AHI question...

[LaurieJ31981]

I have been on CPAP for 8 weeks now... The lowest my AHI has been is 4.8. Normally it ranges between 6 and 14. I finally after 8 weeks seen my sleep Dr. She asked if I feel any better, and of course I do... My original AHI was 113... so I am feeling atleast 80% better then I ever have. She told me to ignore the numbers, just go by how I feel, and I don't have to see her again for a year.

However, I can't just ignore the numbers... It's more or less, I NEED to see a number under 5, or else I get discouraged and upset. I do take into consideration that ResMed machines do read a higher HI number then what it actually is... It's still discouraging.

The Dr knows I have info on the machine and can change the settings... she told me to change the pressure from 10, to 8... during titration 8 seemed to eliminate apneas... however when she sent in the script she put 10... 10 made me feel ok, but my numbers were still high and I was having a lot of discomfort in my lungs and ribs. So I tried 8, that didn't feel like enough... bumped it up to 9 and that's where I have been keeping it. Numbers are still the same though... I feel the same, getting about 8 hours of sleep.

My question is... Even though I have changed the pressure, why does the AHI stay in the same number range? I kept a journal starting 7/23 here are some of the numbers...just for an example

7/23/09
AHI-13.0
AI- 1.8
HI- 11.2
Leak- 0.10 l/s

7/24/09
AHI- 14.2
AI- 1.4
HI- 12.8
Leak- 0.06 l/s

7/25/09
AHI- 6.4
AI- 0.6
HI- 5.8
Leak- 0.00 l/s

[DYNE540]

1. Are you using the resmed software to get a better picture of what's going on?

2. are there any leaks? if so, you have to fix them if they are significant.

3. is your mouth open during sleep? sometimes dry mouth can tell you if that's the case.

[LaurieJ31981]

1. Are you using the resmed software to get a better picture of what's going on?

2. are there any leaks? if so, you have to fix them if they are significant.

3. is your mouth open during sleep? sometimes dry mouth can tell you if that's the case.

I don't have the software right now, hopefully when I have some extra money I can get it...

I rarely have a significant amount of leaks, for the most part the seal on the mask is great. I am however trying my Mirage Quattro tonight, for the 2nd time. First time my AHI was 40, so I stopped and went back to the Nasal... when I use the Nasal, I tape my mouth shut... So the mouth opening is not an issue... But the Dr. said try the FF one again, and not to worry about my numbers, if I feel good then keep using it...

It's all frustrating, yes I feel great. But when I hear your AHI should be 5 or below, mine never is... every once in a blue moon... Maybe that's just how it's going to work for me... I may not see below 5 consistently... I just wish I knew why.

[Pugsy]

It's all frustrating, yes I feel great. But when I hear your AHI should be 5 or below, mine never is... every once in a blue moon... Maybe that's just how it's going to work for me... I may not see below 5 consistently... I just wish I knew why.

Could you tell any difference in the way you felt the next day in the days where you had 12 AHI and the 6.4 AHI?
Anything that you noticed that might account for the AHI difference from one night to another? Leak maybe just a little more?
Do you know if sleep position impacts events?

[LaurieJ31981]

It's all frustrating, yes I feel great. But when I hear your AHI should be 5 or below, mine never is... every once in a blue moon... Maybe that's just how it's going to work for me... I may not see below 5 consistently... I just wish I knew why.

Could you tell any difference in the way you felt the next day in the days where you had 12 AHI and the 6.4 AHI?
Anything that you noticed that might account for the AHI difference from one night to another? Leak maybe just a little more?
Do you know if sleep position impacts events?

Last night I went to bed at 10:30pm woke up at 6:30am wide away and ready to go, my numbers last night were
AHI- 8.2
AI- 3.3
HI- 4.9
Leak- 0.00 l/s

But then again I slept for a full 8 hours, only turned over twice... I think sometimes I roll onto my back, and maybe thats when the apneas and hypopneas start. I think I pretty much always feel the same, I wake up yawning, still feel tired but not enough to fall back to sleep. The strange thing, when I tried the Quattro for the first time and had an AHI of 40, I was less tired then having an AHI of 6 or 12 with the Nasal.

[Pugsy]

But then again I slept for a full 8 hours, only turned over twice... I think sometimes I roll onto my back, and maybe thats when the apneas and hypopneas start. I think I pretty much always feel the same, I wake up yawning, still feel tired but not enough to fall back to sleep.

I woke up sometime last night on my back with mouth open and dry mouth. I thought Oh, boy, tonight's data is going to be ugly but overall it really wasn't. AHI was 2.7. I am almost always 95% AI and very minimal HI. My reports showed only a moderate zipper leak for not very long (no large leaks at all) but a couple more events noted during that time (no clusters though). Still not huge amounts though and the overall average leak was acceptable (I use an auto unit an pressure varies so the flow rate will vary a bit.

When I first started the CPAP thing I had AHI's in the 7-9 range until I got my software. I felt awful. It wasn't till I got the software and increased my pressure from 8 cm to 10 cm that I got my numbers down and felt the improvement.
Since then I have only had one night about the 5 AHI and that one hit 10 AHI. Strangely enough I felt decent that day and no headache. The usual morning head ache is sort of my gauge on how I feel. That is why I asked how you feel overall with the 2 sets of numbers.

We all know that sleeping on our backs can make the events worse. We all know in theory that the ideal pressure setting will take care of those events should that happen. I have noticed that sometimes I need 12 to 14 cm to get some little groups that could very well be happening on my back. I call them my stubborn events since I can't blame them on leaks. I try to stay on my side because I don't open my big mouth on my side but I do a lot of tossing and turning. I have come to accept the fact that staying completely in one position is just not going to happen for me.

Is there any way to get your DME to let you trial an auto unit just to see if sometimes you need higher pressure??
I am worse in REM sleep. I can pretty much spot REM sleep on my reports with the pressure needed increase.
Maybe you just need a little more pressure sometimes?? You may need that 10 cm.. How long has it been since you tried 10 cm? Was it at the start of CPAP while first learning? Getting leaks managed?

Without the software data it makes a hard problem even more difficult to try to solve. We have really only 2 variables to play with. Leaks and pressure. If leak issues aren't the problem, guess what is left?

[rested gal]

However, I can't just ignore the numbers... It's more or less, I NEED to see a number under 5, or else I get discouraged and upset. I do take into consideration that ResMed machines do read a higher HI number then what it actually is... It's still discouraging.

You say you take that into consideration (which you should), yet you speak of a NEED to see a number under 5. I'm not sure how to convince you to get past that "Need"... but trying to compare the AHI numbers from ResMed machines with the AHI numbers from other brands of machines is somewhat like trying to compare apples and oranges.

A person can be getting EXACTLY the same good, effective treatment from a ResMed machine that shows them an AHI of 9.5 (when the AHI is made up mostly of a high HI number and very low AI number) as they would be getting from a Respironics machine displaying half that AHI number.

yes I feel great. But when I hear your AHI should be 5 or below, mine never is... every once in a blue moon... Maybe that's just how it's going to work for me... I may not see below 5 consistently... I just wish I knew why.

That's absolutely great that you feel great, Laurie! That's what it's all about, isn't it?

The "why" (regarding the AHI you see) has to do with where each manufacturer chooses to draw that imaginary line in the sand for calling a flow limitation a "hypopnea."

When you read "your AHI should be 5 or below" -- that statement DOESN'T APPLY TO RESMED MACHINES, in my opinion. With a ResMed machine, if the AI (apnea index) is extremely low and it's the HI (hypopnea index) making up the bulk of the AHI number, I'd say "Your AHI should be below 10 with a ResMed machine." Only then would you be really comparing AHI's between ResMed and Respironics machines, imho.

If you're going to compare AHI's between various brands of machines, you really must take into consideration that each manufacturer uses his OWN DEFINITION of "hypopnea" -- and that definition is different from one manufacturers to another. The different definitions are going to yield different identifying and reporting results. And that's perfectly ok.

I think you should either quit looking for "5", or else convince yourself to chop the HI that you see in half, then re-add your AI and HI (the new chopped one) together to see an AHI that can be more realistically compared (imho) to the AHI you'd be seeing from other brands of machines.

That doesn't mean one brand is right about the HI and another wrong.

It doesn't mean that one brand misses hypopneas that another brand sees.

It doesn't mean that one brand "over-reports" hypopneas or that another brand "under-reports" them.

It's purely a matter of definition of "hypopnea." None of the manufactures uses the same definition of "hypopnea" that is used in a full PSG sleep study anyway, so I'd not worry it.

Enjoy the fact that you're feeling great. Mentally cut the ResMed HI (hypopnea index) in half and do some re-adding, if you want a more realistic comparison of your AHI to the "ought to be under 5" AHI that people who are using Respironics machines often talk about.

Chart posted by Velbor showing the differing definitions used by the different manufacturers:
April 2, 2009
viewtopic.php?p=356255#p356255


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[LaurieJ31981]

I feel much better now... Thanks for all the great info

I guess if I cut the HI number in half my numbers aren't so bad after all...

I used the Quattro FF mask last night and from 1:30 to 6:30 my AHI was 47 and I was snoring...

Back to the Nasal mask for good... I am no longer going to complain about taping my mouth shut lol.

Thanks again It's appreciated.