Help me interpret my second Sleep Study results

[YouTakeMyBreathAway]

OK, I was able to obtain the (more) detailed report!

Here's all the pages: https://imgur.com/a/NVxjA2Z

It looks like at the highest pressure they tried (12cmH2O) I still had 17.39 Hypopneas/h.

The doctor's takeaway was "Let's try to dial in your pressure better", I told him I tried above the 12cmH2O, which is what I'm currently at, and didn't tolerate it well, asking if a BiPap could help in my case, so he begrudgingly agreed to write a prescription for an Aircurve 10 Auto BiPap.

It looks like these hypopneas are somehow not detected by my machine nor the one in the lab and were manually scored by the doctor, which explains why my AHI on the machine usually shows a super low number (<1.0), but obviously makes it more difficult for me to see if treatment is working w/o getting another study...

What would you recommend I do next? Should I try BiPap at a higher pressure? Will I be able to tolerate higher pressure better on BiPap than on my CPAP (where I just end up taking off my mask / having mouth blow-outs even w/ tape)?

I asked him if I needed more pressure support and he said no and wrote the BiPap prescription for 12cmH2O w/ 4cmH2O of pressure support, which seems low, but even when I asked him about it he said he wouldn't do more. Obviously I can change this myself later anyway, but I was a bit confused by why he didn't think I would need more pressure support, because my assumption was that what I was lacking was ventilation/pressure support.

[KeepSmiling]

YouTakeMyBreathAway,

Take the Aircurve 10 VAuto, ResMeds Bi-level machine. You probably will get much better treatment for the hypopneas. At worse you can uses the settings like the AirSense.

Give yourself as much time at it takes. Keep making progress, without giving up. I remember waking up without a mask and no recollection of taking it off. And this was after finding a mask to try for the night. I am having mask leak problems again. It happens.

When you wake up so tired you want to give up is the time to keep pushing to get to waking up better. It will happen.

[Sleeprider]

Your doctor recognizes what we normally recommend, the resolution of flow limitation, RERA and hypopnea comes with pressure support, not pressure. The exception to this is if the hypopnea are central in nature rather than derived from obstruction or flow limitation. The recommended pressure by your doctor ranges from 8.0/4.0 to 12.0/8.0 and this should be sufficient to resolve your issue if the problem is airway resistance. If not, it leaves the door open for further analysis, or even an ASV titration. Your results with CPAP shows worsening hypopnea with increasing CPAP pressure, and that is more typical of central apnea, or therapy onset centrals. If the titration had used something like EPR, then the titration would have uncovered what you showed in your early thread on the forum showed a problem with central apnea with the use of EPR, once again showing why you should KEEP YOUR THERAPY THREADS TOGETHER. http://www.apneaboard.com/forums/Thread-...-CA-events

When you start bilevel, I expect CA events to resurface, and you will hear us recommend reducing PS to 3 and using a high trigger sensitivity. If the CA problem is real, then the increased event rate will need to be addressed by your doctor through a new titration including bilevel and ASV. So far, the methodology used in your titration studies have not delivered either effective therapy recommendations or uncovered what I suspect is the root problem. Your doctor is jumping to the conclusion that your hypopnea will respond to bilevel pressure, but if he were to test that hypothesis, I'm certain you would end up on ASV. Follow his recommendations and eventually things will sort themselves out by trial and error, but this post is to warn you to have realistic expectations for bilevel.

[Sleeprider]

If you doctor is receptive to further discussion, you might want to point out the higher event rate with higher pressure, the predominately CA events when starting CPAP with EPR (aka PS) and that a bilevel titration with progression to ASV if central events emerge, might be an alternative to trying the Vauto without any indication that it will work. You have already had an unsuccessful trial in bilevel with the Airsense Autoset with EPR as shown in the image below at 8.0/5.0 pressure. Many doctors are not receptive to patient input, and you will have to gauge which category your doc falls into.

[YouTakeMyBreathAway]

Thanks for all the detailed infos! 

A few tidbits, curious on reactions to any of them!

1. I did have CAs initially with EPR, but they resolved quickly and I now have none.
2. Both without treatment (home study) ad well as with treatment (lab study), ~100% of my events are hypopneas at this point.
3. When asked if the hypopneas could be central the doctor said this was too rare to even consider before trying regular treatment for longer, given no comorbities. Doctor said “You’re welcome to see a pulmonologits”, but did not specifically say what the pulmonologist would be able to help with.
4. The doctor actually recommended “dialing in the pressure”, but once I told him I am already at the max that I tolerate w/o ripping my mask off and severe leaks, asking that I heard people try BiPap when going to high pressures, he was open to it. I assume for comfort, not PS.
5. The doctor did not mention reducing EPR, but the fact that he only prescribed 4.0 pressure support means you are probably right that he is worried about CAs emerging later. I did mention to him that I had CAs initially that went away when I was asking if the hypopneas could be central. Again though - he does not seem to think CAs are an issue at my current settings.
6. His conclusion in the end was that there likely is no problem and that treatment can take up to a year to work. He said my AHI is low and my oximeter data that shows drop likely is not reliable. I mentioned that the lab study shows though that I am not fully treated w/ my current settings, he said that it is true that these “mini hypopneas” / unflagged / manually scored hypopneas could be happening consistently for me and that higher pressure on the BiPap could help with them.
7. Doctor ordered labs for Vitamin D and checked my previous labs for Ferriting (which were normal)

It sounds like I should try turning EPR off and try a lower pressure before getting my bilevel. Do I understand that right? What exact setting do you recommend starting with?

Would it be correct to say that there are obstructive and central hypopneas and treatment for them will be different?

IIUC for obstructive hypopneas, increasing EPAP is the way to go and for centrals increasing IPAP is the way to go, is that correct? Is there any diagnostic way to differentiate central vs obstructive hypopneas? Should they be able to see this on the lab study with the chest/abd belts?

[Gideon]

Most Sleep Studies do not check for central hypopneas.  Do they exist, absolutely yes.  Look up CSR in the wiki.  The waxing/waning pattern between CA events is a form of central disordered breathing.  Our main signal to breathe comes (simple explanation) from the indication of having enough CO2 and CO2 byproducts to signal the need to remove this "excess" CO2 from our system.  As CO2 levels approach your apneic threshold a reduction in breathing effort occurs, since this occurs over several breaths it is often of enough duration to be classified as a central hypopnea. This is a manual observed determination.  
Similar results can happen with higher levels of PS/EPR as the increased flushing effect impacts CO2 levels .

Treatment Emergent Central Apnea tends to dissipate over several months as your body adjusts to lower CO2 levels.  I prefer to see low insignificant levels of centrals instead of no centrals in individuals proven to be suseptible to TECA to promote this adaption to lower CO2 levels.

I'll add that the knowledge of previous history of centrals does alter how I interpret your CA less titration study.  

A BiLevel is nearly always initiated at a PS of 4 as both a comfort and a therapeutic value to treat flow limits, RERAS, and hypopneas.  This can easily account for a reduced pressure on a BiLevel.

[Sleeprider]

If you are comfortable with EPR and getting good results, the Vauto will be even better because we can customize inspiratory time and trigger/cycle sensitivity. I was aware your CA events had dropped back, but couldn't find any details as you went on to O2 saturation concerns. The vauto is a great machine and provided your issues are not predominately central, you are fortunate to have it prescribed. EPAP is used to resolve obstruction and increases positive end expiratory pressure (PEEP) to increase oxygenation. IPAP is for ventilation, reduce CO2, resolve flow limitations, and reduce inspiratory effort.

[YouTakeMyBreathAway]

Thanks you two, will post my OSCAR data once I get the BiPap, would love your help dialing it in!

Is there any way to better track my hypopneas given they are not automatically flagged by the device? Any other data point I can use as early indication to evaluate treatment? What data points will help evaluate whether higher/lower PEEP and PS are needed?

[YouTakeMyBreathAway]

Hey there!

First night on BiPap went alright. 

I got all excited about my new-found power to increase pressure support and couldn't help myself, so I set PS to 5.0 just to see what it'll feel like (6.0-11.0).

The night went alright, but I can't say I feel more refreshed and my oxygen drops still happened. 

The TiMax of 2.0 (default setting?) was a bit surprising, but not meaningfully uncomfortable. It caused me to end some breaths early while falling asleep, which felt weird but was OK. It does seem like this has brought my inspiration time down considerably, to 1.20 median (before: 1.90) and 1.58 p95 (before: 2.70), i.e. both reduced by ~40%.

My expiration time increased, I believe this to be because the EPR on the Airsense 11 was triggering an inhale more aggressively, whereas the Aircurve 10 does not seem to trigger an inhale until I really start inhaling.

Minute Ventilation seems to have stayed the same - I assume the minute ventilation is what is causing my oxygen desats, does that sounds right?

   

Good news is that there didn't seem to be an increase in centrals w/ the increased PS. 2 had a sharp inhalation before the CA, 1 had weird noisy/junky breaths before, 1 CA looks legit/normal.

[YouTakeMyBreathAway]

Here's one more night:

   

My AHI went up a little because of the CAs, but I am feeling pretty good.

I had 52 oxygen drops >4%, they happened:
- 15 with mask off (29%)
- 14 while my leak rate was elevated (27%)
- 6 during the 20 minutes before end of recording/sleep (12%)
- 6 right after a CA event (12%)
- 11 other (20%)