The Influence of Abdominal Surgical Trauma Upon the Turnover of Some Blood-Borne Energy Metabolites in the Human Leg

Abstract

A moderate elevation of blood sugar and a reduction of glucose tolerance occur in association with surgical trauma. This may be due to an increased release of glucose from the liver or a reduced peripheral uptake of glucose, or both. The present study was undertaken to investigate the peripheral exchanges of energy substrates. Twenty-six patients undergoing cholecystectomy underwent turnover studies on blood-borne energy substrates in the leg before, during, and immediately after surgery. Measurements of leg blood flow and femoral arteriovenous differences in oxygen, glucose, lactate, pyruvate, glycerol, β-hydroxybutyrate, and alanine were made. After induction of general anesthesia, leg oxygen uptake decreased by 34%. Postoperatively, the oxygen uptake was 150% higher than the preanaesthetic level. During surgery, leg blood flow did not change significantly, but postoperatively it was increased by 50%. Arterial blood glucose concentration increased about 1 mmol/liter hr during the operation. Glucose uptake in the leg did not change significantly, although a large number of negative arteriovenous differences were obtained towards the end of surgery. Assimilated glucose was estimated to have accounted for 7% of the leg oxygen uptake before surgery. Toward the end of surgery, and in the immediate postoperative period, lactate release exceeded glucose uptake. During surgery, lactate and pyruvate release from the leg increased. Alanine release was also increased towards the end of the operation. As judged by the raised free fatty acids, glycerol, and β-hydroxybutyrate levels, lipolysis was stimulated during surgery. There was a correlation between leg uptake and arterial concentration of β-hydroxybutyrate. It is suggested that the increased lipolysis and increased uptake of β-hydroxybutyrate contribute to the low glucose utilization during surgery.