Intraoperative epidural blockade prevents the increase in protein breakdown after abdominal surgery

Background: The aim of this study was to investigate the effect of epidural blockade with bupivacaine, restricted to the intraoperative period, on protein catabolism after major abdominal surgery. Methods: Fourteen patients undergoing cystoprostatectomy were randomly assigned to receive either general anaesthesia with isoflurane (control group, n=7) or a combination of general anaesthesia and epidural blockade with bupivacaine from segment T4 to S5 (epidural group, n=7). Rates of urea (Ra urea) and glucose production (Ra glucose) were measured three days before and three days after the operation using stable isotope tracers ([15N2]urea, [6,6‐2H2]glucose). Protein breakdown was calculated from the urea production rate. Plasma concentrations of metabolic substrates (urea, glucose, lactate, glycerol, amino acids) and hormones (insulin, glucagon, cortisol, adrenaline, noradrenaline) were also determined. Results: Protein breakdown significantly increased after surgery in the control group (P