I have been reading about anesthetics and FOG or PCD (see title of post)
Over on Cure PSP there are quite a few threads on this and the subjective consensus seems to be that people having anaesthetics do not suffer a major step functional or cognitive down after surgery. Excepting for FOG from which the person recovers over an hour or two to a week or two or even a month or two.
Fog, simply put is confusion and a lessening of cognitive functioning, sometimes delirium. The worse the state of the brain before operation the worse the FOG is likely to be. It appears to be associated with inflammation of the brain.
This article, though from a Wellness type site, seems well researched and suggests things which might help.
In other articles aspiring was cited to help too.
In summary FOG is the daily bread for anaesthetists, but it might be worth having a discussion with them pre-op.