Interval inhalation application of an oxygen-helium mixture reverses the effects of cerebral arterial air embolism

Oxygen-helium mixture demonstrates marked efficacy of helium mixtures in animal models of ischemia/reperfusion, which opens the possibility of its use as an emergency measure for therapy of vascular embolism. We modelled cerebral arterial air embolism by injecting an air bubble into the internal carotid artery of awake rats. Inhalation of a heated oxygen-helium mixture immediately after modelling arterial embolism normalizes physiological abnormalities and prevents ischemic brain damage, whereas application of a heated oxygen-helium mixture 2 hours after modelling arterial embolism significantly worsens the condition of the animals.