DOPAMINE AND INTESTINAL MUCOSAL TISSUE OXYGENATION IN A PORCINE MODELOF HEMORRHAGE

Haemorrhage is associated with intestinal mucosal hypoxia and impaired gut barrier function. Dopamine increases oxygen delivery to the intes tinal mucosa and may thus counteract haemorrhage-induced mucosal hypox ia. Jejunal mucosal tissue oxygen tension (mucosal P-O2) and jejunal o xygen saturation of mucosal microvascular haemoglobin (mucosal Hb(O2)) were measured in 14 anaesthetized pigs. Seven animals served as contr ols (group C) and seven received continuous infusion of dopamine 16 mu g kg(-1) min(-1) (group D) while 45% of blood volume was removed in t hree equal increments. Resuscitation was performed using shed blood an d fluid. Mean arterial pressure and systemic oxygen delivery decreased significantly during haemorrhage and returned to baseline after resus citation in both groups. Mucosal PO2 decreased from 4.4 to 1.7 kPa aft er haemorrhage (P<0.01) and further to 1.5 kPa after resuscitation (P< 0.01) in group C whereas group D showed an increase from 3.9 to 5.9 kP a after the start of the dopamine infusion (P<0.05), but no significan t difference from baseline after haemorrhage (2.3 kPa) (ns) or resusci tation (3.1 kPa) (ns). Mucosal Hb(O2) decreased from 52 to 32% after h aemorrhage (P<0.05) and increased to near baseline (37%) (ns) after re suscitation in group C whereas group D showed no significant changes f rom baseline (54 %) throughout the experiment. Comparison between grou ps showed higher mucosal PO2 and Hb(O2) values for group D animals aft er the start of the dopamine infusion (P<0.05 each), after the first t wo steps of haemorrhage (P<0.01 each) and after resuscitation (P<0.05 each). We conclude that i.v. dopamine 16 mu g kg(-1) min(-1) improved tissue oxygenation of the small intestinal mucosa during moderate haem orrhage and subsequent resuscitation.