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Bilevel settings (and other factors) revisited - dfunk - 12-12-2023
Hey y'all! Apologies in advance for the long post. I tried to only include useful details, but it's been a long road.I've been on bilevel therapy to treat complex sleep apnea for close to 10 years now and my most recent sleep doctor has really done me dirty. Bad sleep lab experiences, bad advice, increasingly bad sleep. And no help trying to sort out how various symptoms, environmental factors, and comorbidities intersect to result in poor sleep and poor quality of life. So I fired them and am back on my own trying to tweak things based on the settings I was using before I switched to them. Falling back to those old settings is already a vast improvement but I think there's room for more. So a couple questions for starters/
1. ti max/min, trigger/cycle sensitivity:
Everybody seems to say "DO NOT TOUCH THESE SETTINGS" but I can't deny that increasing my ti min/max (1.8/3) and trigger cycle sensitivity (very high/medium) have vastly improved my subjective feelings of restfulness and how my sleep data looks in OSCAR. AHI plummeted and central apneas vanished altogether. I've often wondered if these extreme settings cause my machine (aircurve S) to miss apnea events. But I can't deny that a high TI min genuinely helps me feel better in the morning. For laughs (and desperation) I backed my Ti min down to 1.2 last night. Turns out my natural inspiratory time when I'm getting decent sleep is around 1.4-1.5 seconds, but for whatever reason, giving myself the headroom to breathe so shallowly makes me more prone to obstructive apneas and my respiratory rate just bottoming out. With all other settings the same from the night before, my AHI soared from 1.17 to 14.76! I don't know what gives.
2. Pressures:
So turns out my pressures with the most recent doc were laughably low. Had me on 13/9 after being on 19/15 for a good while before that. Switching back to 19/15 gave instant relief, though it started to wane over the next week or two, before plateauing. I had several days with an AHI of <1 before things started climbing and kind of flipping back and forth between the low 1's and low 2's with nothing in between, and with a noticeable difference in restfulness. I tried raising the pressures as high as 21/17 with no discernable difference, other than some bloating, which I would've accepted if it helped me sleep better. I've been loathe to alter the pressure support though. Any reason to increase the difference between ipap and epap?
3. Easybreathe:
For whatever reason, I've always slept best with easybreathe on instead of using a set rise time. Though again, conventional wisdom seems to eschew this, the rationale being that you don't spend as much time at your prescribed pressure. (could this be why increasing TI min helps so much?) This brings me to:
4. S vs ST
After my most recently sleep study, the doc prescribed an aircurve ST machine to try. On paper, having a backup minimum respiratory rate sounds like a good idea since most nights my respiratory rate would drop all the way down to zero for parts of the night. But even after several nights trying various pressure and backup rate settings, nothing helped. The pressures the doc initially prescribed were 18/9. With no easy breathe option to control the "fall time," for lack of a better term, cycling to epap felt like getting punched in the throat and flung out an airlock into the vacuum of space. Leak was rampant. I couldn't even fall asleep at that pressure. With pressures closer together, I was able to get in synch with a static rise time and fall asleep, but I still felt like garbage, which my AHI corroborated. I tried the old 13/9 pressure from the most recent doc. I tried 19/15 from the previous doc. I even tried 19/9 with my old machine just for laughs. Garbage AHI. Notably, using the ST machine with the 19/15 pressure resulted in probably the worst AHI of my life. (24.1!) And interestingly, with a 18/9 on my old machine, my central apnea came roaring back. It looks like my natural respiratory rate is in the neighborhood of 15 breaths/min. But for whatever reason, setting the backup rate anywhere from 11-15 just made me miserable, no matter what other settings I tried. So I dunno. Easybreathe seems to be more helpful than a set rise time with a backup rate. I dunno.
5. Leak
I've taken a long road to figure out the best mask setup to control leak. I have facial hair and, more problematic, my jaw is uneven and my mouth desperately wants to fall open when I pass out. I've tried numerous full face masks, nasal pillows, chin straps, mouth guards, and eventually tapes. Chin straps kill my jaw. Oral appliances eliminate leak but kill my jaw. (and forget about using them without bipap, lol central apnea) Despite conventional wisdom, I started exploring taping. What I've settled on is the Bleep Dreamport (more on the need for a strapless mask in a sec) and a couple strips of cheap Amazon kinesiology tape. (Same material as that hostage tape stuff for 1/7th the price.) I cut them into short strips and place them vertically because the stretch is directional. For whatever reason, having the vertical stretch makes a difference to my cranky jaw. I just have to keep my mustache meticulously groomed for it all to work and keep the large leak graph zeroed out. I know there's a risk of aspiration, but at this rate I'll take my chances. That said, I still don't understand how to read the "leak rate" overview graph in OSCAR, which seems to be completely independent of the "large leak" graph. Maybe there's some correlation between leak rate and AHI, but overall it seems pretty random. As a final note on leak, it seems like my consistently best AHI's of the last few years (though I think I still felt awful because my neck was still so screwed up) were in late 2020 after I first started using the bleep mask on my old 19/15 but before I'd settled on the KT tape. Both my large leaks and leak rate were much higher. These were times when my AHI was routinely <1. I sometimes kept my TI min much lower at that time as well, which is why I tried lowering it from 1.8 for a night recently, which was disastrous. Could large leak/leak rate cause erroneous AHI measurements? Could a big leak back then causing improved AHI point to my pressures being too high, but 13/9 being too low? I'm grasping at straws here.
6. Neck problems
My most recent round of sleep woes really began at the beginning of the pandemic. I had sinus surgery at the end of 2019 and was told from then on to sleep with a normal pillow on top of a wedge, causing my neck to bend so that my chin touched my chest all night every night. It wasn't until after several months of that when I realized that it was the cause of the gradually increasing, eventually excruciating neck pain I was experiencing. Even after suspending this, my neck has been wrecked for the past 3 years or so (though I've greatly improved, I still have a ways to go. Sometimes I wonder if I'll ever recover completely). The back of my neck was so tender for mask headgear, especially at the pressure I supposedly needed. (hence me eventually googling "strapless cpap mask" and discovering Bleep) My upper traps were not just stiff, they were rigid. I would get dizzy/vertigo at the slightest jostling of my head, taking me from a half-marathoner to somebody who couldn't take 10 jogging steps out my front door without subsequently having to lay on my kitchen floor for an hour. I went to neurologists, audiologists, and neuro-ophthalmologists who thought I had migraines. I saw physical therapists who insisted my problem was vestibular and could be solved by essentially performing sobriety tests. Nobody wanted to listen to my complaints about my neck. Massage helped a little, but not much. It wasn't until about May of last year when I started seeing a different PT and taking a different muscle relaxer that I finally started to see some relief. Dry needling and mechanical cervical traction have made a huge difference. I can run sometimes now. But I feel like I've plateaued. I just recently switched to a new PT at the same clinic because the old one got a new job. The new one is treating me a little more aggressively, which is helping some. But all of this is to say that I think I'm still suffering from...
7. Positional apnea
While my neck is a lot more functional than it was at the beginning of 2020, it's still not great, especially after the recent struggle with trying to make the ST machine work. And I think my AHI and how good I feel correlates pretty strongly with sleeping with my neck in a comfortable position. I've tried a zillion pillows. I've even tried sleeping in my home mechanical traction machine (not with any pressure applied, just kind of as a guide), which sometimes helps. What was working best for a while was propping my shoulders on a couple of rectangular down pillows and hanging my neck/head off the back. But as my neck has improved, that strategy has become less comfortable. So I think the missing puzzle piece is still trying to unf**k my neck the rest of the way. I was using a muscle relaxer that helped a lot for a while. But then I was prescribed a different med for a different condition that I didn't realize worked along the same pathway and the muscle relaxer hasn't worked the same since, even many months after suspending the other med. It doesn't seem to help my neck anymore, it just makes me feel groggy and hung over for the next day or two. I just recently started sleeping with a cervical collar/brace on the advice of the OSCAR tutorial here on apneaboard, which seems to help some. But it's intermittent. So....
8. What to do???
I dunno what else I can do at this point. Different machine settings? Different mask? Finding the goldilocks of pillows and neck braces? Additional graphs in OSCAR that I should be monitoring? Swapping to leaky tape? Blaaarrrrgh If you've got ideas, I'm all ears. If you're curious about screen shots, I'm happy to post whatever would be of interest. <3
P.S. Comorbidities
I've got a couple other health things going on that for a long time I couldn't figure out if they worsened my sleep apnea or were possibly caused by it. Given how things have improved somewhat since switching back to higher pressure, I think the sleep apnea exacerbated these things: weight gain, hormonal imbalance, ADHD/decreased executive function.
RE: Bilevel settings (and other factors) revisited - PeaceLoveAndPizza - 12-12-2023
There is a lot there to unpack. I read through your other threads as well to get background.
I’ll try answering a few of them…
1. TI/Trigger min/max - Bravo! You have the decoder ring. Use what is comfortable and/or improves therapy.
2. Pressures - What you are using seems to work. As long as you are happy with the results and comfortable with it no reason to change except to get a better nights sleep.
3. Easy-Breathe - EB is your friend. Treat it well.
4. S vs ST - I have nothing.
5. Leaks - Can leaks cause erroneous data? I would think so as during a leak events may be lost. The machine does a good job working through it with pressure, but there is a limit to what it detect with the leaks.
6. Neck - I have nothing.
7. Positional - Ibid
8. What to do? - First, take a few breaths. Your charts look good. A bit of arousals in the flow rate, but we’re going to work on that. The main thing to address at the moment is the poor sleep quality. You have good numbers, so now what?
I suspect there are things going on we may see in the flow rate. A few 2-3 minute views at random times may give more information. If it is flow limitations we can make recommendations from there. Typical things to try in case it is the “pressure support” requiring more or less differential, requiring an increase or decrease in IPAP, EPAP, or both.
For example, you are currently at IPAP 19 EPAP 15. You may want to try IPAP 19 EPAP 14 or IPAP 20 EPAP 15. You could also try IPAP 19 EPAP 16 or IPAP 18 EPAP 15.
If it is not flow limitations, then we have to figure out a different path.
RE: Bilevel settings (and other factors) revisited - dfunk - 12-13-2023
First, I can't thank you enough just for reading through all of that. I know it was a lot. Brevity is not my strong suit. :-P
1. Ti min/max, trigger/cycle: It's wonderful just to be validated about this. Doctors have either said "don't touch" or "figure it out for yourself." I've had to argue with sleep techs about it at in-lab studies so much that they've given me panic attacks that prevented me from falling asleep at all. So thank you. I wish I could find more empirical guidance to help me optimize. But what I'm using now seems pretty decent.
2. Pressures: 19/15 definitely works best of anything I've tried over the past 4 years. But I'd like to optimize more if possible, and especially work on consistently keeping my AHI low.
3. Easy-breathe: Again, thank you for validating this.
4. S vs ST: Agreed. It's confusing. I'm returning the ST machine.
5. Noted. This is less relevant after getting my leak mostly under control.
6 & 7: I played with pillows last night, which vastly improved sleep quality and AHI despite being kept awake for 2 hours in the middle of the night for unrelated reasons.
8. See attached screen shots. If analysis of my flow rate offers any guidance on if/how to adjust my pressures, I'd love to learn more. I took advantage of my triple monitors to take 9-minute shots that you can zoom in and view at 3-minute resolution. Following are 3 screenshots each for 3 different nights with different AHIs. If I screw it up, I'll redo it. Here's the first night:
Machine settings for those nights:
Date: 12/6
Pressure: 19/15
Ti min/max: 1.8/3.0
Trigger: Very high
Cycle: Medium
AHI: 0.95
[attachment=57180]
[attachment=57181]
[attachment=57182]
Date: 12/8
Pressure: 19/15
Ti min/max: 1.8/3.0
Trigger: Very high
Cycle: Medium
AHI: 2.39
[attachment=57183]
[attachment=57184]
[attachment=57185]
Date: 12/13
Pressure: 19/15
Ti min/max: 1.8/2.5
Trigger: Very High
Cycle: Very low
AHI: 0.2
[attachment=57186]
[attachment=57187]
[attachment=57188]
RE: Bilevel settings (and other factors) revisited - PeaceLoveAndPizza - 12-13-2023
Generally things look really good, but as we are only looking at one night for each setting it is hard to extrapolate from it, so take this as general observations.
The flow rate waveforms have a nice rounded top. Respirations and tidal volume are good. Only thing I would suggest is continuing to work on is the leaks. Other than that I would stick with the third chart settings as that is your sweet spot.
Basically, with minimal adult supervision, you have done a cracking good job!
Keep it up for a while and let’s review. Don’t lose the plot along the way and start changing things willy-nilly as it only makes it harder to analyse the results.
RE: Bilevel settings (and other factors) revisited - dfunk - 12-14-2023
Sounds good! I got a really good night's sleep last night with those same settings. Only thing I changed was my pillows. No leak, according to the readout on the machine. AHI 0.7! Unfortunately, like a fool, I forgot to put my SD card back in the machine. But I'll keep the same settings for a few days and see how it goes!
RE: Bilevel settings (and other factors) revisited - SarcasticDave94 - 12-14-2023
Dave has a few things to say.
How and why did you get issued an ST running S mode?
What is your actual diagnosis? You mention Complex Sleep Apnea. This means Central and Obstructive Apnea; is this your diagnosis?
Do you have the most recent sleep study detailed report? Can you post it redacted of personal info?
What other Medical issues in the comorbidity?
FWIW if you have to treat Central Apnea, maybe the ASV is better suited.
RE: Bilevel settings (and other factors) revisited - dfunk - 12-15-2023
When I was using the ST machine I ran it in ST mode. None of the graphs above are from that machine. After a week of the ST machine, I went back to my old machine and I'm returning the new one.
Yes, my diagnosis is Complex Sleep Apnea, both Central and Obstructive. As mentioned previously, adjusting my trigger/cycle sensitivity and Ti min/max settings literally made the central apnea vanish overnight. See attached overview timeline. The purple on the far left is the obstructive apnea. You can also see the spikes of dark blue and green on the right where I tried and gave up on the ST machine. I have wondered if changing those settings might have masked central apneas from showing up. But something would've shown up on the daily flow rate graph regardless, right?
See attached sleep study. Apparently, the sleep tech didn't follow the doctor's orders for the titration study, saying: "The 18 was empirically set as the control on the study was not as good as I would like so I bumped up the IPAP a bit to see if that would reduce the hypopneas - ideally the tech would have done that during the titration but didn't. If you feel like it is too much, you can turn it down to 15."
I can tolerate high ipap pressures. I've gone as high as 21. It's the broad pressure support that messes me up. Other than the recent doctor's order to try 18/9, I've always kept my pressure support at 4. Maybe I could try 5 or 6 if that might be beneficial. But I imagine that past that I'll start to run into problems. 9 was unbearable. Didn't fall asleep at all the one night I tried it.
As previously stated, I started experiencing weight gain, worsened ADHD symptoms and hormonal issues that seem to have all started right around when the doctor backed my pressures down from 19/15 to 13/9. (I had just switched to her from another doctor who had become less responsive.) But given how much better I've instantly felt these past few weeks when my sleep is good quality, I feel like a good chunk of those other things are caused by bad sleep in my case, rather than the other way around.
I've wondered about ASV machines. I'm in the process of firing my existing sleep doctor and finding somebody else, again. I will likely talk about ASV machines with them. I bet my insurance isn't going to like that if ASV machines are the expensive new hotness.
Given how intermittent my good days and bad have been lately, despite pretty good leak control, I'm really starting to think my problem is positional. My neck is still messed up after these several years. I think the cervical collar I got is helping some. But I think it might not be tall enough. I'm actually about to run out and pick one up with an adjustable height.
RE: Bilevel settings (and other factors) revisited - SarcasticDave94 - 12-15-2023
OK thanks for posting the info, and my apology if any needed repeated to fulfill my request.
I'm not at all certain of the timing on this, but the ST used to be a common mode to treat complex and central apnea. The ASV has replaced it. Again I don't know exactly when.
You have the evidence to get a script for ASV. It says it in your report as the diagnosis. Does it say ASV, no sorry. But the treatment to combat complex apnea is the ASV.
You'll need to get a doctor willing to script it, or if you've the means to buy one, that's another method. I just saw a new 10 series ASV on DotMed for $1,600, a used with 6.6k hours for $1,100.
Here's the direct quote on your study that I'm referring:
Diagnosis
• Obstructive Sleep Apnea (327.23 [G47.33 ICD-10])
• Central Sleep Apnea (327.27 [G47.37 ICD-10])
Further, they state they were testing for Complex Apnea. And if I'm reading the report correctly, they left some CA untreated and called it a day.
I have complex apnea and Emphysema COPD. Putting COPD aside a moment, higher pressures unless from an ASV was delivered in such a way as to enhance CA not treat.
I think a part of the bridge to ASV is built on complaining your tail off, possibly replacement medical team, or working with another of your doctors to script ASV. You can drive it yourself, as in settings. It's not hard. Now a contraindication is if you need those timing settings the ST includes, then the ResMed ASV can be scratched, that's why I can't use ASV now. Timing is Auto only on that ResMed ASV.
RE: Bilevel settings (and other factors) revisited - dfunk - 12-15-2023
No worries! And thank you for taking a look!
So it sounds like ASV might be worth a try. I can either find a new sleep doctor, or possibly just go through my primary care, who has been cool about treating basically everything. I can't afford to pay out of pocket and he's good at fighting insurance.
Any idea why tweaking my trigger/cycle sensitivity and Ti min/max settings made my central apnea seem to disappear from OSCAR? It definitely made me feel better.
It's these pesky clusters of obstructive apneas (see attached) that keep screwing me up. The neck brace suggestion seems to help. But I think I need a taller one. I might try building mine up with a t-shirt or something.
RE: Bilevel settings (and other factors) revisited - SarcasticDave94 - 12-15-2023
Your primary care is certainly a good option if you think he'll be open to it. It's certainly worth trying.
Edits to the timing have been used successfully here on the Board before, even with VAuto and the trigger, in combatting centrals, at least to a degree. Reason is this makes the transition to fire off an inhale happen with diminished inspiration pull or input, if that makes sense.
I think a parallel involving trigger, firearm with a hair trigger, higher PAP trigger means less input to fire off IPAP transition.
With certain CA, maybe the variable is levels of CA or susceptibility to them, there's still a certain group with CA that ASV is the best answer for treatment.
From ResMed
"The trigger sensitivity determines how easy or difficult it is for your patient to initiate a breath..."