title: Local metabolic changes in subcutaneous adipose tissue during intravenous and epidural analgesia.
abstract: BACKGROUND
  This clinical study aimed at investigating the impact of postoperative thoracic epidural analgesia on extracellular glycerol concentration and glucose metabolism in subcutaneous adipose tissue, using the microdialysis technique. The sympathetic nervous activity, which can be attenuated by epidural anesthesia, influences lipolysis and the release of glycerol.
  
  
  METHODS
  Fourteen patients who underwent major abdominal or thoraco-abdominal surgery were studied postoperatively over 3 days. For postoperative analgesia the patients were prospectively randomized to receive either thoracic epidural analgesia with a bupivacaine/morphine infusion (EPI-group, n=6) or a continuous i.v. infusion of morphine (MO-group, n=8). The concentration of glycerol, glucose and lactate in the abdominal and deltoid subcutaneous adipose tissue were measured using a microdialysis technique.
  
  
  RESULTS
  The abdominal glycerol levels were equal in both groups. In the deltoid region of the EPI-group, glycerol concentrations started to increase on Day 2, and reached significantly higher levels on Day 3 compared with the MO-group. The glucose and lactate levels showed no differences between groups in the two regions.
  
  
  CONCLUSIONS
  The uniform glycerol levels in abdominal subcutaneous adipose tissue in conjunction with the difference in glycerol levels in the deltoid area indicate that the local lipolysis is different in the two study groups. This might be explained by a regional metabolic influence of thoracic epidural analgesia, possibly via the sympathetic nervous system.
authors.affiliation: Department of Anesthesiology and Intensive Care, Lund University Hospital, Sweden. per.ederoth@skane.se
authors.forename: P
authors.initials: P
authors.lastname: Ederoth
authors.forename: P
authors.initials: P
authors.lastname: Flisberg
authors.forename: U
authors.initials: U
authors.lastname: Ungerstedt
authors.forename: C-H
authors.initials: CH
authors.lastname: Nordström
authors.forename: J
authors.initials: J
authors.lastname: Lundberg
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D000328:Adult; D000698:Analgesia; D015360:Analgesia, Epidural; D019540:Area Under Curve; D005110:Extracellular Space / Q000378:metabolism; D005260:Female; D005947:Glucose / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D017551:Microdialysis; D010149:Postoperative Pain / Q000188:drug therapy
chemical_list: D005947:Glucose; D005990:Glycerol