Struggling with BiPAP Settings for Hypopneas/RERAs

[tribute774]

Hi everyone,

I'm looking for some guidance with my BiPAP therapy.
I was diagnosed with sleep apnea recently. My sleep study showed an RDI of about 30, made up entirely of hypopneas and RERAs — no full apneas. Most of my events were noted to occur during REM sleep.

During my initial titration, I was put on CPAP, but it didn’t fully resolve my events, likely due to mask leaks. Since then, I’ve been titrating at home with much better leak control (chinstrap + mouth tape), and I’m using a nasal mask.
Even with good leak control, fixed CPAP wasn't eliminating the hypopneas and RERAs, so I switched to BiPAP.
Here's what I’ve tried so far:

• EPAP: 4 cmH₂O and 6 cmH₂O
  
• Pressure Support (PS): 4 and 5 cmH₂O
  

When I increased EPAP to 6 and decreased PS to 4, I started noticing central apneas appearing — which I hadn't had before. After reading ResMed's titration protocol, I understand that EPAP mainly targets obstructive apneas (which I don't really have), while PS is used to treat hypopneas, RERAs, and flow limitation.
Now I'm thinking about lowering EPAP back to around 4 and gradually increasing PS (or IPAP) to better treat the hypopneas and RERAs, especially during REM, without triggering centrals.
Am I on the right track by keeping EPAP lower and focusing on raising IPAP/PS to clear these REM-related events? What should I try next?
Also, although my machine-reported AHI looks low, I still strongly suspect that my hypopneas and RERAs are not fully resolved — at least during REM sleep. When I look at my OSCAR data, I can see that my flow rate looks really rough and flattened during REM and even during light sleep, which makes me think there's still significant flow limitation happening that the machine isn't flagging.
A little more about me:

• Machine: ResMed AirCurve 10 VAuto
  
• Age: 25
  
• Weight: 80 kg
  
• Sleep study: RDI 30, all hypopneas/RERAs, no obstructive apneas, events mainly during REM sleep
  
• Mask: Nasal mask
  

I’ve attached OSCAR screenshots as well (see below).


Thanks a lot in advance!

[SarcasticDave94]

Welcome to Apnea Board,

Having to deal with Central Apnea myself, I'm going to make one guess and a few suggestions.

The guess, this elevated Central Apnea was one night and not exactly a trend, yet.

Central Apnea will be up and down randomly regardless. They are called consistently inconsistent.

Keep current settings except Trigger to Very High to address CA anyway.

The former higher PS will likely promote CA, so that's likely not a good choice.

We'll want to see no zoomed OSCAR charts to get the full night. Those dark segments indicate zoomed in. Back out to full for at least one chart to give us the overall.

[tribute774]

Thank you for your advice. I have attached fully zoomed out charts. Do you mean I should continue with PS 5 EPAP 4, or PS 4 EPAP 6? Also thanks for noticing about Trigger, I will set it back to Very High.

[SarcasticDave94]

I would go with EPAP 6, PS 4 at least to try. If you go too low like EPAP 4 the pressures need to increase more to get you into therapy pressures. I'd rather you be at therapy pressures already, avoiding some pressure swings. The more the pressure moves, it may increase CA, which you'll want to consider avoiding.

PS 5 by itself may promote more sensitivity to Central Apnea, being a higher step up every breath than PS 4.

[tribute774]

Thanks, I will go with these settings for now. However, I noticed a lot of waxing and waning patterns in my flow rate chart during REM (attached). Could these be RERAs, and do they need to be addressed

[SarcasticDave94]

Going back just for a minute. The zoomed out chart with the frequent Central Apnea in the late area on the right. It's possible these might be Positional Apnea based, in part. If you're able, research our wiki on Positional Apnea.

https://www.apneaboard.com/wiki/index.ph...onal_apnea

[tribute774]

Oh, that sounds right. I slept the first part of the night on my side and the second half in a supine position. I will make sure to sleep on my side from now on.

[SarcasticDave94]

That's not exactly the Position aspect I refer to. Positional Apnea means you may be sleeping in a position that your chin tucks into your chest, kinking off the airway. Back or side sleeping, this can occur with both.