I tried the Dreamports for the last two nights. The first night went well for the first five hours. Completely flat line pressure right at the minimum EPAP and two lonely, short apnea events. I went without the chinstrap that I normally use to prevent mouth-breathing and it showed, as there were a few large leak episodes with the accompanying dry-mouth. At the five hour mark the vent woke me up and I switched the whole thing out for my usual Dreamwear - not a complete give-up, I just didn't want to get up and deal with it.
After reading this whole thread I was a little more prepared for the second night. The Dreamport vents seem to put out a much more noticeable jet of air than I'm used to, so I made a vent diffuser out of a filter as suggested. That worked pretty well to deflect the flow as long as the filter stayed in place. I woke up once to push it back up, so I'll do a little tape work tonight to keep it in place.
The second change I made was to the EPAP setting. As I've shed most of 100 lbs over the past year I've been gradually lowering my EPAP from over 20 all the way down to 13 cm in small increments along the way. As I like to push things I would usually go too far a few nights and have to increase the pressure by .2 or .4 after spiking the AHI. The first night with the Dreamports the pressure felt higher than usual. I'm a SCUBA instructor and very sensitive to pressure changes through my Eustachian tubes and into the middle ear. This is pure conjecture, but I suspect the Dreamport interface is getting pressure transferred more effectively into the airway. This is supported by the fact that the EPAP for the first night never got off of the minimum, despite the mouth leaks. That's unusual for me. Given all of that and to try to minimize the mouth leaking I dropped my EPAP 2 full cm down to 11. That's a big chunk to bite off all at once, but the results are positive - less than 15 minutes of mouth leaking out of 7.5 hours and an AHI of 0.8. We'll see how that holds up over the next few nights, but it was a big rocking success last night. I'll see how low the EPAP can go before before AHI starts to go up.
As well as these are designed the vents definitely need improvement. As a Dreamwear user the hose in the face already feels foreign, and having these twin jets blowing down my chest doesn't help. I'm going to give palerider's test a try tonight to see if I can blow out a candle with the vented air. It might be close!
The last concern I have is with the connection between the hose and the piece that connects to the Dreamports, in yellow below. Mine is loose, on the verge of floppy. It already came off once. I don't see how this can be a tight enough seal to prevent leaks or even hold up long term. Is mine broken or is that the norm?
Here's the obligatory chart.
