Fig. 1. Comparison of blood gas data. Human data: Concentrations of xenon measured in the blood of the internal jugular vein of two volunteers. Xenon was applied intranasally for 30 min at a rate of 1.0 l/h followed by 20 min of washout. Animal data: Concentrations of xenon measured in the venous blood of the sagittal sinus of seven pigs reflect xenon concentrations in the cerebral compartment. Xenon was delivered for 25 min into the application devices at a rate of 1.0 l/h.