Background and Objectives The purpose of the study was to investigate the effect of thoracic epidural administration of local anesthetic, i.e., epidural block on perioperative lipolysis.

Methods Fourteen patients undergoing elective colorectal surgery were randomly assigned to receive either general anesthesia combined with epidural block (EDA, n = 7) or general anesthesia alone (control, n = 7). The rates of glycerol appearance (R_a glycerol), i.e., lipolysis, were assessed by the stable isotope tracer [1,1,2,3,3-²H₅]glycerol before, during, and 2 hours after the operation. Plasma concentrations of metabolic substrates (glycerol, free fatty acids [FFA], lactate) and hormones (insulin, glucagon, cortisol) were also determined.

Results In the EDA group, R_a glycerol decreased to lower intra- and postoperative values than in the control group (P < .05). Perioperative plasma concentrations of glycerol, FFA, lactate, and insulin remained unaltered with both anesthetic techniques. Intraoperative plasma glucagon and cortisol concentrations were lower in the EDA group than in the control group (P < .05).

Conclusions Epidural block suppresses lipolysis during and 2 hours after major abdominal surgery without affecting plasma glycerol or FFA concentrations.