[Treatment] OSA or CSA?

[Unkikonki]

Hi everyone,

Could you help me make sense of the conflicting information between sleep study vs APAP machine please?

Background: I was diagnosed with OSA back in March with an AHI of 26.6. I started APAP treatment in September (I had nasal surgery in-between).

My sleep study indicates my apnea seems to be mostly obstructive:

AHI: 26.6
Apnea: 14.2

• Obstructive (OA): 13.4
  
• Mixed (MA): 0.3
  
• Central (CA): 0.5
  

Hypopnea: 12.4

However, my APAP machine indicates the vast majority of events are Central AI (last 30 days):

Average Hours per Night: 07:57
AHI: 5.49
Obstructive Apnea (OA) Index: 0.08
Hypopnea (H) Index: 0.79
Unclassified Apnea (UA) Index: 0.03
Clear Airway (CA) Index: 4.60

It is worth nothing that my AHI has been fluctuating roughly between 5-6 as I adjust the settings and get used to the machine. However, I believe this is deceptive as this also includes the hours I spend awake with the machine on (which are a lot) where I don't register any events, which brings AHI down. So, while I'm actually asleep, my AHI is probably above 8.

Regardless, the most important indicator is that I wake up feeling tired and unrefreshed, so I'm obviously not making the most of the treatment yet. I was wondering if this was worth looking into.

Thanks for your help in advance!

[SarcasticDave94]

Welcome to Apnea Board,

We can help more after seeing full detailed OSCAR charts. However, sleep study vs CPAP use and seeing increased CA like yours are, it's likely treatment emergent CA. This means your CPAP is helping you exhale more CO2 and the body reacts by not breathing as often, likely with pauses that trigger the CA flags. It should get better with more time on CPAP. There's also setting edits you can try if applicable. If you're using EPR, try reducing it to 1 or off for a night and see if CA reduces. This will likely diminish comfort and could increase other events like flow limits, hypopnea, and obstructive apnea.

[Unkikonki]

Welcome to Apnea Board,

We can help more after seeing full detailed OSCAR charts. However, sleep study vs CPAP use and seeing increased CA like yours are, it's likely treatment emergent CA. This means your CPAP is helping you exhale more CO2 and the body reacts by not breathing as often, likely with pauses that trigger the CA flags. It should get better with more time on CPAP. There's also setting edits you can try if applicable. If you're using EPR, try reducing it to 1 or off for a night and see if CA reduces. This will likely diminish comfort and could increase other events like flow limits, hypopnea, and obstructive apnea.

Thanks, glad to be part of the community.

Right! That makes sense. Yes, I've set EPR to 3. I'll reduce it to 1 like you suggested and see if that helps. Thanks heaps!

CHART: (sorry for the messy links, the forum won't allow me to post images or links yet)

ibb.co/hZ2V6d4
ibb.co/8YXpPnJ
ibb.co/qx50r1Q

[SarcasticDave94]

You're welcome. You can even try EPR 2 instead if you want. Whatever setting you choose it'll probably decrease the CA some right away. After a bit of time on CPAP then you can try increasing EPR back up to 3, it's mainly buying time to get used to CPAP. Overall your goal is low events and good comfort consistently.