CPAPtalk.com

Pugsy wrote:If it were my report I wouldn't be so worried about dissecting it and naming it.. I would be worried about preventing it.

Which of course is exactly what I want to do. Would yew know what if that kewl Sleepyhead software will read data from CMS-50F?

Pugsy wrote: I think that in this particular situation it doesn't really matter what that obvious flow limitation is called. It is extremely long and sure to be a stressor on the body. If it were my report I wouldn't be so worried about dissecting it and naming it.. I would be worried about preventing it.

I'm interested in the question of scoring of apneas in general. I'm concerned that people see "apnea" as black and white, not things of varying duration and severity. If this were a zero flow apnea of 2 minutes length, it would be a very big deal. Unfortunately we tend to treat a 2 minute zero flow apnea the same as an 11 second flow restricted apnea.

That's why I keep harping on the need for examining the flow waveforms instead of just the event numbers.

In Thomas's case, I wonder if it's possible he's getting enough O2 during these long "events". If you look at his 8:12 graph, there are 5 minutes when most of his breathing is a lot lower flow rates than his heavier breathing bursts or breathing afterwards. How much of this time period is an apnea in terms of SPO2 and EEG arousal (and physiological harm)? The machine scores a 128 second event, but his flow rate doesn't really look that bad during that interval. He's clearly breathing, but at a reduced rate.

archangle wrote:In Thomas's case, I wonder if it's possible he's getting enough O2 during these long "events". If you look at his 8:12 graph, there are 5 minutes when most of his breathing is a lot lower flow rates than his heavier breathing bursts or breathing afterwards. How much of this time period is an apnea in terms of SPO2 and EEG arousal (and physiological harm)? The machine scores a 128 second event, but his flow rate doesn't really look that bad during that interval. He's clearly breathing, but at a reduced rate.

That is exactly what *I* would like to know. So I bought an oximeter to find out. Except now I gotta wait for it to arrive in the mail.

ThomasMcKean wrote: Which of course is exactly what I want to do. Would yew know what if that kewl Sleepyhead software will read data from CMS-50F?

I don't know my models but this is listed as now working with SleepyHead. So I am assuming it should. Sure worth a try. I have no idea how to do it though.. I don't have oximeter to test the steps.
copied from SH page
Contec CMS50 Oximeters

archangle wrote:

Pugsy wrote:Apparently the reduction in air flow was significant enough to be called OA (clearly marked).
Respironics definitions for Obstructives and Hyponeas are possibly different from your ResMed definitions.
From the Respironics Provider manual.

I wonder if he has a brief burst of heavy breathing and that sets the "baseline" at a false level, causing it to flag a less severe event as an apnea. We already know some machines flag a lot more apneas than others. Maybe this is one of the areas where the algorithm falls flat.

S9 Series Data Management Guide wrote: An apnoea is the temporary absence
or cessation of breathing. An apnoea
is scored when there is reduction
in breathing by 75% of the baseline
breathing for at least 10 seconds.

That should score more events than Philips' 80%, yet that 3 minute breathing apnea in Thomas's data would never be scored that way on an S9. I honestly can't make heads or tails out of the event flags yet, but if this isn't a bug, the difference in scoring has to be how the baseline is determined.

Thomas has several flags where it's not obvious if the marker indicates the beginning, middle, or end of an event. And yet at 10:44, there's an OA flag up nicely with the end of a short apnea just like I'm used to seeing in my S9 data. What exactly does the 10:40 apnea flag tell an experienced PR1 user? To my eye, it looks like a scoring or reporting error of some kind, but maybe I just don't know what I'm looking at.

ThomasMcKean wrote:

archangle wrote:In Thomas's case, I wonder if it's possible he's getting enough O2 during these long "events". If you look at his 8:12 graph, there are 5 minutes when most of his breathing is a lot lower flow rates than his heavier breathing bursts or breathing afterwards. How much of this time period is an apnea in terms of SPO2 and EEG arousal (and physiological harm)? The machine scores a 128 second event, but his flow rate doesn't really look that bad during that interval. He's clearly breathing, but at a reduced rate.

That is exactly what *I* would like to know. So I bought an oximeter to find out. Except now I gotta wait for it to arrive in the mail.

Did you order from China? Substantial discount of you do it that way, but at the cost of a longer delivery time. The oximetry data should help clear up some of the mystery.

In the meantime, maybe you ought to reboot your machine. Coherent event flags would be a help in adjusting your therapy. The s9 has a lot of data bugs, and rebooting usually helps. Perhaps after a reboot you'll find that similar periods are scored as hypopnea or not at all.

Otter wrote: Did you order from China? Substantial discount of you do it that way, but at the cost of a longer delivery time. The oximetry data should help clear up some of the mystery.

Yes I did.

In the meantime, maybe you ought to reboot your machine. Coherent event flags would be a help in adjusting your therapy. The s9 has a lot of data bugs, and rebooting usually helps. Perhaps after a reboot you'll find that similar periods are scored as hypopnea or not at all.

Eh? Reboot? As in unplug it and plug it back in again?

ThomasMcKean wrote:Eh? Reboot? As in unplug it and plug it back in again?

Yes. Hurts nothing Just forces the machines firmware to reboot? May or may not make any difference but won't hurt a thing.

Pugsy wrote:

ThomasMcKean wrote:Eh? Reboot? As in unplug it and plug it back in again?

Yes. Hurts nothing Just forces the machines firmware to reboot? May or may not make any difference but won't hurt a thing.

Latest image: http://thomasamckean.com/cpap/Data-22.jpg

Sez Obstructive lasted for 2 minutes and 49 seconds.

My opinion for what it is worth....(probably not much) is that the OA as flagged appears to be maybe 15 seconds...notice the straight flow line which means no flow and the OA marker is in the middle of the straight line & is followed by the time of possible reduced flow for that 2 plus minute time frame. I don't think that the unnamed 2 minute 49 second possible decrease in flow (ragged line) followed by the deep breath is part of the obstructive apnea. Looks more like just a slight reduction in flow, irregular and may or may not be enough to cause any desat. When you get your oximeter you should be able to tell if those type of flow patterns are a problem or not.

Pugsy wrote:My opinion for what it is worth....(probably not much) is that the OA as flagged appears to be maybe 15 seconds...notice the straight flow line which means no flow and the OA marker is in the middle of the straight line & is followed by the time of possible reduced flow for that 2 plus minute time frame. I don't think that the unnamed 2 minute 49 second possible decrease in flow (ragged line) followed by the deep breath is part of the obstructive apnea. Looks more like just a slight reduction in flow, irregular and may or may not be enough to cause any desat. When you get your oximeter you should be able to tell if those type of flow patterns are a problem or not.

Exactly. I just printed these three out and took them to Dr. to try and get an oximeter tonight. Waiting for them to call me back. It may be nothing, as yew say, but better to be safe than sorry, yew know...

ThomasMcKean wrote:better to be safe than sorry, yew know...

Tis true. Hurts nothing to be cautious. During my initial sleep study I had some 45 second apneas and desats to 73%.
Until this past spring I used the M series machines so didn't have a clue as to possible length of events.
I did get the DME to let me try their Oximeter for over a weekend back when I was about 4 months into therapy.
I didn't have any significant desats at that time so I never bothered with the expense of my purchasing an oximeter. Now I have the wave form data available but I don't have any burning desire to put it under a microscope.
I have no problem with those that do want to put it under a microscope though. I am just content with things as they are.

I can see where you might be concerned and if I were in your shoes with some of these long "whatever they are"...I probably would also be wanting to check the O2 levels just as precaution. It may not be anything to be concerned with but peace of mind is worth an awful lot.

Pugsy wrote:My opinion for what it is worth....(probably not much) is that the OA as flagged appears to be maybe 15 seconds...notice the straight flow line which means no flow and the OA marker is in the middle of the straight line & is followed by the time of possible reduced flow for that 2 plus minute time frame. I don't think that the unnamed 2 minute 49 second possible decrease in flow (ragged line) followed by the deep breath is part of the obstructive apnea. Looks more like just a slight reduction in flow, irregular and may or may not be enough to cause any desat. When you get your oximeter you should be able to tell if those type of flow patterns are a problem or not.

It might not be worth much either, but I agree. It does look like a problem to me, but not nearly as big a problem as a two or three minute zero flow apnea. That really would be scary.

Otter wrote:It might not be worth much either, but I agree. It does look like a problem to me, but not nearly as big a problem as a two or three minute zero flow apnea. That really would be scary.

The OA itself is flagged by the machine as being 169 seconds in length. I suppose that doesn't necessarily have to mean it is true, but that is the PRS1 Auto's interpretation of the event.

ThomasMcKean wrote:The OA itself is flagged by the machine as being 169 seconds in length.

I don't think it is flagging the whole thing as an OA. I think only the part where the OA letters are sort of in the middle of the straight flow line. Now the rest of that segment does have flow to it. Maybe reduced but flow is there nonetheless and doesn't seem to be quite as reduced as your previous events in question. I could be wrong. I often am. I wish Respironics would give us a little box above the event telling us how long they think the event was like ResMed does. Would sure come in handy here.