New Machine - Feedback on the Data?

[ajack]

I just had a look at your old charts. I'm surprised the sleep study gave you an ASV. I thought that there was enough there to use a BPAP, your CA must have went through the roof.

You have excess tidal flow at the moment, (med 800) this should settle down as you adjust to asv
PS:3 reduces breathing effort by 50%, so it will make it more comfortable for you.

"A main remaining concern is RR and Tidal flow in spontaneous breathing mode and ASV is not being aggressive. It seems like raising EPAP Min might help lower AHIs but also pragmatically, effectively restrict rather than help RR & Tidal flow. Do I have this right or am I missing something?"

The ASV won't set a tidal flow, it follows the last few minutes of minute vent. It can rise or fall and will follow you down to the gutter. How you fix the apnea is by the min epap..then after all the obstructive is fixed, you look at what your min minute vent/ tidal volume us. this you can adjust with the PS, but not as much as can be done on other home machines. Using my s9 asv as an example, because the most I can set as a base/minimum PS is 6.

"I am still seeing a few OSA and Hypopnea events and I am wanting increased Tidal flow per min when I am in spontaneous breathing and ASV is not active. To raise Tidal flow would it actually be better to increase PS from 3.0 to 4.0 (EPAP = 4.0, PS=4.0) rather than leaving PS at three and raising EPAP Min 1cm (EPAP Min = 5.0, PS = 3.0) ? If I understand this right Increasing PS by 1cm will lift IPAP by 1cm but not min EPAP"

First you get the UA and H sorted, it's common enough to be well under ahi:1 on an ASV. Then you look at minute vent and tidal volume. Depending on the cause, the PS keeps the minute vent and tidal volume out of the gutter. I don't like to see a fall to under 350/375 tidal volume. This is normally first fixed by epap, as they are generally for a short period and obstructive. A long period of low TV/MV I would increase the min PS.
The ASV algorithm will set the PS up to what you set as a max, that is need to overcome a CA and give the MV/TV of the last few minutes.

My settings for me are min epap:10 PS:5, my max is the max available on the machine, it works out what it wants. I can dial back the max to be just above my highs, to take out a wild spike, if I want to. How you set up yours will be different

people shouldn't have lung issues, obstructive copd/obese, restriction or weak muscles and be on a normal ASV, PS:6 is the most that can be set on the min PS on my s9 asv. this can be an inadequate minimum PS for people with issues.

[WillSleep]

Thanks Ajack!!

" .. CAs out of control"

With the Dreamstation APAP could not consistently get OASs under control with less than an IPAP min of 16cm and A-flex=0.  At Flex = 0 and Min pressure so high the machine was just painful to use and I was seeing AHI of 4-11 with 80% of events being CAs & H so following the protocol I had titrated to complex apnea.    Paying cash (No insurance ) for the next xPAP with no chance of machine exchange or refund I popped for the ASV rather than spend almost as much on a BiPAP VAuto and 'maybe' then go have to buy a ASV as well.

"Tidal .. "

I had fully expected someone would pick up talk about the low tidal numbers in the first post in this thread.  Ha ha ..

That 20 min nap yesterday had a Tidal Volume of 800 was an anomaly.  

Thus far on my nightly data captures my tidal/RR numbers have constantly ranged from (Tidal Vol = 328 & RR = 17) to a Tidal & Vt high last night with the ASV of (Tidal Volume of 420 * RR of 16 = 6720).   At this new Tidal high I was still seeing too much de-sat using the ASV but you guys convinced me to first work on Tidal/Vt via EPAP Min and wait to see later if Tidal is still a problem.      


"First you get the UA and H sorted, it's common enough to be well under ahi:1 on an ASV. Then you look at minute vent and tidal volume. Depending on the cause, the PS keeps the minute vent and tidal volume out of the gutter. ...  "

Sounds good.  Based on comments you guys have made on increasing min EPAP / PEEP to drive oxygenation, for the next experiments I will leave PS where it is at 3.0 and start incremental increases to EPAP Min. 

Thanks again!

J

[Sleeprider]

I agree with your approach as outlined above. Thanks for rising to the task of reading the material I linked. It is probably more beneficial to make that available to you to apply as you see relevant, than to try to explain it in a post. We're always glad to help, but it is really much easier when you are familiar with the information on ventilation principles. Most of all it lets you make your own informed decisions as you wrote in post 12, and we can resume our proper role as the "Dear Abbey" of Apnea.

[WillSleep]

The results are in.  


Last Night 

• AHI = 1.66
  
• Settings: ASVAuto default settings except I raised EPAP Min to 5.2cm 
  
• Oxygenation was better, not done yet but for sure better
   
  

Charts for the the first and third nights are included below.  Failed to capture data on the second night. 

Feedback on next steps with the adjustments? 

[Sleeprider]

This looks pretty manageable. I think you're getting pretty close. Stick with or add 0.4 to EPAP and see if the hypopnea is reduced.

[ajack]

Most of the night was ok. If it were my chart, I'd also add more to min epap. The UA will settle with more epap and so will the H you posted in the last chart. Then have a look at what's left of the H. Your ipap is 20cm at the 95%, (it's really epap and PS, but the machine doesn't see that and gives IPAP.) so I doubt a bit more epap will bother you.
It's early days and it's as much getting use to the 20cm pressure rises. You are doing well with the nasal mask, I would expect more mouth breathing/leaking than that with the pressure

[WillSleep]

 
I had a dream!
 
People still dream?   I cannot remember having a dream in the last 15 years.  
 
 
Sleeprider & ajack, thanks much for the posts!  
 
 
Did not see any response until late so based on data, was going to go with uplifting EPAP from 5.2 to 6.6cm but after Sleeprider's post decided to go with a smaller step first and so went with EPAP Min of 6cm
 
 
Results:
- AHI at .61 is GREAT!  Wow!  Many thanks to you guys and all the other great people here on the forum.  
- Oxygenation, heart rate variability and avg. heart rate better but still not good enough.  Oxygenation lower and Avg Heart Rate 7bpm higher than with the Dreamstation.
 
FYI.. The End state Goals I am working toward:  
- Consistent AHI < 2.0
- Oxygenation, heart rate variability, avg heart rate to be as good as I know is possible for me (note I wrote this so it could be applied more generally than just to myself).  
- Proper healthy sleep, participating in appropriate percentages of time in each stage of sleep (REM is so elusive for me) 
 
 
Comment around using Sleepyhead as to help me improve Heart Rate Variability & Oxygenation.   From Comparing Pulse-Ox charts to Sleepyhead have concluded that for me the use of Sleepyhead chart metrics of IMAP variability (in the "Pressure" waveform chart) and density of <1.0 events in the Sleepyhead "Flow Limit" chart make a good proxy to measure and help me design to improve Heart Rate Variability.   The IMAP pressure variability rate metric might be a good metric to use to describe and measure what Sleeprider has called "a 'busy' AVS machine"
 
 
Near term plan:
- I will target reducing Hypopneas, Flow Limit events and ~'near-hypopneas' and increasing oxygenation while avoiding determent to AHI.
- In last night's pulse-ox chart and the sleepyhead chart below I noticed that the 20 min period that had the best combination of AHI, breathing waveforms, MV and heart metrics had EPAP = 7.3 & PS of 3.3.  Reaching toward these numbers make incremental adjustments to EPAP min and PS Using .4 to .6cm increments, assess results and plan the next night's adjustment.  
 
 
Tonight's specific next step:
-  Raise EPAP min from 6 to 6.6  
 
Feedback?  



















One reference for target MV=~7.2 while in Non-REM sleep 
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC459437/

[Apnea Infant]

Hiya WillSleep

Have no input as not conversant with ASVs at all. Just wanted to say, you might want to make your text a tad larger as it is hard for an old fogey like me to read.

Great numbers, btw.

[ajack]

Yes, keep bumping up the epap, till it settles, you are getting close.
The 7.2 you reference is a guide, your's will be different. Your target MV looks ok for now, If you want to talk about target MV, it would help if you put the tidal volume and minute vent chart up as well. You can right click on the chart name and adjust the Y-axis scale to make it clearer. Then you can see what it is doing over the night.
after the basics of leaks and such are fixed. I mainly use my pressure. minute vent and tidal volume charts

[WillSleep]

Thanks Apnea Infant and ajack for the inputs.   

I will take a look.

And by golly some day I "will sleep"   Ha, ha, ha..


Willsleep.