[Gastric mucosal tonometry: more than splanchnic circulation and oxygenics]

The tonometric measurement of the arterial-intramucosal PCO2-difference and the calculation of the intramucosal pH is currently the only parameter which is available in the clinical routine for the assessment of perfusion, oxygen kinetics and metabolic activity of the patho-splanchnic region. Since this region with its unique both parallel and serial blood supply net comprises several organs with different metabolic performance, among which moreover the synthetic activity of the liver has to be taken into account, tonometric data have to be interpreted independently from blood flow and oxygen transport and uptake in this region. In fact, tonometry is an integrative parameter for perfusion, oxygenation and cellular energy balance. Therefore, it more completely reflects the complex anatomical and physiological conditions.