The why…could be blood flow, shallow breathing,low respiratory rate, some types of autonomic dysfuction caused from central nervous system ect. A build up of paco2 is the lungs not pushing the amount needed out. If o2 is normal, the body is properly oxygenated but is not properly ventilating out the toxic carbon out, which can lead to acidosis. Going to a card and pulm, neuro, or electrophysiologist would be your best bet. Im guessing a ent is just gonna wanna do surgery…What were her oxygen levels? Doctors on here feel free to add or correct me if i misspoke! Im just a mom who studies a lot!!!