Pulse Oximeters in CPap machines.

[Thumper1947]

Rubicon,
The only reason I copied and pasted that info was to give some sense of how many of these arousals can take place in a given night. At first, I had no idea what was happening when the flow chart showed me in sound sleep, only to have a a chaotic few seconds, followed by a return to sound sleep. This thread was about pulse oximetry in cpap machines and by observing the pattern of movement, pulse increase, and arousal happening, it explained how it was actually only a position shift that was triggering these events. If you have any interest in arousals, just google, "arousals in cpap". By the way, I don't have a cpap with oximetry, but a simple ring that seamlessly imports the information into Oscar. If anyone doesn't want it, simple, don't do it.
Thumper

[Rubicon]

Yeah well all this "incidental data", "suggested normalcy", "you may sometimes might maybe consider possibly gee that's a gray area" doesn't offer a lot of help.

The question specifically is:

In patients over age 60, is spontaneous AI < 28 normal?

If the answer is anything other yes or no, IMO we need to throw that ad out.

[Tec5]

To Rubicon:
1. What is AI ?
2. What “ad” are you talking about?
3. What does this have to do with equipping CPaPs with an oximeter sensor?

[palerider]

@Rubicon
Actually he is NOT saying that 27 (non-respiration triggered) arousals is "normal", he actually said that "If you are over 60 years old you MAY have as many as 27 arousal per hour" (emphasis added).

Could there possibly be anything more meaningless than what you're alleging?

Rubicon MAY be able to levitate using the power of his mind alone.

Pugsy MAY be a wizard and can turn people that post stupid things into toads... (alas, probably not).

You can make *any* ridiculous statement and say MAY and weasel out of it.

You MAY post something sensible.

Again, unlikely, (I'm betting Rubicon levitating as more likely).

[Centennial1]

@Palerider
Now I remember why I was warned about this forum. Offers some useful information if you can weed through the bullsh*t and aggression of bullies like PaleR* and his merry band of santimonious henchmen.

At the time I had no idea who PaleR* was, but now it's clear.
I've got no time for random strangers who seem intent on provoking useless arguments.

[robysue1]

To Rubicon:
1. What is AI ?

Arousal index = (number of arousals)/(hours of sleep). In the context of what's being discussed by Thumper1947 in his post upstream we can assume the arousals being talked about are spontaneous arousals rather than ones associated with sleep disordered breathing (including snoring) and periodic limb movements.

2. What “ad” are you talking about?

The second link in Thumper1947's post upstream goes to the website for a dentist advertising his services for maxillofacial procedures, including those advertised as "the ideal treatment for snoring and obstructive sleep apnea" among other things.

3. What does this have to do with equipping CPaPs with an oximeter sensor?

To the best of my knowledge, Rubicon hasn't written anything (pro or con) about whether CPAPs should be equipped with an oximeter sensor somehow built into them. His posts are solely aimed at legitimately questioning the claim by Thumper1947 that a spontaneous arousal index of 27 may be considered normal in folks over 60.


I will add: The whole idea of trying to use oximeter data to "tease out" whether a specific "arousal" in CPAP data is a spontaneous arousal or a respiratory related arousal is a bit ridiculous: While we may infer that an arousal has likely occurred based on what's going on with the respiratory rate and flow rate, we cannot actually prove an arousal has occurred because a CPAP has no EEG data. And while some breathing patterns are likely to scream out "spontaneous arousal" to people who look at flow rate data for a living (i.e. PSG techs), CPAPs have never been designed to flag spontaneous arousals. Moreover, the way CPAPs attempt to score RERAs is, itself, controversial specifically because the machine's programming is inferring both that arousal likely happened and that there was increasing respiratory effort before that inferred arousal occurred.

CPAPs are designed to flag breathing patterns in the flow rate data that are associated with known sleep disordered breathing problems. Since both apneas and hypopneas are associated with significant reductions in flow rate, CPAP machines are programmed to identify the places where the flow rate has dropped by a substantial amount. This is pretty easy for a CPAP machine to do since the flow rate can easily be measured.


Getting back on topic: Resmed and PR use different criteria for scoring hypopneas, and neither company's definition of when a hypopnea is scored is an exact duplicate of the flow rate part of the AASM definitions. (See notes at end of post.) It's also worth noting that neither Resmed nor PR claim that the data recorded by their machines is identical to, or close to identical to, what would be scored on an in-lab PSG. Rather, they say the CPAP data should be used primarily for trending information and the AHI numbers are estimates of what the true numbers would be.

The OP in this thread posed the idea that CPAPs should have an integrated oximeter of some sort and that they should use the oximeter data along with the flow rate data to score hypopneas, presumably to eliminate the hypopneas that can get scored during periods when you are awake or when you are dozing lightly and the missing EEG data would show that you are not fully asleep. I believe the OP's idea is that if there is a drop in flow rate while you are awake, it won't have an associated O2 desat, but if you are asleep and you have a "real" hypopnea, there will be an associated O2 desat. Hence integrating an oximeter into the CPAP machine ought to weed out "false positive" events from the number of events used to calculate the AHI.

My counter position has been---and continues to be---that using oximeter data to decide which hypopneas are "real" and which are "false positives" is misleading: A real hypopnea scored under AASM H3a does not require an O2 desat in order to be scored. Hence only including hypopnea-type events in a CPAP's calculation of an AHI only if an integrated oximeter shows there is a corresponding O2 desat is guaranteed to miss every single "hypopnea with arousal"---i.e a hypopnea scored under H3a that has an arousal but no O2 desat.


----------------
Notes: Criteria for scoring hypopneas
Resmed. Glossary of Sleep Apnea Terms:
Hypopnea is a partial blockage of the airway (shallow breathing). During a hypopnea, breathing is reduced by 50% for 10 seconds or longer.

Philips Respirionics. Interpretation guide for Encore software compliance reports:
Hypopnea(H): defined by a 40% reduction in airflow for at least 10 seconds.

AASM. AASM clarifies hypopnea scoring criteria:

• Recommended (H3a)
  1A. Score a respiratory event as a hypopnea if ALL of the following criteria are met:
  1. The peak signal excursions drop by ≥30% of pre-event baseline using nasal pressure (diagnostic study), PAP device flow (titration study), or an alternative hypopnea sensor (diagnostic study).
  2. The duration of the ≥30% drop in signal excursion is ≥10 seconds.
  3. There is a ≥3% oxygen desaturation from pre-event baseline and/or the event is associated with an arousal.

OR

• Acceptable (H4a)
  1B. Score a respiratory event as a hypopnea if ALL of the following criteria are met:
  1. The peak signal excursions drop by ≥30% of pre-event baseline using nasal pressure (diagnostic study), PAP device flow (titration study), or an alternative hypopnea sensor (diagnostic study).
  2. The duration of the ≥30% drop in signal excursion is ≥10 seconds.
  3. There is a ≥ 4% oxygen desaturation from pre-event baseline.

Please note that the criterion involving arousals is included in 1A and excluded from 1B.

[palerider]

@Palerider
Now I remember why I was warned about this forum. Offers some useful information if you can weed through the bullsh*t and aggression of bullies like PaleR* and his merry band of santimonious henchmen.

At the time I had no idea who PaleR* was, but now it's clear.
I've got no time for random strangers who seem intent on provoking useless arguments.

Don't post most excellent organic fertilizer and people won't call you out for it.

[Rubicon]

To the best of my knowledge, Rubicon hasn't written anything (pro or con) about whether CPAPs should be equipped with an oximeter sensor somehow built into them. His posts are solely aimed at legitimately questioning the claim by Thumper1947 that a spontaneous arousal index of 27 may be considered normal in folks over 60.

Yeahbut...

All these points are inextricably linked (Whew! I've been waiting for 21 posts to to be able to say "inextricably").

Why is it so difficult to get a simple answer to a simple question?

@Palerider
Now I remember why I was warned about this forum. Offers some useful information if you can weed through the bullsh*t and aggression of bullies like PaleR* and his merry band of santimonious henchmen.

At the time I had no idea who PaleR* was, but now it's clear.
I've got no time for random strangers who seem intent on provoking useless arguments.

Smooth exit.

Guess I never will get my answer.

[Rubicon]

Getting back on topic:

Au contraire mon petit croissant, this is the topic. Very early in this thread (post #5)(not counting blocked posts from foes) Thumper started talking about arousals, with normals being like 2.5 or 27.

Doncha think we need a little clarity?

So to preface, they ain't gonna find anybody that says AI 27 is normal in 60 year olds.

I mean, they might have pointed to Mathur 1995



or Boselli 1998



but those were tiny studies, a long time ago, and done in a Sleep Lab.

done in a Sleep Lab.

done in a Sleep Lab.

done in a Sleep Lab.

So if we're talking with some degree of scientific basis AI for a 60 year old would more likely be in the neighborhood of 16.83 (second night effect).

[Rubicon]

So hold that thought.

Meanwhile can we agree on 3 things (or maybe not):

1. OSA is bad because it causes oxygen levels to drop;

2. OSA is bad because it causes hemodynamic pressure swings; and

3. OSA is bad because it causes breaks in sleep continuity.

So you guys brought up Hypopnea 1A, which may only include arousals.

And AHI 5 - 15 causes the world to stop turning and OMG we need to start wingin' those dials around.

So let's really let that sink in for a minute...

[Rubicon]

Rubicon,
... If you have any interest in arousals, just google, "arousals in cpap". ... If anyone doesn't want it, simple, don't do it.

And then you guys wonder why you get "thumped".

[palerider]

All these points are inextricably linked (Whew! I've been waiting for 21 posts to to be able to say "inextricably").

We've all got to have goals. I applaud yours.

@Palerider
Now I remember why I was warned about this forum. Offers some useful information if you can weed through the bullsh*t and aggression of bullies like PaleR* and his merry band of santimonious henchmen.

At the time I had no idea who PaleR* was, but now it's clear.
I've got no time for random strangers who seem intent on provoking useless arguments.

Smooth exit.

We can hope, but unfortunately so many of those who flounce out, decrying the "bullies" (generic term for "someone who calls them out on their bullshit") are just drama queens that lie about it and don't actually in making the forum a better place by leaving.

[palerider]

Getting back on topic:

Au contraire mon petit croissant,

that's the best laugh I've had in days... still chuckling about. You have forever changed how I think of RobySue.

[Dog Slobber]

Getting back on topic:

Au contraire mon petit croissant,

that's the best laugh I've had in days... still chuckling about. You have forever changed how I think of RobySue.

Me too.

petite_croissant.jpg (395.59 KiB) Viewed 1274 times

[palerider]

Well done, sir!