I was just released fromthe hospital. I have COPD but have not been on oxygen, I had a Cpap. They changed me to a Bipap. I was told my Co2 was in the upper 90s. I've never even heard about Co2 before. Now I'm on 2 liters of oxygen. I guess I'm asking, has anyone eles been through this? Can you help me understand it. Any help would be appreciated.