It's doubtful that your supplemental oxygen is making you hypercapnic. Very doubtful. Like the previous poster said, go have some abgs drawn and then they can check and see if you in fact ARE hypercapnic and also check you out for acidosis (which often goes hand-in-hand with hypercapnia.)
The reason supplemental oxygen would most definetely NOT be the reason you're retaining co2, is because the supplemental oxygen would increase the oxygen tension inside your lungs, or it would make oxygen take up more of the airspace inside your lungs, while the nitrogen and co2 tensions would stay the same. So then, less co2 would get back in your blood.
It could be a couple things. It's possible that you're not getting enough oxygen (that you need to up your dose) and that the mild hypoxia is what's making you feel crappy, or it could be a metabolic problem.
So it could be your lung problem getting worse, or ... a metabolic problem? I know, doesn't really make a lot of sense, but let me give you an example. Your kidneys are responsible for eliminating excess acids from your body, and if they are not functioning up to par then you can start having a buildup of acids. Since the carbon dioxide -- carbonic acid buffer is one of the most important buffering systems in your body, too much acid in your blood means less carbon dioxide is carried from your tissues to your lungs to be let go. So you retain carbon dioxide.
Having too much carbon dioxide can have the same effect (high acids in the blood) but that is rarer, as to make it happen you'd have to breathe in a slow, even, shallow manner, which would be rather uncomfortable. So if anything, try to hyperventilate a little bit, and see if you feel better.
So in that case, I'd also look into having your kidneys checked. Just for the heck of it.
[This message has been edited by wrin (edited 01-03-2003).]