The relationship of circulating endogenous endotoxin to hemorrhagic shock in the baboon

Experiments were carried out to test the hypothesis that during hemorrhagic shock endotoxin enters the circulation from ischemic bowel by way of the portal venous system and is then associated with irreversibility of the hemorrhagic shock state. After placement of sampling catheters in the portal vein, right atrium, and aorta, 14 awake, restrained baboons were subjected to 1 hour of hemorrhagic shock at a mean arterial pressure (MAP) of 60 torr followed by a second hour at 40 torr MAP. Six animals were resuscitated with Ringers lactate and their shed blood; 8 were maintained hypotensive until death. Serial blood samples were analyzed for the presence of endotoxin. Endotoxemia was found infrequently, with no greater incidence (p > 0.6) in portal venous samples than in systemic blood, so these data were pooled for further analysis. Furthermore, endotoxemia was no more frequent (p > 0.6) late in shock than it was in early shock or during the baseline period. Autopsy showed no evidence of ischemic damage to the splanchnic viscera. It was concluded that spontaneous endogenous entotoxemia is not a common feature of hemorrhagic shock in baboons and is not related to the duration or degree of severity of hemorrhagic shock in this subhuman primate species.