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Wulfman... wrote:

palerider wrote:

Wulfman... wrote:Looking at the amount of flow limitations you're having in proportion to your actual "events", I'd suggest going back to straight pressure and try 8 cm. for a few nights and see what those reports look like.
You've got a pretty good AHI, but if you're getting bumped out of your restorative sleep stages and into lighter ones, the sleep "quality" won't be there.

wulfman refuses to acknowledge that flow limitations *ARE* actual events and *DO*, in and of themselves, disturb sleep, and can contribute to "getting bumped out of your restorative sleep stages and into lighter ones".

You lying piece of .......... You can't stop mischaracterizing and lying about things people say.
You ARE the "forum bully" that many have complained about.........and RIGHTLY SO!

Yes, I KNOW they are actual events (breathing anomalies in the shape of the airflow) which the APAP machine algorithms are programmed to increase pressures in anticipation of POSSIBLE apneas. They're believed to be POSSIBLE clues to impending airway collapses. The algorithm predictions of impending apneas are many times false because of the users' breathing characteristics due to nasal structures. For many users with these nasal structure issues, NO amount of pressure can reshape the airflow and can cause much sleep disturbance from the resulting pressures.


Den

.

RIGHTLY SO is a understatement Been waiting a long time to see a post like this from you!

Did you read what that sick man said to Hawthorne... a woman of nearly 90 years old??!! My God!!

Do you think that FINALLY something will be done here???????? Do you think that flooding the Goodmans with email would help??

Wulfman... wrote:

palerider wrote:

Wulfman... wrote:Looking at the amount of flow limitations you're having in proportion to your actual "events", I'd suggest going back to straight pressure and try 8 cm. for a few nights and see what those reports look like.
You've got a pretty good AHI, but if you're getting bumped out of your restorative sleep stages and into lighter ones, the sleep "quality" won't be there.

wulfman refuses to acknowledge that flow limitations *ARE* actual events and *DO*, in and of themselves, disturb sleep, and can contribute to "getting bumped out of your restorative sleep stages and into lighter ones".

You lying piece of .......... You can't stop mischaracterizing and lying about things people say.
You ARE the "forum bully" that many have complained about.........and RIGHTLY SO!

Yes, I KNOW they are actual events (breathing anomalies in the shape of the airflow) which the APAP machine algorithms are programmed to increase pressures in anticipation of POSSIBLE apneas. They're believed to be POSSIBLE clues to impending airway collapses. The algorithm predictions of impending apneas are many times false because of the users' breathing characteristics due to nasal structures. For many users with these nasal structure issues, NO amount of pressure can reshape the airflow and can cause much sleep disturbance from the resulting pressures.

how can you call it "mischaracterizing and lying" when it's YOUR words (see above) that are separating flow limitations from quote actual "events" unquote? flow limitations *IN AND OF THEMSELVES* are disruptive to sleep, something you don't even acknowledge in your diatribe above.

Doctor Steven Park wrote:... sleep doctors will tell you that by normalizing these flow limitations, sleep quality can be significantly improved.

however, out of respect for your feelings, I'll go back and edit the original post I made.

joannebc,

For what it's worth, this time I agree with Den (aka Wolfman): I'd switch back to straight CPAP for a night or two to see if the leak problem goes away and to see if the Flow limitation graph becomes less cluttered. The fact is that switching to APAP did create some leaks and it increased the activity in the FL graph quite a bit. Since 6cm didn't feel comfortable to you, I'd suggest 7cm instead of 8cm. But then I have a lot of issues with aerophagia, and with your treated AHI, I just don't see the need for more pressure than is absolutely necessary.

In your case, the Flow Limitations were *better* with straight CPAP. And while flow limitations can be "real" in the sense that they really can be a sign of a slightly compromised airway, they can also be misscored (i.e. not real FL) under a number of circumstances. They may be misscored if there is restlessness going on (i.e. they can be part of we call Sleep-Wake-Junk around here) or they can occur when a person has a sinus problem or a congested nose and not represent a real event anyway. Or they can be caused by certain physical anomolies in the nose. And all of these "not-real FsL" do NOT get better with additional pressure But if the machine is detecting false FLs in Auto mode, it still increases the pressure. And if pressure changes are bothersome to the person using the machine, then that can increase the overall restlessness of the user, which can aggravate the SWJ, and that can lead the machine to detect even more false FLs. And you report a lot of restlessness during one of the periods where the FL were at their worst on the APAP night. So it is reasonable to hypothesize that you may be more sensitive to pressure variations than many people are.



To Den and Pale Rider: Once upon a time I was experimenting with opening my PR S1 BiPAP Auto up quite wide to try to determine just how much pressure I would need for my FLI numbers to drop from their usual 2.0-3.0 range to something much lower on the grounds that Sludge (in one of his much earlier incarnations) and -SWS had looked hard at my data and concluded that I might very well have more of a problem with UARS than OSA. I got a belly full of air with IPAP pressures going as high as 14cm (if I recall correctly) and no reduction in FLs. If anything, on the nights with where my average IPAP was much higher than my usual cap of Max IPAP = 8cm, the FL were worse than they usually are, and the aerophagia was much, much worse. At some point during this 2 week experiment I asked the then-current-Sludge incarnation about this and his response was along the lines of "Those FLs may not be real. And even if they are real, given your problems with aerophagia, you're better off tolerating more FL activity than is desired and a lot less aerophagia."

You missed the part I added from an afterthought......

Wulfman... wrote:And, Flow Limitations are so "BAD", that practically NO in-lab sleep studies check for them or make note them in the sleep studies.

Did YOU have any flow limitations noted on YOUR in-lab sleep study?


Den

.

Wulfman... wrote:You missed the part I added from an afterthought......

Wulfman... wrote:And, Flow Limitations are so "BAD", that practically NO in-lab sleep studies check for them or make note them in the sleep studies.

Did YOU have any flow limitations noted on YOUR in-lab sleep study?

I didn't have an in-lab sleep study.

as with many things, pioneers in a field (like Steven Park) find new things (like the significance of flow limitations) and established methodologies like sleep studies catch up in time.

but, you raise a point, and I'll certainly start looking at posted sleep study reports seeing how many do mention flow limitations.

of course, there are a wide variety of sleep study methodologies and a great variation i the reports that they produce.

robysue wrote:joannebc,

For what it's worth, this time I agree with Den (aka Wolfman): I'd switch back to straight CPAP for a night or two to see if the leak problem goes away and to see if the Flow limitation graph becomes less cluttered. The fact is that switching to APAP did create some leaks and it increased the activity in the FL graph quite a bit. Since 6cm didn't feel comfortable to you, I'd suggest 7cm instead of 8cm. But then I have a lot of issues with aerophagia, and with your treated AHI, I just don't see the need for more pressure than is absolutely necessary.

In your case, the Flow Limitations were *better* with straight CPAP. And while flow limitations can be "real" in the sense that they really can be a sign of a slightly compromised airway, they can also be misscored (i.e. not real FL) under a number of circumstances. They may be misscored if there is restlessness going on (i.e. they can be part of we call Sleep-Wake-Junk around here) or they can occur when a person has a sinus problem or a congested nose and not represent a real event anyway. Or they can be caused by certain physical anomolies in the nose. And all of these "not-real FsL" do NOT get better with additional pressure But if the machine is detecting false FLs in Auto mode, it still increases the pressure. And if pressure changes are bothersome to the person using the machine, then that can increase the overall restlessness of the user, which can aggravate the SWJ, and that can lead the machine to detect even more false FLs. And you report a lot of restlessness during one of the periods where the FL were at their worst on the APAP night. So it is reasonable to hypothesize that you may be more sensitive to pressure variations than many people are.



To Den and Pale Rider: Once upon a time I was experimenting with opening my PR S1 BiPAP Auto up quite wide to try to determine just how much pressure I would need for my FLI numbers to drop from their usual 2.0-3.0 range to something much lower on the grounds that Sludge (in one of his much earlier incarnations) and -SWS had looked hard at my data and concluded that I might very well have more of a problem with UARS than OSA. I got a belly full of air with IPAP pressures going as high as 14cm (if I recall correctly) and no reduction in FLs. If anything, on the nights with where my average IPAP was much higher than my usual cap of Max IPAP = 8cm, the FL were worse than they usually are, and the aerophagia was much, much worse. At some point during this 2 week experiment I asked the then-current-Sludge incarnation about this and his response was along the lines of "Those FLs may not be real. And even if they are real, given your problems with aerophagia, you're better off tolerating more FL activity than is desired and a lot less aerophagia."

As a side note to the Flow Limitation and increased pressure scenarios........
I've worked with a number of forum members off of the forum with regard to tweaking their settings because there was so much pressure from "certain members" suggesting that the user just needed MORE pressure and to use wide open maximum settings. Well, in this one case, the more pressure that was added, the greater the Flow Limitations became. It was like a feeding frenzy. The individual had quite high flow limitations (flow limited breathing) among other issues. We finally settled on a fixed pressure of 15 cm. and that seemed to be a pretty good compromise.

I've seen in a number of cases where the Flow Limitations seem to be like a reflex reaction to increased pressures. The person has a series of Flow Limitations, the pressure increases and then the subconscious reaction LOOKS LIKE more Flow Limitation to the machine and the cycle continues till the pressure maxes out.


Den

.

Wulfman... wrote:I've seen in a number of cases where the Flow Limitations seem to be like a reflex reaction to increased pressures. The person has a series of Flow Limitations, the pressure increases and then the subconscious reaction LOOKS LIKE more Flow Limitation to the machine and the cycle continues till the pressure maxes out.

I'm curious, did you examine the flow waveforms to see if there actually were flow limitations, or that it was something else the machine was mistaking as flow limitations?

palerider wrote:

Wulfman... wrote:You missed the part I added from an afterthought......

Wulfman... wrote:And, Flow Limitations are so "BAD", that practically NO in-lab sleep studies check for them or make note them in the sleep studies.

Did YOU have any flow limitations noted on YOUR in-lab sleep study?

I didn't have an in-lab sleep study.

as with many things, pioneers in a field (like Steven Park) find new things (like the significance of flow limitations) and established methodologies like sleep studies catch up in time.

but, you raise a point, and I'll certainly start looking at posted sleep study reports seeing how many do mention flow limitations.

of course, there are a wide variety of sleep study methodologies and a great variation i the reports that they produce.

I know.
And, I was trying to make a point that unless certain situations present themselves, patients are NOT tested for Flow Limitations.
There are many things......structural anomalies, congestion and other circumstances.......which can LOOK like flow limitations to the machines. From a personal standpoint, even though I don't consistently have a lot of FLs, in hindsight, I always thought that I should have been sent to an ENT before my sleep study because none of the doctors asked me "Can you breathe through your nose?" And, like many users, I had always been a mouth-breather prior to therapy.
But, I didn't and haven't and worked around the issue.

It would be interesting to know how many others besides Park and Krakow are focusing on flow limitations (or flow limited breathing). Or, if they're the only ones and the "normal" sleep studies are just "income generators".


Den

.

palerider wrote:

Wulfman... wrote:I've seen in a number of cases where the Flow Limitations seem to be like a reflex reaction to increased pressures. The person has a series of Flow Limitations, the pressure increases and then the subconscious reaction LOOKS LIKE more Flow Limitation to the machine and the cycle continues till the pressure maxes out.

I'm curious, did you examine the flow waveforms to see if there actually were flow limitations, or that it was something else the machine was mistaking as flow limitations?

No. I was not familiar enough with the software and whether that data was available at that time.
But, whatever they were, they kept driving up the pressures and the reports looked like a train wreck.


Den

.

Wulfman... wrote:

palerider wrote:

Wulfman... wrote:You missed the part I added from an afterthought......

Wulfman... wrote:And, Flow Limitations are so "BAD", that practically NO in-lab sleep studies check for them or make note them in the sleep studies.

Did YOU have any flow limitations noted on YOUR in-lab sleep study?

I didn't have an in-lab sleep study.

as with many things, pioneers in a field (like Steven Park) find new things (like the significance of flow limitations) and established methodologies like sleep studies catch up in time.

but, you raise a point, and I'll certainly start looking at posted sleep study reports seeing how many do mention flow limitations.

of course, there are a wide variety of sleep study methodologies and a great variation i the reports that they produce.

I know.
And, I was trying to make a point that unless certain situations present themselves, patients are NOT tested for Flow Limitations.
There are many things......structural anomalies, congestion and other circumstances.......which can LOOK like flow limitations to the machines. From a personal standpoint, even though I don't consistently have a lot of FLs, in hindsight, I always thought that I should have been sent to an ENT before my sleep study because none of the doctors asked me "Can you breathe through your nose?" And, like many users, I had always been a mouth-breather prior to therapy.
But, I didn't and haven't and worked around the issue.

It would be interesting to know how many others besides Park and Krakow are focusing on flow limitations (or flow limited breathing). Or, if they're the only ones and the "normal" sleep studies are just "income generators".


Den

.

when was your last in-lab sleep study?

palerider wrote: when was your last in-lab sleep study?

March 29, 2005. Coming up on an "anniversary" in about 10 days......this month.
Split night study.........AHI of 47.1 and desats down to 66%.
5.0 hrs. total sleep time. 36% Stage 1, 38% Stage 2, 0% Stages 3 & 4, 26% REM


Den

.

joannebc wrote:Well the process of figuring this out is long and hard. I just got my CPAP and was excited that I would possibly have my first night of sleep. Sadly no. I installed the sleepyhead and will insert screen shots. Can someone help? The thought of another 30 days of only sleeping an hour at a time is daunting. TIA!
http://imgur.com/a/SdFgC

I hope you can get some help for this issue. I've been struggling with multiple wakes for a really long time. Only recently have things improved somewhat. Things that have changed with the reduction of wakes from an average of 11 per night down to 4 to 6 or so are: increasing my supplemental O2 to get my nighttime SpO2 up to about 94% and an aggressive walking exercise program that got me up to averaging 30+ miles per week. Some time ago, my neurologist put me on a low dose of gabapentin to see if controlling my RLS/PLMD symptoms better would help. It did.

Keep on with the CPAP therapy and look to other things in you life that may be affecting sleep quality.

Gosh there is a lot of information on this thread. I printed it and will try to learn as much as I can.

Below is last night's data. Restless for 136 minutes, 14 x. I had two "major" periods of uninterrupted sleep 11:09 - 11:54 and then from 2:35 - 3:34. There were a couple of others, but less than 40 minutes each. I did go to an ENT before the sleep lab. The ENT didn't see any blockages or obstructions. I do wake up with dry nose and the feeling of needing to cough. I have the humidifier on 5.

I know I am up when the fit bit marks restless sleep because I get woken up by something. I don't look at the clock unless I use the bathroom, or feel I cannot go back to sleep and wonder how close I am to the time I have to get up.

In the last 2 months, I've been to an ENT, a retina specialist (lack of sleep is giving me tunnel vision), had an MRI on my brain and orbits, ultrasound on my carotid artery, all tests are normal. No one can explain the sleep problem. I was referred to an insomnia specialist who is booking 6 months out... I can't go another 6 months. The thought of that is incredibly depressing. I'm 48, normal weight, had a total hysterectomy 6 years ago, my gall bladder removed 4 years ago, but other than that healthy. I teach and cannot remember my students names. I get lost in my thoughts.

I will adjust CPAP to 7 tonight. What do FLOW LIMITATIONS mean and how do I normalize them?

Hi Joanne,
Don't get discouraged. This sleep stuff is pretty complicated, not very well understood, and highly individualized. In my experience, one has to become as knowledgeable as possible, learning what may affect sleep and apply that knowledge in a methodical manner. Rule out (or in) one or two variables at a time. When making changes, give them time to work. It takes a while for the body to become accustomed to each change. I would give any change at least 3 days or longer to asses the effect.
Most of the time, once AHI is normalized, no one can tell you why you aren't obtaining restorative sleep. They can only suggest things to try. A good example is Pale Rider and Wulfman, who have somewhat opposing views on Flow Limitations and APAP. Both are right and both are wrong. It depends on the individual being addressed.
My advice is to learn all you can, find a sleep doctor that respects your knowledge and will work with you and start the process of eliminating things that might prevent restorative sleep and adding things that might help.
Start with a Google of "Sleep Hygiene" and make sure you are practicing it in the best way possible. Watch out for caffeine in all forms. Make sure you getting adequate exercise everyday. Carefully review all meds and supplements for possible ill effects (nearly all commonly prescribed and OTC sleep meds negatively impact sleep architecture). If you are taking any supplements or meds make sure you need them and they are not negatively affecting your sleep (dose timing can sometimes be an issue). Get your blood tested for deficiencies which might prevent good sleep, like Vit D3, B12, ferritin, magnesium, thyroid function, and a couple others you can find with Google. And lastly, don't obsess about sleep. The more one worries about it, generally the worse it becomes.
To answer your question, Flow Limitations are abnormalities in the flow (inhalation) such that the flow rate curve becomes flattened (limited) at the top generally caused by a restriction somewhere in the airway, You can see the shape of your flow rate curve breaths by zooming in on the chart. The flatter, the more limited. There's a good diagram somewhere, I'll find it and add it later.
Generally Flow Limitations are overcome by adding more pressure, but as we've seen in the discussion above, that could be counter productive. A soft cervical collar may reduce Flow Limitations as well as the type of mask used.
Your sleep charts look pretty good, you can probably largely rule out (except for a few tweaks) respiratory treatment and start looking for the other (unfortunately much harder to find) things that are preventing you from obtaining good sleep. As one of our esteemed members is fond of saying, "You can't fix poor sleep with CPAP".
Good luck and good sleep to you,
j

edit: Here's a good video describing Flow Limitations https://www.youtube.com/watch?v=rmn4noEboCE

palerider wrote:

Wulfman... wrote:I've seen in a number of cases where the Flow Limitations seem to be like a reflex reaction to increased pressures. The person has a series of Flow Limitations, the pressure increases and then the subconscious reaction LOOKS LIKE more Flow Limitation to the machine and the cycle continues till the pressure maxes out.

I'm curious, did you examine the flow waveforms to see if there actually were flow limitations, or that it was something else the machine was mistaking as flow limitations?

If the machine is mistaking something for a FL and raises the pressure and the problem gets worse, it doesn't really matter whether the scored FL is "real" in the sense of being visible in the wave form data or not: The machine is reacting to something it thinks it is seeing and raising pressure.

And when the machine is mistaking something that's not a real FL for a FL in auto mode, the machine raises the pressure inappropriately. If you happen to be a person where the machine is frequently mistaking something that's not a real FL in your breathing pattern as a FL, you can wind up getting a lot of unneeded pressure increases from the machine. And if whatever it is that the machine is misreading as a FL is a reaction to the pressure, the problem can get worse as the pressure increases.

That has happened to me when I've opened up the max IPAP on my machine as an experiment in an effort to reduce my FLI. With the result of a whole lot more aerophagia and no reduction in scored FL. As for whether these FL are "real" or not, the changes in the waveform data needed to score a FL can be very subtle. Sometimes I see stuff that looks like a FL and sometimes I don't.

It's important to remember that as good as our full efficacy data machines are, they're not perfect. I've had Hs, OAs, and CAs, scored that when I look at the data, I go "Huh? Why the heck does the machine think it's seeing something there? More rarely I see chunks of breathing that look pretty ragged to me, and there's not scored event anywhere in sight and I wonder, why didn't the machine score that as a <something>? Sometimes drilling down a bit further answers the question---often the thing that I think is a missed event is more like 7-8 seconds long rather than the needed 10.