Sierra

The only real guidelines are on AHI. It is generally accepted that having an AHI of less than 5 is OK. Not sure there are any hard links between flow limitations and health risks. They would be considered less severe than actual apnea events.

I use a down alternative pillow as it gives and does not push back so much. Have not tried a cervical collar, but it is only likely to help if you are having excessive OA events especially in close succession. A pillow is unlikely to have any impact on CA event frequency.

I find that my nasal pillow mask can help with decongestion, but each person may be different. From time to time I used to use Otrivin just before bed to help with congestion. You can't use that drug too long though or it will make things worse instead of better.

Unfortunately when your IPAP pins at the maximum pressure of 20 cm, that is an indication you may need to look at a BiPAP. Also the flow limitation issue can also indicate the need for more pressure support. The other option is to set an IPAP pressure limit of less than 20 cm and just accept the flow limitations. To a degree that is what my wife's preference is. She has issues with snore and flow limitation that could probably be solved with more pressure, but she says she would rather limit the pressure (14.4 cm), and suffer the consequences! I don't often actually hear her snore, but I also don't sleep with my hearing aids on.

As far as the graphs I always leave the event flag bar showing as it is more informative than the cumulative AHI graph.

One thing you may want to do is zoom in on the flow chart at those times when flow limitation are spiking higher and you are at the maximum pressure of 20 cm. You want to zoom in to the point where you can see each individual breath flow. My understanding is that flow limitation can be seen as a flat top on the inhale (upward) flow part of a breath cycle.

The other possibility is that if there are issues of asthma or COPD there may be medications (inhalers) which could help too. You would want to discuss with your doctor of course.

Yes. I didn't see this post when I posted above. Turning EPR off is probably not a good thing for you.

OK, if your EPR is off then IPAP and EPAP will be the same. Perhaps OSCAR chooses to display the green line instead of the red, but they are the same when EPR is off. Having EPR off may be contributing to your flow limitation which is in turn driving your pressure up.

Make sure your SD card is plugged in to the machine. If it is the detailed data will still be collected there. You can view it with OSCAR. The data which should be sent to MyAir is very limited summary data for each night.

What I see unusual about the first session is that from 1:20 to 2:40 your EPAP is 16 or less, but there is no IPAP (red trace) showing. I assume your EPR is at 3 cm and your IPAP should have been at 19 cm or less. Perhaps an OSCAR display problem. Your second session is showing a requirement for even more pressure and some events. The number of events is not that concerning, but it looks like you may get some benefit from a BiPAP machine which can provide more than 3 cm of pressure support and IPAP can go up to 25 cm. Overall it looks like flow limitations are driving your pressure requirement up.

I am told that you need to hold two fingers on the screen of an A11 for about 4 seconds to get to the clinical menu on it. A change from the A10. If you are going back to visit your sleep doctor be sure to take your SD card in and ask them to look at the data. For discussion it would also be good to print out some of your OSCAR charts where you are having frequent CA events and sections where CSR is flagged. It is good to zoom right in where there are lots of CA events and CSR to show the detail of your flow rate. Include a graph of your Minute Ventilation. That can be telling too. And you can post it here for comments too.

That is interesting and very different from the CA patterns I experience. Now I am not so sure it is a control system problem. That said part of it may be, as those last 4 events on the second graph do have some similarities to mine and indicate a control system issue. As far as CPAP options about all I can see is further reductions down to 6 and possibly 5 cm. The hope would be that it would reduce CA without causing much of an increase in OA events. Beyond that, I think you are best to find a good sleep apnea specialist, and show them what you are getting for results. A central apnea frequency like you have is not really acceptable, and you need to get to the bottom of it. Acetazolamide which is prescribed for altitude sickness and is off label for central apnea treatment, has worked in some cases. You should ask about it when seeing a specialist. See this article:

The role of acetazolamide in sleep apnea at sea level: a systematic review and meta-analysis

Another kind of last resort option may be to investigate use of an Adaptive Servo Ventilation machine instead of a CPAP, They go beyond just using pressure to keep the airway open, and adjust inhale and exhale pressure on a breath by breath basis to maintain regular breathing. ResMed makes one called the AirCurve 10 ASV which looks very similar to your A10 machine, but operates in a much more sophisticated way. It essentially forces you to breath regularly. Phillips also make one that some claim is better. I have not done much research on them, as I have managed to solve my issues with just the regular A10 machine by using a fixed pressure of 11 cm, and adjusting my beta blocker med.