Question on Polysomnograms and Ideal Therapy

[cmpman1974]

I was really wondering about things now that I better understand some of the apnea terms from being on here.  I looked at my last 10 years of polysomnograms done at my sleep specialist's office. 

Most studies were 6-7 hrs long.  The odd part is 'optimal pressures' often were ones where I had AHI ranges of 10-15 or sometimes 7-8.  Never did I get a pressure that brought the AHI under 5.  All studies, regardless of titrated pressures, had tons of hypopneas throughout the night.  Min O2 levels were mid 70s recently and ten years ago 81-82% at best.  Average O2 levels during sleep weren't terrible (87% or so). Highs were in the low 90s. 

Mask leaks were high during EVERY test from what I see.  I don't know if the mask leak levels recorded incorporate both intentional and unintentional mask leak or just unintentional.  

Is it plausible I never had the proper therapy, if one exists for me, all those years?  Is there a 'target' acceptable level for a patient to hit to be considered proper or is it simply do the best you can with what you can when the patient has issues?  I find this all confusing.  I have never felt like CPAP/BPAP helped with the sleepiness.  Now that I see titrated BPAP studies had pressures recommended that reached AHI levels of 13-15 at times, would I ever expect to feel rested?  There were endless RERA events too shown during titrations. 

Example: 8 yrs ago, I had a BPAP pressure recommended that produced an AHI of 26.9 for the period tested. Arousal index was 34+.

I am sure there is so much I don't understand of course.  Just trying to learn.

[Gideon]

The issue with titration studies is that for "CPAPS" only a single pressure is used. That resolves OA events. But it is the differential pressure such as from PS (BiLevels) or EPR (CPAPS, only some of them) that actually treats the hypopneas, so yes, it is likely you never have had optimum treatment.

Please post your daily OSCAR charts and we can help you get there.

AHI of 5 and under is the medical standard. Often our efforts halve that or better, not always and no guarantee.

[cmpman1974]

Gideon, I have been posting a lot of OSCAR data on a different post (Low O2 levels is the header).   All of my titration studies for 10+ years were for BPAP therapy, not CPAP.  I stopped CPAP 13+ years ago as I was unable to tolerate the high exhale pressure.  The figures I'm mentioning here were all on BPAP if that helps.

This is the thread that shows my sleep charts.

http://www.apneaboard.com/forums/Thread-...th-Low-AHI

I made this post as a general discussion based on what I saw on previous studies.

[Gideon]

I'll add that most BiLevel.titrations only look at a PS of 4, and if so same issue as CPAPS.

Did you try EPR=3 with min pressure >=7

[cmpman1974]

Yes, I have been on various therapies over the years like 16/9, 16/9, 21/11, etc.  Recently put on BPAP ST-A with EPAP: 10.0; PS Min: 5.0; PS Max: 10.0 with a target Vt rate assigned. There is no official 'EPR' level on the two machines I've used - previous ResMed Air Curve 10 VAuto and now ResMed Air Curve 10 BPAP ST-A.

I had a polysomnogram in 2021 where they tried ASV therapy and it had a very low AHI - total events less than 20 whole night including RERAs. Mean O2 in sleep 89%. Apparently, insurance wouldn't pay for the machine so I had to keep the BPAP I had. My most recent polysomnogram titration started with BPAP ST and I had low apeas, but 120 min+ of time I was under 88% O2 level so IVAPS was needed. I don't have enough detail on the report to see how much time I was on IVAPS during the night and what it brought my O2 to. It's confusing as data is limited. How did I do well on ASV but not as well on BPAP ST-A if I don't get Central Apneas?

[Sleeprider]

CMPman, your question on ASV vs ST-A is one we dealt with in your other thread. The Resmed ASV targets your 90 second running average minute vent and respiration rate and maintains that with adaptive pressure support. Over the course of several hours, people with severe COPD or hypoventilation may see a reduction in that target minute vent because the machine constantly sets a new average based on the previous 90 seconds. As a result the ASV is contraindicated for individuals with those conditions you have said affect you. An interesting difference between Resmed and Philips is that the Philips BiPAP Advanced SV does have a setting for minute vent, and actually might work for you.

I still think you should incorporate a recording oximeter into your therapy to verify oxygen as you have shown a potential for low SpO2 even with good efficacy for AHI.

[cmpman1974]

CMPman, your question on ASV vs ST-A is one we dealt with in your other thread. The Resmed ASV targets your 90 second running average minute vent and respiration rate and maintains that with adaptive pressure support.  Over the course of several hours, people with severe COPD or hypoventilation may see a reduction in that target minute vent because the machine constantly sets a new average based on the previous 90 seconds.  As a result the ASV is contraindicated for individuals with those conditions you have said affect you.  An interesting difference between Resmed and Philips is that the Philips BiPAP Advanced SV does have a setting for minute vent, and actually might work for you.

I still think  you should incorporate a recording oximeter into your therapy to verify oxygen as you have shown a potential for low SpO2 even with good efficacy for AHI.

 I have a continuous O2 meter on the way.  Definitely will be monitoring it moving forward.  It makes sense what you said. I was just curious what made the doc do an ASV study a year and a half ago as my health issues have been the same as far as I'm aware.   Well at least it sounds like I'm on the right machine now so that's good.  I just need to somehow maximize effectiveness by reducing mask leaks more than now.  The average mask leak will not go below 45 L/min and it's all attributable to a 30-45 min window of leaking.  Other than this, numbers look fine.  I'll report back once I have some reliable O2 figures.