Expiratory flow limitations?

[Michael2]

Your AHI is consistently zero, as are flow limits and any apparent respiratory based issues.  Arousal is a common feature of normal sleep and it is a kind of hard-wired mechanism that may have contributed to our survival in our early evolution. https://www.verywellhealth.com/arousal-d...ep-3014849  https://en.wikipedia.org/wiki/Arousal  If you research sleep arousal you will quickly learn that some level of arousal is very normal, and it varies between individuals.  It is generally not related to respiratory distress or effort, but often is when sleep apnea is inadequately treated. You are not inadequately treated.

You don't have hypopnea or other respiratory issues.  I admire your persistence, but when you have solved the CPAP puzzle to this excellent outcome, it's time to start looking elsewhere for the cause of your arousals, or accept them as normal and not get stressed about it, or treat them with natural or pharmaceutical options.

I ask because the quality of my sleep has degraded over the past year. For the first 5 years on PAP, I slept very well. On a typical night, I was unaware of any awakenings, and I woke up refreshed. Over the last year, my sleep quality has severely degraded. On a typical night, I am consciously aware of 5 - 10 awakenings, and I wake up feeling terrible. You don't think hypocapnia could be the cause? Over the last year, I have raised my PS from 3 to 6. With my Trigger setting set to Medium, I see quite a few CAs. It seems my Trigger set to Very High is masking the CAs. Maybe the hypocapnia is causing my poor sleep?

Anyways, I want to rule out any respiratory issues before I focus on other potential causes.

[Sleeprider]

I don't see evidence of hypocapnea in the form of central events or depressed respiration rates or volume. If you are concerned with hypocapnea, why are you using high PS which would make that worse?

[Gideon]

Sleeprider and I are in lockstep on this.
With that high of a PS I expect your CO2 levels to be on the low side of "normal" to possibly just below that. Look yon your metabolic lab tests, that's where mine is at a PS of 6. I don't use a higher trigger level. And IMHO that doesn't mask CA events it actually treats them.
I do understand the need for higher PS and higher EPAP to feel comfortable, my min is 11 and under 10 just doesn't feel right. You may want to try to slowly back off your high pressures and PS and see if that helps you some. That is simply a trial to find a sweet spot for comfort.
I don't feel your Arrousal level is abnormal.

[Michael2]

I don't see evidence of hypocapnea in the form of central events or depressed respiration rates or volume.  If you are concerned with hypocapnea, why are you using high PS which would make that worse?

When I use lower PS, I feel I cannot get enough air. I don't know why. I have tried many times to lower the PS, but the end result is always the same: I lie in bed unable to fall asleep because I feel like I am suffocating. 

I don't think I have any respiratory disease. I had a spirometry test done about a month ago. It ruled out any obstructive disease like COPD. There was some indication of slight restrictive disease, but it was ambiguous because of an issue with the test. I will have a follow-up test in September to rule out restrictive disease.

[Michael2]

Sleeprider and I are in lockstep on this.
With that high of a PS I expect your CO2 levels to be on the low side of "normal" to possibly just below that.  Look yon your metabolic lab tests, that's where mine is at a PS of 6.  I don't use a higher trigger level.  And IMHO that doesn't mask CA events it actually treats them.
I do understand the need for higher PS and higher EPAP to feel comfortable, my min is 11 and under 10 just doesn't feel right.  You may want to try to slowly back off your high pressures and PS and see if that helps you some.  That is simply a trial to find a sweet spot for comfort.
I don't feel your Arrousal level is abnormal.

Why do you think a more sensitive trigger level actually treats CAs and doesn't just mask them?

[Michael2]

Could my poor sleep be due to PLM?

Here is a copy of my PSG study report from April:
https://drive.google.com/file/d/1eGZcD0H...sp=sharing

This sleep study was done au-naturel -- that is without PAP therapy and my SleepTight mouthguard. I did take some trazadone to help me sleep. Note my PLM index is 20.1 but there were no associated arousals. This suggests my PLM is not causing my arousals. However, it may be that the trazadone suppressed any PLM arousals.

[Gideon]

A high leak rate might mask a CA but show me a CA in the Flow rate, and I see nothing there that would mask such an event. To a point CA events are prevented by initiating an inhale easier, they never happened.

By your definition an ASV is ineffective, (it is very effective) because it "masks" or hides CA events, it doesn't prevent them( it does prevent them)

[Sleeprider]

PLM at 20 events per hour is roughly every 3-minutes. Do I think that might be disruptive? Of course. Pathological significance is greater than 5 per hour. PLMS at the rate of 15 or more/hour of sleep is considered abnormal and is supportive for diagnosis of PLMD if associated with hypersomnia/insomnia, which could not be explained by other current sleep disorders or other disorders. I’m not sure if your results remain valid with your current therapy efficacy.

[Michael2]

A high leak rate might mask a CA but show me a CA in the Flow rate, and I see nothing there that would mask such an event.  To a point CA events are prevented by initiating an inhale easier, they never happened.  

By your definition an ASV is ineffective, (it is very effective) because it "masks" or hides CA events, it doesn't prevent them( it does prevent them)

I see your point. Perhaps it is more accurate to say a very sensitive trigger prevents CAs but not necessarily hypocapnia. I wonder if hypocapnia can cause arousals in the absence of CAs.

To better understand what is causing my poor sleep, I will be doing two tests.
1. I will try EERS to reduce any hypocapnia I have:
    https://www.apneaboard.com/wiki/index.ph...ace_(EERS)
2. My sleep doctor has prescribed me a two week course of mirapex to stop my PLM.

I will also get some bloodwork done to test for any abnormalities.

Thanks to your input, I think I can rule out that flow limitations are causing my arousals.

I really hope I can figure this out and improve my sleep.

[Michael2]

PLM at 20 events per hour is roughly every 3-minutes. Do I think that might be disruptive?  Of course. Pathological significance is greater than 5 per hour. PLMS at the rate of 15 or more/hour of sleep is considered abnormal and is supportive for diagnosis of PLMD if associated with hypersomnia/insomnia, which could not be explained by other current sleep disorders or other disorders.  I’m not sure if your results remain valid with your current therapy efficacy.

In my sleep study, none of my PLMs were associated with arousals. But I did take trazadone to help me sleep (with the permission of my sleep doc). Maybe the trazadone stopped the PLM-induced arousals. By looking at my flow rate chart, is there any way to tell if my arousals are caused by PLM? All my arousals look like those in my snapshots. The arousals do not seem to occur at regular intervals. 

My sleep doc did give me a two week course of mirapex to stop my PLM to see if it improves my sleep quality. I will start the test soon.