[The postoperative protein and energy metabolism during infusion therapy with high-calorie carbohydrate solutions, compared with low-calorie amino acid solutions].

In a comparative study two infusion regimens applicable via the peripheral veins were examined with regard to their efficacy for the protein and energy metabolism. 20 male metabolically normal patients having undergone gastric resections were divided into 2 groups: Group I received a combined 17.2% carbohydrate solution containing no amino acids, group II received a combined 5% carbohydrate solution together with a 2.5% amino acid solution. In group I an optimal protein sparing was observed with significantly lower serum urea levels than preoperatively and in group II. The serum urea levels of group II showed a significant increase without exceeding the upper normal range and thus indicated partial utilization of amino acids for gluconeogenesis. Nevertheless, the nitrogen balances of the postoperative days 1-4 in group II were significantly improved in comparison with group I. The amino acid utilization in group II was therefore considerable despite increased gluconeogenesis. The concentration of free fatty acids in the serum of group II which was significantly increased during the postoperative days 1-5 suggested an enhanced endogenous production of energy by way of lipolysis. In group II the low-dosed supply of carbohydrates produced a correspondingly lower insulin secretion which on the one hand enabled increased lipolysis and on the other hand resulted in the utilization of carbohydrates in insulin-independent organs essential for glucose utilization. In contrast to group II there was found to be a significantly lower concentration of free fatty acids in the serum of group I because of insulin-induced reesterification rates and impaired lipolysis.