Love My AHI Going Down But What About Time in Apnea and sleep quality?

[S. Manz]

................ You have to first try low PS on the PR machine to see if you have remnant hypopnea at those settings before can know it is required and to my knowledge you just carried over settings from failed Resmed titration and haven't used low PS on the PR yet (if you have just posting a couple examples may satisfy my curiosity). 

The drop to 89% SPO2 is potentially relevant to these discussions depending on what caused it. Did it happen during a period of hypopnea, spontaneous breathing or machine initiated breathing? I would be curious to see an OSCAR shot if you aren't sure. 

Thanks for a great discussion. 
That's just it, ASV titration is an entirely different cattle of fish to regular APAP PR machine titration in that with ASV therapy little to no titration should even be  necessary as the spectrum of settings are left wide open so the machine can take care of variations in servo feedback and react accordingly, except that in the past you may have been advising from a PR user viewpoint while I have been focusing on ASV therapy.

And No the drop to 92% was the median (occasionally going below 90% level) and looking at the session graph it was uniformly low all night during the session. (i'e no clear correlation between individual Hyp events and SpO2 drops.  My lowered RR seems to have driven the O2 sat median down, which we will confirm with further sessions).

I am glad we got to this point and even more so now that you may no longer think that "S.Manz is just winging it" 


Have a great day.

[Geer1]

For the record my opinion has not changed since day 1. Here was my original post saying the exact same thing I am still saying, to which you responded combatively saying I need to learn about ASV machines.

http://www.apneaboard.com/forums/Thread-...#pid414277

I still 100% believe this and every piece of data you eventually share slowly tells a bit more of the story.

Central apnea only causes lower oxygen levels during episodes of central apnea/hypopnea/periods of reduced breathing effort (periodic breathing as an example that may not meet apnea/hypopnea). If your oxygen levels are dropping and staying lower when reduced respiratory effort is not present then that is not being caused by central apnea. That issue is called hypoventilation and ASV machines are not designed or meant to be used to treat it (at least not severe cases). Using high PSmin as you have is one of the things that can treat hypoventilation but what these machines lack is the ability to limit the PS when your spontaneous breathing is sufficient so that you don't end up over ventilating yourself at those times. Part of the reason I have been trying to see you use low PSmin is to confirm the hypoventilation/level of it if.

And boom... Just looking back at your Small AHI, Big Oxygen Drop thread I finally see a very brief mention of what explains everything... Wish I would have seen this earlier...

"S. Manz
I also have low level COPD but not serious enough yet to be on medication for it, which explains the lower overall saturation levels."

Lets finally get things clear. I was right and you do not only have central apnea. You have COPD and central apnea... Your central apnea provides periods where your brain takes a break from breathing and your COPD causes hypoventilation which your ASV is not designed to treat... The reason you require higher PS is because of your COPD, your spontaneous breathing effort is not sufficient unlike normal central apnea cases... You are far from the average case having this sort of combination, SarcasticDave94 is the only one that pops into my head as having this same condition on here. 

The ideal machine for you is AVAPS and it is something SarcasticDave94 has been trying to get for a while (although he is trying to get the Resmed equivalent, St-A with iVAPS). AVAPS allows you to program in the minimum level of ventilation the machine needs to provide to overcome your COPD, the machine then fluctuates the PS as necessary to battle both COPD hypoventilation and central apnea. In essence the primary difference to ASV is that AVAPS adjusts both PSmin (to treat the COPD) and PSmax (to treat the central apnea) whereas your ASV only adjusts PSmax to treat the central apnea which is why you resorted to self titrating a high PSmin to account for the COPD. 

Knowing this now your settings on this ASV are probably close to what you need. Probably should go back to 10 for backup rate and might be able to fine tune PSmin slightly. Goal is minimum PSmin that maintains oxygen saturation levels and keeps TV/MV in correct range for your height/weight etc. Looking at PR titration for AVAPS they target a 8 ml/kg tidal volume although they use an ideal weight based on height. Can see here.

http://incenter.medical.philips.com/docl...%3D9792335

Hopefully this all makes some sense. 

This also explains why the PR machine works better for you. The Resmed machine is very aggressive in comparison and once you get the PSmin high enough to treat your COPD the machines aggressiveness and higher pressures was likely interrupting your sleep through a mixture of over ventilation and high pressure/pressure swing effects. The PR machine being less aggressive doesn't treat your central apnea as well (hence the remaining hypopnea) but that keeps you from being over ventilated and being subjected to as high of pressure/swings allowing you to sleep better.

[SarcasticDave94]

Great detective work Geer1. I'll admit this info was lost in the big pile of posts. I agree S. Manz is not going to get great therapy with ASV or SV Auto with COPD in the mix and it does explain why he accurately contends Philips is better, because in this case it is. It comes down to timing.

But the inclusion of timing controls can't make SV Auto correct for him. Mostly because SV Auto has a different algorithm that targets other parameters than COPD therapy needs, in my opinion and based on my own experience. You'll probably have to go over to AVAPS for consistent therapy results or you're going to keep your current ok, then bad, rinse and repeat state you're in now.

And you need to admit this ok then bad state exists, or there's no need for all these threads trying to get help to get a round machine to fit your rectangle therapy.

[Geer1]

The big question is whether he would do better on PR AVAPS or Resmed ST-A iVAPS, wish we had more data on here about people that have tried both. The ST-A has all of the extra features Resmed ASV lacks so would think it could match his breathing and give good results, only thing doesn't have that can be a pain at times is the easybreathe waveform but I don't know how PR AVAPS compares for waveform. I assume the PR AVAPS would continue to under treat the central apnea/hypopnea which would be its potential downside.

S. Manz if you can convince doctor of what is going on I would request a titration study or trial period with one of these machines. Note they are quite involved to titrate due to so many variables that can be changed. On top of pressures and PS ranges now you have full timing controls if waveform shape and ventilation requirement variables and obviously as you make some changes to some things (like waveform shape) may have to make other changes to compensate.

[SarcasticDave94]

If it helps, I've used both ResMed 10 ST-A and ASV. They feel somewhat similar with ST-A feeling less abrupt to me. ST-A wasn't tuned to me fully and timing controls were a big help with my combo.

[Geer1]

If it helps, I've used both ResMed 10 ST-A and ASV. They feel somewhat similar with ST-A feeling less abrupt to me. ST-A wasn't tuned to me fully and timing controls were a big help with my combo.

I have seen that in the data of others. The ST-A isn't as aggressive because it doesn't need to be, the more square like waveform supplies more air whereas the ASV easybreath waveform has to supply much higher pressures to supply the same air volume increase.

[S. Manz]

Ok detectives, I am glad you agree with one another :-)
UPDATE-3,
My O2 levels remain at the new lowered 92% so the RR level will be changed back up to its original tonight and then as expected my O2 levels will rise to their previous levels at 94-95%.
   

FYI, I have no issues with my therapy . The only issue I used to have was with my Resmed ASV which turns out to be a gimmick, more so than a therapeutic medical equipment.
I find "having to blow" into the machine in the hope that it may do its job better, a bit of an oxymoron and its consistently ineffective therapy that "one must simply get used to" , a bit of a nonsense.
I still remain at my opinion that Geer1 needed to get a better understanding of how ASV machines operate and trust that these discussions have helped him considerably, in particular when it became clear that he had not even noticed the fineprint regarding the maintenance of a Min-Ps higher than 4CM, to reduce Hypopnea events, at the bottom of the Philips titration guide that he was forwarding. (remember min Pressure Support has always been the point of disagreement here, since the very beginnings of all these posts), perhaps because neither fully appreciate Central Apnea.
Maintenance of a minimum pressure support to reduce hypopnea events is a well documented fact.

Dave , even though that will not be in the immediate future, if and when I am ready to elevate my therapy towards a more ventilator type home therapy, I will count on your experience with the Astral and Resmed 10 S-TA with iVaps support, however my experience with the Resmed ASV has left a bad taste, so I will gravitate towards a Dreamstation avaps, possibly even an E30. Right now neither my doctor nor I see the need to elevate my therapy.

Have a great day both of you !

[Geer1]

You have more than just central apnea. You have to understand that and treat situation appropriately. Your conclusions that machines are or aren't working right for your central apnea are misguided because it isn't your central apnea creating the issues you are trying to fix.

Do you know what else is documented in the PR titration guide.

https://www.documents.philips.com/assets...3de0e6.pdf

Page 2: AVAPS for COPD...

Resmed is even more clear, page 33

https://document.resmed.com/en-us/docume...er_eng.pdf

• ASV’s algorithm is not cleared or appropriate for the
following patients:
- Chronic and profound hypoventilation
- Moderate to severe COPD
- Restrictive thoracic or neuromuscular disease
• ASV will likely under treat patients with the above conditions, and you should consider moving to iVAPS

Treating COPD and Central Apnea is like trying to stop bleeding in a patient on blood thinners. You can't handle it the same way as a basic bleeding case because part of the treatment (PS to treat COPD) is contradictory to part of the other treatment (central apnea).

Edit: I learned from the basics. You have learned by winging it and testing settings. That is why I knew from day one that something didn't add up here because none of it made any logical sense.

[S. Manz]

You have severe COPD which has been getting progressively worse on a full-tilt Astral ventilator, and yet you just wrote in another discussion :

"I have used the ResMed AirCurve 10 ASV from late summer 2017 for almost exactly 2 years in 2019. Therapy was excellent with 4 pressure settings and a Mode setting. "

COPD does not suddenly start with the onset of bronchitis, so you must have had it back in 2017 when you were admittedly "benefitting from ASV therapy".
Forgive the readers for getting confused here because on the one hand you insist that I should give up ASV therapy and jump right onto IVAPS ventilator therapy because somehow you have diagnosed me with COPD, even though you know nothing about my clinical history than a few OSCAR charts I have pasted here, while on the other hand you admitely benefitted from ASV therapy while you had COPD.


Like I mentioned already , if and when my doctors diagnose me with a condition that warrants an IVAPS or a ventilator, then I shall get right on it 


Let me know if I can be of further help and have yourself a great day.

[S.Huxley]

What a great OP, although it appears that the same poster(s) have hijacked the thread again with their incessant and unwanted medical advise. If you recall, I suggested earlier in another thread that you should not feed them but it looks like you didn't get the memo.:-) I too find it interesting how Hypopnea events are frequent when on a DS machine, yet the calculated aggregate time spent in apnea is very low or zero most of the time. This is of course because even though the events are registered, hypopnea in each even has not been allowed to last long enough. It sounds like you are back on track, enjoying your therapy again. Good job.