Electron Paramagnetic Resonance Assessment of Brain Tissue Oxygen Tension in Anesthetized Rats

Abstract

Using in vivo electron paramagnetic resonance oximetry, we studied the patterns of cerebral tissue oxygenation (PtO(2)) during exposure to various inhaled and injected general anesthetics, and to varying levels of inspired oxygen. These data show that inhaled anesthetics result in larger levels of PtO(2) in the brain than do several injectable anesthetics. The results highlight the experimental utility of electron paramagnetic resonance in measuring PtO(2) during anesthesia and serve as a foundation for further study of PtO(2) in response to physiologic perturbations and therapeutic interventions directed at preventing cerebral ischemia.