please help me make sense of my central apneas

[p4ncaketim]

hey all. been finding this forums posts on google a lot and figured it may be a more helpful source than reddit. some background on myself:

on cpap for about 4 months.

flow rate is trash - i am getting deviated septum fixed and mandibular device to help.

Lanky Lefty told me that a pressure of 15 (epr of 3) is below my optimal pressure, but I can’t handle anything higher. We decided I’ll wait til after my deviated septum is fixed to find the right pressure.

some nights look fine - the flow rate is meh, and there can be lots of post arousal apneas, but every event makes sense.

what doesn’t make sense is these central apneas that look like they have a football in front of it. or centrals that are not precipitated by an arousal. they are freaky and idk what to do about them! i've attached screenshots with the football like flow rates. this is not every night, but the nights that it happens it happens a good bit. any ideas?

[p4ncaketim]

one additional screenshot of a central apnea that seems to come out of nowhere!

[Sleeprider]

This would be much easier to understand if presented as a full detail chart of your therapy. Without any doubt you have some apneic periodic breathing with centrals. This alternating hyper/hypo ventilation is something we see a lot, and without the context of your full night with the events, flow rate pressure, flow limits, leaks is very hard to comment on in isolation. For example, why do you need high pressure? What is your AHI rate and distribution between obstructive and central? Based on what you have said, you would be much better served by a bilevel device or perhaps ASV if the centrals are persistently high. Let's get some more complete information, and I may or may not have a different take than Lefty.

[p4ncaketim]

Hi, thanks for taking a look. i was recommended to move my pressure up as on lower pressure, there are countless more arousals in my sleep. Additionally, the flow rate does not have a nice rounded top and instead has a jagged or flat top. increasing the pressure created a more rounded top. 

I experience virtually no leaks. Most nights I have 0L/min of leaks. 

My AHI on a good night is under 1. On nights where I have much more centrals, my AHI is in the 3s. 

I rarely have obstructive apneas under this pressure. 

I have attached a fuller view of a rough night with much more centrals! I hope that helps.

edit: i would be so grateful for any help and can provide whatever info you request! these centrals are quite anxiety provoking for me. again, this does not happen every night. last night i had 4 centrals total over 7.5 hours and they were all clearly post arousal central apneas (big inhale precipitating the central).

[Sleeprider]

Let's try moving pressure back to a comfortable level. Respiratory effort related arousals are what we can control with our PAP machine, and EPR, rather than pressure allows us to achieve that. I coach many users to move to bilevel therapy if we can't accomplish that with the 3-cm of EPR in the Airsense CPAPs. In addition to providing more pressure support which eliminates flow limitation, the Resmed bilevel machines also have features like trigger sensitivity that can reduce central apnea events.

Right now you're using CPAP mode at 15/12 (inhale/exhale) pressure and your 95% flow limits are at zero. This may not be accurate due to the use of CPAP mode. So the next step is to see how far we can move that pressure down for comfort, and not increase flow limits or obstructive apnea events.
You seem to have a pretty good grasp of what you're comfortable with, so I'll just ask. Have you tried 12/9 pressure? The objective is to get some data and subjective feedback so we can find the most effective and comfortable pressure. Steady CPAP pressure can help avoid some arousals, so we will continue with that, but turn on Autoset mode as it may be more revealing about the actual flow limits. If you would like to try this, these settings will give us another data point. Feel free to share your Statistics data with me so I can see the results you have had at other pressures.
Mode: Autoset
Minimum Pressure 12.0
Maximum Pressure 12.0
EPR On, Full-Time
EPR setting 3

[p4ncaketim]

thank you so much for your thoughts. i will use those exact settings tonight and report back tomorrow. for what it's worth, this is my Oscar data from last night (15 with an epr of 2, but everything else is the same).

[Sleeprider]

That will help as a comparison to the lower pressure with more EPR. I don't see anything that should be a problem with lower pressure, however if we see OA events, we will need and increase or Autoset pressure. Were automatic pressure settings a problem for you?

[p4ncaketim]

auto settings were not a problem for me. I was suggested to not use them as if the auto setting ramps up the pressure, it could be too little too late - meaning, the apnea event already started and it wouldn't have if the pressure was there to begin with. I was also told that an auto adjustment in sleep could cause an arousal because i would be adjusting to a new pressure. 

at lower pressure settings, i do not have a higher ahi, however, my flow rate is disgusting to look at. Significantly more arousals, flat tops at the peaks, and much more jagged lines. I have been told that the peaks of the flow rate should be nice and round. This is much more the case for me at higher pressure settings. 

unfortunately, i have plans to drink alcohol tonight, so the data i would get won't be accurate. i may have to report back in two days.

[Sleeprider]

P4, Let's do a small modification on my previous recommendation.
Mode Autoset
Minimum Pressure 12.0
Maximum Pressure 15.0
EPR On full Time
EPR setting 3

If we control flow limits, the pressure will be stable, and we will not let it go above 15 in any event. Sounds like a better plan for a night with drinks...I'll join you.

[p4ncaketim]

thank you so much for the guidance sleeprider! will report back soon.