How to reduce Hypopnea

[zorrro13]

Using rescan I have slowly been reducing my pressure from 10.6 to 10.2 in auto mode and studying the results (10.2 at 90 %). My A.I is virtually 0 every night including last night (1 episode for 12 seconds) however my H.I is relatively high at 2.8.
Once A.I is reduced to 0 Are hypopneas better treated by highering or lowering pressure?

[jimbassett]

Your numbers sound good to me. You have to realize the ResMed machines will always show a higher number of hypopneas than other machines. I have a S8 that will show my hypops at 8.5 while my Ai is at or near zero. I can switch to a different make of machine with the same pressures and same masks and they will show a HI of 3,5 with a AI of 0 . So I don't pay too much attention to the HI index on a ResMed. Jim

[zorrro13]

Thanks very much Jim I didn't know that. I'm not unhappy with 2.8 but since I have the software its sort of become a game or hobby of sorts. Think i can leave the numbers where they are or perhaps see how low I can go and still get zero A.I

[DreamStalker]

only way to reduce HI below 1 is to use a Respironics or P&B machine. I think ResMed machines include snores and flow limitations in their hyponea detections. I was never able to bring hypops below one on a ResMed machine although I often was able to get zero AI values.

[hobbs]

Been using a Resmed S8 Vantage for about a month and a half now. Been making changes every sixth day. APAP 9-16, 10-16, 11-16 and 12-16. straight CPAP at 12, 12.5 & 13. AI has never been higher than 0.1 and about half the time it has been 0.0!. AHI has ranged from a low of 3.9 for the week to a high of 5.8. It does seem getting a low AHI is very hard with a Resmed unit.

I wounder if with these low numbers if getting the Rescan software would be a worthwhile investment?

[zorrro13]

Im a total newbie at this but i have found a few very handy features
eg if for some reason you AHI shoots up you can check and see why. In My case all of the spikes in AI increased in correlation with large leak's at exactly the same time.
Also you can see how long you are in Apnea if it happens. And where and when hypos occur. I found a lot at the beginning of the night so I will try settling feature tonight
apart from that you can probably get what you want on your screen

[bigk]

only way to reduce HI below 1 is to use a Respironics or P&B machine. I think ResMed machines include snores and flow limitations in their hyponea detections. I was never able to bring hypops below one on a ResMed machine although I often was able to get zero AI values.

Hmm. Isn't Resmed's definition of a hypopnea "flow limitation"?

Resmed also don't report snores.

According to my wife I haven't snored since I went onto my APAP. My AHI rarely gets below 4.

[dsm]

[quote="zorrro13"]Using rescan I have slowly been reducing my pressure from 10.6 to 10.2 in auto mode and studying the results (10.2 at 90 %). My A.I is virtually 0 every night including last night (1 episode for 12 seconds) however my H.I is relatively high at 2.8.
Once A.I is reduced to 0 Are hypopneas better treated by highering or lowering pressure?

[zorrro13]

Dsm, not high but high relative to A.I of zero. Thanks for the info on how Hypos can occur again I had no idea
Believe it or not I have had a AHI of 0.6 and below 1 on several occasions but never on my old Vantage, only on the new series 11 available outside USA. Very happy with the low score though

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CPAPopedia Keywords Contained In This Post (Click For Definition): AHI

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CPAPopedia Keywords Contained In This Post (Click For Definition): AHI

[rested gal]

But Resmed machines score hypops differently to other brands

I agree.

(I really believe Resmed do it right & the others fudge it)

LOL!! Aw, geeze, Doug, not again! You still haven't given up that notion based on the reports the machines generate, huh?

Despite all the explanations people have given you about how each manufacturer has different definitions designed into their specific machines for when a flow limitation is to be regarded as (and reported as) a hypopnea instead of "flow limitation" and when a hypopnea is to be reported as an apnea instead of as a hypopnea?

Like this, written by a guest on page 6 of an old thread:
viewtopic.php?p=57153#57153

"One other question deals with either manufacturer's definition or cut-off point between scoring an obstructive sleep event as a hypopnea versus scoring that same obstructive sleep event as an apnea. While the Remstar Auto uses the more sensitive flow sensor of those two machines, either sensor type is more than capable of measuring flow limitation well enough to distinguish apnea versus hypopnea. However, the apnea/hypopnea definitions or cut-off point may actually be different between these two models by design.

AutoPAP manufacturers do not necessarily agree on how to score sleep events, and there are subtle differences in scoring criteria. Anyone whose sleep events tend to consistently border between hypopnea and apnea may return drastically different AI-to-HI ratios between two different manufacturers for this reason."


And this, by ozij at the top of page 7:
viewtopic.php?p=57261#57261

"Saying it is simply a difference in how 2 different manufacturers interpret results" was not a an argument for one thing or the other, it was an explanation of a fact of life. Hypopneas have different definitions -
http://www.aasmnet.org/PDF/hypopneaposition.pdf
---
- and it's the definition that guides the software. Software is what helps the APAP decide what it is identifying, and how to react to it."


And the Guest's further comment, at the bottom of page 7:
viewtopic.php?p=57355#57355

"APAPs aim to treat, then measure those treatment results. You should, indeed, expect different brand test meters to yield the same "readouts". But you should never expect different treatment chemicals or algorithms to yield identical results or datum across a patient population."


and ozij at the top of page 8:
viewtopic.php?p=57356#57356

"there is no agreement on the definition of what they measure. The alignment has to start in agreeing on the definition.
---
Can you imagine a Respironics engineer suggesting "how about we build our machines in accordance with Resmed's definition of hypopnea"? "

Differences in definitions (among other things) lead to differences in design. Differences in definitions and differences in design lead to differences in reporting.

Those differences do NOT mean one manufacturer has it right and another has it wrong, imho. They are simply... different. They each use their own different definitions to try to prevent events. Treatment can be equally effective for most people regardless of whether one machine is reporting a higher residual HI (by its own definition of "hypopnea") and another reports a lower residual HI (by its own DIFFERENT definition of hypopnea.)

Or in other words as I see it: the cutoff point for one designer's "This is still called a flow limitation for our design purposes" is another designer's "This is now what we will call a 'hypopnea' for our design purposes."

The residual events...the events that sneak through despite treatment... will also be reported differently, too. Doesn't mean one got it "right" and another didn't. They are simply different designs using different definitions.

Or, in other words as I see it: It doesn't mean that a resmed autopap found hypopneas that another brand of autopap "missed." Nor does it mean another brand prevented hypopneas that sneaked through with the resmed machine. It's simply a difference in at what point a flow limitation is called "hypopnea" in each manufacturer's machines.

A yawn can generate a high HI

I kind'a doubt that. Surely it takes more than one long, slow, deep breath in and out, which is what a "yawn" is, to generate a hypopnea flag on ANY manufacturer's autopap.

I consider anything under 4.0 on a Resmed to be damned good

I agree. I'd even say any HI under 8 on a resmed is quite good...probably equivalent for most people to half that HI on other brands.

PS Resmed do monitor snores but on the std report don't show em

Right.

[dsm]

RG

I know we don't agree on this HI scoring. Definitions of Hypopneas are one thing - a machines ability to score its definition of hypopneas is yet another.

The Resmed machines can be adjusted in 0.2 increments because they can do it. Other brands can't so the manufacturers don't try. Being able to adjust CMS so finely reflects the Resmed's ability to detect subtle flow changes that some other can't.

So I will continue to believe, based on using all the brands continuously, that some machines score flow limitations more accurately and more meningfully than some others.

Each brand of machine has its own strengths & weaknesses. Respironics are great with exhalation relief, I believe Resmed are very good at detecting the subtlety of flow limitations.

I know we will continue to disagree on this but that is what makes the debates interesting

Cheers

DSM

[freepostg]

I just love reading well written and informative posts. In this case, a relatively in depth look at a couple of the better machines out there.
A sincere thanks to the two of you and your very interesting descriptions and opinions. I just love this website!!

[rested gal]

The Resmed machines can be adjusted in 0.2 increments because they can do it. Other brands can't so the manufacturers don't try.

"can't" so "don't try"? Perhaps the other manufacturers don't think 0.2 increment adjustments are necessary and choose not to design theirs that way.

Being able to adjust CMS so finely reflects the Resmed's ability to detect subtle flow changes that some other can't.

I don't think that necessarily follows...or makes sense. Adjustments and detection are different things.

So I will continue to believe, based on using all the brands continuously, that some machines score flow limitations more accurately and more meningfully than some others.

ok, if that's what you want to believe. I'll continue to think it's more a matter of designers' definitions. We all use machines without fully understanding every one of them.

Each brand of machine has its own strengths & weaknesses.

Right.

[zorrro13]

I just love reading well written and informative posts. In this case, a relatively in depth look at a couple of the better machines out there.
A sincere thanks to the two of you and your very interesting descriptions and opinions. I just love this website!!

I'm listening with ears wide open

[rested gal]

I just love reading well written and informative posts. In this case, a relatively in depth look at a couple of the better machines out there.
A sincere thanks to the two of you and your very interesting descriptions and opinions. I just love this website!!

Well, take what any of us write with a grain of salt, freepostg. We can all sure be wrong about things.

I'm listening with ears wide open

LOL!! The main thing, zorro, is that your HI of 2.8 is extremely low for a ResMed S8 machine.

dsm said, "I must admit I chuckled when I saw you say 2.8 was a high HI score." I shared that chuckle!

Your ResMed S8 HI of 2.8 was like having an HI of 1.0 or less with other brands the way I look at it. Maybe you hit zero (by some definitions ) and didn't even get to celebrate!

My edit: Added "S8" to all my references to ResMed machines in this old post, since the definition of hypopnea was changed by ResMed in the later S9 series machines.