Inhalation of carbogen causes the body to react as if it were not receiving sufficient oxygen: breathing quickens and deepens, heart rate increases, and cells release alkaline buffering agents to remove carbonic acid from the bloodstream.
Carbogen was once used in psychology and psychedelic psychotherapy to determine whether a patient would react to an altered state of consciousness or to a sensation of loss of control.
Meduna administered carbogen to his patients to induce abreaction, which, with proper preparation and administration, he found could help clients become free of their neuroses.
A carbogen mixture of 95% oxygen and 5% carbon dioxide can be used as part of the early treatment of central retinal artery occlusion.
On this same premise it has also been proposed to be used in the management of sudden sensorineural hearing loss which can increase the blood flow to the inner ear and also possibly relieve the internal auditory artery spasm.