[CPAP] Sudden spike in Central Apneas (AHI 25!) after EPR change - Need help understanding

[daneboi]

Background

1. Machine: Resmed Airsense Autoset 11
   
2. Mask: Full face mask
   
3. Pressure: 10-15
   
4. EPR: Recently varied between 0-3
   
5. Sleep study results attached to this post
   
   

Typical Pattern
My typical AHI is 0.9-3. I have been trying to optimize despite my low AHI because I still feel exhausted/experience brain fog day to day after consistent CPAP usage. Attached is what a good night for me looks like. My goal was to eliminate remaining hypopneas and obstructive events. So, I upped the min pressure and changed my EPR to 1 too. This got rid of of all obstructive events and hypopneas, but it ended up increasing my central apneas - I am hoping these are treatment emergent.
   

Last Night's Issue
Due to enlarged turbinates (reduction surgery scheduled), I couldn’t nose breathe at all. So, I changed EPR from 1 to 3 due to difficulty exhaling while mouth breathing (couldn’t nose breathe due to full congestion). At 6:20 AM, woke up for bathroom, nose worked again so I lowered EPR to 2, went back to bed.

The result was the worst night, totally out of the ordinary:
   - Overall AHI: 6
   - During worst stretch: AHI of 25 (all Central Apneas)
   - Spike occurred right after EPR change to 3, somewhat normal after change to 2. 
   

 Key Questions
1. What could cause this sudden spike in Central Apneas?
2. Would an upcoming turbinate reduction help prevent this?
3. Is this related to the EPR changes or the nasal congestion?
4. If I have to pick, should I optimize for eliminating CA or Hypopneas?

Any insights on preventing these CA events or suggestions for setting adjustments would be greatly appreciated.

Attachments
1.  Original Sleep study results
   
2. Screenshot of a good night (EPR 0, no nasal congestion)
3. Screenshot of last night's data

[PeaceLoveAndPizza]

If you go back to the original settings, do things settle back down?

Regarding the hypopnoea's and centrals in the original chart, I would not be concerned with them. What I would be concerned about are all the arousal breaths going on. For the centrals in the second chart, ignore them as EPR is not something you seem to need.


I suggest trying the following. It gives a bit more pressure, but leaves the rest alone.

Mode APAP
Min pressure 10
Max pressure 11
EPR off
Ramp off

If the min=10 feels like too much pressure, the try min=9, but no lower. It may feel a bit strange at first, but as you relax and let your mind wander it should be barely noticeable. 

Whilst awaiting surgery, try using OTC Flonase and/or possibly a nasal rinse like NeilMed (be sure to use distilled water). That may help enough for now.

[SarcasticDave94]

Note: your PSG sleep study reports 7 Central Apnea, 0 Obstructive Apnea, 17 Hypopnea per AASM, 1 Hypopnea per CSM... The Hypopnea are total overall, meaning they're not separating between Central vs Obstructive based events (only in these Hypopnea).

I'd say you have a form of complex Apnea, not just Obstructive Apnea.

Two options, get a VAuto that you can use High or Very High Trigger to minimize some CA. This is not a treatment but an avoid CA action. Or get ASV to treat CA. The deciding factor, how well or poorly you do on AutoSet.

Again you had zero OA on the sleep study.

[daneboi]

Thank you so much for the reply! Do you think once I get rid of the nasal congestion that the arousal breaths will improve? or is that more likely to be fixed with the increased min pressure? Also, how did you tell that EPR is not useful for me? 

If I go back to my old settings with no EPR, yes the centrals go down to 0.2-1 but hypopneas return at 0.5-1.5. I know they are low numbers, but I wouldn't be discussing this if I didn't still feel so tired day to day. 

Let me try the suggested settings for a few weeks and report back. Excited to see how this helps. As for flonase/nasal rinse, unfortunately I tried those for a long time, as well as other medicines, and they didn't help with the congestion hence needing the surgery :-( - I appreciate the suggestions!  Way more than all the sleep doctors I've gone to have been able to say. 

[daneboi]

Hey SarcasticDave94 - thanks for the insights -  the lab study done with CPAP at 7.0 set pressure does show 0 obstructive; not to bore you with more data, but copying below my results for 2 at home study nights done WITHOUT any CPAP, and it appears that there were more obstructive events than central events 


Measure                                          Night 1              Night 2
------------------------------------------------------------------------------
Sleep time (hours)                                7.9                  6.2
Sleep Efficiency %                               92.0                 91.4
Wake time                                     8% (0.68h)          8.6%(0.58h)
Stage REM Total                              19.7%(1.55h)        15.9%(0.98h)
Stage REM Phasic                             10.4%(0.82h)        10.3%(0.63h)
Stage N1                                      3.1%(0.24h)         3.5%(0.22h)
Stage N2 Total                               56.4%(4.44h)        61.5%(3.80h)
Stage N2 Light                                3.9%(0.31h)         3.8%(0.23h)
Stage N3 Total                               20.8%(1.64h)        19.0%(1.17h)
Sleep-NOS                                           0                   0
Sleep latency (minutes)                            18                  17
REM Latency (minutes)                             159                 133
Stage N3 latency (minutes)                         18                  11
Wake after onset (minutes)                         22                  17
Cortical arousals per hour                       17.5                13.9
Microarousals per hour                            1.1                 1.1
Autonomic activations overall per hour           26.9                28.8
Autonomic activations - Forehead - NON REM       18.7                24.0
Autonomic activations - Forehead - REM           53.7                43.7
Movement arousals per hour                        2.7                 3.4
Awakenings per hour ≥30s                          2.8                 2.6
Awakenings per hour ≥90s                          0.7                 0.5
Spindle duration(min)                            12.9                11.1

Overall AHI - 4% Desat (events)                3.0(24)             5.7(35)
   Supine(events)                             3.9(17)             5.3(24)
   Non-supine(events)                         2.0(7)              6.8(11)
   NREM(events)                               1.1(7)              3.1(16)
   REM(events)                               11.0(17)            19.3(19)

Overall AHI - 3% desat + arousals (events)    6.5(51)             8.1(50)
   Supine(events)                            8.0(35)             7.9(36)
   Non-supine(events)                        4.6(16)             8.6(14)
   NREM(events)                              4.4(28)             5.2(27)
   REM(events)                               14.8(23)            23.4(23)

Apnea Index (events)                           0.6(5)              0.6(4)
   Obstructive Index (events)                 0.5(5)              0.6(4)
   Mixed Index (events)                          0                    0
   Central Index (events)                       0.1                   0

Oxygen Desat ≥4% index                         1.0(8)             2.1(13)
Sleep time sp02 under 90%                          0                    0
Sleep time SPO2 under 88%                          0                    0
Lowest desaturation respiratory                   93%                  86
Mean SPO2±1 S.D.                              98±0.8%             97±0.8%

[SeePak]

Short answer......I totally agree with Pizza for the settings, going with 9cm min.

Longer spiel

Daneboi, those CA events you had there, i can get those a lot, and much much worse, like 140 in a night.

And looking back it did not matter if EPR was on or off. But there were times when i used it after being off or changed from EPR 0 to EPR 3 and all hell broke loose!
You were probably not in a rested state by the time you made the change and laid back down, so breathing was probably already hyperventilation type thing.
That's something to watch and make sure of, and this Wiki site has a great article that suggests sleep hygiene to follow.

To answer one of your questions, yes the EPR could have triggered this.
However, once you get your therapy to a constant or at least narrow band pressure, we will see how you do with the CA events.

This is a bio chemical type problem, it is psychological too. CO2 intolerance which is felt by you as 'air hunger' makes you take big breaths to expel the CO2, then CO2 drops and the call to breathe gets all mixed up so you stop breathing for a period, can be 40 sec. for me.
I see this when you make the change , see the big flow of breath, then the CA events start and it causes a feedback loop.
There are excellent breathing exercises to help lower intolerance, i do them every day, and they work fantastically!
Not that i have seen any better looking charts, but i am sleeping better and not tired or fatigue during the day.

Sometimes i felt great when i used EPR, sometimes not.

The worse part was having EPR set such that Expiratory Pressure is BELOW what causes your obstructives, which i know were not a part of your sleep study, but that was only a one night snapshot.
And you did get a couple there in that chart, keep an eye on that.
So if 9 cm was found to be the pressure that keeps OA events away, and if EPR 1 then min pressure needs to be 10cm.

About the turbinates, no personal experience, however i have read about percentages for falling back to same as before surgery are pretty high after a certain time, like 1 year.
And i know many here on this site have good outcomes.
You gotta make the call there.
Personally, knowing what i know and breathing exercises, i would say at least wait till you try Breathwork to get that nose back in shape. Its as easy as keeping your mouth shut all day whenever possible including exercise ( thats when its awesome ) Mouth breathing causes nasal pluggage, and most likely you can get immediate relief like this....

Take a gentle breath in, out, in out and hold your breath until you get a medium 'air hunger' . Dont hold it so long that you cant get a good breathing rhythm within a couple breaths after the hold. Then wait 30 to 60 sec and do it again, up to 5 times. You will be surprised i think!

Now here's where there is some major irony in your situation....
You are having a hard time breathing, so you want to use EPR which was made for comfort like you want. That's a very valid request.
So does that mean you can't use it due to CA events?!?
hmmm
I dont have an answer, but getting your pressure to 9 or 10 cm and constant, will tell you what you need to know i think.

[PeaceLoveAndPizza]

Did you have issues feeling tired before using CPAP? I am assuming you did which was part of what drove you to use a CPAP.

Standard APAP only has a few knobs to tweak. Pressure and pressure support are the primary ones we use. Bilevel has more and ASV has even more. The challenge is every night is different for your needs, so we try to find the most effective settings with the minimal amount of pressure and pressure support needed. It can take 2-3 months to fully adapt to things, so patience is key.

While you are adjusting, give this article a read and see if anything resonants. A good nights rest is so much more than any CPAP can do such that that looking at the adjacencies may be of value.

https://www.sleepfoundation.org/sleep-hygiene

Note: Dave made a good observation that deserves consideration. A Vauto may be a future step, but for now we can work with what you have today.

[Dormeo]

You may just have had some sleep-transition CAs. This is a minor glitch that can happen during the hand-off from the waking neurochemical system for breathing to the sleeping system. I wouldn't worry about it unless you see it a lot and find that it interferes with sleep.

Judging from the left panel, you actually got a fair amount of benefit from EPR, which reduced your flow limitations. It would help to be able to see your flow-limitation graphs. No need to repost, but please be sure to include it in future charts. In your place, I would use EPR, perhaps starting with just 1 to see how that goes.

Whenever you make changes to your settings, make one change at a time and give it at least 3 days before evaluating the results, unless it's a total disaster. Sleep is so variable from night to night that you need to see whether there's a trend or not.

It's normal to experience arousals throughout the night. (We don't remember most of them.) We experience more of them as we get older. Mini-arousals may make no difference to the quality of sleep; arousals that wake you up completely and leave you lying there awake for a long time are most certainly a problem -- and there's a spectrum in between.

You mention that you continue to have brain fog and tiredness during the day. Have you had blood tests to rule out other possible causes for the symptoms that led you to have a sleep test? These would include tests for thyroid, iron, testosterone, vitamin D, B vitamins, and autoimmune diseases, especially in the connective-tissue-disease family. Any chance of Lyme disease or long Covid?

[SarcasticDave94]

The CA with any person, regardless where or when they show, can have the consistently inconsistent attribute. Here a little, there none, there a lot, gone for a bit. Random.