Help optimizing APAP

[SomeUser]

Hi all,

I am currently working on optimizing my APAP therapy which I am now using for about 7 month. First, a small recap:

I was diagnosed with OSAS in december with an AHI of 44, desaturation index 36, AI 50, snore index 62, average saturation 95% and lowest 83%, PLM index 4, PLM arousal index 4, REM sleep about 4%. As I had to wait about 4 months on a CPAP machine from my doctor (in Germany), I got myself a Resmed Airsense 10 Autoset and P30i and started to optimize the settings. I ended up at a wide pressure range of 6.2-16 with EPR 1 and was somehow satisfied for the short time. My AHI was at most 0.5.

Then I had a night at the sleep lab where they tuned a device to my needs. I was not really satisfied when they gave me the settings 6-12 (no EPR or equivalent) and forced me to get a Löwenstein device. During titration there was not even a doctor present... they just let the APAP mode settle. They diagnosed a remaining AHI of 9 (and said if this was the value initially, they wouldn't have done anything...), desaturation index 6, suppine AHI 25 (I usually sleep on my side), REM AHI 18 and AI 15. Average saturation 95% and lowest 84%, REM sleep about 18%.

I tried with this device for some weeks and without SoftPAP (EPR for Löwenstein) and it was ok I guess. Not a difference to Resmed without EPR. But as I felt better with EPR I tried SoftPAP and immediately stopped after 1 night. I felt incredible bad, had a 95% flow limitation of 0.27 and about 47 flow limitation events per hour according to the device. I could feel the pressure relief as if the mask was slightly beating in my nose. I could get to sleep but subjectively and objectively it was horrible.

So I switched back to the Resmed device with EPR. Since end of april I am trying to tune this device and feel that I reached about 80% of my goals but I seem to hit a wall. Most of my symptoms are gone or severely reduced but I still do not have a "well rested" feeling in the morning. I am incredibly well adjusted to sleeping with my mask and I love it. The current state of my analysis is:

• Min Pressure of about 6 seems to be enough to prevent almost all obstructive events. Maybe 1 or 2 detected events per night, AHI below 0.5
  
• Min Pressure at or above 7 leads to detected central apneas, AHI usually between 1.5 and 3. I never tried min pressure above 9. Max pressure is always min pressure + 6.
  
• No EPR: 95% flow limitation usually between 0.1 and 0.15 or above
  
• EPR 1: 95% flow limitation usually between 0.04 and 0.09
  
• EPR 2: 95% flow limitation usually between 0.02 to 0.05
  
• EPR 3: 95% flow limitation usually between 0.00 and 0.02
  

I have added 3 images showing some of those results,

• one for pressure range 6-12 with EPR 3,
     
  
• one for range 7-13 with EPR 3
     
  
• and from that a 3 minute excerpt without event.
     
  

However, my problem is that the flow rate graphs with the somehow optimal setting of min pressure at 6 or at most 6.6 and EPR 2 (or 3 but effectively lower as the device cannot go lower than 4 for EPAP) still look not optimal. I compared my graphs to multiple sources and think there is still something missing in the diagnosis or treatment, like UARS. One of the most recent posts I found is this reddit post (as I cannot post links yet, search in reddit for "Dr. Barry Krakow: Why bi-level and ASV bi-level is more effective at treating UARS than CPAP") and the linked graphs and the quoted source video. My flow rate graph seems to be better with higher EPR, but to still have plateaus with EPR 2 and the graphs are jagged (as in the video), especially with higher pressure. Going to EPR 3 and min pressure 7, I start to get about 2 detected central apneas per hour. While this is not that much, there are many undetected events or irregularities in my flow rate, indicating that I have many more short events.

And that is the wall I seem to hit with this kind of device. I cannot increase the pressure due to central events so I cannot increase EPR to 3. And even if I could do this, EPR 3 would be the limit of the Autoset device. My question after this very long description is, do you think my analysis is somehow correct and goes in the right direction? Could I get more out of this device? And might a bilevel or ASV device show further improvements?

Of course I would like to discuss this with a doctor, but for that I have to find a better doctor who knows UARS, bilevel and ASV and have to wait for my new insurance.

Thanks

[SomeUser]

*bump*

What I also observed is that my tidal volume seems low. The median is usually between 380ml and 400ml, about half of while being awake. If I understand this correctly my (male, 184cm and 97kg) tidal volume should be between 460ml and 620ml?

[gainerfull]

You tidal volume is low but cannot be solved with either of the devices you have access to. How compliant have you been since December with your CPAP therapy? It takes months for people to see results but are you dreaming more now? Do you feel better overall?

There is an adjustment period if you experience TECSA (treatment emergent central sleep apnea) but some people adapt to the therapy after continued usage and the centrals disappear eventually. I think ideally you'll want to keep your flow limits 95% below .05 so either EPR 2 or 3 will work for you for the time being. My advice would be to seek assistance of a doctor for the hypoventilation you may be experiencing and stick with your settings for 30 days to see how you feel after. Also, as an aside, the Lowenstein device provides better therapy in auto-mode typically than Resmed.

https://www.youtube.com/watch?v=v6_NHkXgSRU

Also, sleeping on a wedge pillow changed my therapy dramatically so you may consider it. I've been using APAP for 8 years and only after elevating my upper body at night on the wedge pillow have I gotten my best results.

[SomeUser]

Hi gainerfull,

thanks for the reply and the linked video.

You tidal volume is low but cannot be solved with either of the devices you have access to. How compliant have you been since December with your CPAP therapy? It takes months for people to see results but are you dreaming more now? Do you feel better overall?

I thought so about the devices  I only had to adapt the first 2 weeks or so and took it off for an hour or so at most. Since then I have 100% compliance. I still wake up at night, but mostly due to my daughter as I am currently on parental leave. The few nights without her I still wake up maybe 1 or 2 times a night. I started dreaming again in the first weeks (I did basically not dream the years before). Initially I dreamt a lot, now it is back to a normal level again. And yes, I feel better overall. Normal blood pressure, gaining muscles and loosing weight, more energy, especially in the evenings, and better memory. But still not back to normal I think. I also do not feel very well rested in the morning, at least not as before this all started. But I see no further progress anymore, that is why I wanted to get some outside advice or second opinions and was looking into e.g. tidal volume.

There is an adjustment period if you experience TECSA (treatment emergent central sleep apnea) but some people adapt to the therapy after continued usage and the centrals disappear eventually. I think ideally you'll want to keep your flow limits 95% below .05 so either EPR 2 or 3 will work for you for the time being. My advice would be to seek assistance of a doctor for the hypoventilation you may be experiencing and stick with your settings for 30 days to see how you feel after. Also, as an aside, the Lowenstein device provides better therapy in auto-mode typically than Resmed.

Flow limits I figured and EPR 2 or 3 is also what I perceived to be the best right now. For hypoventilation I am not sure which doctor to go to, but I still have to wait for my new insurance (faster than the normal process right now...). I also see this hypoventilation only due to OSCAR, and there mostly in the Resmed device. For Löwenstein my tidal volume is 550+. This might not be perfectly comparable to the Resmed values, but looks somehow normal. My problem with the Löwenstein is just that without SoftPAP I have a 95% flow limitation of 0.10-0.14 (or 10-14 in their own scale). Again, not completely comparable to Resmed, but still huge. Even the median flow limitation is 0.01. And SoftPAP (at least on 1) seems not to work for me. Maybe I'll give SoftPAP 2 a try.

[gainerfull]

Glad to hear you're experiencing some of the benefits of therapy already! It sounds like your next big hurdle is sleep fragmentation and working towards not waking up at all during the night if you can help it. I'd be interested to see the OSCAR data for the nights where you wake up on your own because maybe there's something to tweak there.

I've found that my sleep quality is vastly superior if I go to bed between 9p-10:30p and am strict about sleep & wake times every day. There's a lot to be said for circadian rhythm.

Just to touch on the elevated sleeping position again here's some documentation:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5700252/

I went from a 2.5 - 3.5 avg monthly AHI to 1.38. It's not a silver bullet but it's helped a considerable amount.

[SomeUser]

Glad to hear you're experiencing some of the benefits of therapy already! It sounds like your next big hurdle is sleep fragmentation and working towards not waking up at all during the night if you can help it. I'd be interested to see the OSCAR data for the nights where you wake up on your own because maybe there's something to tweak there.

I've found that my sleep quality is vastly superior if I go to bed between 9p-10:30p and am strict about sleep & wake times every day. There's a lot to be said for circadian rhythm.

Just to touch on the elevated sleeping position again here's some documentation:

[...]

I went from a 2.5 - 3.5 avg monthly AHI to 1.38. It's not a silver bullet but it's helped a considerable amount.

Here is a night where I slept alone and with earplugs. I woke up maybe 1 or 2 times.

   

The OA and H events are actually really rare lately. Most nights I only have central events. No sure why this night is different. Even in other nights alone I rarely had those. Maybe the pressure was higher then.

However, one night before I had a really unpleasant morning headache that lastet about half the day. There is not much different in the data. Maybe only a slightly lower tidal volume. But these 20ml less shouldn't have that much of an effect I think.

   

Which devices are commonly used for low tidal volume? I know there is an iVAPS device targeting that metric specifically, but shouldn't all BiPAP devices be enough to target that?

Regarding sleep hygiene, that was one of the first things I optimized when I had sleep apnea but didn't know. Not sure there is much more to optimize. Regarding your wedge pillow, I looked up the options and may get something similar soon.

[SomeUser]

A small update to my current therapy. I got my hands on a cheap (barely) used Resmed Aircurve 10 ST and have used it for 2 weeks in S mode as a pure bipap device. I started with the best known Autoset settings and increased the pressure support to 4. My breathing patterns immediately looked better while I also got quite some central apneas, probably treatment emergent central sleep apnea. I started with an AHI of 8, then 4, then 2 and then back to 10 (probably an outlier as I was out that evening and got late to bed) over the course of these 2 weeks. However, I feel better than with the Autoset before and have currently EPAP of 7 and IPAP of 12. Hypopneas range 0.7 to 2 per hour, but I am slowly increasing EPAP. Tidal volume also seems to be higher now between 420 and 460 while with the Autoset I usually hat below 360.

As comparison, here are the flow rates (note the scale from -50 to 50) for the Autoset
   

Löwenstein

   

Aircurve

   

These graphs explain the increased tidal volumes with the Resmed devices (360-460ml), but not the larger value of the Löwenstein device (540ml). They could also explain why my well-being seemed not to improve any further.

[shawsg]

Hi,  

I found this thread almost a year later - my situation seems about the same as yours in all the details except I seem to need a much higher inspiratory pressure. 

I have an Airsense 10 and Lowenstein Prisma Smart and am getting the same discrepancy and terrible sleep on the Lowenstein as you report -  EPR feels better for me than Softpap by a mile, but I'm nervous that the Lowenstein reports are more accurate than the Airsense and that the cozy data out of the AS10 is illusory.  I subjectively feel the same on both machines even when the Lowenstein says the sleep sucked and the AS10 says it was good.   I can't get a sleep doctor with any comprehension of this stuff.

Where did you land on this?  I also got ahold of an Aircurve (but ASV model) I havent' tried it much yet, but I find the bilevel aspect quite nice.  I think i also might have UARS - severely restricted upper airways around my sinuses.

[SomeUser]

Hi shawsg,

I can give you a "summary" of my journey and where I currently am at.

I slowly increased pressure and pressure support to my current sweet spot at EPAP 7.4 and IPAP 14 with PS of 6.6. Every time I hiked the PS I got some more CA for one to two nights but it reduced to normal levels again. With these settings I have a tidal volume of about 500ml (based on my ideal body weight this should probably be in the range 470 to 630) but these devices are known to underestimate the real tidal volume. Also I get inspiration time of 0.9-1.25 and expiration about 3.5 (incl. pause), both as median values.


Going lower with EPAP I notice some wheezing when dozing off. With lower PS I feel slightly worse, as I would expect. I also tried further increasing EPAP and PS, but with both I feel quite worse with less being able to concentrate and increased blood pressure after about a week. I went up to PS 7.6 that got a tidal volume of 600ml. I might also get some air swallowing when going too high. I am not sure what exactly is the problem with going higher (I was hoping for a further increase in sleep quality). I suspect it is either uncomfortable for me while sleeping as there is too much air pushed in my lungs which wakes me up at night. Or it is another wave of central apneas due to improved therapy which I would have to wait out which I currently do not have the time for.

My air leakage through the mouth is under control with a chin strap. I also tried to replace that with a ruff (one normal size for me, one larger and loose). Initially I thought I slept better (less air leakage, less waking up), but after two weeks I noticed higher blood pressure and felt generally worse. I concluded that in combination with my pillow the ruff restricts my throat more and I have probably more flow limitations. And worse sleep means also more sleep pressure so I woke up less.

As you mentioned your sinuses: I visited a new ENT (as I moved) and got a CT as he suspected chronic infected sinuses. They confirmed the infection and polyps which also explains my permanently slightly stuffed nose. I got some cortisol spray which further improved my wellbeing. Strangely, unstuffing my nose (either through decongestant nasal spray or cortisol) both increase my AHI (from around 1 to 2-3) but I feel better. Also when looking at the charts directly I do not see a real difference. No clue why the device detects more events but I assume the cleared nose allows for a better therapy which explains me sleeping better. Maybe with the better connection of my upper airways and the mask (through my unstuffed nose) the device is more sensitive to events?

With the cleared nose through cortisol spray I tried to lower EPAP and PS (also tested what an increase does), but there was no change in the behaviour and my sweet spot remains the same.

Open questions (maybe someone can give an opinion):

• What could be the reason I cannot go higher with PS and EPAP? There might not be a need to do so, but I would still not expect to feel worse.
  
• My partner notified me that when sleeping I breathe fast and shallow. She notices this since I got my first CPAP (she thinks), so this is not specific to BiPAP. My stats seem in the normal range (tidal volume 500ml, inspiration time of 0.9-1.25 and expiration about 3.5 incl. pause) so no clue if this is really the case. But could there be a problem?
  

Todo list:

• Radiotherapy turbinate reduction will be done as soon as I have time for it. Will also ask doctor if a valve reconstruction (I think that is what it is called in englisch) and removal of polyps could help. Until then, cortisol spray helps. This should increase therapy quality and improve my wellbeing in general.
  
• Will soon see a specialist with UARS so I could get another opinion with BiPAP or any other therapy device. They could also give an opinion on my (maybe) shallow breathing.