AHI measured by CPAP devices

[seekingwellness2016]

How does a device like the ResMed AirSense 10 actually detect apneas/hypopneas, in order to define the AHI? Don't these by definition require measurement of oxygen desaturations and/or arousals? How can the estimated AHI possibly be accurate without measuring these parameters?

[LSAT]

How does a device like the ResMed AirSense 10 actually detect apneas/hypopneas, in order to define the AHI? Don't these by definition require measurement of oxygen desaturations and/or arousals? How can the estimated AHI possibly be accurate without measuring these parameters?

AHI is a measurement of apneas and hypopneas. An apnea is a full blockage of air for 10 seconds or longer...a hypopnea is a partial blockage of air for 10 seconds or longer. The CPAP device detects these blockages. That is what is measured. AHI does not measure O2. O2 along with AHI is used to determine Sleep Apnea.

[Pugsy]

These machines measure air flow or the reduction or lack of air flow.
While oxygen levels might be involved in the diagnostic sleep study to meet diagnosis criteria they aren't needed by the machine to measure air flow or to record the lack of or reduction in air flow using the criteria predetermined by the machine's algorithm for flagging apnea events.
The criteria is a certain % of reduction in air flow that lasts at least 10 seconds. Oxygen levels aren't needed for this flagging.
You don't need oxygen levels to get an AHI result.

[seekingwellness2016]

I guess the bottom line is that there are many different definitions of AHI, because there are different definitions of what constitutes an apnea or hypopnea.

[BlackSpinner]

I guess the bottom line is that there are many different definitions of AHI, because there are different definitions of what constitutes an apnea or hypopnea.

No there is only one. 10 secs or more of obstruction of air flow. It is very specific.
Drops in oxygen are not required.

[chunkyfrog]

Google "apnea-hypopnea index".
Wikipedia's explanation is quite clear and fairly simple.
As you can plainly see, oxygen saturation is ANOTHER criteria to describe severity of apnea.
Both are important, but they are not the same thing.
Even without desaturation, there are negative effects on the body.

[LSAT]

I guess the bottom line is that there are many different definitions of AHI, because there are different definitions of what constitutes an apnea or hypopnea.

WRONG! There is only 1. Where are you finding YOUR information?

[seekingwellness2016]

I'm done some of my own reading now on this topic, and am satisfied with the conclusions I've been able to draw myself.

For those who are interested, there are in fact several different definitions of AHI.

See, for example, the following abstract/article:

http://www.ncbi.nlm.nih.gov/pubmed/19238801

where AHI(recommended), AHI(alternative), and AHI(Chicago) are all described.

[Goofproof]

Congrats, you learned to read, now it's time for realizing everything you read isn't always true, As long as people get paid they are going to publish papers, it's how they stroke themselves and get paid. The government pays be the word, your tax dollars, it doesn't have to make sense or be true. Jim

[Julie]

There are posters here who've been here for years, knowledgable and very experienced in dealing with OSA/Cpap, some could easily give much better courses on AHI etc. than many/most of the authors of old or just badly researched papers you've found to prove what's unproveable! You're just plain WRONG about AHI (the most basic and easy aspect of Cpap features) and you're doing yourself an injustice by wasting your time with that stuff trying to convince the people here who've worked with it all forever. Use your time more productively! Stop trying to justify a mistake!

[BlackSpinner]

I'm done some of my own reading now on this topic, and am satisfied with the conclusions I've been able to draw myself.

For those who are interested, there are in fact several different definitions of AHI.

See, for example, the following abstract/article:

http://www.ncbi.nlm.nih.gov/pubmed/19238801

where AHI(recommended), AHI(alternative), and AHI(Chicago) are all described.

Nobody these days cares about this anymore. All sleep studies use 10 seconds or more of obstruction only. All cpap machines use the same. Industry standards prevail. Suck it up.

[palerider]

I'm done some of my own reading now on this topic, and am satisfied with the conclusions I've been able to draw myself.

well, now we've established one fact: seekingwellness2016 is the type that lines to come in, ask questions and then argue about the answers given. also, likes to dig up old stuff (2009 Feb) for arguing purposes. you and avi will get along great.

[LSAT]

I'm done some of my own reading now on this topic, and am satisfied with the conclusions I've been able to draw myself.

For those who are interested, there are in fact several different definitions of AHI.

See, for example, the following abstract/article:

http://www.ncbi.nlm.nih.gov/pubmed/19238801

where AHI(recommended), AHI(alternative), and AHI(Chicago) are all described.

The study you are posting is from 2009...maybe you can find something more current. Research continues......
I don't know what you are trying to prove...that you don't have Sleep Apnea?

[palerider]

I'm done some of my own reading now on this topic, and am satisfied with the conclusions I've been able to draw myself.

The study you are posting is from 2009...maybe you can find something more current. Research continues......
I don't know what you are trying to prove...that you don't have Sleep Apnea?

that he's *obviously* smarter than the rest of us?
cuz we dun't know nuthin 'bout ahi or how machines guesstimate it.