Intestinal O₂ transport and energy balance during hyperdynamic endotoxic shock in the pig: comparison of noradrenaline and N^G-monomethyl-L-arginine (L-NMMA)

Introduction

Vasopressor therapy is current practice for treatment of arterial hypotension associated with septic shock, but may result in gut dysfunction due to intestinal vasoconstriction. Therefore we compared the effects of vasopressor treatment with the nitric oxide synthase inhibitor L-NMMA with those of noradrenaline (NOR) on intestinal O₂ transport as well as energy balance in a porcine hyperdynamic endotoxic shock model.

Methods

Thirty anesthetized pigs were studied; 12 h after induction of endotoxic shock with continuous LPS infusion animals were randomly assigned to receive either no drug therapy (ETX, n = 8), or vasopressor support with noradrenaline (NOR, n = 11) or L-NMMA (L-NMMA, n = 11), respectively, in order to maintain MAP at preshock levels. Portal venous blood flow (Transonic flow probes), arterial-portal venous O₂ extraction, ileal mucosal intracapillary HbO₂ saturation (remission spectrophotometry EMPHO) and arterial-ileal mucosal PCO₂ gaps were measured.

Results

Data are median and interquartile range. *P < 0.05 vs preshock (RM ANOVA on ranks). (See table overleaf.)

Conclusions

Despite well-preserved O₂ availability neither of the two treatments could reverse the endotoxin induced derangement of intestinal energy balance.

Table