Cortical pO2 distribution during oligemic hypotension and its pharmacological modifications.

pO2 measurements in the cerebral cortex of cats have shown that the distribution of oxygen within the tissue becomes considerably affected by hypovolemic hypotension, in particular in the late period of oligemia. Pharmacological studies on this model show that the treatment of shock with a vasodilating drug such as papaverine leads to shunt-perfusion, thus impairing the oxygenation of brain tissue. In contrast, administration of the metabolically active drug dihydroergotoxine (DET, Hydergine) results in an improvement of the tissue pO2 distribution in the direction of a pre-shock state.