medium or major surgeries. Interventions and Measurements: The experimental design included a 12-hour period before surgery (P1), a trans-operative period of 6 hours (P2), an early postoperative period (P3, 18 hours), and a late postoperative period (P4, 24 hours). Urinary amino acid and nitrogen were analyzed from P1 through P4. Group I, nine patients, received Ringer’s lactate solution with 5% glucose, and Group II, another nine patients, received a 6.6% amino acid and 16.6% glucose solution over a 6-hour trans-operative period (P2) starting from the anesthesia procedures. All surgical procedures lasted a maximum of 3 hours. Results: There was no statistically significant difference in urinary amino acid or adrenaline excretion between P1 and P4 in either group. Nitrogen excretion values were also similar for both groups, i.e., 0.39 ± 0.16 and 0.39 ± 0.28 g/hour, respectively. The nitrogen balance showed greater nitrogen retention (﹣0.25 ± 0.24 g/hour) in the group receiving the amino acid infusion compared to the group receiving Ringer’s lactate solution (﹣0.59 ± 0.26 g/hour) (P < 0.05). Blood plasma urea nitrogen and glycaemia did not increase at the end of the study (P4 period) in either group. Conclusion: These data indicate that trans-operative infusion of glucose and amino acids can be beneficial for patients submitted to surgical stress in terms of nitrogen retention.