title: Effects of norepinephrine alone and norepinephrine plus dopamine on human intestinal mucosal perfusion.
abstract: OBJECTIVE
  To evaluate the effect of norepinephrine alone and norepinephrine combined with dopamine on jejunal mucosal perfusion, gastric-arterial pCO(2) gradient, and global splanchnic oxygen demand-supply relationship after cardiac surgery.
  
  
  METHODS
  A prospective interventional study.
  
  
  METHODS
  A university cardiothoracic intensive care unit.
  
  
  METHODS
  Eighteen patients were studied during propofol sedation and mechanical ventilation after uncomplicated coronary artery bypass surgery.
  
  
  METHODS
  After control measurements, each patient received norepinephrine (50+/-26 ng.kg.min) to increase mean arterial blood pressure by 30% followed by addition of low-dose dopamine (2.6+/-0.3 microg x kg x min). Postdrug control measurements were performed 120 min after discontinuation of the catecholamines.
  
  
  RESULTS
  Norepinephrine induced a 32% increase in systemic vascular resistance with no change in cardiac index. Neither jejunal mucosal perfusion, assessed by laser Doppler flowmetry, nor gastric-arterial pCO(2) gradient (tonometry) was affected by norepinephrine. Splanchnic O(2)-extraction increased ( P<0.05) and this increase was positively correlated to the individual dose of norepinephrine ( r = 0.78, P<0.0001). Splanchnic lactate extraction was increased by norepinephrine ( P<0.05). None of the patients had splanchnic lactate production during norepinephrine infusion. The addition of dopamine increased cardiac index by 27% ( P<0.001) and decreased splanchnic O(2 )extraction. Dopamine increased jejunal mucosal perfusion by 32% ( P<0.001) while the gastric-arterial pCO(2) gradient remained unchanged.
  
  
  CONCLUSIONS
  Vasopressor therapy with norepinephrine after cardiac surgery did not jeopardize intestinal mucosal perfusion in spite of a dose-dependent increase of the global splanchnic oxygen demand-supply relationship. The addition of dopamine increased intestinal mucosal perfusion.
authors.affiliation: Department of Cardiothoracic Anaesthesia and Intensive Care, Sahlgrenska University Hospital, 41345, Göteborg, Sweden.
authors.forename: Andreas
authors.initials: A
authors.lastname: Nygren
authors.forename: Anders
authors.initials: A
authors.lastname: Thorén
authors.forename: Sven-Erik
authors.initials: SE
authors.lastname: Ricksten
mesh_terms: D000368:Aged; D002316:Cardiotonic Agents / Q000008:administration & dosage / Q000494:pharmacology; D001026:Coronary Artery Bypass; D004298:Dopamine / Q000008:administration & dosage / Q000494:pharmacology*; D004338:Drug Combinations; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000098:blood supply / Q000187:drug effects*; D017078:Laser-Doppler Flowmetry; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000008:administration & dosage / Q000494:pharmacology*; D010477:Perfusion; D011182:Postoperative Care; D011446:Prospective Studies; D014662:Vasoconstrictor Agents / Q000008:administration & dosage / Q000494:pharmacology
chemical_list: D002316:Cardiotonic Agents; D004338:Drug Combinations; D014662:Vasoconstrictor Agents; D004298:Dopamine; D009638:Norepinephrine