Volume kinetics of glucose 2.5% solution and insulin resistance after abdominal hysterectomy

Abstract

Background. We hypothesized that volume kinetics can be used to predict the rate of infusion of glucose 2.5% solution required to yield any predetermined plasma glucose level and degree of plasma dilution during the postoperative period. Methods. In 15 women, mean age 50 yr (range 37-63), 2 days after an abdominal hysterectomy, a volume kinetic analysis was performed on an i.v. infusion of 12.5 ml kg-1 (∼900 ml) of glucose 2.5% given over 45 min. The insulin resistance was measured by a glucose clamp, and it was compared with daily bioimpedance analyses, which indicated the hydration of the intra/extra-cellular body fluid spaces. Results. The clearance of glucose was 0.42 litre min-1 (0.60 litre min-1 is normal) while the other five parameters in the kinetic model were similar to those obtained in healthy volunteers. computer simulations indicated that in a 70-kg female, at steady state, the rate of infusion (ml min-1) should be three times the allowed increase in plasma glucose (mmol litre-1). To maintain a predetermined plasma dilution the corresponding rate factor was 160. The glucose uptake during clamping was 3.9 mg kg-1 min-1 (7.0 is normal), which, during the second day after hysterectomy, correlated with the dehydration of the intracellular space (r=0.77; P<0.002) and with the protein catabolism as indicated by the urinary excretion of 3-methylhistidine (r=-0.76, P<0.002). Conclusion. The anaesthetist can prescribe postoperative administration of glucose 2.5% to reach any desired plasma glucose level and dilution by using the two presented nomograms. Insulin resistance correlated with intracellular dehydration and protein catabolism. © The Board of Management and Trustees of the British Journal of Anaesthesia 2004.