Epidural anaesthesia with bupivacaine does not cause increased oedema in small gut anatomoses in pigs.
OBJECTIVE
Epidural analgesia is widely used for abdominal surgery due to the properties of 'stress-free' anaesthesia and superior pain control. Nevertheless, sympathomimetics are known to antagonize inflammation. The present study was performed to investigate if epidural local anaesthetics caused increased local oedema formation.


METHODS
Thirty Dansk Landrace pigs were randomized into three groups: epidural bupivacaine, epidural morphine or intravenous (i.v.) fentanyl. All animals were anaesthetized with isoflurane and i.v. midazolam and received an identical fluid regimen. Six small bowel resections were performed over a 3-h period and during the following 3 h the anastomoses were resected. Primary end-points were water content in small bowel and mesentery samples before and after gut anastomosis, lymph flow and urine production.


RESULTS
The water content in the small bowel samples was not changed by surgery or by the different anaesthetic protocols. In the mesenteric tissue, there was a highly significant increase in water content of the postanastomotic samples compared to pre-anastomotic samples (P < 0.001) and a significant time treatment interaction was revealed (P < 0.05) suggesting an increase in oedema formation in the epidural local anaesthetic group. Lymph flow did not change during the experiments and there were no significant differences between the groups (P = 0.80). The mean total urine output was 44% higher in the epidural morphine group compared to the local anaesthetic group (P = 0.17).


CONCLUSIONS
Surgery did not increase gut wall water content, but acute oedema formation resulted in the peri-resectional mesenterial tissue, more prominently so in the bupivacaine group.
Fedder
A
A
Institute for Experimental Clinical Research, Skejby, Aarhus University Hospital, Denmark.
Dall
R
R
Laurberg
S
S
Rodt
S A
SA
D000701:Analgesics, Opioid / Q000008:administration & dosage; D000704:Analysis of Variance; D000714:Anastomosis, Surgical / Q000379:methods; D000767:Anesthesia, Epidural / Q000379:methods*; D018686:Anesthetics, Intravenous / Q000008:administration & dosage; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000009:adverse effects*; D000818:Animals; D001826:Body Fluids / Q000187:drug effects; D002045:Bupivacaine / Q000008:administration & dosage / Q000009:adverse effects*; D004487:Edema / Q000139:chemically induced / Q000209:etiology*; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage; D006439:Hemodynamics / Q000187:drug effects; D007421:Intestine, Small / Q000601:surgery*; D008643:Mesentery / Q000187:drug effects* / Q000601:surgery; D009020:Morphine / Q000008:administration & dosage; D013552:Swine; D013997:Time Factors; D014556:Urine
D000701:Analgesics, Opioid; D018686:Anesthetics, Intravenous; D000779:Anesthetics, Local; D009020:Morphine; D005283:Fentanyl; D002045:Bupivacaine