Are you having fun yet?

An ABG can be useful, especially for those patients who can't breathe into a damn tube! They are still used but it's not necessary if they believe they have a good grasp of what's going on with you, your muscles and your breathing. Venous carbon dioxide, however, is not as good a measure as arterial CO2. I wouldn't push the issue. They are taking you seriously, so let them do it their way.

Have you spoken to a pulmonologist? Have they showed you the results of the PFT's (did you ask to see them?)? Let the O2 walk go too. My pulmy always does it but that's her. She is thorough. You're in a hospital and all costs are like triple of what they'd be in a regular doctor's office. They're probably trying to find the best answers with the least amount of tests, as per usual. Don't sweat it.

And try to get some sleep!

Annie