How does respiratory failure lead to papilledema?

papilledema: A difficult question ! papilledema is swelling of optic disc:a sign of raised intracranial pressure from many causes. Respiratory failure increases co2 levels, stimulating cerebral vasodilation with increased cerebral blood flow ; raised cerebral venous pressure causing elevated intracranial pressure ; other neurological signs, which may overshadow underlying pulmonary failure.

Not connected : In the intensive care unit where i practice, respiratory failure and papilledema can occur in the same situation but one does not cause the other. I can think of situations such as high blood pressure emergency causing both, or trauma situation, or meningitis etc. This is typically a very dire situation where danger of dying or remaining handicapped for the rest of one's life is quite high.

Brain swelling: Papilledema is swelling of an area in the back of the eye called the optic disc, ( an area where the optic nerve enters the eyeball ) It is often related to swelling of the brain. In respiratory arrest if there is lack of oxygen and blood supply to the brain the brain may swell and this can cause papilledema. The opposite can happen too, with brain swelling causing respiratory failure