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Hi there. New to the board but longer time reader.
Got sleep tested after long time complaints of day time sleepiness (and difficulties driving at night).
Male 38yo, Healthy BMI, generally fit (work-out 3 times a week).
-Sleepstudy revealed 'mild' AHI10/hr, RDI17/hr. No centrals, mostly hypo if I remember correctly.
-First advice was MRA, which I got but was painful to use and I stopped after 6 months (no complaints at night, but during the day jaw thightness & tinnitus) while I did not rested still.
-Got CPAP since August last year (Lowenstein, with P20 mask)
-Got DISE study in December which revealed full tongue-base and epiglottis collapse.
I am trying to make CPAP work for me, but I am having a hard time. Did not get a titration study but got fixed pressure 6 for four weeks , thereafter fixed pressure 5 four weeks, then fixed pressure 6.5 for another weeks. Next I proactively asked for APAP 5-10 to see whether that might work (and give a hint whether higher pressure is needed). Thereafter I started experimenting on my own a bit to improve, as I did not feel there was an adequate feedback loop. Currently trying to minimize pressure swings as it seems I am subjectively sleeping better with that.
Currently I am stuck. AHI varies a lot per night, not really knowing how to improve.
-Flow Rate seems really messy, even with low number of events.
-At pressure >10, sometimes air seems to get into my 'system' and blowing from mouth even when taping
I wonder if the Epiglottis collapse is the cause of failing treatment.
Some OSCAR screenshots of different pressure settings
Those AHIs don't look great for someone on CPAP but it has to be said that your min pressures are really quite low. If you had a higher min pressure the machine wouldn't need to detect and react to events (by which time you could have been "woken").
At the other end of the scale everyone has an 'aerophagia' limit where air starts getting pumped into the stomach. Mine is 13. It might be worth quantifying yours - it won't be a pleasant experience - but you then know to set the max pressure one below your limit.
How would you feel about increasing the min pressure to 8 or 9? Does that give you problems with comfort / mask issues?
I'm not familiar with Lowenstein so I looked it up and in this test about 5 years ago it was not good at spotting apneas. During the test the machine said AHI of 1.0, a home sleep study done at the same time said AHI 12.7.
If that's still the case it might be worth using it as a fixed machine (it may or may not be spotting the things its supposed to react to) and using the highest pressure you are comfortable with.
DaveSkvn is right about the pressure. You are running in CPAP mode so you need to get your minimum pressure high enough to eliminate the vast majority of your apneas. It is hard to determine exactly what that pressure should be due to running in CPAP only at a fixed pressure. All you can do is keep increasing the pressure until you get rid of the apneas. I would start at 8cm and go up from there if needed. You may also be having some Positional Apnea (apnea clusters). This is usually caused by chin tucking, you can try sleeping on your side rather than your back, get a shorter pillow or trya soft cervical collar to help keep your airway straight. Pressure alone will not help Positional Apnea. I have to sleep on my side every night to eliminate my Positional Apneas. See the link below for more information on Positional Apnea. I think that your CPAP has settings to lower your exhale pressure, ResMed's 10 & 11 CPAPs have what they call EPR, it can lower your exhale pressure up to 3cm lower that your inhale pressure. The lowering of your exhale pressure helps with Flow Limits and is more comfortable, so you may want to try that sometime in the future. For now try the 8cm a few days then post some more charts and work on your sleeping positions. Welcome to the forum and good luck with your treatment.
Thanks. Air in my stomach started a few days after setting max pressure at 12. Some days pressure would just be stuck at 12, even with me being half awake, resulting in reported AHI of around 20 (and a terrible day after).
Might indeed try higher fixed pressure, but I never, at my now known pressure levels (5-12) witnessed longer ‘calm periods’ within my flow graphs.
I would say you are right to try higher fixed pressures. Right up to fixed 11, if 12 is aerophagia territory. That's the max pressure you can deal with. If that doesn't make a significant impact then your current machine is probably not going to be the solution.
@StaceyBurke mentions positional apnea. I'm not sure if your events are clustered enough for that but I have positional apnea on my back (probably tongue rolling back) and pressure makes no meaningful impact on them. I now use a "positional device" to keep me off my back and the Apneas are pretty much gone. A soft foam surgical collar also made a huge difference - if you haven't tried it, do so. If you have tongue/epiglottis 'collapse' CPAP pressure may well not shift them.
As @OldSteve mentions there is the notion of having a difference between the inhale and exhale pressure. In Resmed world you get a difference of up to 3 cmH2O called EPR (I'm not sure if Lowenstein has an equivalent.). Many people seem to benefit from a higher difference giving the blockage a kick with every breath - but that requires a BiLevel machine. See the before and after in this thread. The flow limitations, the "blockages" / breathing problems that the Resmed machine has detected, are what to look at.
I suggest you set a small range of pressure, as it will be easier to see what you need. Use autoset mode and try 7 to 11. That should help you avoid aerophagia and help you learn where you need the pressure to be. Most of us prefer autoset mode as our needs vary on many nights.
