Substrate balances across the forearm during the early postoperative period

The substrate metabolism of skeletal muscle has been studied by the forearm technique in 23 patients after abdominal operation. The data were compared to those of 55 healthy volunteers after an overnight fast. While the uptake of glucose into forearm muscle tissue was increased in relation to its elevated arterial concentration, its rate of oxidation was clearly reduced and the muscle extraction of ketone bodies was increased. Simultaneously, the production of lactate was doubled and the output of glycerol and alanine significantly enhanced. From these data one may conclude that 3 hours after abdominal surgery the energy requirements of skeletal muscle tissue are adequately met by the substrates provided that glucose sparing occurs in association with a rising arterial concentration of KB, and that the release of alanine is accelerated in spite of abundant caloric supply.