Visited Sleep Doc Interesting HI/OSA Central Comments

Today I made my first visit to the Sleep Doc with Data in hand.

We discussed my AHI especially my sweet spot at 9cm.

At 9cm my AHI is the lowest but at 10 my HI keeps dropping but my OSA starts going UP.
Thanks to MyEncore AHI/Pressure Graph.

AS the pressure increases my HI goes down but my OSA goes sharply higher.

Here's the hose-line: (No Medical advice, blah, blah..)

My Sleep Doc says that a rising OSA with a dropping HI is a good indication of Centrals. My Centrals start kicking in at 10 and go sharply higher with pressure. Hypop's on the other side drop off the table.

If this is not clear I can publish my data so you can see how pressure impacts my HI & OSA respectively.

Conclusion: If OSA starts rising with pressure, they are probably centrals - especially if Hypop's are falling.

BTW: I'm the first to come in with their own data: Doc was very interested in it.

I hope this is of some value to all of you.

Best Tom

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

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

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

Tom,

I had a discussion with my NEW sleep doc yesterday and he finally had the data dictated etc from last Tuesdays sleep study.

He said the same thing you did. My ending number was 7cm with no apneas or hypopneas. Maybe I should have let them start at 5 but through experience 5 to 6 just wasn't enough air to feel comfortable so we picked 7.

My chart shows exactly the same thing as yours and if you wish to post it or e-mail it that would be great to compare to mine. My graph for 105 hours showed an AHI of 1.6 at 7, .5 at 8, 1.3 at 9, 1.8 at 10 and 2.2 at 11 (more like 10.5 since that is what I set the max for even though the software rounds things out.

Like yours, after 8 there was a sharp increase in OSA and a sharp decrease in hyponeas.

CENTRALS was the first thing out of his mouth. Not a good thing!! He said that you don't have to be at 16 or 18 to have centrals and every person is different when it comes to that magic number that gives you centrals.

So he gave me the option of straight 7 or 7 to 9 max auto, preferably 7 to 8.5. He said the software was a general idea of things but not to take it to heart. Some people it may work great with, others not so great but still a nice way of charting your progress.

Today was the first day in 4 months that I have slept through the night and felt half way decent.

So to follow up with my previous post, sometimes LESS is better than MORE.

I fault my first titration and the place that did it saying they thought they were in the ball park however I had only slept 108 minutes, enough for one sleep cycle.

Of course I could be an isolated case but this new doc said it's not uncommon to come up with the wrong number if you don't have a reasonable number of hours sleeping to set things.

Tom, Please send the data so I can look at it...

mab@wake180.com

Later,

Marc




[quote="roztom"]Today I made my first visit to the Sleep Doc with Data in hand.

We discussed my AHI especially my sweet spot at 9cm.

At 9cm my AHI is the lowest but at 10 my HI keeps dropping but my OSA starts going UP.
Thanks to MyEncore AHI/Pressure Graph.

AS the pressure increases my HI goes down but my OSA goes sharply higher.

Here's the hose-line: (No Medical advice, blah, blah..)

My Sleep Doc says that a rising OSA with a dropping HI is a good indication of Centrals. My Centrals start kicking in at 10 and go sharply higher with pressure. Hypop's on the other side drop off the table.

If this is not clear I can publish my data so you can see how pressure impacts my HI & OSA respectively.

Conclusion: If OSA starts rising with pressure, they are probably centrals - especially if Hypop's are falling.

BTW: I'm the first to come in with their own data: Doc was very interested in it.

I hope this is of some value to all of you.

Best Tom

Marc:
You should recieve an email of my data.

Feel free if you want any more specific charts.

tom

Friends, for the sake of those who are still very new, I think we should be careful about the terms used.

Roztom and Malibu, you're actually both refering to an increase in Apneas, as indicated by the growing Apnea Index, AI at higher pressures.

OSA (the term you're unfortunately using) stands for Obstructive Sleep Apnea. And while you're having an increase of Apneas at higher pressures, those are not obstructive. There are no obstructions interrupting your breathing at the higher pressures. The apneas appearing in your case at higher pressures are, according to the doctors, central apneas - a result of the fact that your central nervous system has not given the instruction to breathe.

The obstructions, causing your Obstructive Sleep Apnea syndrome get cleared at a lower pressure.

O.

Thanks for sharing those results. I don't have access to my data, but have felt my cpap was causing episodes of CSA, to the point I have not been using my machine. I posted something a few weeks ago about my odd dreams of near-death experiences. Haven't had one since I quit using the machine. So I'm sleeping in my recliner until my upcoming appointment at Cleveland Clinic. So, are your centrals resolved?

Tom Swift,

Nice work, that's for the report.

One caution regarding your doctors interpreation (not that I think he's wrong). With an APAP the higher pressures can be in response to the occurance of (obstructive) apenas rather than the cause. So what he says is certainly a likely interpretation but with APAP monitoring you can never know absolutely for sure which is cause and which is effect. The doctor is using his experience to make that judgement and is also if he errs, erring on the conservative side (especially since you are getting good results any way you look at it).

Interesting stuff indeed.

ozij,

As usual, you make a valuable point. The terminology in this whole area is full of the kinds of dangers you point out. In this case, I don't know why Respironics isn't more careful to use the words "apnea" and/or "apnea index" since that's what they mean.

Basically a Central APnea is when the body does not signal you to breathe as oppossed to an obstruction.

The comments I made above referred to the labels on the MyEncore Chart AHI/Pressure.

A Central is not an obstruction however the data does not recognize centrals - you need to be in a sleep lab to be sure but as my post meant to indicate when the Data shows increasing OSA's and Dropping Hypopneas, that is a reasonably good indication that those OSAs are Centrals - Apneas caused by pressure - not obstruction.

Tom

The key to my Docs opinion is that the data showed increasing OSA (Centrals) with Dropping Hypopneas.

His opinion was if I was having trouble breathing my HI would be rising with the OSA Index but it didn't.

Another thing of interest. When I had my sleep study, acknowledging a one night event, I had almost all Hypopneas and only 2 OSA.

According to the APAP I have many more OSA's. than 2. MY Doc fels the Dropping HI with pressure and the increase in OA are an indication of centrals. It makes sense to me.

I was wondering why as my APAP increased pressure my OA would go up. I look at the daily ENcore charts and I have OA's at the higher pressures and very few at the lower pressure where my Hypop's occor. I was wondering what came first - chicken or the egg.

For me this helps clarify it.

Furthermore my Doc was not concerned that I was having the centrals since my numbers even with centrals is low around 2.0 ish. If I tweaked it to a tighter pressure range (Now 5 - 11) I'd have more leaks. According to the Doc I wouldn't feel the difference for a 0.5 reduction in AHI. SO I won't adjust it much.

Not waking up to mask leaks makes for better sleep than a possible 0.5 reduction in AHI.

Hope everyone got something out of this.

Best,

Tom

Brent, I knew you could be relied on to point out the correlation vs. causality issue.


Tom, if "My Encore" uses OSA instead of Apneas, then derek who wrote it made an assumtion that all apneas were obstructive, or else he made a mistake.

If I remember correctly, Respironics does not mix the terms up. In Encore Pro you'll see reports of "apneas" (OA) Hypopneas and NR (non-responsive) apneas - nothing about "centrals", because as you say, they cannot be identified by that APAP. It's interesting that you have increasing OAs, and not increasing NRAs - which is what one would - theoretically - expect if the apenas were pressure induced. (This is not an argument agains your doctors interpretation).

Not waking up to mask leaks makes for better sleep than a possible 0.5 reduction in AHI

Bingo.

O.

I don't have enough consistent data yet but this whole thread it very, very helpful. I would like to see Tom' and Malibu's data - Encore Pro, not My Encore if possible. I'll PM with e-mail address.

I also really appreciate the comment about no leaks v. a .5 drop in AHI. That makes so much sense as to be painful. I will heed that.

SB

ozij wrote:If I remember correctly, Respironics does not mix the terms up. In Encore Pro you'll see reports of "apneas" (OA) Hypopneas and NR (non-responsive) apneas - nothing about "centrals", because as you say, they cannot be identified by that APAP. It's interesting that you have increasing OAs, and not increasing NRAs - which is what one would - theoretically - expect if the apenas were pressure induced. (This is not an argument agains your doctors interpretation).

Ozij, just as a matter of clarification: Encore Pro classifies all apneas as OA's. Additionally, under some very specific circumstances it will also set the NR (non-responsive) flag, but the NR flag does not signify a specific apnea event, instead it results from multiple failed pressure increases.

It's a bit of apples to oranges comparison. The NR flag may signify the occurrence of centrals, but it is certainly not a direct measurement, and even when it does, it is not limited to a single apnea event.

Hope that helps clarify.

Regards,
Bill

I've never had an NR Apnea flag pop. As you said a NR is non-responsive to pressure, the software recognizes it and stop raising pressure - my understanding.

As far as Centrals go there is no way to know for sure unless you are in the lab and they detect you are not taking a breath vs not able to get air when you breathe.

My Doc's opinion was Apneas registering with pressure increases while Hypop's are dropping is a good indication of Centrals. Consider a Hypop is a smaller % drop in air flow while an apnea is the stopping of breathing.
It's logical that is your breathing is stopping then your Hypops or partial flow resrtrictions would also increase.

Since Hypops are dropping, indicating an open airway, then OSA'a that are registering are most likely Central in nature.

I find this interesting and also explained my concern with my own take on the numbers as I "suspected" my OSA's were pressure induced or Central in nature.

If anyone wants to see my chart AHI/Pressure PM me your email and I'll be glad to send it to you for your review.

Best,

Tom

Would you mind publishing the chart so we could all see it?

O.

I do not have the ability to publish my chart but send me a PM with your email and I'll gladly send it to you.

Tom