introduction, and a history of apap->bipap->central apneas?

[palerider]

Just thought of some other questions -

1) Please, can someone help me understand why higher pressure support can trigger central apneas -if anyone can help direct me to a thread that discusses this, I would be full of gratitude.

It's pretty simple, (ok, it's not simple at all)... but, your body's 'urge to breathe' is driven by the amount of acid in your blood. Dissolved carbon dioxide causes carbonic acid. (that's what gives fizzy drinks that 'bite' on the tongue). When you're talking bilevel therapy, (in hospitals, for breathing issues) you've got two main components... the peep (or epap, as we call it) which is where oxygenation happens, (so if the patient's blood oxygen levels are low, they raise epap), and PS, or the amount of extra pressure the machine gives to 'support' inhalation. When the patient's CO2 levels are too high, they raise PS, because that causes more ventilation, blowing off more CO2. More ventilation = lower CO2, if you blow off too much CO2, you can get to a point where the body's respiratory drive is depressed to the point where your body says "nope, i'm good, no need to breathe just yet", until more CO2 builds up.

It has nothing to do with oxygen.

Fun fact, a few years ago, I ended up in the hospital, with, among other things, acidosis... and for a while before that, I was *panting*, I couldn't *stop* breathing, the only thing that helped (a little) was cranking up the PS on my machine, then I could at least stop *briefly*, but I was getting physically worn out from the effort of breathing.

Here's some reading material:
https://www.youtube.com/watch?v=BdeOiDJmbrk
https://www.youtube.com/watch?v=A-SlO2dU8Og
https://www.youtube.com/watch?v=sa0m29jDkGM (not much cpap related, but there is a lot about blood gases and their effects.)

2) How do you learn about things like Timax, trigger, etc? is this in a book on bipap?

Thank you all for your time and responses and sharing your experience and knowledge.

I just got what I know out of the manual.

TiMin, minimum time it stays at IPAP, TiMax, maximum time it stays at IPAP. Trigger and Cycle are how sensitive the machine is to the start of an inhalation, (trigger), and how sensitive it is to the end of the inhalation (cycle). basically it Triggers the ipap and then cycles back to epap.

[palerider]

Most people do no use more pressure support than 4 or 5 cm. When I first started treatment, my IPAP was set at 20-25 cm with PS of 5.

Correct... there *are* reasons to have more PS, (obesity hypoventilation, timed high PS breaths for central apnea, etc.)

[dogsarelife]

@ Fred Thanks for sharing your experience that you have seen central apneas with higher pressure support - that is helpful to hear, because it is always nice to know I am not a unicorn!

@ Okie bipap

Most people do no use more pressure support than 4 or 5 cm. When I first started treatment, my IPAP was set at 20-25 cm with PS of 5.

Thanks for sharing this as well! After your comment and some of the other explanations I received, I changed my PS to 5 and unfortunately I woke up with aerophagia. I really think that like your wife, the process of getting pressures to where they should be is going to be a slow process for me.

May I ask if it took you a while to adjust to your IPAP of 20-25 and PS, or were you able to sleep at that level right away?

@ Palerider

they say the devil is in the details, with cpap, it's in the breath shapes.

Yes, I am finding this to be true!

Thank you for the links to the videos on Bi-level machines and also the explanation of CO2 and respiratory drive. Watched the first video and will watch the other 2 later today.

This -

Fun fact, a few years ago, I ended up in the hospital, with, among other things, acidosis... and for a while before that, I was *panting*, I couldn't *stop* breathing, the only thing that helped (a little) was cranking up the PS on my machine, then I could at least stop *briefly*, but I was getting physically worn out from the effort of breathing.

sounds like quite an ordeal and I'm glad that your bipap was able to help you through it until you were able to get help for the acidosis.

1) From the first video on bilevel that bilevel helps with ventilation along with oxygenation - can you deduce anything if a person feels better on higher levels of PS? Like would that indicate they have ventilation issues? a need to see a pulmonologist?

Correct... there *are* reasons to have more PS, (obesity hypoventilation, timed high PS breaths for central apnea, etc.)

2) When I slept with 14/7 or 15/8 - even on my first night at those pressures, I did not have aerophagia. So last night I slept at 15/10, and woke with aerophagia. Would one chalk that up to a one-off and persist, or is there actually something to greater pressure support helping to decrease aerophagia and comfort that should give me pause?

Thanks to anyone who responds and for your willingness to share your knowledge and experiences.

[Pugsy]

Try the PS of 5 with EPAP set at 8 and see if you still get aerophagia issues.
You reduced IPAP by lowering PS but you increased EPAP which is the baseline consistent pressure.
Doesn't surprise me that you experienced aerophagia issues with that increase in baseline EPAP.

[Okie bipap]

Actually, I had very little problem getting used to the high pressure. For me, it felt about the same as when I was having an asthma attack. When my asthma flares up, the effort to breath wears me out. It took about a week before I was sleeping through the night but it more just getting used to having that alien thing on my face than the pressure.

[palerider]

1) From the first video on bilevel that bilevel helps with ventilation along with oxygenation - can you deduce anything if a person feels better on higher levels of PS? Like would that indicate they have ventilation issues? a need to see a pulmonologist?

I wouldn't want to try and guess *why* someone would feel better, maybe it's just what they're used to, maybe it's because it's helping to prevent flow limitation events that disturb their sleep... maybe lots of things.

Give it a couple days and see if you still don't feel as good with the lowered PS.

Sleep varies, from hour to hour, and night to night, which is why we typically say "don't make any changes based on a single night's results"

Correct... there *are* reasons to have more PS, (obesity hypoventilation, timed high PS breaths for central apnea, etc.)

2) When I slept with 14/7 or 15/8 - even on my first night at those pressures, I did not have aerophagia. So last night I slept at 15/10, and woke with aerophagia. Would one chalk that up to a one-off and persist, or is there actually something to greater pressure support helping to decrease aerophagia and comfort that should give me pause?

Thanks to anyone who responds and for your willingness to share your knowledge and experiences.

It could be a one off, or it could be the higher EPAP. Personally, I would have lowered the IPAP instead of raising the EPAP to reduce the PS.

[dogsarelife]

To Okie bipap - Interesting that you didn't have issues adjusting to higher pressure, while your wife did and I do. There is just so much customization that has to happen for every case I guess. Has your asthma improved since starting bilevel pap? I remember that after starting bilevel pap I woke up with mildly sore intercostal muscles and finally felt like I could fully breathe again and I can only imagine how difficult it would have been to deal with asthma on top of sleep apnea induced breathing difficulties.

To Pugsy - Thanks for responding. I found an old post from you about IPAP and EPAP and I'm trying to follow the logic behind what you told me, because of my curiosity. So in an old post - posting.php?mode=quote&f=1&p=897522 you wrote

In general we have been told that EPAP for obstructive stuff and IPAP for hyponeas.

Snores and FLs are normally an indication of some sort of upcoming collapse of the airway....which may or may not grow up to be an obstructive apnea or hyponea but from what I have seen with my own reports and other peoples...EPAP is sort of like APAP minimum pressure and those pesky snores and FLs go away real easy with just a little more EPAP or APAP minimum.

Stent the airway open better at the base level and those little early signs of an impending collapse just don't happen.
Now how much of it might also depend on is the collapse part of exhale or inhale...I never could figure out how to get a handle on that and to be honest...that's digging real deep and IMHO why not just fix it the easy way first if it needs to be fix.
[...]

Past experience has shown me time and time again that minimum APAP or EPAP minimum...seems to be the most critical setting in not just my situation but in the others that I have helped. Get that minimum APAP (or EPAP minimum) set optimally and the top end doesn't really have to do much.

I prefer PS of 4...3 isn't too bad and 5 isn't either but above 5 PS, I have seen correlation between higher PS and emergence of complex sleep apnea in more than an occasional person. Now most often it has been when PS was fix (like ResMed machine) and people try PS of 7 to 10....which can make a person feel like they are hyperventilating and when looking at the high number of centrals...I guess they did. So that's why I like to keep PS around 4 or so...just as a precaution. Less chance for unstable breathing O2/CO20 exchange causing centrals.

So that's why I suggested a little more EPAP...past experience with hundreds and hundreds of ugly reports that turned beautiful despite what the manual might say would maybe work better.

1) So is this still your line of thinking - increasing epap until things sort of fall into place, while not worrying about ipap too much? and IPAP of 13 and EPAP of 8? (corrected these from before when I accidentally wrote EPAP of 13 and IPAP of 8 - sorry about that!)

2) I guess I'm a little confused on how lowering ipap won't hurt me later in the night, as I'm pretty sure my pressure needs tend to be higher in REM sleep. Wouldn't dropping ipap to 13 result in events in REM that would cause more disturbed sleep? Or is the idea that you don't need as high an IPAP by raising the EPAP because you are catching events before they blow up as you mention in the old post I copied?

I know my sleep doctor mentioned that when EPAP is too low that it takes much longer to climb back up to the IPAP and that can cause people problems....

clearly I don't understand nearly enough about bilevel because my mind is still trying to understand how ipap doesn't do as much as I thought it did. and it would seem Palerider is thinking along the same lines as you.

Thank you if you have time to explain.

To Palerider:

Thanks for the tips from a pro about not drawing conclusions from one night and also responding to the question about how there may not be any conclusions to be drawn from preferring mildly higher pressure support.

I hadn't yet logged into cpaptalk to see all the responses from you, Palerider, and Pugsy, and all I knew was that waking up this morning I was exhausted, so I adjusted my machine to have a very high trigger sensitivity and took a nap and that seems to have helped. The nap was at 15/8.6 and it wasn't too bad as far as aerophagia. No central events or obstructive apneas, but I still feel exhausted. But at least no centrals and no aerophagia.

I might sleep with that setting tonight until I better understand bilevel pap for my specific situation.

I also found this gem from Pugsy - that while going by numbers is somewhat helpful, it has also led me astray before, so...

-

My number one goal has always been good sleep first...feel decent...and not a perfect AHI or beautiful report.

Thanks again for all the input everyone. Hope you all had an ok day, and that this technology may help you to sleep peacefully and restfully.

[Pugsy]

1) So is this still your line of thinking - increasing epap until things sort of fall into place, while not worrying about ipap too much? and EPAP of 13 and IPAP of 8?

2) I guess I'm a little confused on how lowering ipap won't hurt me later in the night, as I'm pretty sure my pressure needs tend to be higher in REM sleep. Wouldn't dropping ipap to 13 result in events in REM that would cause more disturbed sleep? Or is the idea that you don't need as high an IPAP by raising the EPAP because you are catching events before they blow up as you mention in the old post I copied?

1....Yep. Still what I believe in....EPAP to do the hard work and IPAP to help out sometimes but mainly for comfort.

2...My OSA is worse in REM sleep...5 times worse...so I have some personal experience in this area and my pressure needs during REM can sometimes be 6 to 8 cm more than in non REM. REM amounts to about 20% of the night.
Personally I wouldn't be using IPAP to maybe deal with REM event pressure needs in the first place... but even if it did work like you are saying you are using something a lot higher all night just to deal with something that is only needed 20% of the night.
Why over inflate or potentially hyperventilate just to maybe deal with something that only occurs 20% of the night.
Overkill IMHO.

EPAP is the most critical setting no matter what mode of operation anyone is using when dealing with OSA...be it cpap with some exhale relief built in or some sort of bilevel machine.
IPAP can be used to help out a little but it's not the most important setting.

[bonjour]

Think of bilevel this way.


Manual or "S" mode:
EPAP is Pressure in a CPAP, adjust this to treat Obstructive events, the same as a CPAP.
IPAP is used to treat Hypopneas and Flow Limits. it is always the same or greater than EPAP.

Auto Mode:
EPAP is again used to treat Obstructive events, the same as a CPAP. The setting is called EPAP Min. EPAP is adjusted per algorithm and IPAP follows
Pressure Support / PS is used to modify IPAP to manage Hypopneas and Flow Limits.
IPAP Max the IPAP pressure that will not be exceeded.

[Okie bipap]

It may just be coincidental, but I have less asthma problems since I started using the machine at night. I have also had less problems with bronchitis. However, it did not keep me from catching the flu two years straight, even though I had gotten the flu shot. My flu seemed to be much milder than others I know that had it the same years. I went to the doctor as soon as I started feeling bad and was having a little problem breathing. I have learned that when I start having breathing problems, I need to head to the doctor right away. The one time I let it go over 24 hours before going to the doctor, I ended up with pneumonia. Now, as soon as my fever starts and I have even the slightest problem breathing, I am at the doctor's office.

[dogsarelife]

@Fred - Thanks for the explanation and breaking it down for me! Seems you have been around for a while?

@Okie Bipap - Probably some wise advice to go to the doctor when one has any sort of respiratory issues! I am so sorry you have gotten the flu 2 years in a row, but glad that you made it through! I feel that my immune system has strengthened considerably since getting my auto-pap and now bi-level pap. I think OSA affected my breathing in a way that I'm just now starting to feel a major difference with restorative sleep at night?

@Pugsy - Thanks for your help. I took your comments into consideration and then slept last night at 14/9 because in my experience, keeping IPAP at 13 gives me feelings of choking and waking up.

I hope that you understand how much I value your input and educating me, and that my not taking the exact numbers you recommended isn't anything personal - but more that it's much better for me to learn and make mistakes in my slightly hard-headed way than just do what someone says.

So results:

1. Centrals obviously gone- Yay!
2. Aerophagia not too bad
3. Hypopnea coincided with dreams of dying (took my mask off right after to kind of mark it). Don't feel too great today, but perhaps that's sort of expected after the ordeal with trying 17/10 and getting all those centrals and trying to undo the damage of listening to my doctor.

Sleepyhead020719.png (165.77 KiB) Viewed 3097 times

Really wishing I had an auto-bilevel to take care of those 2 or 3 events, but I don't know if I'm being unrealistic?

General question -

How did anyone who has an autobilevel pap convince their doctor to prescribe it? My doctor said "you can't expect sleep to be perfect - you're gonna have some events" - which I agree with. But is it too much to expect not to have these choking / dying dreams? is asking for an autobilevel pap like asking for a rolls royce when a perfectly nice ford taurus will do?

I don't know if it's relevant - but when I have a cluster of obstructive events, like in my sleepyhead around 6 AM, my blood sugar drops and then spikes back up and I get these surges of adrenaline and wake up hot? It's measurable with a continuous glucose meter I got from my endocrinologist, before I connected that these events were caused by OSA.

My blood sugar used to drop really low before bilevel and now it mostly stays flat all night long. And that's how I learned that the sympathetic nervous system getting triggered by OSA events can affect glucose metabolism.... Man what a journey this has all been. thanks for letting me vent everyone.

[palerider]

Really wishing I had an auto-bilevel to take care of those 2 or 3 events, but I don't know if I'm being unrealistic?

Yes, there's no guarantee that an auto would have taken care of those. They may have happened out of the blue without any other issues that an auto would have responded to.

0.5 is great.

General question -

How did anyone who has an autobilevel pap convince their doctor to prescribe it? My doctor said "you can't expect sleep to be perfect - you're gonna have some events" - which I agree with. But is it too much to expect not to have these choking / dying dreams? is asking for an autobilevel pap like asking for a rolls royce when a perfectly nice ford taurus will do?

Well, for me, I just *bought* mine. used.... I wasn't even looking for an auto bilevel, I was looking for an autoset, but found a great deal on a S9 VPAP Auto... and decided I really like it.

As far as a doctor? just finding one that's not a dumbass is all that's required... having an auto *makes sense*, they give you more options, (at the same price when dealing with insurance).

[Pugsy]

Hey...I am good with the 14/9 you elected to use. I don't have a problem with someone not wanting to do exactly what I suggest.

I am just not comfortable with suggesting someone use more that 6 PS unless they have a good reason and they aren't having centrals from the higher PS. Not everyone using higher PS will have centrals pop up...but it's always the first thought when we see someone using a higher than usual PS and having a bunch of centrals. That's why we suggest reducing PS and see if the centrals also reduce.

The most commonly used/prescribed bilevel PS settings coming out of a titration sleep study when only OSA is involved and no other complicating factors is 4 or 5 and occasionally 6.
I have a friend who gets a truck load of centrals with PS of 4 (like 15 per hour) and essentially none at a PS of 3. Go figure that one.
Sometimes there is a very fine line to straddle.

And I agree with PR about it being an unrealistic expectation to think we can totally eliminate all events. Nor do we really need to.
Your doctor is right...we don't sleep the same each night...we don't get the same sleep cycles and we don't stay in one position (most people don't).
It might be that you were in REM when those events got flagged...you might have been on your back or maybe on your back and in REM.
They do sometimes just happen without any warning signs and the machine wouldn't have had time to increase the pressure anyway.
I see it happen frequently and I use an auto adjusting machine. Now I could use a little more pressure (EPAP) to maybe better prevent that from happening but it's rare and I sleep through it so I just don't worry about it anyway.

If you ever want to try auto adjusting....get yourself a used machine like PR says...you are going to want one eventually for a back up machine anyway. I found an AirCurve 10 VAuto on my local craigslist for $350 with only 86 hours on it. It went to a guy in Europe or I would have kept it myself. Good deals are out there if you are patient and just keep looking.

[dogsarelife]

@ Pale rider and @ Pugsy

Thanks for your comments and explanations, so that I don't have to suffer alone. Much appreciated. I will keep what you said about pressure support in mind, Pugsy. I'm guessing this is something that will change over time for me, just a feeling, that things will tighten up as I get better used to the treatment, like Okie bipap's wife.

I am starting to see based on some of the other threads that getting things right with any of our equipment is really a process and moreover an art, not a science.

It seems like the two of you both played around a lot with equipment and settings before settling on something very different than what your doctors initially prescribed.

I've been part of another patient advocacy group that had a list of 40 or so doctors from around the world who the group members had been using and rated highly, and additionally people were constantly giving feedback each year so there weren't duds on the list. and I'm wondering if there's anything like that as far as a list of DMEs or MDs/PAs/nurses per state who really understand the art of setting epap/ipap pressures but also focusing on little tweaks for patient comfort?

Are people allowed to list doctors or clinics that do telemedicine that they found helpful?

thank you and hope you all are having a good Friday.

[palerider]

@ Pale rider and @ Pugsy

It seems like the two of you both played around a lot with equipment and settings before settling on something very different than what your doctors initially prescribed.

That's true for pugsy, her prescription was *way* off. Me, I went rogue from the start, and never subjected myself to the .... "challenges" of "the system", (my brother did the sleep test and didn't give a damn doctor and incompetent DME thing first, and I said "I'll take a pass on that"). I thought myself what to do, using the resources here, and elsewhere on the net. (Mostly here).

While I, like pugsy, have bad nights and poor sleep at times, it's not because of sleep apnea, my year average ahi is 0.19.