How do I fix AHI ???

[sleepyangler]

The best thing I ever did with my resmed auto cpap was replace it with a sandman auto. First one had no way of changing what the manufacturer thought would work for everyone; the sandman lets me tailor the machine to my therapy. The A10 algorithm simply didn't respond to my apneas over 10cm and yes I wasted the $200+ on the software and reader. The sandman does a much better job for me and I can see it on the software that cost a fraction of what resmed charged.

[ozij]

OK, the UBB code is too complicated with multiple layers of quotes to keep up with individual points.

However, everything I posted is what Resmed has up on their site currently, regarding the Autoset II.

So is this:
http://www.resmed.com/en-us/patients/tr ... u=products

How do AutoSet devices know to adjust pressure?
After you fall asleep and your pressure needs begin to vary, your AutoSet device responds to three separate parameters: inspiratory flow limitation, snore, and apnea. AutoSet devices act pre-emptively by increasing pressure in response to inspiratory flow limitation and snore, both of which typically precede obstructive apneas. The AutoSet device calculates the pressure you need based on the severity of the event. This early intervention prevents obstructive apneas and reduces respiratory arousals.

How do the AutoSet devices handle hypopnea events?
AutoSet devices respond to obstructive hypopnea events when they are associated with flow limitation or snoring. Hypopneas that are central in origin (related to your central nervous system, not physical obstruction) should not be treated with increased pressure.

In addition, I have a Resmed Autoset machine, and it does respond to hypopneas. Unless we want to say the software is not correct, in which case all bets are off. My sleep study claimed all of my hypopneas were obstuctive, which is the opposite of what the expert you quote above claims. [/quote]
The man who designed the machine designed it not to respone to hypopneas. The autoset algorithm has not changed. It responds only to flow limitations, snores and apneas. The designer may have been wrong in his assumptions, but that's the way the machine's algorithm still works.

I may be wrong about that, but, as far as I know, ResMed's software does not ever show you the flow limitations or snores it responds to, unless you use the Reslink module.

As to whether I have a misconception about how long it takes to respond, the Resmed raises the pressure in response to flow limitation, which occurs before the apnea, so it CAN respond to prevent the apnea.

No argument about that - Auto attempt to prevent events, to preempt event, and to raise pressure after an even has been identified.

But it only raises the pressure in a set pattern, .2 every so many seconds, so if the apnea only lasts 10 seconds, then it may not respond quickly enough to prevent that particular apnea, or at least to prevent it completely. It may shorten the span. I'm sorry, I don't have the quote, and I think at this point it is better to read entire pages of information, rather than quotes out of context. I do see patterns on my data that completely support this. I don't know as much about how the Respironics work, but that is how the Resmed does. There is plenty to read on the Resmed site, some of it older, some more current.

Reading articles and patents is a great way of learning how the machines work, and I did suggest you read the full article I quoted from. I also gave you the link to the article.

This is what you reported about your therapy on another thread:
viewtopic.php?f=1&t=40009&p=350154#p350154 (the full text is there)

I started out with the recommended auto pressure of 4-15, but quickly found that was not doing it. I was having higher AHI than during my study, including much higher AI, and I figured it just wasn’t moving fast enough to correct the apneas. I moved the lower setting up to 7, where I was titrated. Over the last month, I have bumped it up to 8.4, watching how things go. For a couple of weeks, I have had lung issues after a chemical exposure that caused serious inflammation in my lungs and sinuses. I am thinking that made things worse, but it is also a common experience for me, at least at lower levels, as I am very sensitive to inhaled chemicals and fragrances. So I can expect to have periods of respiratory tract inflammation.

You alse added that your 95th percentile is at a pressure of 9.
Therefore, your statements about what you see in your own software, if it refers to the way your machine behaves at a prerssure above 10, is based on the 5% of the time that your machine is above 10. There is a less than 5% chance for you to see your machine applying the A10 algrorithm.

Whether or not this is the best machine for Protageegal, I can't say, but I think without more data, nobody can.

True. Nobody can say whether or not the ResMed is the best machine for Portageegal, withuot more data.

Speaking of interpretations: When my brother was a kid, he misinterpreted the speed of a scooter, and the scooter hit him. My dad picked him up, put him in the car and took him to the hospital (my brother had two bad cuts). My brother's inteprataion was wrong.
So was the interpretation of my classmate and neighbor who came to school late and told me my dad had run over a child, and then put him it his car to take care of him (my dad is a doctor).

Not all interetations are equally valid. Therapy has to based on valid interpretation of reality. The more facts we gather, the better chance we have of finding interetations that fit reality.

O.

[riverdreamer]

Ozij, not sure what I said to piss you off, but I am sorry if it has hijacked the thread.

[ozij]

The topic is Carol's high AHI. Carol (Protageegal)'s machine is a Remsed Auto, whose pressure is set at 10-14.

I consider an AI of 6.6 too high. Add to that an HI of 9.2, and I understand why you feel frustrated, Carol.

To return to where the topic started:

My leak rate was 0.0 last night, with a pressure of 12.8. My AHI was 15.8 with the AI 6.6 and HI 9.2. What do I do? My pressure is set for 10-14 on auto. I have the S8 auto and a quattro FFM. I am so damned frustrated. I feel a lot better than before, but really crave that perfect AHI. My sleep study AHI was 58.7.
Carol

And this was - and still is - my response.

Protageegal,
On Resmed machines, the machine will never respond to hypopneas (at any pressure), and when the pressure is above 10, the machine will respond to apneas only if they are acompanied by snores or flow limitations. If you happen to have eliminated snores and flow limitations with your minumum pressure, then you're up against the stream without a paddle when an apnea happens.

Which leaves you with two options on the Resmed:
Set the minimum pressure to eliminate most of your apneas - that would either be your Rx-ed pressure, or the machine's 95% reccomendation.
Alternatively:
Drop the minimum pressure so that you have flow limitations and snores to drive the pressure up where apneas never happen. It's a slightly paradoxical option - I can imagine it won't work often - and I've never had a Resmed machine and so have never tried it - but it is a logical option.

Other autos behave differently.

O.

Whether 12.8 is your average pressure, or your 95% pressure the 10-14 is not not doing what it should. If your 95% recommended pressure in close to 14, then moving the maximum upwards may help. On the other hand, if 12.8 is the 95% recommended pressure, then a drop to less than 10 may help be supplying the proper triggers for the machine to preempt apneas.


O.



O.

[Portageegal]

Now I'm frustrated AND confused. All this mathematical talk is over my head.

[ozij]

Ignore the mathematical talk.

What was the pressure they recommended for you after your sleep study? Look for it in your PSG report.

When you look at your machines, can you identify which pressure is average and which is your recommended 95% of the time?

Post the both.

We need three numbers:

The pressure recommended after your sleep study
The average pressure you machin reports
The recommended 95% of the time pressure your machine reports.

O.

[KengEsq]

My leak rate was 0.0 last night, with a pressure of 12.8. My AHI was 15.8 with the AI 6.6 and HI 9.2. What do I do? My pressure is set for 10-14 on auto. I have the S8 auto and a quattro FFM. I am so damned frustrated. I feel a lot better than before, but really crave that perfect AHI. My sleep study AHI was 58.7.
Carol

Hi Carol,
Everybody is different. My titrated pressure was 7 cmH2O and I started on the S8 Elite II CPAP but that failed to control my numbers so I was switched to the S8 AutoSet II as you are using. My pressure range is now set for a minimum of 8 cmH2O to a maximum of 18 cmH2O. My results are great. Typically, my AHI is now less than 5.0 (usually 3.9 or less) and my AI is now usually less than 0.5. My 95% pressure is typically around 12.2 cmH20 (shows you the accuacy of my sleep study). My leak rate is under 0.2 L/s - often 0.
If you know how to adjust your minimum and maximum pressure settings, why not give it a try with a wider range starting at or 1 cmH2O above your titrated pressure and your maximum pressure set 10 cmH2O above your minimum pressure. I also use the EPR set to level 2 (reduces the pressure 2 cmH2O on exhale) and an H3i humidifier. If you are not using EPR, if you know how to adjust your pressures using the Clinical Menu, you can also turn on EPR and set it to 1, 2 or 3.
Good luck.

[KengEsq]

Ignore the mathematical talk.

What was the pressure they recommended for you after your sleep study? Look for it in your PSG report.

When you look at your machines, can you identify which pressure is average and which is your recommended 95% of the time?

Post the both.

We need three numbers:

The pressure recommended after your sleep study
The average pressure you machin reports
The recommended 95% of the time pressure your machine reports.

O.

The S8 AutoSet II does not report the "average" pressure on the LDC screen. For that you need the ResScan software and card reader. It does report the 95% pressure on the LCD and if you read the LCD while using the APAP it will tell you the current pressure. When I wake and before I take off my mask I look at the LCD for the current pressure and it is usually 10.4 give or take a few tenths. My ResScan software reports my "average" (median) pressure at 10.4 so I expect one can get a good idea of the median pressure by checking the LDC reading before taking off the mask in the morning after awakening.

[KengEsq]

Now I'm frustrated AND confused. All this mathematical talk is over my head.

One more thing to keep track of - your usage. When checking the LDC readouts, check your usage per night. I also recommend keeping a log of your numbers each day so you can see patterns to make any needed adjustments. All of those numbers can be found on the LDC screen but they only remain available until noon each day. Hopefully, you have learned how to navagate around on your APAP to get your numbers. To get a good idea of your median daily pressure, each morning after you awake but before you remove your mask and turn off the machine, look at the LDC and see the pressure currently being provided.
Even though I have the ResScan Software and card reader, I still keep my daily log. I record the following information each morning:
3/14/09 Leak = 0.10 L/s
AHI = 3.9
AI = 0.2
HI = 3.7
Use = 7.34 hrs
95th percentile pressure = 12.2 cm H2O
I copied the above directly from my log (I keep it by writing the numbers each day and then put those into a file I keep on my computer). Since you do not have and probably do not need the Software and card reader, you might want to add one more number on your daily log: "pressure upon awakening."
Good luck and don't let these things trouble you. You will get the hang of it all as you go on with your treatment.

[riverdreamer]

Carol, you said you usually see a pressure of between 11-13. If you raise your lower pressure, which is currently 10, to closer to the number you see most (between 11-13), you will probably see an improvement in your numbers.

You MAY also want to raise the upper limit, so that the machine can respond if you need that much pressure. But it helps to find what works if you make one change at a time. I find when using my Resmed that it works better if the lower setting is close to what works most of the time. For you, that seems to be somewhere between 11-13. You could raise a it a bit at a time if you want, and watch the results for a week or so, and raise it again if needed.

[ozij]

Thank you, Ken for the information about the numbers on the LCD.

I have meanwhile discovered from you previous posts (on other threads) the you've tried a minimum of 6, Carol, and resuts were not too good either.

Carol, you said you usually see a pressure of between 11-13. If you raise your lower pressure, which is currently 10, to closer to the number you see most (between 11-13), you will probably see an improvement in your numbers.

You MAY also want to raise the upper limit, so that the machine can respond if you need that much pressure. But it helps to find what works if you make one change at a time. I find when using my Resmed that it works better if the lower setting is close to what works most of the time. For you, that seems to be somewhere between 11-13. You could raise a it a bit at a time if you want, and watch the results for a week or so, and raise it again if needed.

I also think those are the steps to be tried now.

O.

[Portageegal]

Okay ..... I put the pressure range back to where the dr. recommended in the start. 6 -14 Last night my usage was 8.36 hrs, which is pretty normal for me.

Pressure 13.4
LEAK 0.0
AHI 19.6 (highest ever)
AI 9.
HI 10.6

My monthly figures are:

Pressure 11.6
Leak 0.6
AHI 14.4
AI 5.3
HI 8.8


Last night was the first time I woke myself up snoring since being on APAP. I used to be the champion snorer in a house with 36 people.
I'm stumped. It seems whatever advice I follow I can't improve the numbers. I feel better than before, but the #'s suck.

[riverdreamer]

Carol, as I said above, I think you will do better if your lower pressure limit is somewhere between 11-13, which is the average pressure you were seeing. I have found I do best if I keep the lower end of my pressure set at the number that my data shows I need most of the time.

Trying the pressure of 6-14, and seeing your results, makes me think even more that you need to raise the pressure, not lower it. I don't think it can get from 6 to the pressure you need fast enough. So, for example, setting it to 11-14. Then watch it for a week or two, because other factors can impact the results. If that is better, but still not good enough, then you could raise the lower number again. If it is worse, then you could try lowering it slightly.

[KengEsq]

Okay ..... I put the pressure range back to where the dr. recommended in the start. 6 -14 Last night my usage was 8.36 hrs, which is pretty normal for me.

Pressure 13.4
LEAK 0.0
AHI 19.6 (highest ever)
AI 9.
HI 10.6

My monthly figures are:

Pressure 11.6
Leak 0.6
AHI 14.4
AI 5.3
HI 8.8


Last night was the first time I woke myself up snoring since being on APAP. I used to be the champion snorer in a house with 36 people.
I'm stumped. It seems whatever advice I follow I can't improve the numbers. I feel better than before, but the #'s suck.

Hi Carol,
Interesting numbers. I also think you need to adjust your pressure range and you might also try the EPR at a setting of 2. The problem is you need to stick with one set of settings for awhile to really get a feel for what, if any changes, you might want to try. I believe you need to keep trying with one set of settings for 4 to 7 days before making any changes. However, if your 95% pressures are averaging 11.6 and the nightly 95% pressures are as high as 13.4, you might try a low setting higher than your current 6 - say something between 8 and 9 and a high setting well above the 95% pressure of 11.6 - say 16 to 18. If you are sleeping on your back, you might also try sleeping on your side.
Let us know what you try and how you do.

[Hoover]

Hi,
I traded my cpap for an apap because I thought that would give me greater flexibility in treatment. I had used the cpap for about 2 weeks and was getting decent numbers - as I recall my AHI was around 5.0. When I tried the APAP with the doctor's suggested range my AHI went up considerably - I don't remember the numbers now. I consulted with the doctor and reset the machine myself to other ranges with no improvement. I put the machine in CPAP mode and my AHI dropped again and now it is usually 1.0 or less. You might want to try your machine in CPAP mode to see what that does for you.

Best wishes,

Hoover