Rapid and persistent decrease in brain tissue oxygenation in ovine gramnegative sepsis

Abstract

The changes in brain perfusion and oxygenation in critical illness, which are thought to contribute to brain dysfunction, are unclear due to the lack of methods to measure these variables. We have developed a technique to chronically measure cerebral tissue perfusion and oxygen tension in unanesthetized sheep. Using this technique, we have determined the changes in cerebral perfusion and PO2 during the development of ovine sepsis. In adult Merino ewes, fiber-optic probes were implanted in the brain, renal cortex, and renal medulla to measure tissue perfusion, oxygen tension (PO2), and temperature, and flow probes were implanted on the pulmonary and renal arteries. Conscious sheep were infuse..