Effects of intraoperative glucose administration on circulating metabolites and nitrogen balance during prolonged surgery.

Study Objectives: To compare the effects of intraoperative administration of 2.5% glucose or Ringer's solution on metabolism during prolonged surgery.

Design: Prospective, randomized study.

Setting: Teaching hospital.

Patients: 20 ASA physical status I and II adults patients scheduled for thoracic or abdominal surgery lasting at least 3 hours.

Interventions: Patients received Ringer's solution (Group R) or 2.5% glucose solution (Group G) 10 ml.kg-1.h-1 during surgery and 2 ml.kg-1.h-1 during the first two postoperative hours (Ringer's or glucose), then 40 ml.kg-1.day-1 of 5% intravenous (i.v.) glucose postoperatively.

Measurements And Main Results: Plasma glucose, free fatty acids, ketone bodies, lactate, insulin, glucagon, cortisol, and growth hormone concentrations were determined after an overnight fast (T0), on induction of anesthesia (T1), at the end of surgery (T2), 2 hours thereafter (T3), and on the following morning (T4). Capillary blood glucose was determined every 30 minutes from T1 to T2. Urinary nitrogen and 3-methylhistidine were measured every day for 5 days. There were no differences between groups in demographic data, anesthesia, or surgical procedures. All data were comparable at baseline and on the following morning. In Group R, no patient experienced hypoglycemia, but plasma fatty acids and ketone bodies increased during surgery. In Group G, glycemia rose to very high levels, with a significant increase in insulin during surgery. Other hormones were the same within the two groups. Urinary nitrogen and 3-methylhistidine were similar in both groups.

Conclusion: The absence of glucose infusion in prolonged surgery did not cause hypoglycemia, and no increase in protein catabolism was observed.