title: Effect of thoracic epidural anaesthesia on splanchnic blood flow.
abstract: BACKGROUND
  Thoracic epidural anaesthesia (TEA) is used widely in colorectal surgery. However, there is increasing concern that epidurals are associated with postoperative hypotension, mediating a potential reduction in splanchnic flow. The aim was to review the literature on the effects of TEA on splanchnic blood flow.
  
  
  METHODS
  PubMed and Cochrane databases were searched. Search terms used were: English language, 'thoracic epidural splanchnic flow', 'thoracic epidural gut blood flow', 'thoracic epidural intestinal blood flow' and 'thoracic epidural colonic blood flow'. Abstracts were reviewed by two independent researchers and irrelevant studies excluded. The full text of the remaining articles was then retrieved.
  
  
  RESULTS
  Twenty-two abstracts were reviewed and three excluded. Nineteen papers were reviewed in full and seven irrelevant articles excluded. Five human studies investigated the effects of TEA on splanchnic flow. Two studies measured splanchnic flow directly and found an epidural-mediated fall in flow, unresponsive to intravenous fluids and requiring vasopressors or inotropes to restore baseline flow. The remaining three studies had inconsistent findings and haemodynamic stability was maintained. The seven animal studies identified were heterogeneous in both methodology and findings. Three suggested a protective role for thoracic epidurals in septic shock and pancreatitis.
  
  
  CONCLUSIONS
  These findings are inconsistent; however, the two studies that investigated the effects of vasoconstrictors on splanchnic blood flow directly both found a significant epidural-mediated reduction in splanchnic blood flow that was unresponsive to fluid therapy.
authors.affiliation: Joint Gastroenterology Research Unit, Scarborough General Hospital, Woodlands Drive, Scarborough YO12 6QL, UK.
authors.forename: E R
authors.initials: ER
authors.lastname: Richards
authors.forename: S I
authors.initials: SI
authors.lastname: Kabir
authors.forename: C-E
authors.initials: CE
authors.lastname: McNaught
authors.forename: J
authors.initials: J
authors.lastname: MacFie
mesh_terms: D000767:Anesthesia, Epidural / Q000379:methods*; D000818:Animals; D004285:Dogs; D015991:Epidemiologic Measurements; D005440:Fluid Therapy; D006801:Humans; D007422:Intestines / Q000098:blood supply; D051381:Rats; D013152:Splanchnic Circulation / Q000187:drug effects / Q000502:physiology*; D013552:Swine; D013909:Thorax; D014655:Vascular Resistance / Q000502:physiology; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents