EARLY EFFECTS OF CATECHOLAMINE THERAPY ON MUCOSAL INTEGRITY, INTESTINAL BLOOD-FLOW, AND OXYGEN-METABOLISM IN PORCINE ENDOTOXIN-SHOCK

Objective to determine the early effects of therapy of endotoxin (ET) shock with epinephrine, norepinephrine, or dopexamine on splanchic cir culation, oxygen metabolism, sigmoid mucosal pHi, bacterial translocat ion, and morphologic integrity of the ileal, colonic, and sigmoid muco sa. Summary Background Data Conflicting concepts exist concerning the catecholamine therapy of septic shock, but little is known about the e ffects of catecholamine treatment on splanchic circulation and mucosal integrity. Methods ET shock was induced in pigs by ET infusion over 3 0 minutes, and animal were studied for 4 hours. All animals were resus citated with fluid. To mimic the treatment of septic shock in humans, mean arterial pressure was maintained in two groups at > 70 mm Hg with the administration of epinephrine or norepinephrine. A third group of animals received dopexamine at 7 mu g/kg per minute. Systematic and s planchic blood flow and oxygen metabolism were studied, sigmoid colon mucosal pHi was obtained tonometrically, and bacterial translocation w as determined by culture of portal venous blood, mesenteric lymph node s, liver, spleen, and lung specimens. Histologic sections of ileal, co lonic, and sigmoid mucosa were morphometrically examined for therapy e ffects. Results All investigated catecholamines increased cardiac outp ut and systemic oxygen delivery, whereas intestinal blood flow and oxy gen delivery remained unchanged. Sigmoid mucosal pHi decreased in all study animals, but the decrease was most pronounced in the epinephrine group. Pigs receiving epinephrine also showed >40% damage of the muco sa of the ileum and colon, whereas animals receiving ET alone, norepin ephrine, or dopexamine showed only moderate lesions with signs of rest itution. No animal showed bacterial translocation. Conclusions Systemi c hemodynamics and oxygen metabolism data do not reflect intestinal pe rfusion. Norepinephrine or dopexamine administration in ET shock cause s no additional impairment of intestinal integrity. Epinephrine therap y, in contrast, is associated with a significant reduction of mucosal pHi and considerable early mucosal damage. Its application in septic s hock is hazardous.