title: Gastrointestinal permeability following cardiopulmonary bypass: a randomised study comparing the effects of dopamine and dopexamine.
abstract: OBJECTIVE
  To compare the effects of dopexamine and dopamine on the mucosal permeability of the gastrointestinal tract (GIT).
  
  
  METHODS
  Prospective, randomised clinical trial.
  
  
  METHODS
  Intensive care unit of a postgraduate teaching hospital, London, England.
  
  
  METHODS
  Thirty patients undergoing elective surgery involving cardiopulmonary bypass, performed by a single surgeon.
  
  
  METHODS
  Patients were randomly assigned to receive either dopexamine 2.0 micrograms/kg per min or dopamine 2.5 micrograms/kg per min for the duration of the study period.
  
  
  RESULTS
  Hemodynamic parameters and gastric intramucosal pH (pHi) were measured at intervals throughout the study. GIT permeability was measured once, post-operatively, using the ratio of absorbed lactulose to L-rhamnose. The groups were similar with respect to demographics, pre- and post-operative risk factors. The lactulose/rhamnose ratio was (mean +/- SEM) 0.44 +/- 0.10 in the dopexamine group vs 0.65 +/- 0.08 in that receiving dopamine (p < 0.05). The dopexamine group had a significantly higher oxygen delivery preoperatively (479.5 +/- 32.0 ml/min per m2 vs 344.4 +/- 23.9 ml/min per m2 for dopamine, p < 0.01), but no other significant differences emerged between the groups.
  
  
  CONCLUSIONS
  Compared to dopamine, dopexamine reduces GIT permeability following surgery involving cardiopulmonary bypass. The mechanism of this effect remains unclear.
authors.affiliation: Unit of Critical Care, National Heart & Lung Institute, London, UK.
authors.forename: D G
authors.initials: DG
authors.lastname: Sinclair
authors.forename: P E
authors.initials: PE
authors.lastname: Houldsworth
authors.forename: B
authors.initials: B
authors.lastname: Keogh
authors.forename: J
authors.initials: J
authors.lastname: Pepper
authors.forename: T W
authors.initials: TW
authors.lastname: Evans
mesh_terms: D018806:APACHE; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001692:Biological Transport / Q000187:drug effects; D002241:Carbohydrates / Q000493:pharmacokinetics*; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D004298:Dopamine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D005260:Female; D005767:Gastrointestinal Diseases / Q000188:drug therapy* / Q000209:etiology; D005947:Glucose / Q000493:pharmacokinetics; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects*; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism; D007792:Lactulose / Q000493:pharmacokinetics; D008297:Male; D008875:Middle Aged; D010539:Permeability / Q000187:drug effects; D011446:Prospective Studies; D012210:Rhamnose / Q000493:pharmacokinetics; D016896:Treatment Outcome; D014994:Xylose / Q000493:pharmacokinetics
chemical_list: D002241:Carbohydrates; D007792:Lactulose; D014994:Xylose; D005947:Glucose; D012210:Rhamnose; D004298:Dopamine