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If a 0 AHI is not possible because of the accuracy of the machine, does that not also call into doubt an AHI of any other number? Can you believe an AHI of 5.6? 20.5?

How will we know?

When I had a follow-up sleep study, the doctor said that I had my machine set to match what my titration showed to be ideal. The tech used those pressures (bi-pap) to achieve 0 AHI. Do I now have to doubt their titration as well?

How will I sleep tonight? Do we work so hard to get this right only to find there is no "right"? Are we kidding ourselves that CPAP does treat sleep apnea? Am I wearing this mask and leaf blower for naught?

Now you have me worried. At least I have forgotten about the bail-out for a few minutes.

With my Resmed I may have achieved an AHI of 0 a couple times, but it usually was between 1 and 3. With my Respironics machine, I hit a 0 AHI every few weeks, but stay mostly between .5 and 1.5 lately.

Recently got a new mask and hose and my leak rate dropped and is now pretty much straightline. Didn't affect my AHI though, so I guess my machine really was compensating for the small leaks. My numbers stay so consistent, I look at them only every month or two just to be sure.

Catnapper wrote:If a 0 AHI is not possible because of the accuracy of the machine, does that not also call into doubt an AHI of any other number? Can you believe an AHI of 5.6? 20.5?

How will we know?

When I had a follow-up sleep study, the doctor said that I had my machine set to match what my titration showed to be ideal. The tech used those pressures (bi-pap) to achieve 0 AHI. Do I now have to doubt their titration as well?

How will I sleep tonight? Do we work so hard to get this right only to find there is no "right"? Are we kidding ourselves that CPAP does treat sleep apnea? Am I wearing this mask and leaf blower for naught?

Now you have me worried. At least I have forgotten about the bail-out for a few minutes.

Catnapper,
I think what you are saying is that the AHI has to be better than nothing as a guide to how our therapy is doing. That of course is a very very valid point & is all we mere mortals have to go by, apart from how we feel over time.

I do believe the numbers are very helpful to establish a relativity to how our therapy is matching up night to night.

The point about can we trust any AHI scores of any number, well if we were wanting scientific accuracy, all AHI scores are of little use. But if we want relativity to our own night-to-night progress, those inaccurate numbers suddenly take on a meaning.

There is a doubt in my mind about anyone convincing themselves that a 0.0 AHI score is some kind of Nirvana or deserves an achievement medal - I just don't think the machines we buy are that accurate. I don't think we could ever stage an Apnea olympics for the lowest AHI (but I do sometimes think some of us think that way & put a lot of effort & worry into trying to take out a track record ).

I do put a lot more trust in the numbers I get from a good brand of SpO2 recording PO. Those numbers to me keep the xPAP numbers in balance. The xPAP is more likely to be wrong than a good SpO2 readout.

DSM

Yes!!!!!

I will be glad to post a chart of either total apneas or AHI over 100 days where I have had the fortune of watching it come down from 40-46 apneas per night at the prescribed pressures to a level of about 1 apnea/night with several 0 apneas showing up often.

I had to go to straight CPAP to finally get to the levels of 3-20 apneas per night and finally setting up a narrow range Auto that works much better. This really surprised me as I had several months of really bad results with the auto mode to finally find a range where it really seems to work exceptionally well.

I believe it would be an absolute coincidence for the prescribed value for a patient to achieve anything close to the optimum results for those patients and the wide open autos sure don't seem to work for me.

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

Certainly, some (perhaps many) would.

As for your topic title: "Is a 0 AHI score actually possible ?"
Sure. Happens fairly often for me with several different machines. I keep the minimum pressure (or EPAP, depending on which machine I decide to use) set high enough to keep the airway well and truly open.

"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"
Yes.

Even though it happens at least once or twice a week for me, getting zero AHIs on my own data don't impress me. I feel equally rested whether it was 0 or 3.something.

It has been estimated that about 20 percent of the general population have an AHI over five:

"The prevalence of OSAH is approximately 20 percent if defined as an apnea-hypopnea index (AHI, the number of apneas plus hypopneas per hour of sleep) greater than five events per hour [2,3] . In contrast, only 3 to 9 percent have OSAH if defined as an AHI greater than five events per hour accompanied by at least one symptom that is known to respond to treatment (eg, daytime sleepiness) [2] . The different prevalences suggest that it is common to have an AHI greater than five events per hour without symptoms . . . In the United States, nine to 12 percent of women and 27 to 35 percent of men have an AHI greater than five events per hour."--Overview of obstructive sleep apnea-hypopnea in adults. Author: Kingman P Strohl, MD.

http://www.uptodateonline.com/patients/ ... dQH6KUUPQ_

rested gal wrote: Happens fairly often for me with several different machines. depending on which machine I decide to use)

Help me understand:
what is the purpose of having multiple model machines?
I know I am just a newbie and I have only used
one machine. I'm don't consider myself a
babe-in-the-woods either.
I have taken my therapy by the horns and am doing quite
well. Reading and listening here, I have an AHI avg.
for Sept. of 2.2, w/a number of days below 1.

So....how do you decide what machine to use each night?

carbonman wrote:. . . what is the purpose of having multiple model machines? . . .

carbonman:

I think her usual answer is similar to this one from a few months ago:

"I've used a lot of different brands/models, just for the heck of trying them."--rested gal, Apr. 24, 2008.

That's what she says. But I have a feeling that the real reason is that some people, like her, make it a point to be knowledgeable enough to be helpful to people like you and me.

dsm wrote: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

Yup, I'm with ya

Just to muddy the subject further, when I look at my numbers, I immediately go the the length of time in apnea. If I recorded 3 during the night with a total of 36 seconds, to me that's negligible. Now, the night I had 1 at 57 seconds, that caught my attention.

I get zero AHI realtively often (about 2 to 3 time per week) and have a long-term average of about 0.3 to 0.4. I've had 5 zero AHI nights in a one week session before but the longest consecutive run is 3 in a row. Getting all zeros -- zero AHI and zero FL is a bit more rare for me (maybe once every couple of weeks).

Generally, I feel no difference if my AHI is below 1.0 or 2.0 (above 1.0 is fairly rare and maybe only once a month)... but when above 2.0 and I can feel the difference (above 2.0 is even more rare like maybe once every 3 or 4 months). My AHI has gone above 5.0 only once since I started treatment about 2.5 years ago.

Thanks to this forum, I have done very well considering my untreated AHI was 102 with 99 of them being apneas.

Does a consistant reduction in AHI happen as your
body "learns" how to sleep again and your sleep
hygiene improves as your therapy becomes more consistant??

Man, I hate to say this, but.....

Jerry (6ptstar) brags to me all the time about his 0 AHI. See how much good that did him?

I'm just saying, sometimes we focus too much on numbers that are NOT MIRACULOUS IN THEIR CURING POWERS.

Good luck to all,
Babs

carbonman wrote:Does a consistant reduction in AHI happen as your body "learns" how to sleep again and your sleep hygiene improves as your therapy becomes more consistant??

It did for me (using straight-pressure CPAP). Beyond that, I'm not about to make any generalizations as to whether it would for others, but I wouldn't be surprised. That's one reason I like straight pressure.....I can see any subtle (or not-so-subtle) changes in my numbers and the way I feel, when "all things are equal".

Den

I sometimes do think the software is faulty but then it could be the setup too. A hose 10ft or longer could cause the machine not to sense some events.

My avg. ahi is less than .3 - when I look at mine I include FL's.