Adjusting AHI for Positional Apneas?

My concept is to ignore the AHI that is produced by all apneas per sleep session and only look at how well APAP is doing outside the positional clusters. If I have no control over positional sleep and the APAP does not treat the apneas during positional apnea clusters no matter how high the min./max setting is, I may as well adjust min. pressure down to the most comfortable level that delivers therapy outside the clusters and adjust max pressure down to where large leaks do not occur.

This goes against the often-suggested min. pressure setting to be that of the median pressure on the chart.

It is my theory that when on my back during sleep tissues sag/collapse to a degree that the air pressure of the APAP will not support them...give therapy. I may as well not be using APAP at all during these episodes. Maybe 10 cm CPAP would be better. As I lower the max APAP I'm nearing the state of CPAP by closing the gap.

I also found that turning off EPR helps reduce AHI for me. I get no comfort out of EPR anyway.

ejbpesca wrote: ↑

Sun Feb 09, 2025 9:33 am

"I've tried every suggestion to resolve the positional apneas and failed. (collar, tape, chin strap, ultra-thin pillow, backstop wedge, and tennis ball."

Anything I missed in the above?

1. Small backpack containing a hardback book or two.

2.

ejbpesca wrote: ↑

Thu Feb 06, 2025 7:25 am

I must sleep on my back part of most nights due to spinal issues.

OK. That's a given. Though it sounds more like: "I have to take a break from sleep and lie on my back due to spinal issues".

ejbpesca wrote: ↑

Wed Feb 12, 2025 1:09 pm

My concept is to ignore the AHI that is produced by all apneas per sleep session and only look at how well APAP is doing outside the positional clusters.

Why APAP and not CPAP? APAP is used for people who benefit from the pressure changes. You're saying you're not.

If I have no control over positional sleep and the APAP does not treat the apneas during positional apnea clusters no matter how high the min./max setting is,

on this type machine. And the active word here should be "prevent" not "treat". The aim of APAP is to raise pressure at the first indications of obstruction so that further ones wont' happen. In you case, especially when EPR lets you go very low, the APAP can't respond fast enough, or possibly high enough either.

I may as well adjust min. pressure down to the most comfortable level that delivers therapy outside the clusters and adjust max pressure down to where large leaks do not occur.

You have to keep the minimum from dropping down to a level where it lets flow limitations and hypopnea appear when you're not on your back.
And given your stated need to avoid letting the pressure go up, I would definitely go for CPAP, set at a level that lets you sleep properly when your not on your back.

I'm not at all sure the "sleep" you get when you're on your back is worth it, since you said your oxygen drops to the 70's when that happens.

I wonder if in the long run, it wouldn't be better for your health to have some kind of alarm waking you up when you turn on your back / go down to low oxygen levels. Maybe it would be better for you to lie on your back awake, giving your spine the needed respite, instead of trying to sleep through that period.
In any case, whether you want to be awake on your back, or not, you should aim for a CPAP pressure that keeps your airway open when you're *not* on your back. And no EPR. Breathing obstruction start happening and the end of a person's exhale. Take a look at your exhale pressure just before the cluster starts on Jan 27. Ditto for the period between 04:30 and 05:30 on Feb 9. I'd say the machine it going too low for your needs, and then starts playing catchup when all hell breaks loose.

Good news. I turned off EPR and lowered max cm to 11.6. AHI went down like magic. It was 3.6, 1.89, 0.42, and 0.68 for the last four nights which have included back sleep with NO apnea clusters. I also changed the F40 mask setting from the prescribed pillow to full face. I'm not sure what that does to pressures or detections.

I have never needed EPR for comfort. I had read here or on another forum that it would reduce flow limitations is why I turned it on. EPR now off for four nights may have made the big difference. Reducing max pressure is making the machine almost in CPAP mode.

Thank you all so much for your time and consideration.
ejbpesca

ejbpesca wrote: ↑

Thu Feb 13, 2025 7:44 am

Good news. I turned off EPR and lowered max cm to 11.6. AHI went down like magic. It was 3.6, 1.89, 0.42, and 0.68 for the last four nights which have included back sleep with NO apnea clusters.

Very good news! Are you feeling the benefits that?

I also changed the F40 mask setting from the prescribed pillow to full face. I'm not sure what that does to pressures or detections.

That skews your leak report.
That last graph has a pretty high leak - see if you can improve that, and let us know how it goes.

I have never needed EPR for comfort. I had read here or on another forum that it would reduce flow limitations is why I turned it on. EPR now off for four nights may have made the big difference. Reducing max pressure is making the machine almost in CPAP mode.

Some people's flow limitations may be helped by EPR, the problem with EPR is its timing. Unlike real bi-level machines which go up to inhale pressure immediately, EPR raises the pressure too slowly. In you case, your minimal exhale pressure now is 8.8 preventing most of the sagging. It was 6.8 when you had EPR at 2, too low for you.

Thank you so much for the advice.

My F40 cushion is leaking a lot but I guess that does not matter if I am getting low AHI scores, lower than I have in a long time.

The F40 is very flexible, both frame and cushion which may explain why I cannot pass a mask test at current max pressure. It is okay at the min. I tried F20 out again after a year's absence from it, but couldn't stand its irritation now that I'm spoiled on the F40.

Maybe there is a good place between my current min and max pressure for low leaks and effective therapy.

Thank you so much for your advice. I was about to give up.
ejbpesca

Try an F30.
If leaks overwhelm the machine, it measures are unreliable.
Are you feeling OK?
Can you measure your oxygenation during the leaks?

I found the source of the leak problem. It was a loose water chamber...again. I don't use humidity or heat. I must have bumped it loose making adjustments.

I can test O2 with my Lookee O2 ring.

The way I feel does not always correlate with AHI or OSCAR chart data. My poor quality sleep is often due to chronic pain so I go by OSCAR data to see if I'm getting quality PAP therapy. An indicator upon waking that I will feel better is the rare occasion I wake without a dry mouth which I guess means I did not mouth breathe as much as I usually do. I've tried all methods to stop mouth breathing without success.

I have felt exhausted most of the time for the past 30 years due to severe sleep apnea (4 sleep studies) and chronic pain from spinal injuries (long story).

A nap sleep test conducted an hour after my last overnight sleep study produced a diagnosis of narcolepsy 2 which I think is a product of my severe sleep apnea, but I don't know how narcolepsy truly relates to apnea. Narcolepsy 2 is not the kind where someone passes out, but they do feel overwhelmed by fatigue/sleepiness. It could be a neurological condition PAP therapy cannot help.

Thanks to your help and a review of videos from Sleep HQ and Lankylefty concerning EPR and pressures, I just may be figuring out how to set up my machine for the first time in 18 years! I feel hopeful for the first time in a long time.
Thank you!

https://sleephq.com/public/teams/share_ ... f1e071c404

The above link (if it works) shows my effort to find proper pressure settings and reduce mask leaks.

I have had two days in a row without debilitating fatigue and sleepiness. I think I may finally be on the path to getting quality APAP therapy. The F40 mask is sealing well enough to allow me to raise the min. pressure. My F20 would not. If aerophagia stays away I may be able to keep the higher effective min. pressure. Looking at last night's pressure uptick I'm not sure why the machine went near the max a couple of times. I guess there is something in the breath waveform I'm not understanding.

Turning EPR off made a huge difference. I had forgotten that the min. pressure needs to be raised as per the amount of EPR. I don't notice much difference with it off. When the machine first turns on I feel the pressure by a bit strange sensation of a balloon inflating in my nose, but that feeling subsides quickly.

The little flexible mask allows me to move as needed to relieve pain from pressure points. The increased min pressure without EPR just may be warding off the apnea clusters I get when on my back...finally. Those clusters are terrible having an AHI of 70 for over an hour. I had been told by advice on a forum that "they," had little success with positional apneas. In other words, the only way to treat them is to not allow them or wear a collar to prevent chin tucking. My positional apneas are not due so much to chin tucking, they are due to gravity.

Thank you all for help. I have learned so much and hope to help others as I have been helped to finally get maybe continually, the therapy benefits I have read about but rarely experienced for 18 years.

I am getting better filtration too from my AirSense 10. I bought ResMed filters. My chronic bronchitis has lessened in symptoms. I wish a STICKY message would be posted about the dangers of cheap defective filters.

ejbpesca wrote: ↑

Thu Feb 20, 2025 8:14 am

Looking at last night's pressure uptick I'm not sure why the machine went near the max a couple of times.

It responded to the increase in Flow Limitation.

ChicagoGranny wrote: ↑

Thu Feb 20, 2025 8:45 am

It responded to the increase in Flow Limitation.

10/4 Chicago Granny...I see it. I bet that was a roll to the back, that would have been an AHI 70 cluster without the rescue of the APAP. Cool. I have hope again.