OK, getting back to your original questions, RonS. I'll offer my own thoughts on the matter, relating to what I went through when I started therapy.
RonS wrote:Is this a common sensation? If not, anyone else get this? Does it go away over time? Is it just me being anxious?
A lot of us go through variations on this. I've not heard of any documented or researched answers though. It's tempting to dismiss as purely psychological, but there is some evidence suggesting a physiological phenomenon relating to CO2 retention, or lack thereof.
Your respiratory drive is largely controlled by the amount of CO2 in your blood. Now, you can consciously change that CO2 level with deliberate breathing exercises. If you've heard of "apnea" divers before (not sleep apnea, btw), they manage to stay under water for several minutes at a time because they have succeeded in changing their long-term CO2 threshold. That CO2 threshold change occurs gradually over a period of days. It's not the sort of thing which one changes by simply taking a number of deep breaths just prior to diving (although I'm sure they do that as well).
My theory (and I may not have all the pieces exact about how this happens) is that for someone with OSA the repeated apneas can, and often do, affect one's long-term CO2 threshold. In my own case, prior to CPAP therapy I'd frequently wake up "hyperventilating" and was even documented as such via blood gas analysis during one emergency room visit. Every night I'd wake up at least once "hyperventilating", often multiple times, and would then struggle to consciously control my breathing for a number of minutes until it finally returned to "normal". As soon as I started CPAP all of that stopped, just as if somebody had turned off a switch. Even though I still experience some apneas, the experience is quite different now. When I awaken after a long apnea, struggling to catch my breath, I simply breathe until I get caught up on my breathing. I no longer experience any tendency toward hyperventilation.
Anyway, for what it's worth that's my story to share this morning. I'd guess that what you were experiencing resulted from a long-term CO2 threshold shift which is now correcting itself due to CPAP therapy. Have a great day, Ron.
Regards,
Bill