[Differences in postoperative metabolism in reference to pre- and postoperative initiation of total parenteral...

We investigated the postoperative metabolism of patients undergoing gastric resection by beginning total parenteral nutrition pre- (group 1) and postoperatively (group 2). A third group remained fasting until 3 h after the surgical intervention. Because of the high serum glucose concentrations and the high glucose losses in the 24-h urine on the operation day in group 1 and 2 only the base glucose requirement (150--250 g/24/h) should be given in the early postoperative period. The low blood glucose concentration in group 3 and the elevated lactate values in group 2 underline this recommandation. Compared with group 2 and 3, group 1 had low free fatty acid concentrations of 250 micronVal/l because of the continuous pre-, intra-, and postoperative infusion. Compared with normal metabolic conditions, the free fatty acids do not seem to have the same insulin-antagonizing effect in the posttraumatic state. The fall of cholesterol after the surgical trauma reached its maximum after 12--15 h and amounted to about 40 mg% in the first two groups. Albumin and total protein fell continuously in group 1 and 2. The electrophoresis in group 1 showed a rise of alpha 1- and alpha 2-globulin to more than double the initial value, the beta-globulin showed only slight changes, the gamma-globulin dropped only slightly up to the 4th postoperative day. As a sign of an augmented catabolism the serum urea concentration rose during the postoperative state. Group 1 and 2 had a favourable nitrogen balance. The postoperative bilirubin rise could be held lower in group 1 compared to group 2.