Souffrance de la muqueuse intestinale au cours du choc endotoxinique expérimental

Abstract

To ascertain tissue oxygenation during conversion from hypo to hyperdynamic state with vascular volume expansion, venous outflow from a segment of ileum was isolated in anesthetized and pump-ventilated endotoxic dogs to measure gut oxygen uptake (V̇ o 2), lactate metabolism, intramucosal P co 2 and tissue P o 2 (Pti o 2). Tissue P o 2 was measured by multipoint surface Mehrdraht Dortmund Oberfläche electrodes placed on mucosal and serosal surfaces of gut. Six dogs were infused with 2 mg · kg −1 E. coli lipopolysaccharide (LPS) in one hour followed by a two hour 0.5 mL · kg −1 · min −1 dextran infusion. Two dogs were used as controls and received dextran infusion in order to assess time and hemodilution-dependent effects. LPS infusion resulted in an hypodynamic sepsis with supply limited V̇ o 2, increased arterial lactate and increased lactate output by gut. Resuscitation resulted in an hyperdynamic sepsis with improvement of whole-body V̇ o 2. In the gut, V̇ o 2 remained low and intramucosal P co 2 as well as lactate output remained high, despite increased flow. Gut Pti o 2 results suggested blood flow maldistribution with tissue hypoxia in the mucosa despite increased total flow to the gut. Gut V̇ o 2, lactate flux, intramucosal P co 2, and tissue P o 2 were consistent with regulatory responses that shut down mucosal perfusion and oxygenation in spite of increased blood flow to gut.