AHI NUMBERS

[RAMBLINMAN]

Hi All,

It's been awhile since I posted on here...but still come on to see whats going on, but i just came up with a question.

I guess it's been about a year on cpap and I have a Remstar Auto machine and during the time I've been using it I've downloaded several bits of data...tried running on apap, cpap, with or without cflex.

Also from looking at the data I also tried to always improve my AHI numbers. in the beginning i was doing ok with numbers between 2 and 5.

I also tried doing apap setting to see where my machine would run most of the time during the night (90%). Now my machine's data would tell me that my setting should be higher than what was prescribed.

So I tried setting my unit to theses settings and most of the time I can't really say these numbers made me feel better in the morning.

For example I was prescribed by the doctor 7cm straight cpap. At one time I set my machine as a apap from a range 7 -13 and with this setting it told me 90% of the time it was at 10cm. So I figured lets try raising my cpap setting for a while each time (2 weeks at time ) to 8, then 9 then 10., and then checking to see how my AHI numbers were and to be honest they kept climbing to about an average of 10 - 17.

Unfortuntely I haven't seen my AHI numbers down to 5 or lower in quite a long time.

Would anyone know how true the results from these machines are and if they are reporting that higher numbers should be the settings why it doesn't make me feel better when used?

[Slinky]

Since my sleep pulmo adjusted my pressure up from 6 to 8 after two weeks on an Auto to tweak my settings my HIs have jumped sky high. I won't be seeing him for another couple of weeks - BUT - my theory at this point is that I'm having more air escaping thru my lips. NOT mouth breathing, just the air escaping thru my lips. I'm just a newbie, working on 4 months on PAP so what do I know? Besides I'm still feeling more rested than prior to PAP and not noticing that I'm more tired now than before the pressure adjustment.

How's your leak rate? Compared to your original and lower pressure settings?

[dsm]

AHI & HI/AI numbers are an interesting topic. Based on experiments I have done myself, I can do tests where in CPAP mode I can incrementally raise the CMS setting over a few nights & also see AHI go up.

On bilevels - there are some tests where expanding the gap between epap & ipap causes AHI to start to go up markedly (e.g. at my best setting: 10/13 showing typical 3.0 AHI, at 8/15 showing 40+ AHI, at 10/15 showing 20+ AHI & 10/16 showing 26 AHI).

What this tells me is that playing with pressure settings can be a tricky business - my advice to anyone doing so is to do it in small changes & really only if you are monitoring your nightly data. A Pulse Oximeter can be of great help during any such testing.

One thing to note if you have Resmed machine is that they report higher HI scores than some other brands - this has a bit to do with how they measure air flow (or Minute Ventilation as it is called). The main thing with AHI numbers is to regard them as relative to the brand of cpap you are using & not get bothered about the differences but they do exist.

Ever since I set my bilevel to 10/13, my therapy has been very effective. It took me close on 18 months of experimenting & trying different masks etc: but am feeling it was worth every bit of the time.

Good luck with yours

DSM

[JimW]

When your 90% pressure reading is 10, that means, as I understand it, that your pressure was 10 cm or less 90% of the time, not that your pressure was 10 90% of the time. Not to oversimplify, but if you were getting better numbers (and feeling better) before, why not go back to those settings which allowed those better numbers?

Also, were you doing better on autopap mode than on the higher pressure CPAP? Do you know whether you had significant central apnea events during your study? Others here are much more qualified than I to advise you as to how to proceed, but I suspect you may need to provide more information to allow for this to occur.

[jskinner]

Would anyone know how true the results from these machines are and if they are reporting that higher numbers should be the settings why it doesn't make me feel better when used?

Have you tried using MyEncore or EPA to analyze your Encore Pro data to determine at what pressure you have the least amount of events? The Pressure vrs AHI graphs can be helpful in determining the optimal pressure.

As an example, here is my Pressure vrs AHI graph over a few months:



As you can see this chart makes it pretty easy to determine that a pressure of 9cm is the best.

[Guest]

Can anyone tell me what a central apnea event is and how can I tell if I am getting them?

[lion]

I am using Remstar Auto with C Flex M series and profile lite mask. My A.H.I is 0.3. that is apneas 0.3 and hypopnea nil. Could I suspect tthat I have central apneas also which are not represented by these comparitively good A.H.I. figures. My PSG showed that I have some small number of centrals or mixed apneas. But i AM CONTINUING WITH CPAP MACHINE, BECAUSE I DO NOT KNOW ANY OTHER OPTION. KINDLY HELP ME ON THIS POINT.

[Goofproof]

I am using Remstar Auto with C Flex M series and profile lite mask. My A.H.I is 0.3. that is apneas 0.3 and hypopnea nil. Could I suspect tthat I have central apneas also which are not represented by these comparitively good A.H.I. figures. My PSG showed that I have some small number of centrals or mixed apneas. But i AM CONTINUING WITH CPAP MACHINE, BECAUSE I DO NOT KNOW ANY OTHER OPTION. KINDLY HELP ME ON THIS POINT.

If your AHI is 0.3, you need something else to worry over, as your Apnea is under super control. Whatever you are doing, keep doing it. Jim

[blarg]

What's your NR or Non-Responsive Apnea Score? Centrals that the machine couldn't fix for you would be included in that score.

Being that your AHI is 0.3, which includes Non-Responsive Apneas, you really do seem to have something else going on, but that's where those centrals would show up.

[javaide]

Dear Blarg

My non responsive Apnea Hypopnea score is 0.0. That means I have apnea hypopnea which has not been responded or adressed by cpap machine. Does it mean that I had no central event during the night.

By the way I would also like to state, that the Encore Pro gives the N.R. (non responsive) score only when I am in auto mode. No such figure is given in the cpap mode. As you are an expert engineer in software, could you explain why is this so. Further, I am not able to connect to Encore Pro Analyser. Sorry for so many questions.

[blarg]

It doesn't so much have to do with being a software engineer, so much as knowing what APAPs do, vs what CPAPs do.

A non-responsive apnea means just that. That the machine tried to up the pressure, and the apnea didn't respond to the pressure increase and fix itself. Being that CPAPs don't change the pressure at all, to them, an apnea is an apnea and there's no attempt to make it "respond", thus no non-responsive apneas.

Now what I can tell you is that your NR index of 0.0 is a good thing, but it doesn't rule out centrals entirely. Your centrals could be short enough to not register as NR on your APAP but still be occurring. The only way to know for sure would be a sleep study.

My non responsive Apnea Hypopnea score is 0.0. That means I have apnea hypopnea which has not been responded or adressed by cpap machine.

Actually it means that you did NOT have apneas/hypopneas that couldn't be addressed. (So every apnea/hypopnea you had was resolved by pressure increase, or at least the machine thinks so. That's a good thing.)

So, next question, did they mention centrals on your sleep study? If not, it's a relatively safe bet that you're not having too many issues with centrals. Only way to be sure is a sleep study, and if you're not feeling rested, then that might be a good course of action. At least bringing it up with your doctor would be good. But if you feel good, AHI < 5, NR = 0, then really there's not much to complain about.

As for your Encore Pro Analyzer question, we'll let that unfold in the other thread.