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+--- Thread: [CPAP] Much higher AHI with a full face mask (/Thread-CPAP-Much-higher-AHI-with-a-full-face-mask)
Much higher AHI with a full face mask - vas2000 - 02-09-2017
I posted this on a different thread and realized that it might be better to create a new thread.
I started using my machine about a week ago initially with a Dreamwear nasal pillow. I felt very good and the numeric results seemed pretty decent (AHI generally less than 3) but I had a leakage problem.
I tried out the Amara View FFM to deal with the leakage and the results seem to have been rather disastrous from an AHI perspective. The AHI for the night was over 18. I tried increasing the max IPAP in the middle of the night and that didn't help the AHI.
The leakage numbers for the Amara View seem good compared to the leakage numbers with the Dreamwear mask.
While searching through a few other forums, I came across this possible explanation for it: it seems to me if your apneas are due to tongue blockage, air coming from the back of your mouth (via nasal mask) would push the tongue forward, out of the way, while air through the mouth would force it down your throat, making apnea worse.
Any ideas about what might be causing this high AHI? I have attached my chart from last night.
[attachment=3173]
RE: Much higher AHI with a full face mask - Gideon - 02-09-2017
I would try to bring your min to above the 6 the auto set for most of the night, si I would try to 7 then evaluate. Purpose to bring more support to the OA and the H
RE: Much higher AHI with a full face mask - Russatrice - 02-09-2017
My experience with switching from pillows to full face mask is that the FFM requires up to 2 cm more pressure. I felt starved for air with the FFM. So raising the minimum pressure from 5 to 7, like Bonjour said, sounds right. Your chart also shows that the machine was hitting the upper threshold of 14 while trying to respond to a cluster of OAs, so raising that to 16 seems reasonable to me. I will say though that I don't have as much experience as some folks here, but this is what I would do in your situation. Best of luck with your therapy, I'm sure it will only get better.
RE: Much higher AHI with a full face mask - Beej - 02-09-2017
If you are sleeping on your back, try sleeping on your side to see if that helps. For those who switch, it may help reduce the obstructive apneas considerably.
If already sleeping on your side, consider other factors - physical activity increased? Alcohol or other depressants ingested? Respiratory illness? Other lung disease?
RE: Much higher AHI with a full face mask - vas2000 - 02-10-2017
Thanks for all the suggestions. I have been sleeping on my back once I started using the machine so I can try sleeping on my side. I'll also look at increasing the pressures.
I really liked the Dreamwear nasal pillow and it seemed to work pretty well except for some leakage issues. I'll try going using it againn and using the chin strap to see if it will help with the leakage.
RE: Much higher AHI with a full face mask - Ghost1958 - 02-10-2017
Your min will usually have to be 3 to 4 cmh2o higher. Max about the same amount higher to get the same results from a ffm.
RE: Much higher AHI with a full face mask - Sleeprider - 02-10-2017
You need to increase EPAP min until those centrals are at a satisfactory level. Events are obstructive, and I'm a bit surprised your machine is not increasing pressure in auto mode much faster in response. At your current settings, your maximum EPAP pressure can only go to 10. Take a look at my settings in comparison. It's a bit surprising this much difference for you comes from a change in mask alone. Did you have similar sleep position with the nasal therapy?
BTW, it does not help to start a new thread. It would be great to easily go back and look and any previous graphs you posted to compare. In this forum, history matters.
RE: Much higher AHI with a full face mask - PaytonA - 02-10-2017
If you were having a lot of leakage before you changed to a FFM, that could have caused an erroneously low AHI so the AHI you are seeing now might be more realistic. With that said, it is normally the case that pillows masks need less pressure to be effective than full face masks. I think the suggested increases to EPAP and IPAP are worth a try.
I do not see enough centrals to be a concern but reducing the PS a little might be a good and possibly temporary method for avoiding any increases in CAs with higher IPAP and EPAP settings.
Best Regards,
PaytonA
RE: Much higher AHI with a full face mask - vas2000 - 02-10-2017
Thanks for all the replies. Since I liked the Dreamwear nasal pillow, I went back to it, tightened it a bit more and also used a chinstrap. As you can see from the charts, it seems to have been successful in terms of making the leakage rate a lot better. The AHI went back to what I saw earlier with the Dreamwear (below 2) though there are still a few CA, OA and H.
I didn't change the IPAP Max or the EPAP Min last night (to not change too many variables). I'll now increase the IPAP Max to 12 and EPAP Min to 6 and if the pressures max out again, I'll increase them again.
There seems to be a 200 kb limit to the images I can upload so I used imgur to upload a new set of charts.
http://imgur.com/2AlgfYx
RE: Much higher AHI with a full face mask - Sleeprider - 02-10-2017
As a general guideline, EPAP treats obstruction, and pressure support increases ventilation. EPAP supports oxygenation, and too low can result in obstructive apnea. IPAP helps with CO2 blowoff, and having too much pressure support can lead to CA. In your case, results are already satisfactor, but most events are CA, with some interspersed OA and H. I would increase EPAP min a bit to resolve the OA, but might reduce pressure support to avoid the CA events. The only reason you are maxing out on IPAP is your requirement for PS of 4.0. The machine is doing its best to try to fight OA, but your pressure support looks like it might be better at 3. When mixed events are present, it is not as simple as just raising pressure, but to balance your needs.