Effects of norepinephrine alone and norepinephrine plus dopamine on human intestinal mucosal perfusion.
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.
Nygren
Andreas
A
Department of Cardiothoracic Anaesthesia and Intensive Care, Sahlgrenska University Hospital, 41345, Göteborg, Sweden.
Thorén
Anders
A
Ricksten
Sven-Erik
SE
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
D002316:Cardiotonic Agents; D004338:Drug Combinations; D014662:Vasoconstrictor Agents; D004298:Dopamine; D009638:Norepinephrine