Effect of epidural analgesia on metabolic profiles during and after surgery.

Blood concentrations of glucose, lactate, alanine, free fatty acids, glycerol and 3-hydroxybutyrate were measured during 24 h in 12 females undergoing elective hysterectomy under either general anaesthesia or epidural analgesia extending from T4 to S5. The results showed that the peroperative and immediate postoperative metabolic profiles in the group receiving general anaesthesia reflected substrate mobilization (increased glucose, lactate, 3-hydroxybutyrate), and that epidural analgesia blocked these changes, probably mediated through an inhibited adrenaline response to surgery. Peroperative values of free fatty acids and glycerol were significantly lowered by epidural analgesia, indicating inhibition of lipolysis. Alanine decreased similarly in both groups. In the later postoperative period metabolic profiles were similar in two groups, indicating that the influence of fasting may override the effect of the relatively minor trauma.