Simultaneous Measurement of PO₂ and Flow at the Same Locus during Seizures and Barbiturate Suppression of EEG

Abstract

This is a progress report of our effort to measure local blood flow by the hydrogen clearance method and PO₂ at the same point in tissue with the objective of gaining information about oxygen consumption rate. In initial trials we followed Lubber’s example that platinum electrodes polarized at -600 mV were responsive to both O₂ and H₂. We have found that bare palladium works equally well. This method has the effect of superimposing a H₂ saturation and clearance curve on the PO₂ as a baseline. While this is satisfactory in such organs as the carotid body where flow is extremely fast, in the brain, particularly in the presence of ishemic injury, a 10 to 20 minute H₂ clearance is difficult to define accurately because of lack of constancy of the PO₂ baseline.