Is a 0 AHI score actually possible ?

General Discussion on any topic relating to CPAP and/or Sleep Apnea.
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dsm
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Is a 0 AHI score actually possible ?

Post by dsm » Thu Sep 25, 2008 3:37 pm

I started this thread after doing some research on how different machines say they score AIs & His and comparing different models within the same brands. Some of the conclusion I reached included

1) that a machine that scores a 0 AHI may be failing to record properly
2) that those that seem to record AHIs when we feel we have slept very well, may be very sensitive to changing sleep

One question I want to pose is ...

"is it realistic for *anyone*, (diagnosed with apnea or not) to archive a perfect 0 repeatedly"

The case against anyone achiving perfect 0 scores from what I see, is that everyone moves or adjusts a bit during the night for a variety of reasons - partner disturbs you - feeling cold - feeling hot - cat walks on you - noise disturbs you - days events or days meals may affect you - REM sleep may cause shifting.

When people move they tend to momentarily change their breathing pattern & it seems some machines can & do interpret this as an event & record it.

So to start the debate, I repeat "is a zero AHI score, for anyone, unrealistic" ?

DSM
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Re: Is a 0 AHI score actually possible ?

Post by Wulfman » Thu Sep 25, 2008 3:59 pm

dsm wrote:So to start the debate, I repeat "is a zero AHI score, for anyone, unrealistic" ?
Not at all. So far this year, I've averaged about one a month. I think last December I had about three in one week. Even rarer (for me) is to have ZEROS in ALL three categories......especially Snoring......but I HAVE managed at least one night when they were all zeros this year. I may have had more, but I usually don't pay that much attention to the snore index since it's low anyway. And, keep in mind that this is with at least three Legacy models that I rotate and with different firmware levels.

DreamStalker "claims" to have many nights of AHIs of 0.0's. Others have mentioned frequent nights of ZEROS, too.

Den
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Catnapper
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Re: Is a 0 AHI score actually possible ?

Post by Catnapper » Thu Sep 25, 2008 4:04 pm

My machine frequently records nights of 0.0 AHI. So that is definitely possible. Is it accurate? Maybe that is the question. I had a week recently where every night was 0.0. That was not the usual, although I generally do have one or more 0AHI nights a week.

This does not happen if I change masks. My AHI goes up as do the leaks. The Headrest works best for me.

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dsm
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Re: Is a 0 AHI score actually possible ?

Post by dsm » Thu Sep 25, 2008 4:13 pm

I guess a variation of the question might be.

"Is a machine that scores 0 AHI actually accurate ?"
combined with
"Would someone who is diagnosed as not having apnea, score zeros ?"

I suspect the answer to the second point above is no but that is open to debate. I strongly suspect
that everyone if monitored (that is monitoring their respiration & not applying any PAP) would score
some HIs & some may also score AIs yet be considered as not having apnea.

DSM
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Re: Is a 0 AHI score actually possible ?

Post by Wulfman » Thu Sep 25, 2008 4:29 pm

dsm wrote:I guess a variation of the question might be.

"Is a machine that scores 0 AHI actually accurate ?"
combined with
"Would someone who is diagnosed as not having apnea, score zeros ?"

I suspect the answer to the second point above is no but that is open to debate. I strongly suspect
that everyone if monitored (that is monitoring their respiration & not applying any PAP) would score
some HIs & some may also score AIs yet be considered as not having apnea.

DSM
You're getting to sound like my sleep doctor......

Like I've said before, after thinking through my situation, I'm of the opinion that most of my problem was in my nasal passages when I slept. They closed up and then I'd mouth-breathe and then suck my tongue back and seal off my airway. With the nasal irrigation and cold humidification, my nasal passages stay open. I only have a couple of apneas in any given week and sometimes go for weeks without one. A night with more than one apnea is rare and more than that is extremely rare......always has been according to three-plus years of my reports.

Den
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dsm
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Re: Is a 0 AHI score actually possible ?

Post by dsm » Thu Sep 25, 2008 5:11 pm

Den,

If we put what the machine report says to one side (allowing that different brands just don't agree)

Do you think that a person not diagnosed with apnea, would score HIs & perhaps AIs just in normal sleep.

What is in the back of my mind here is the constat comment we hear that an AHI of 5.0 scored in a
sleep test, is considered normal. Thus am leading to the issue of is zero possible - I know that some
machines will score zero, but then we have to say d we believe that score allowing the other point that
few brands will score the same.



DSM

PS I think you are one among us who probably knows your cause / effect better than your doctor does
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gasp
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Re: Is a 0 AHI score actually possible ?

Post by gasp » Thu Sep 25, 2008 5:51 pm

We could get really into this and wonder if zero on one machine is zero on another? Unless we could have the two machines hooked up to one person at one time, we'll never know : )

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Snoredog
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Re: Is a 0 AHI score actually possible ?

Post by Snoredog » Thu Sep 25, 2008 6:00 pm

my opinion:

possible but NOT sustainable
someday science will catch up to what I'm saying...

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Re: Is a 0 AHI score actually possible ?

Post by Wulfman » Thu Sep 25, 2008 6:03 pm

dsm wrote:Den,

If we put what the machine report says to one side (allowing that different brands just don't agree)

Do you think that a person not diagnosed with apnea, would score HIs & perhaps AIs just in normal sleep.

What is in the back of my mind here is the constat comment we hear that an AHI of 5.0 scored in a
sleep test, is considered normal.
Thus am leading to the issue of is zero possible - I know that some
machines will score zero, but then we have to say d we believe that score allowing the other point that
few brands will score the same.



DSM

PS I think you are one among us who probably knows your cause / effect better than your doctor does
First one....."yes".

Second one......I THINK the "5.0" number (as has been suspected by some of us in previous discussions) is a number that was determined by the insurance industry (with the help from the medical community). In the case of "older" people.....Medicare guidelines (as I understand them) uses a number of "15.0" as their magic number.

Den
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dsm
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Re: Is a 0 AHI score actually possible ?

Post by dsm » Thu Sep 25, 2008 6:05 pm

Gasp,

The other aspect of this is - by striving for zero AHI is it kind of a pointless goal - if someone has an AHI of say 3.0 irrespective of brand, are they in fact already as normal as most of the population

Snoredog

Yup that could well sum it up

DSM
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dsm
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Re: Is a 0 AHI score actually possible ?

Post by dsm » Thu Sep 25, 2008 6:11 pm

Den

That 15 number is an interesting one - hadn't heard it before but it makes sense to me. I just hope I can
keep well below that particular number.

My SV machine on an average night gives me an HI of 0 and an AI of 1.0 even if there are only 4 marks on the AI chart for the night.
If there has been some daytime activity (been drinking or eaten a rich meal) the AI can go up to 2.0 & HI may hit 1.0

I tend to think that many of the scored AI marks reflect me turning over in the night rather than a genuine AI (zero flow ) AI event
and thus am inclined to think that anyone would score AIs & some HIs on some machines.

DSM
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Morebirdies

Re: Is a 0 AHI score actually possible ?

Post by Morebirdies » Thu Sep 25, 2008 6:14 pm

It's not possible for me with my machine...not even close.

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Re: Is a 0 AHI score actually possible ?

Post by freepostg » Thu Sep 25, 2008 6:48 pm

I've hit 0 ai's but never 0 hi...again, resmed's generally speaking tend to be a little more sensitive on the h.i. side...I'm thinking they mark the slightest shortened breath as a hypopnea...who knows. My best h.i has been 2-3 on my vantage with a 0 a.i.

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Re: Is a 0 AHI score actually possible ?

Post by Wulfman » Thu Sep 25, 2008 7:17 pm

dsm wrote:Den

That 15 number is an interesting one - hadn't heard it before but it makes sense to me. I just hope I can
keep well below that particular number.

My SV machine on an average night gives me an HI of 0 and an AI of 1.0 even if there are only 4 marks on the AI chart for the night.
If there has been some daytime activity (been drinking or eaten a rich meal) the AI can go up to 2.0 & HI may hit 1.0

I tend to think that many of the scored AI marks reflect me turning over in the night rather than a genuine AI (zero flow ) AI event and thus am inclined to think that anyone would score AIs & some HIs on some machines.

DSM
One has to take into consideration that these machines use airflow sensors and their internal programs (algorithms) to report what's going on in our sleep. Once I learned more about how these things work and accepted the fact that a number of these "events" are related to being awake and tossing and turning, etc., I quit worrying about it. Personally, I've never TRIED to achieve the lowest number I could. When I initially reset my machine to 10 cm. from my prescribed pressure of 18 cm, I was trying to find a pressure I could START with (18 was a lot of pressure to try to get used to). Since I had the software, I knew that I could adjust it from there. Well, lo and behold, after a couple of nights, my AHI was dropping below 1.0. It wasn't consistent, but it gave me pause to think that maybe the sleep study had been flawed. So, I kept it there for about a year and watched my AHI become more consistent (averaging 1.0 or less every month). It was only after that 1-year mark that I decided to see what some other pressures would do. I then went to 12 for a little while and then back to 11. It was about this time when I acquired my first Auto, so I set it in the range of 10 - 15 for one week. During that time, my AHI was slightly over 1.0, I was waking up more during the night, I only got to 15 for a minute and a half on one night and it looked like 12 cm was my best pressure (mainly to take care of the detected snoring). So, that's where it's been ever since.....July of '06. Curiously, my AHI numbers are statistically identical at all three pressures, but "12" is the number where I got rid of the snoring (nasal sounds).
Sure, I like to SEE a 0.0 on my reports in the mornings, but there are many nights when I can tell that I've slept "deeper" and it's confirmed when I see something like a 1.5 AHI on the report.

So far this month, I've only had three nights when my AHI went slightly over 1.0 and a total of 8 apneas in 7 nights scattered throughout. AHI this month, so far, is 0.7 and year-to-date is 0.6......not that I'm keeping track or anything.

Den
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Re: Is a 0 AHI score actually possible ?

Post by Goofproof » Thu Sep 25, 2008 7:52 pm

AHI of zero is obtainable, as long as you don't use a Resmed. Can you do it all the time, NO!. If you didn't have would your AHI be zero all the time? NO!

AHI under 5 is considered to be the normal standard, that would mean in 8 hours of sleep you could have 40 events. I don't think that's good enough for me, I like breathing, I've got addicted to it over the years, like other things like food. Before treatment my AHI was 450, now it's avg is 0.7. If it goes over 3 for three days in a row, I feel it, so I take the effort to keep it treated correctly. It's well worth the effort. As well as the number of events the O2 destats need to be monitored, they are what causes the damage. That's why software that can give you these stats are so important. Jim
Use data to optimize your xPAP treatment!

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