I’m also a caretaker for COPD patient, my mom. She refuses medical care or treatment, and I have searched her symptoms which I also see as CO2 issues, because the lungs are damaged and cannot exchange gas. She is down to one meal a day because her nose runs for hours at a time and she cannot eat & breathe at the same time. It is a rough row to hoe. That said, the Holy Spirit is in the healing business and I lift up your husband to the Spirit for complete healing.