Hi, barry, and welcome aboard.
barry15 wrote:I recently got a Respironics System One Auto machine, and I notice that in the daily report, AHI is composed of three things – Obstructive Airway Apneas (OA), Hyponeas (H), and Clear Airway Apneas (CA).
My first question is this – is Clear Airway Apnea just another term for Central Apnea? I don’t see anyone except Respironics using the Clear Airway Apnea terminology, even with a Google search. I like the fact that this machine claims to be able to distinguish CA’s from OA’s, which is something that my old Resmed Autoset II didn’t do. They say that they don’t make any change to the pressure due to CA’s, but they do report them and they are included in the AHI.
I believe so, yes. My understanding is that the new PR One does report central apneas. Do you know if your sleep study indicated that you experienced centrals? Some people with Complex Sleep Apnea need a far more sophisticated machine (adaptive servo ventilation, or ASV) to treat centrals.
I have been varying various factors, including the “flex” settings (A-Flex, C-Flex, and no Flex) and the pressure limits (slightly).
You should only change one thing at a time, and give that change at least a few nights before you change anything else. (If you change two things at the same time, you won't be able to determine what helped and what didn't.)
I have also been trying both my Ultra Mirage nasal mask and my Ultra Mirage II full face mask. The preliminary data seems to show that my OA index is more or less the same under any scenario (about 0.5 on average), my H index is about the same also (about 1.7 on average), but my CA index is higher with the full face mask (about 2.3 rather than about 0.5 for the nasal mask.
Sorry, but I have no idea why a different mask would cause your centrals to either increase or decrease. Could simply be night-to-night variation in quality of sleep, which we all experience, in which case more data collection is needed to make any reliable observation. Hopefully, someone more knowledgeable than me will address this question.
My second question is this – is this significant? Does it matter? To look at it more broadly, my AHI is about 2.5 with the nasal mask and about 5 with the full face mask. I plan to continue to collect data, to separate all the various variables, but can anyone give me any insight about this seeming difference between the full face mask and the nasal mask? Is there some reason that the full face mask should cause more CA’s, or is it likely just the effect of how the machine distinguishes a CA (by sending out several puffs of air when it detects an apnea)? Even if it is the latter, the AHI is still almost twice as high with the full face mask, so it makes me wonder. I have nasal issues, and the full face mask is more comfortable for me, but I don’t want to compromise my therapy if it matters.
As long as your AHI is under 5, you're considered to be effectively treated; what really matters is how you feel. As to the FFM causing more CA's, that's a mystery to me. I would think a FFM might produce a higher AHI if the design of the mask is pushing your lower jaw further back, so as to obstruct your airway. But CA's aren't obstructive, so I'm stymied.
How's your leak rate with each mask? If your leak is under control, you can trust the other data; if you're experiencing too much leak, the data is suspect, because your machine isn't able to give you effective therapy if the air is escaping your mask.
This might sound like a very picky, technical question, but I have noticed that there are some very knowledgeable people here, and I thought I would see if I could gain some insight.
Have no fear in asking questions here. We're a helpful and understanding group.
Before anyone asks, I don’t have the Encore Pro 2 software yet, but my sleep doctor’s office is very cooperative and less than five minutes away. They will gladly print me out my data every week at no charge, so I have been getting the information that way.
EncorePro 2 isn't yet available to any patients; there's talk of end-user software for the PR One machines becoming available sometime in 2010, but that's just hearsay.