[CPAP] Mixed apnea

[void]

I had a sleep test (without CPAP) and got diagnosed with mixed apnea with 20 apneas per hour.
The doctor recommended auto CPAP with pressure range 5-10cm.
I already got Aircurve 10Vauto and I tried it with auto mode and pressure support=0, EPAP=5 and IPAP=10.
The treatment till now was not successful - I wake up with suffocation feeling and low oxygen levels in my pulse-ox ring.
1. Do you think the Aircurve with ps=0 will function same as auto CPAP?
2. I understand that the higher the pressure, the higher the risk of developing more central apneas. So why recommend CPAP that does not treat centrals?
3. How long should I try to use the CPAP until I change to BiPAP?
I read that bipap st is not easy to adjust, bipap asv is for hyperventiliation and bipap ivaps is for hypovetilation.
4. How do I know if I got hypoventialtion or hyperventilation?
5. What BiPAP is usually recommended to try instead of the auto CPAP with my condition (asv or ivaps)?

[Gideon]

Welcome to the forum.
You have no reason to get either a CPAP or an APAP, you have a VAuto.
Why do you have a VAuto, it's not a bad thing.

Please post a daily chart from your VAuto using OSCAR One with the full night, one with a 10 minute view of the central/ mixed events and another with a 2-3 minute view of the central/ mixed events.
The above with standard charts

Also what are your trigger and cycle settings.?

Also a full day view of the advanced charts. While the standard charts give us an overview of your breathing charts the advanced charts focus on the breathing stats. Your sex and weight will help us evaluate them.

From OSCAR'S menu click " View / Reset Graphics / Advanced" and change Advanced to Standard to for the normal charts. Also import your ring data into OSCAR

We are not there yet, we haven't seen your charts, but without other conditions impacting your breathing that ASV is the device of choice

Try these settings. This is to overcome the suffocation feeling and the low oxygen readings
Assuming the VAuto is/was used, perform a factory reset to place all settings in default mode.

Mode: VAuto
EPAP min=4
IPAP max= 15
PS = 3
Trigger = High

The trigger setting is to address some of the centrals

[Geer1]

Your machine (vauto) is a bilevel.

Your settings with IPAP of 10 and EPAP of 5 are providing 5 PS which is a high level mostly used for people with noticeable breathing restriction. High PS makes central apnea worse and considering you were diagnosed with mixed apnea you are probably inducing central apnea or preventing it from being treated with these settings.

As mentioned you should drop PS to 3 at most and post some OSCAR data to help interpret what is going on. No point worrying about other machines etc until you get this one set up decently and see how breathing is responding.

[void]

Sorry I wasn't accurate:
The pressure support is 0, the max ipap and min epap are not the actual values but the range limits:
mode=VAuto
ps=0
Max IPAP=10cm
Min EPAP=5cm

[Gideon]

From your description, you NEED some Pressure support and likely an increase in your trigger setting!

[Geer1]

Ok that makes more sense.

As mentioned high trigger sensitivity can help some central cases but it only makes a difference if PS is active and increasing the PS can also make centrals worse. You would have to trial that to see if it causes improvement or worsening.

Depending on what else is present in data (obstruction, flow limitation etc) other changes in pressures etc may be warranted and helpful. OSCAR screenshots will help determine that. If unsure how to do that in OSCAR you can click view, take screenshot. Then in posting a reply you can add the attachment, the screenshots will be in documents/oscar data folder.

To answer some more of your questions ASV is the most capable machine for treating central apnea but CPAP is capable of doing so in some cases. Since ASV is more invasive and expensive CPAP always gets trialed first. On these forums we are quick to jump to conclusions about ASV being required in large part because most of the central apnea patients we see are ones that have failed CPAP rather than the ones that have been treated adequately by it. I am a proponent for giving CPAP a fair trial but also recognize that many doctors fail to advance to ASV when warranted.

ST bilevel has minimal effectiveness for central apnea and should be avoided, it is pretty much an antiquated mode that has little use anymore now that ASV and IVAPS etc exist. ASV is not really meant for hyperventilation but what you might be getting confused by is that many central apnea are considered due to hyperventilation because hyperventilating recovery breaths cause a central apnea, the real issue in those cases isn't per say the hyperventilation but rather the bodies inability to regulate breathing back to normal so they keep oscillating between hyperventilation and apnea. ASV is the best treatment for central apnea when CPAP isn't adequate. IVAPS is for hypoventilation which is where your body is not capable of maintaining oxygen levels even with normal breathing (usually due to diseases etc) and is not warranted in your case.

First step is refine settings on current machine to see how effective/ineffective it is. Second step would be ASV if this machine fails. Most doctors will want to trial you on this machine for 3-6+ months as it can take that long for body to adapt to CPAP and reduce treatment emergent central apnea. Since you had central apnea before CPAP your doctor should be more willing to speed that process up depending on your results but some patients get stuck with doctors that either don't know how to treat central apnea or are not willing to do so.

[void]

I don't think I can sleep with the BiPAP for a whole night - it makes my apnea worse.
The O2 ring data got deleted. I tried to read it before the data was saved. If it is important, I can try again.
The O2 ring alarms when O2<92%. It alarmed at least 3 times.
I attached the Oscar report (first time I use it...).
Does Clear Airway event = Central Apnea?
I do have an unspecified lungs/throat problem. I feel like the airway is not 100% open and maybe dry.
Before that I had mild apnea (AHI=12).
Pulmonary function test / x-ray were fine. I saw several doctors that suggested reflux or post covid or empty nose syndrome...

[void]

I will not try the CPAP for 3-6 months...
What do you think about the screenshots?
Should I try ASV or iVAPS?
Also is there a good alternative for Resmed? most US shops are out of stock.

[Gideon]

Can you post a 10 minute view of some of the centrals, just the first chart please. I want to see what the centrals look like.
In the screen shot, what is the trigger setting?

[void]

Attached OSCAR 10 min view.
Also attached O2 + heart rate without the BiPAP from previous nights.
Without the O2 ring alarms, the low oxygen sections would probably be bigger.