Mags and Terrib

You may also want to consider that your husbands' conditions are part and parcel of radiation induced variant of COPD, with the sleep apnea just being a symptom. (Chronic Obstructive Pulmonary Disease)
I kept waking up and choking and being short of breath etc too for months after this TX and it kept getting worse. It's only been 4 days using a nebulizer and doing steroids but the change is astounding. I'm not out of the woods, but my nightime sleep is much improved.
According to the ENT group at my CCC, which did hospitalize me this week, the two conditions are often confused since the symptoms are so similar. While I wouldn't quit the CPAP if it's helping, but it would not do any harm to try the standard TX for COPD to see if that treats the cause instead of the symptoms.
Any doctor can order a rental nebulizer and give a script
(a good one is DuoNeb or its generic) that really opens up the airways. The theory is that intensive use can actually fix this at the root instead of just responding to the symptoms.
But if there is no wheezing at all, then it's probably not the COPD variant. I laughed about the fighter jet sound: while I was waiting for a hospital bed, the doctors and nurses kept running in to see what that loud sound was only to find it was me "breathing".
Sometimes, we need more than one approach to our problems. It is frustrating.
Charm