Anabolic effects of insulin and amino acids in promoting nitrogen accretion in postoperative patients

The present study evaluates the effect of insulin and amino acids on nitrogen balance in the immediate postoperative period in moderately stressed patients who have undergone major abdominal surgical operations. Patients were randomly assigned into two large groups (n = 16 each) and four subgroups (n = 8 each). Groups ICON and IINS received an infusion of total parenteral nutrition solution containing 0.25 g of nitrogen per kilogram per day with a calorie:nitrogen (C:N) ratio of 150:1. Groups IICON and IIINS received twice the load of nitrogen with a C:N ratio of 75:1. Groups IINS AND IIINS received an additional continuous infusion of insulin at a rate of 1.0 mU/kg per minute for 7 days. During the total parenteral nutrition period, the patients were kept NPO, and 24-hour urine output was collected for estimation of total nitrogen excretion and nitrogen balance. Net nitrogen excretion (grams per kilogram per day) averaged 0.143 +/- 0.06 in IINS and 0.23 +/- 0.08 in ICON (p < .05) and 0.178 +/- 0.6 in IIINS and 0.25 +/- 0.10 in IICON (p < .05). Nitrogen balance (grams per day) was positive in the four groups: +0.65 +/- 3.8 in IINS and +6.74 +/- 2.94 in ICON (p < .05), and +14.4 +/- 2.61 in IIINS and +11.63 +/- 6.44 in IICON (p = not significant). The average nitrogen incorporation (percent per day) was: 41.3 +/- 6.2 in IINS and 14.6 +/- 20.1 in ICON (p < .05), and 58.3 +/- 4.5 in IIINS and 38.7 +/- 26.2 in IICON (p = not significant).(ABSTRACT TRUNCATED AT 250 WORDS)