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+--- Thread: [CPAP] Beyond ASV with Overlap Syndrome! (/Thread-CPAP-Beyond-ASV-with-Overlap-Syndrome)
RE: Beyond ASV with Overlap Syndrome! - Plmnb - 02-13-2020
Hello Sarcastic Dave.
I have just read your thread for the first time. I too have been having the oddest SA journey, for different reasons, I know.
However, I was drawn to the fact that you will be making a choice soon on a new machine, possibly the same machine I will be acquiring next week. (ResMed AirCurve ST-A) Sleeprider suggested it to me. This has brought me now to machine #3 in about 3 months. I am very interested in your thread and I could learn something, maybe. I'll want to see how you are doing at least.
I'll be posting in my main thread about my use of the machine, not sure you would be able to glean any useful information for your particular concerns, but ya never know.
GOOD LUCK!
Plmnb
RE: Beyond ASV with Overlap Syndrome! - SarcasticDave94 - 02-13-2020
Thank you and best wishes your ST-A gives great therapy results ASAP and for many years to come.
RE: Beyond ASV with Overlap Syndrome! - Sleeprider - 02-13-2020
Plmnb has no central apnea but has some of the most amazing flow limitations you will ever see, in spite of pressure support approaching 7 cm. So the need for pressure support to maintain rate and volume comes and goes, and iVAPS appears to be the only therapy out there that matches that. The problem is intermittent, and unexplained from a physiological point of view, but obstructive issues seem to be in the wheelhouse for ST-A.
Dave, you have COPD and I haven't really seen a problem with ASV therapy, but you are within the spectrum of issues ST-A claims to address. As far as Medicare, you have ASV so your are not technically changing from HCPCS E0471 that you already use. I assume it depends on the instructions and prescription of your doctor. I don't think you will have the same difficulty bieng approved for ST-A as you did with ASV. I'm as confused by Medicare as anyone out there, so I won't make any predictions.
RE: Beyond ASV with Overlap Syndrome! - SarcasticDave94 - 02-13-2020
Understood, Sleeprider. Just goes to show that each of us on AB are unique. You may have CPAP, BPAP, ASV, ST-A, etc. but each circumstance is unique in itself.
I'm still charting new territory just like a few years ago on the ASV path. I'll cross the bridges in my way as they come up. As in the past, I'll be successful at this too. I'll take one battle at a time if I can, and if given the choice, I'll only pick the battles that are necessary and avoid the ones that aren't.
RE: Beyond ASV with Overlap Syndrome! - Geer1 - 02-14-2020
I looked through things and you have very little recent data posted so I am mostly commenting based on old results and the one recent chart you posted. I see why things have been difficult as OSA, CSA and COPD combined is quite the situation.
A few things stuck out to me.
1) Your original CPAP prescription was for 20 cm pressure. During your bilevel titration you had OA's up to 13-14 EPAP. During ASV titration recommended EPAP was 13. Yet you have consistently chosen to use lower EPAP including from what I see you didn't even try the prescribed ASV settings and just switched to EPAP of 7 based on the recommendations here. ASV makes things a bit more difficult to interpret apneas and to know when to increase EPAP, I have seen a couple sources that talk about ASV titration and flow limitations, snore and periodic like breathing need to be considered. AHI alone doesn't appear to be enough to go off of and I believe this is due to ASV's ability to punch through both OA's and CA's. Some of your graphs posted show bilevel and ASV EPAP increasing to around that 13 range as well. Based on all of this I think you really should try higher EPAP if you haven't already. I personally would probably try EPAP at 13 and turn off ASVauto mode.
2) I didn't see any original sleep study results (prior to trying CPAP) but one thing I did note is that during your bilevel titration you had 0 centrals when PS was 0 indicating that your CSA is most likely treatment induced. All of your bilevel titrations were done at higher PS levels (4-5) and none had a AHI under 20... That bipap titration was done fairly poorly and they never should have considered their job done and recommended the machine/settings that they did... Minimizing pressure support will help minimize CSA and its affects.
3) You complain that the machine is fighting you. I don't know exactly what you mean by that but I believe you find it hard to breath out. Currently at PS of 3 your machine appears to be working overtime to maintain your minute vent. The average PS in your recent graph was over 5 and my guess is that you need a bit higher PS for comfort and to overcome the OSA and COPD. Especially with your PS induced CSA I would start off slow, maybe just try the higher EPAP to start then bump up PS to 3.5 if needed and then maybe 4.
You have been on a long journey and keep on hoping to find what will help you find good sleep. The question is what is ST-A going to do to help you? From reading through this I am not sure that you really know and I believe you should have all the information available to have an idea as to whether or not the ST-A will help. I think if you review data a bit further and maybe try a few more things out with ASV before committing to ST-A you might have a better indication of what to expect (unless insurance is going to pay for everything in which case sure go for it).
From what I understand iVAPS is only going to offer you two, perhaps three things your ASV currently does not.
a) Target ventilation rate. Rather than relying on your spontaneous effort it will try and force you to maintain a programmed ventilation rate. In your last data your average minute ventilation was 6.25, ASV is only going to work to maintain around 5.6 (90% of spontaneous)but if you program iVAPS it will work to maintain 7 etc. This is most likely the biggest advantage of iVAPS but the question is do you need that extra minute ventilation and will it help? Lets step back a step, what does increasing ventilation accomplish? Increases oxygen levels and decreases CO2 levels. So how can we check if extra ventilation is necessary? Well you can monitor O2 levels with an oximeter and CO2 levels you can get an idea of based on arousals and determining if centrals are present (turning down PS max would confirm). The other way would be to keep a sleep diary and check how you rated your sleep vs median minute volume. Higher minute volume days should correlate with better sleep if ventilation is an issue.
b) Ticontrol. You will be able to set a minimum and maximum amount of time for inspiration pressure. This is the ONLY extra time adjustment related iVAPS has over ASV. Based on what you have posted I see no advantage of this as I do not see breathes ending early or being extended, if you see that in your data then there may be some advantages here though.
c) I don't know how much is different here but it appears that the backup rate is a little smarter on the iVAPS. This may help a bit but I don't see this as being a significant change.
The respiratory coach video you shared doesn't really touch on anything applicable in your situation (unless your other data is different than the one recent example you have posted). As he was indicating he believes the ST-A could help over an ST because if has the fluctuating pressure support, you already have this in ASV.
In short iVAPS is pretty much set target ASV with Ticontrol. If you can figure out how a higher ventilation affects your sleep you will already have an idea of what you are going to get out of ST-A machine. iVAPS is just going to increase PS to maintain the target ventilation, if your ventilation is stable (doesn't have periods of obvious decline) than you can easily test this on ASV by increasing min PS until you are achieving the results you would be targeting on iVAPS. Results will only be significantly different between the two machines if your spontaneous ability is not capable of maintaining the higher ventilation rates which you will be able to confirm by looking at charts (will show a steady decline in MV).
Just a different opinion for you to consider.
RE: Beyond ASV with Overlap Syndrome! - SarcasticDave94 - 02-14-2020
Thanks for the comments Geer1. I find I have trouble selecting the correct words or phrases to explain what my trouble with the ASV is and what it causes. My attempt this time is to go over again why I think timing controls seem to possibly be what I need to fix the issue.
Everything between the ASV and me seems fine until about the 2 hours of use mark. My assumption is that if stacking is involved, it takes that long to become an arousal issue. At that time, I awaken from actually being asleep and not a sleep/wake transition as best as I can tell. I'm now awake and feel that my lungs are full but having some restriction in exhaling, at which time the only remedy is to mask off. It seems like inhalation gets a bit more difficult with a "back pressure" feel. I am able to begin breathing my normal rate of inhale and exhale, and feel better within a few seconds. I'm noticing those feelings as I am awakening, but it seems I can somehow sense something is "off" as I'm awakening. My belief is I need more exhale time, which I cannot control with this ASV. My COPD wants longer exhale now than in the past. Do I have timing documenting this and comparing the past to now? No, it is what I feel.
OK. Now here's a curious question: I see Supplier #33 has a NEW ResMed AirCurve 10 ST-A with ClimateLineAir Oxy hose for $2,750. Good or bad deal?
PS as for pressure settings of EPAP Min/Max and PS Min/Max with the ASVAuto mode, I've self-titrated at the settings shown, which other than this current unnamed issue, has been giving very good to excellent results in feel and data stats. When this issue began, I did edit settings a bit as in the early days of my ASV ownership. I adjusted one setting and reviewed. To me, settings that strayed from the former did not help to resolve my issue or make the already great results better. Therefore, I reverted back to the prior setting and kept it there.
RE: Beyond ASV with Overlap Syndrome! - SarcasticDave94 - 02-14-2020
Take note that I believe it's my COPD that causes the need to add a bit of "force" behind exhalations, not a lot of effort is implied, but also not the relaxing of the diaphragm etc. to bring about exhaling as would be normal. The normal relaxing of my diaphragm isn't enough to exhale enough on a consistent basis. I have to consciously add a bit of chest/abdomen "push".
PS I now recall the RT yesterday mentioned she thought some air trapping is occurring.
RE: Beyond ASV with Overlap Syndrome! - Geer1 - 02-14-2020
Feeling difficulty of exhale implies PS needs to be increased.
Feeling rushed during exhale implies backup rate is too short. Ticontrol will not help this and I am not certain if or how iVAPS backup rate differs from ASV to know if it would allow any longer exhale duration. ST-A titration guide recommends leaving backup rate at or above 15 bpm which is what I believe ASV is set to.
The reason COPD requires longer exhalation is because more time is required to effectively expel CO2. Increasing PS increases exhalation effectiveness which allows for shorter exhalation times.
iVAPS will probably be an improvement but it will just be because it will provide higher PS to increase exhalation period. I do believe you can mimic this by increasing min PS so that your ASV will promote a higher spontaneous minute ventilation.
Now one theory that may be important is that the reason you have trouble 2 hours in might be because your trouble is related with rem sleep. Relaxation of muscles leading to weaker respiratory drive etc. If this is the case then this is where iVAPS would really shine over ASV because it will increase PS to maintain ventilation whereas the ASV is just going to slowly let your ventilation and sleep fall apart. You should be able to get an idea if this is happening by looking at OSCAR details, some hints would be a change in breathing waveform potentially indicating rem, minute ventilation beginning to fall etc.
You should also be able to see the backup rate problem if it is in fact the issue. You will be able to see that if the mask pressure waveform start to occur earlier in the flow waveform indicating it is working to maintain your breathing rather than you just spontaneously breathing.
If it would be of any help I would be willing to review data and see if there seems to be any correlation/indication as to what is actually happening that is creating the problem. Maybe I am wrong but I believe it should be possible to see what the issue is and if there is nothing obvious I wonder if there isn't another part of the puzzle(besides SDB) that is being missed. I know you just had another sleep study so maybe that will provide something of use, was it another titration study or no PAP?
Edit: You could also be right that lack of ventilation slowly leading to CO2 increase could cause arousal. Again only answer is PS though.
RE: Beyond ASV with Overlap Syndrome! - Geer1 - 02-14-2020
Do you have/use a recording oximeter?
RE: Beyond ASV with Overlap Syndrome! - SarcasticDave94 - 02-14-2020
Not yet on the pulse oxy meter, but I'll grab one next month. I think I'll get the CMS 50F. For my "advanced" GOLD level 1 COPD, my oxygen levels are pretty good to excellent COPD or not (94-99 most Dr. visits).
My typical resting BPM is 10 +/- according to what I recall. I'm sure 15 BPM isn't in my sleep breathing range as I'm a slow breather, likely even slower in sleep. When I get the ST-A, BPM would be set with about 10 as my normal in mind.
Thanks again for the input and insight.
From ResMed titration PDF
"Rise Time
The Rise Time setting adjusts the rate at which pressure transitions
from EPAP to IPAP. Rise Time may be adjusted for comfort or
according to lung mechanics. A longer time would slow the
transition and may be more comfortable for patients with normal
lung mechanics or those who breathe slowly. Patients with high
ventilatory demand may prefer a shorter Rise Time. A typical Rise
Time for a patient with normal lungs is 300 milliseconds (ms).
Restrictive patients may also prefer a 300 ms Rise Time. Patients with
obstructive lung diseases may prefer faster Rise Times to fill their
lungs quickly (potentially leaving more time for a prolonged exhalation
to reduce air trapping). Rise Time should not be set longer than the
patient’s normal inspiratory time. On the BiPAP S/T, Rise Time settings
are represented as a range (0, 1, 2, 3). On ResMed’s AirCurve™ ST
VPAP ST-A, Rise Time settings are presented in milliseconds (ms) and
adjusted in 50-ms increments."
Obviously this only applies if I'm accurate in thinking air trapping is present in me