I don't have a CPAP machine yet and I have only used one for 1 night at the clinic. It was great and I am looking forward to getting one. I have read the benefits for treating sleep apnea due to the air splint created with the forced air provided by the machine. Does that mean that there is an increased air pressure in your lungs? I have also been reading about the overall health benefits of increased air pressure provided by hyperbaric oxygen chambers. On the surface it seems that both devices provide air under pressure to the lungs. Does the CPAP raise the blood oxygen level above normal daytime breathing? If it does it would be interesting to see if the same general health benefits seen in hyperbaric oxygen chamber sessions would also be seen in CPAP users.

They're completely different.  CPAP pressure is in your airway and acts as an "air splint" to keep your airway open.  Chamber has an overall pressure difference but does not "splint" your airway open.