Flow Limit and frequent waking issues

[Premier1991]

I have been using a cpap for over 5 years. I’ve always had problems with aerophasia, flow limitation, blocked nostrils and waking several times during the night. I use the ramp whenever I wake as the high pressure gives me aerophasia. After recently seeing an ENT specialist I’m booked in to the hospital to fix my deviated septum in August. After seeing a sleep doctor a year ago I was advised to increase my pressure to around 11 minimum and 17 maximum. My 95% pressure is now around 12-13. This has improved my AHI (0.68 last year). It has also increased the number of hours I sleep. But I still wake up often during the night (4-11 times). It has also improved my flow limit somewhat but my 95% flow limit still remains at 0.14 for the past year. I dont have any problems with leakage or snoring. I would like to know what your thoughts are on whether a ResMed AirCurve 10 VAuto might help to reduce my flow limit and perhaps reduce the amount of times I wake during the night. I have included a couple of different nights graphs to demonstrate.

[Sleeprider]

With your Autoset, you are using a pressure range of 11.6 to 17.0 with EPR 3, starting with a ramp from 4.0. In spite of using EPR 3, your flow limits remain notable, both in your closeup of the flow rate, and in the statistic of a 95% flow limit of 0.15. That's very high and indicates you main problem is upper airway resistance. The way to resolve this is with more pressure support which will require a bilevel machine. If you agree, I think we should focus on how to get the upgraded Aircurve 10 Vauto if possible. I know in Australia, devices can be very expensive and the health system seems reluctant to upgrade.

The reason you need bilevel therapy is, pressure alone will not resolve the inspiratory resistance that these flow-charts represent. As you know, your AHI is low, but you don't feel rested. That's because you are working all night just to get a breath. It's as though you are trying to breathe through a thin straw. It takes a long time to fill your lungs, which is why your inspiration time is much longer than expiration time. Each breath starts out strong and flow increases until it hits the "flow limit" where it flattens out, because no amount of spontaneous respiratory effort will let more air/second pass. So there is a long flat peak before you relax and this falls off into expiration.

Why bilevel? Because we can still stent the airway and prevent obstruction with the expiratory pressure (EPAP) and then we can recruit pressure support, an increase of pressure during inspiration, to supplement your spontaneous effort with mechanical assistance. This should normalize the respiratory curve allowing a full breath to be obtained in less time with less effort resulting in...better sleep. This will resolve flow limitation, RERA, Hypopnea and will continue to be effective against obstructive sleep disorders. Another member from AU recently bought a Resmed Aircurve 10 Vauto bilevel from a U.S. company CPAPspecials for $1530 AUD including shipping https://www.apneaboard.com/forums/Thread...#pid503654 That is probably much lower than you can buy the device locally.

[Premier1991]

Thanks very much for your help Sleeprider. That is just what I need to take to my doctor. I guessed that was the solution to my problem but have not been able to convince my sleep doctor to provide me with a prescription. I will probably just bite the bullet and buy a machine here as I want to have local help and support in case I have any problems. I really appreciate your assistance.

[Sleeprider]

Take some time to read Deborah K's thread, Upgrade CPAP to Bilevel  where we went into a lot of detail on how to ask for bilevel.  That answer is that it's actually easier than you think, especially if your doctor is supportive. But lots of good ideas were discussed there.