If your mom is at a point where they sent her home with the bi-pap, you probably aren't doing anything wrong, but the bi-pap may not be doing as much for your mom as it needs to do. I would suggest that you talk with her pulmonologist and ask about switching her bi-pap for a Trilogy, which generally is a little more successful that the bi-pap and can be used during the day if necessary. The settings are much more precise and individualized on the Trilogy. The CO2 will continue to be a problem for her, most likely. Once you're at a point where you can't blow it off yourself and require additional help after hospitalization, like a bi-pap, you're probably not going to get back to where you were before the bi-pap. I wish I had a better answer, but that's my experience.

Thank you so much for answer our questions. This offers a great point of reference for us to discuss with her pulmonologist.