Why doesn't APAP respond to apneas?

Since I got James Skinner's Analyser program now, I realize that even though I have my leaks under control and my apneas down, the ones that I have are long! I can't figure out why the APAP doesn't even try to increase pressure to eliminate them. I can see missing a few that are 12 seconds long, but how about an average of 36 seconds? Isn't this why we have these machines?








Help, someone?

Bev

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Beware: this is going to sound totally counter intuitive and totally wrong. But it's true.

By design the Respironics algorithm will not respond to the first apnea or first hypopnea in a cluster. It will intentionally take a pass on that first one. Then the algorithm will respond to the second apnea or second hypopnea in that same cluster. Thereafter, in that same cluster, the algorithm will continue responding only to every other apnea or hypopnea in that cluster. So that means isolated or unaccompanied apneas/hypopneas never get responded to, by design.

I can only guess that this cautious approach has to do with avoidance of pressure induction of central events or homestatic disturbances. The design approach also tries to leverage the prevention of those apneas/hypopneas in the first place using snore and flow limitation as precursor signals for proactive pressure increases. Regardless, the algorithm is not well suited for everyone. That statement stands true for any APAP algorithm, however.

Mike,

It took me a year of experimenting to get to this point. I also blow up like a balloon every night. Some nights I have to sit up and belch, or walk around to get some of the air out before I can go back to sleep. All day and all night, I pass gas. It's as if the air goes right through me. Very uncomfortable and embarrassing. I've been using the CPAP cap, by PurSleep. It has a chinstrap that actually stays on. I also double tape my mouth with medical tape and then blue painters tape. The medical tape is a little porous and leaks air so the blue tape goes over it. I don't like the blue tape against my skin, the edges are sharp. I really, really want to make this work. I need to feel better and I have hope that some day I'll get it right.

Good luck to you,
Bev

mth712 wrote: I am thinking that CFLEX contributes to leak and to air in the stomache. I don't know but it is starting to make me scared to use the machine. I have a swift 2 on the way and I hope it helps with the leaks. I am thinking the cflex and the active mask are a contributing factor.

For some reason C-Flex causes me to experience slightly more aerophagia as well. For other posters it's the exact opposite.

If you think C-Flex might be problematic for any reason at all, you can always experimentally turn that feature off. I know that I'm not the only one around here who prefers to leave C-Flex turned off.

SWS,

So you are telling me that this is as good as it gets?

Bev

OutaSync wrote:SWS,

So you are telling me that this is as good as it gets?

Bev

Dunno if that question is aimed at the algorithm or just xPAP therapy in general, Bev.

I can only say that the algorithm is doing exactly what it's designed to do. So the occasional isolated apnea or isolated hypopnea just sits there untreated. And most people would probably sleep and feel pretty good with the results on those charts. However....

I also know what a challenging time you've had sleeping and feeling rested on xPAP, Bev. Did you ever find out if you happened to be experiencing excessive cortical arousals or Cyclic Alternating Pattern (CAP) while using CPAP? Any PLMs, bruxism, GERD, arthritis pain, medications, etc. that might be thoroughly trouncing that sleep architecture?

I never heard of CAP. No PLMs show up on my sleepstudy, although I occasionally have trouble with restless legs. I do have GERD (have the head of my bed raised), I often wake up having bitten my cheek or lips, but I don't think I grind my teeth. I have a lot of back and shoulder pain from a fall two years ago (had surgery in March, somewhat better now) and I don't think I take any medications that might affect my sleep other than Ambien, which is the only reason I can even get to sleep.
If the APAP missed a few 15 second apneas, I guess that would not be so bad, but if they average 36 seconds, some of them must be longer than that.

Is there a machine that would be better for me. I do not have a cooperative doctor. He just tells me that I'm doing fine.

Bev

OutaSync wrote:I do have GERD (have the head of my bed raised), I often wake up having bitten my cheek or lips...

Perhaps something's going on here that detracts from restful sleep architecture, Bev. That cheek/lip biting could be the result of GERD eruptions, undiagnosed bruxism, or even a defensive response to those unresolved apneas. Then again it could be unrelated to all the above. But I don't think it's indicative of restorative sleep.

OutaSync wrote:I have a lot of back and shoulder pain from a fall two years ago (had surgery in March, somewhat better now)

Pain can and will utterly devastate my sleep architecture. For me it's neuralgia pain. And when that pain acts up even slightly, I'm a slap happy semi-comical walking zombie!

OutaSync wrote:and I don't think I take any medications that might affect my sleep other than Ambien, which is the only reason I can even get to sleep.

If we take the Ambien out of the above statement, what might account for that part I have underlined? Caffeine? Circadian rhythm disorder? Stress? Bad sleep hygiene by definition? Anxiety about poor-quality sleep related to unresolved SDB? Bev, my layperson's hunch is that resolving the part I have underlined just may turn out to be even more important than trying a new machine.

OutaSync wrote:If the APAP missed a few 15 second apneas, I guess that would not be so bad, but if they average 36 seconds, some of them must be longer than that... Is there a machine that would be better for me.

Any algorithm that doesn't take a pass on the first apnea might very well take care of those isolated stragglers. The 420e might be a good algorithm to try. But that's assuming those isolated stragglers are not central, not mixed, or not sympathetic/defensive type closures.

My hunch is that simply fixing those isolated straggler apneas may not sufficiently fix up your sleep problems and daytime energy issues. I have a hunch that you may have a variety of sleep issues that need to be collectively addressed. Perhaps it's time to find a more cooperative sleep doctor.

Bev

Your numbers actually look pretty good !. I think it is comfort issues that are your challenge.

Re C-Flex - turn it to 1 or off as SWS has suggested. I am one who got severe aerophagia from C-Flex set to 3.

Re aerophagia in general. I finally got on top of that when I obtained a bilevel machine. I suspect that a lot of
folk would see big improvements in this type of a switch. I am a GERD sufferer as well which I think, means
that air gets into the stomach much easier than for non GERD folk.

Severe Aerophagia is a real bummer of a problem & enough to cause folk to think of giving up.

Good luck & keep asking

DSM

What SWS said, and I think that is what it does when it gets over 12 cm pressure, below that it uses a different schema.

Have you ever tried Bipap? Might be easier for you to tolerate, if I was a doctor and seen those pressures during a titration I would have given you a Bipap from the start.

While you mention a bit of RLS, was there any spontaneous arousals listed on any of your PSG? If you are still feeling fatigued you may have UARS in which a bilevel may help there, but unfortunately with frank apnea still showing up at 14 cm, you probably would still need an EPAP pressure of 14 to take care of those and an IPAP=18 or higher to address any UARS.

So for your aerophagia, you most likely wouldn't see any relief. Now that you know what your AHI does and how you feel at that pressure, how does it compare to using a lower Minimum pressure? For example, if you lowered Minimum to 7 or 8 cm and allow the Auto algorithm to take care of those events, you may end up with a higher AHI but you might see an improvement to the aerophagia. If you feel no better with that lower AHI then go for the comfort.

IF you have an AHI of 5 or 10 and feel better go for the higher AHI and don't worry about it.

Snoredog,

I tried lowering the pressure earlier in the summer and , as you predicted, my AHI went way up and the aerophagia wasn't any better. Considering the length of my apneas, it felt as though I hadn't gotten any sleep at all. I will try turning Cflex down to 1. I have Aflex set at 3. It shows up as Cflex on the Analyser.

SWS,

I think I have pretty good sleep habits. Sometimes I stay up an hour later than I should to watch Boston Legal (cracks me up and I need some good laughs). THe problem I have getting to sleep is that I keep jerking awake, just as I'm drifting off. This can go on for an hour or more, after which I get very frustrated. The Ambien helps with that. Once I get to sleep, I only wake up to roll over to adjust my back, to throw off the covers when the internal furnace comes on, or to situp and belch. Yes, i can belch with the tape on.

DSM,

My co=workers and family will have to live with the flatulence, it's the barely being avle to hold my head up that is bad.

I don't really understand this study, done on a bipap:





Any clues in there?

I'm wondering just how long your hose is?

Using a hose 10ft. long will make it harder for an auto to respond. Adding more hose on some masks or external HH you add more length to the whole setup.

Standard 6' hose that came with machine. The Activa has a little extra hose. Could it be CO2 build up in the mask?

Bev,
About thos APAP graphs
I don't know if a Respironics can be set up to start a "somehthing and a half", but if it can, I'd jog the pressure up just 0.5 cms.

It seems to me the machine is getting confused by your breathing pattern, and assuming it can go lower than is should. So its spending a lot of time doing a lot 2 step up and then one big step down test of pressure - and back over the same ground; over and over again. You're speding about 20% of those nights at 15 or more - but its all done in wee bits and pieces. I don't know how those constant pressure change can affect aerophagia, but I blieve the may be a cause of arousals, keeping you from restful sleep. We don't really know when the longer apneas happen -but they could be happening at this slightly lower than optimal pressure.

The sleep study graph:
A number of things stand out to my mind:
Its a bi-level study - then why are you on a single level, albeit automatic machine?
The majority of central apnes happened at lower pressures - I guess they are those the accompany the obstructive events +destats + arousals (absolute guessing, and I'm not a professional in this in any way).
You were aroused by most the breathing disturbances you had (3rd graph from bottom).

The most event free hours you had were between 01:00-02:00, and then between about 03:00 and 04:00 and between 5 and 6. -- that's just about when the pressure was maxed. Between 1-2 you slept deep, had hardly any events, and you oxygen was great and stable. It looks simlar between 05:00 and 06:00 However, it looks like you were awake between 03:00 and 04:00

Accoding to the pressure table, you Sa02 mean also gets better an better the higer the pressure - though you do get drops - even when the pressure is maxed.

I have no idea how they decide on final pressure in bi-level titrations. I think I would go the the most rested and oygenated perios in which you tasted deep sleep - that hour between 1 and 2. If it were amateur untaught me, I would got for 20/16.

Which brings us back to why are you on a APAP instead of Bi-level?

O.