How to interpret my data?

[snnnark]

Of course the one thing we haven't asked is... How are you feeling?

[Mark NJ]

Couple of additional questions/observations about CA.

I'm recording CA values of 2.6 - 7.6 plus an outlyer of of 12.1. Can anyone give me some feel for what this value should be? E.g., with AHI I've found that < 5 is OK; around 15 is concerning; 30 and above is really bad. So, how serious are values of 2.6 and 7.6 (and so forth)?

How accurate are a CPAP / APAP machine's records of these values? In my early usages of my machine on Auto I was curious as to how my machine would respond to my breathing; so, I deliberately held my breath on several occasions. On the historial chart of my dataI observed huge spikes in my CA values early on. While I can't be certain these spikes coincided with my deliberate breathholding, it's a reasonable assumption that they were.

On subsequent occasions - not often - I've also deliberately held my breath. Not often, but that too may affect some of my old history. Now that I know that this will squeue my data I'm not holding my breath deliberately any more.

Though I am not doing so deliberately, reflecting on my old experiments with breathholding makes me wonder how accurate xPAP machines are in recording CA values (and any other values for that matter). All measurements are subject to some degree of error; yet, we usually know the scale of error. E.g., if I cut a piece of lumber I can figure on about 1/16" of error. With xPAP CA values I have no idea what sort of error to expect. E.g., with CA values should I expect that they will be accurate within 10% or 50%? Should I expect error to be biased high or low?


I understand that CA is caused by the failure of the brain to register an accumulation of CO2 as the inducement to breath. I recalled noticing on a blood test that I had low CO2; so, I checked my records and found a couple of tests in 2008 and 2007 that registered 16 and 19, which isbelow the range of 20 - 32. All the subsequent blood tests over the recient yers were in the 24 - 28 range, well within the norm. I doubt that the very old readings from 3 years ago mean much today but I thought I might mention it in casee someone recognized it as significant. (The hypothesis would be that if my blood level of CO2 is low then it would take a larger accumulation of CO2 to reach a level sufficient to trigger the brain to breath.)

Thaks for any comments.
Mark

[Mark NJ]

Of course the one thing we haven't asked is... How are you feeling?

Thanks for your concern.

Maybe I'm feeling better; however, I hessitate to put any stock in my subjective sense about how I feel. Some people have a good sense of how they are feeling; I'm not one of them. I think I have a bias toward a placibo effect which goes away in a few days after trying something new. So, I don't trust my subjective sense of things.

I'd much rather have objective data to tell me where I am. I accept that not everything is in the data. Even so, in my view, the data comes first and subjective feelings second. If folks on the forum tell me that my CA data are a matter of concern I figure I should take that seriously irrespective of whether I think I feel better or feel no different from what I felt before.

Once I understand what my data are telling me about how I'm doing I'm open to taking seriously what I think I feel about my well-being.

Mark

[Mark NJ]

Of course the one thing we haven't asked is... How are you feeling?

Thanks for your concern.

Maybe I'm feeling better; however, I hessitate to put any stock in my subjective sense about how I feel. Some people have a good sense of how they are feeling; I'm not one of them. I think I have a bias toward a placibo effect which goes away in a few days after trying something new. So, I don't trust my subjective sense of things.

I'd much rather have objective data to tell me where I am. I accept that not everything is in the data. Even so, in my view, the data comes first and subjective feelings second. If folks on the forum tell me that my CA data are a matter of concern I figure I should take that seriously irrespective of whether I think I feel better or feel no different from what I felt before.

Once I understand what my data are telling me about how I'm doing I'm open to taking seriously what I think I feel about my well-being.

Mark

[Lizistired]

If folks on the forum tell me that my CA data are a matter of concern I figure I should take that seriously irrespective of whether I think I feel better ...

But if you're feeling better....
I think there can be an obsessive attempt to over-fix this therapy.
I can get up in the morning and see how I feel.
I can get up in the morning and check the machine data to see how I should feel. I will probably feel that way.
What's wrong with a little placebo effect?
Maybe go with how you feel during the day and check the data in the evening.

[snnnark]

Couple of additional questions/observations about CA.

I'm recording CA values of 2.6 - 7.6 plus an outlyer of of 12.1. Can anyone give me some feel for what this value should be? E.g., with AHI I've found that < 5 is OK; around 15 is concerning; 30 and above is really bad. So, how serious are values of 2.6 and 7.6 (and so forth)?

Again, 5 seems to be the magic number. And the amount of time you spend in PB could be significant if your oxygen levels go down in those periods.

I'd much rather have objective data to tell me where I am. I accept that not everything is in the data. Even so, in my view, the data comes first and subjective feelings second. If folks on the forum tell me that my CA data are a matter of concern I figure I should take that seriously irrespective of whether I think I feel better or feel no different from what I felt before.

Most of us are not professionals! And the last thing a doctor wants to hear is that "the people on the forum said ...." ! Your situation is a little out the norm so it behooves you to find a Doc who is experienced in what you exhibit i.e. centrals and periodic breathing. If for nothing else, just for your piece of mind!

Keep us posted.

[mayondair]

Go to set up, hold down both buttons until you access the clinical menu, scroll down below flex type, look for SYS One resistance, this is the mask resistance setting(1-4 I think) only Phillips Respironics masks will have correlating numbers, for Resmed or other brand masks you have to find a similar one, ie nasal , nasal pillow, by pillow size, of full face, in PR And use that number. It does look like you have leaks mostly under control, but sure have a lot of centrals and PB. I sometimes see small clusters of centrals when drifting off or when half awake in am, but nothing like the amount your data is showing. JMO, but maybe a sleep doc with neurology or pulmonary background would be a good consult

[ozij]

I've had my Respironics REMaster Auto A-Flex for several months, but just learned out to access its data. Now I want to know how to use the data I can see to assess my condition and adjust my machine's settings.

How accurate are a CPAP / APAP machine's records of these values?

Funny you should ask about using the data before you ask about its accuracy. The question about the data's accuracy should have been the very first you put you mind to.

Whose reply are you going to trust about the accuracy? Which sources would you consider reliable sources on that issue?

I'd much rather have objective data to tell me where I am. I accept that not everything is in the data. Even so, in my view, the data comes first and subjective feelings second. If folks on the forum tell me that my CA data are a matter of concern I figure I should take that seriously irrespective of whether I think I feel better or feel no different from what I felt before.

Back to trusting the data I see. OK, this is info from a person who had been on the forum for way before the first PR Sys1 APAP appeared, and has seen many reports: Your CA and PB data are a matter of concern, and should by brought to a professional's attention.

In my early usages of my machine on Auto I was curious as to how my machine would respond to my breathing; so, I deliberately held my breath on several occasions.

Most of us do that in the beginning. The problem is that all self adjusting machines use analysis of breathing patterns over time to decide when your breathing is interrupted. Breathing patterns while we're awake are chaotic, and anything identified by the machine during that time is meaningless. The machine's accuracy can only be tested whan a the user is asleep.

APAP's ability to identify events has been tested more than once in peer reviewed studies with machine reports compared to PSG analysis, and has been shown to be reasonable. It it up to you - are any other user for that matter - to decide whether you trust those studies or not.

Many of us on this forum have used machine generated data to improve our treatment, objectively - beyond placebo effects.

Please start keeping track of when you were awake and when you were asleep for those machine reports.
And please please go to a qualified professional.

Most of us are not professionals! And the last thing a doctor wants to hear is that "the people on the forum said ...." ! Your situation is a little out the norm so it behooves you to find a Doc who is experienced in what you exhibit i.e. centrals and periodic breathing. If for nothing else, just for your peace of mind!

Well said, snnark!

[Mark NJ]

Thanks Ozij,
Yes, good points.
I have neglected to mention that I have an appointment with my 2'nd doc scheduled for tomorrow. So, it's not that I'm ducking the professional avenue of inquiry in in favor of the forum. Quite the contrary, I'm using the forum to better prepare myself to make the best use of my time with the doc.
Of course, I wouldn't tell my doc "the people on the forum said . . . " I can imagine how that would go over. Moreover, it would forego the entertainment value of seeing his reaction when I could - instead - tell him: "snnnark and pugsey said . . . " (Too bad there is no one with the handle "Snookey" on the forum!).
You folks have all been so kind as to ask me questions that seem to you to be relevant; my plan is to collect these questions and pose them myself. (Forgive me, but I now realize that by not mentioning my pending appointment I might have left some members with the impression that I wasn't intent on obtaining professional input.)

"Funny you should ask about using the data before you ask about its accuracy. The question about the data's accuracy should have been the very first you put you mind to."

I take your point. However, I look at the matter slightly differently. (I work with data professionally; and so, have developed my own peculiar habits of approaching data. Perhaps my habits aren't very sophisticated, yet, in my subject matter, they work for me.) First, I examine the raw data looking for anything that might be interesting somehow. Eventually, I begin to ask about the accuracy of the data. I don't presuppose that whatever data I'm looking at is accurate simply because it's in numerical form. I presume the contrary; it must have some degree of inaccuracy, how much inaccuracy I must investigate. (I once encountered a case of flags which seemed to be all "true" when they should have been all "false" and vice-versa. In this instance there was no one to ask about accuracy; I had to see the data myself to realize that it was 100% opposite to what it should have been.) It's not that I see one question comes before another question. (Perhaps you think of data by asking about accuracy before you look at the data itself whereas I look at the data and then ask about accuracy.) I doubt that either of us operates strictly in one sequence or the other. It's more so a simultaneous consideration of both the data and the accuracy (and other questions such as relevancy).

"APAP's ability to identify events has been tested more than once in peer reviewed studies with machine reports compared to PSG analysis, and has been shown to be reasonable. It it up to you - are any other user for that matter - to decide whether you trust those studies or not."

This remark is very helpful. So, I have some reason to believe that my CA figures are "reasonable". This is one of the questions I was accumulating for my doc; What degree of confidence should I have in my xPAP machine's data? I have no idea of the answer he will give me; one possibility might be is a dismissive answer. Should that be the case, I should inquire as to the correlation - or lack thereof - between my sleep studies and the data from my xPAP. If they correlate, then I'll ask why I should ignore my xPAP data and rely exclusively on the sleep study data (which I wasn't shown). If they don't correlate, that will lead to a more interesting discussion as to what factors make the xPAP data unreliable. Either way, there is a learning opportunity here.


"Breathing patterns while we're awake are chaotic, and anything identified by the machine during that time is meaningless. . . . . Please start keeping track of when you were awake and when you were asleep for those machine reports."

This is a fascinating insight. I'm not immediately sure how I'm going to figure this out. I also have a Zeo machine that gives me graphs and summary data on my sleeping. I think I'll try to print out the graphs and see if the times when my EncoreViewer CA events seem to correlate - or not - to the ZEO graphs on sleep/awake states. The Zeo machine shows that I often am awake at night; e.g., last night I was awake for 6 short periods. From my recent data it seems as though 40% - 60% of my AHI is attributable to CA; a fairly significant chunk. Perhaps - if the CA seems to coincide with awake periods - my CA data is in large part meaningless and my AHI is lower than my PAP machine is registering. Conversely, if my CA data is corroborated by my sleep studies (and doesn't seem to be dismissable on account of coinciding with awake states) then my CA data is a large part cause of my overall AHI.

Thank you all for your input; it has been very fruitful.

Mark

[Mark NJ]

. . . look for SYS One resistance, this is the mask resistance setting(1-4 I think) only Phillips Respironics masks will have correlating numbers, for Resmed or other brand masks you have to find a similar one, ie nasal , nasal pillow, by pillow size, of full face, in PR And use that number.

Thanks mayondair,
So often I find that something is right under my nose and I don't see it. I was scanning for "mask" but missed ". . . based on the specific Respironics mask. Each Respironics mask may have a "System One" resistance controll setting . . . "

Now then, for ". . . other brand masks you have to find a similar one . . . " I'm wondering how to approach this. I have a full-face mask; so, it seems obvious that any nasal mask would be a poor basis to imagine a match. However, I'm hesitant to simply take any full-face Respironics mask and assume that my mask must have a similar leakage profile. Am I being overly cautious here? Perhaps you will advise me that - though it isn't very scientific - I'll be in the ball-park and that's better than just leaving my xPAP machine on a resistance of zero.


As mentioned in another posting, my mask has a graph of leakage vs. pressure. Am I foregoing anything my leaving my xPAP machine on a resistance of zero and relying on the mask's graph to make an arithmetical adjustment to my leakage rate?


Yet another alternative - the first that occurred to me - was to observe the lowest leakage rate I actually observed. Given a reasonable body of data (which I haven't yet accumulated) if my lowest leakage rate were X then I might infer that it was on that night that I got lucky and had no leakage other than that attributable to the ventilation holes. (Every man deserves to get lucky one night in his life.) By simply subtracting the observed value X from all other observations of leakage I could calculate an adjusted leakage rate that would more fairly represent the degree of excess leakage. (While I didn't think of this immediately, it now occurs to me that I need to observe various values of X at various values of pressure and then use the X value corresponding to the pressure I was using to make an adjustment.)

(Incidently, I've thought of a possibility for reducing my leakage rate. I'm a SCUBA diver and I have an awful problem with my diving masks leaking. I have to choose carefully to find a diving mask make and model that conforms to my face perfectly. I happened upon a product - a very viscous "grease" sold for divers to smear on the skirt of their masks to reduce leakage. Tried it last night with my CPAP mask and it seemed to be effective. If it continues to work well I'll make a separate posting of the vendor's contact info in case other members want to try it.)

Thanks,
Mark

[Pugsy]

The mask setting in a Respironics machine will not alter the leak data. It has no impact on leak data like ResMed machines do. From what I have read the setting feature might impact how the machine might function when presented with possible leaks but it does not factor in a certain setting for a certain type of mask in leak reported by the machine.

http://sleepapnea.respironics.com/techn ... ement.aspx

It doesn't say that it subtracts a certain mask vent rate before it reports the leak. It doesn't even know for sure which mask to get an exact leak rate. Best thing to do regarding leak rate and line is just to look at it and see if there are variations or lots of ups and downs indicating leaks.

Looking at your reports we see some minor ups and downs but none extremely large and all within what the machine should be able to handle.

[ozij]

When you talk to the doc, keep in mind that in some cases, CA appear only on CPAP, and not it the diagnostic study.
Good luck, and keep us posted.

[DreamDiver]

When I had my sleep titration study the tech actually told me that it was against a Federal law for me to have the software.

What I find interesting is the complete lack of Flow Limitations. That and the fact that the centrals did not increase with pressure.

I agree with Ozij. Oximetry data during those PB periods will be very interesting.

I have all centrals with a near complete lack of flow limitations too. My centrals also do not increase with pressure, but only up to a certain point, somewhere about 12cm (for me). Mark NJ may likely have a higher sweet spot pressure before open-airway apneas begin increasing again.

@Mark NJ
It might be nice to post example graphs showing flow where periodic breathing is indicated for the night of 2/22 around hour 7, and the night of 2/24 right around hour 5.5.

When you talk to the doc, keep in mind that in some cases, CA appear only on CPAP, and not it the diagnostic study.
Good luck, and keep us posted.

Once again, this comes down to a matter of trusting the data. Centrals are technically supposed to include a measure of thoracic effort. If an effort is detected, even during a clear airway apnea, the event is apparently technically classified as an obstructive.

[mayondair]

Now then, for ". . . other brand masks you have to find a similar one . . . " I'm wondering how to approach this. I have a full-face mask; so, it seems obvious that any nasal mask would be a poor basis to imagine a match. However, I'm hesitant to simply take any full-face Respironics mask and assume that my mask must have a similar leakage profile. Am I being overly cautious here? Perhaps you will advise me that - though it isn't very scientific - I'll be in the ball-park and
I think the ballpark is good enough, probably not much variation in any full face mask, I'd set it and forget it,

(Incidently, I've thought of a possibility for reducing my leakage rate. I'm a SCUBA diver and I have an awful problem with my diving masks leaking. I have to choose carefully to find a diving mask make and model that conforms to my face perfectly. I happened upon a product - a very viscous "grease" sold for divers to smear on the skirt of their masks to reduce leakage. Tried it last night with my CPAP mask and it seemed to be effective. If it continues to work well I'll make a separate posting of the vendor's contact info in case other members want to try it.)
I have no experience with scuba gear, grease or otherwise , I find remzees mask liners helpful when I use my quarto. I don't like the feel of silcone on my face, and they help with leaks. Also like pad a cheek forehead and nose bridge pad.she also makes a liner, or you can make your own from old tshirts or undies. Kathy

Thanks,
Mark[/quote]

[Mark NJ]

Hi everyone,
This will probably be my last interim post before my meeting with my doc tomorrow.

I've learned so much from all your help that my head is beginning to spin. It may spin even faster for a while digesting whatever my doc might tell me.

I have data for 5 days at 8 cm, 2 at 10 cm and 3 at 12 cm. Probably not enough data at any of these 3 levels to suggest which level is best. In any case, the data I have doesn't suggest that higher or lower pressure is better.

So, the biggest question I have for my doc is what influanced his decision to prescribe 8 cm. Next, if and when he thinks that a different setting ought to be tried, should that be +1 or -1 cm? (Or, some smaller or larger increment such as 0.5 or 2 cm).

Next questions are about the CA figures. Was there evidence of CA in my formal tests? If so, did it seem to be associated with an awakened state? In that case, is the CA evidence to be discounted?

Do I really have CA? If so, is it serious? If so, what to do about it?

No one has commented on my OA and H values. For the most part, they are as large as my CA values. So, absent a reason to doubt the validity of my OA and H values, my OSA is about as much a concern as my CA values might be.


In fact, some of my CA values might be discounted to whatever extent they may coincide with periods of wakefullness. (I've tried to eyeball my graphs from my ZEO data vs. my xPAP data, but it isn't at all clear whether CA events coincide with being awake. Some seem to be and others seem not to be and too many are too close in timing to be distinguishable visually). If my CA values deserve some discounting then my OSA values are of somewhat greater concern than are the CA values.

My xPAP machine should be able to lower my OSA; as well as potentially worsening my CA. So long as my pressure setting isn't worsening my CA, perhaps I ought to look for whatever pressure setting will minimize my OSA.


I don't see in the comments that my xPAP machine could have a positive effect on my CA. Perhaps I'm inferring something form a lack of comment, and that's faulty reasoning. Yet, if it's the correct idea (xPAP can't help CA) then . .. If my xPAP machine only has a potential to worsen my CA - but not to help my CA - then what (if anything) is there to do to treat my CA?

The foregoing are the questions that seem most important for my doc. If anyone sees more relavent questions I will appreciate the input.

Mark