Gut perfusion in experimental shock.

The gut seems to play a very important role in the shock syndrome, since it is an organ that is early and profoundly affected by insufficient tissue perfusion. Once affected by inadequate oxygenation, the gut can also act as a "motor of shock" by the release of toxic mediators and through the translocation of bacteria and bacterial endotoxins. It thus would be of benefit to monitor the gut during shock, and this can be accomplished by tonometry, a method to calculate the intramucosal pH (pHi). As hypoxia results in anaerobic metabolism and accumulation of acid metabolites, tissue acidosis is a sign of insufficient oxygenation. However, recent experiments have shown that, in septic states, a decreased pHi cannot be explained by decreased regional blood flow alone.