Passiflora wrote:...because my husband, even with mild sleep apnea (I think his AHI was 4 over the night but higher while on his back), wakes up throughout the night, is tired in the morning, suffers from depression and irritability, takes a nap when he comes home from work, and has to drink a lot of caffeine every day to feel marginally better. Then at night there is the snoring, the sudden gasps and gurgles followed by coughing (can we say reflux?) which lead to full wake ups.
If I were your husband, here is what I would do.
1. Have a close look at the sleep study (get a copy) and if you can trust the doc ask him to go over it with you. If indeed his AHI was 4 for the night and it is worse on his back, then by simple math that means his AHI is less than 4 on his sides (or stomach). Ask the doc about his AHI on his sides, how long he slept on his sides, and what sleep stages did he hit on his sides.
2. If, as well as can be determined, his AHI is much less than 4 on his sides, I would go into a trial at home sleeping exclusively on sides. Use the tennis ball trick or similar to make sure of no backsleeping.
3. Wean completely off caffeine - no coffee, no soft drinks containing caffeine, no chocolate. Take it down over several days to prevent withdrawal.
4. Stop all daytime naps. Go to bed the same time every night.
5. Learn what good sleep hygiene is and practice it religiously. Points 3 and 4 are part of this.
6. After a couple of weeks of 2 through 4 make a subjection evaluation of how your husband is feeling and performing. This evaluation will also include your observations of his sounds and movements during the night.
If he sticks with the program for several weeks and shows no improvement you have to consider another plan of action. If he shows significant improvement you have to consider what this means and whether he should continue with the program or do something else.
Based on what you have said so far I am not yet convinced that CPAP is appropriate for your husband.
Does he have any health problems beside what you mentioned so far?