12-12-2023, 06:28 PM
Bilevel settings (and other factors) revisited
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.
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.
