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[secret agent girl]

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[secret agent girl]

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[M.D.Hosehead]

Just after 26:25, the pusle and oxygen lines meet--is this a false reading of some sort? Maybe I was moving around?

IMO, you're correct that's movement artifact. O2 in your nailbed can't drop suddenly from, say 92% to 85%, then suddenly jump to 95%.

I disregard any pO2 drops that look like movement artifact. The ones that count are gradual desats that occur at the same time as events flagged on the XPAP report.

Again, IMO.

[M.D.Hosehead]

Oh, I forgot:

The pulse line doesn't seem erratic to me; it looks like mine on a good night.

The little bars identify "events", for example a decrease of so many % in so many minutes. (I don't remember the numbers). Problem is, the bars flag both artifacts and real desats.

[HoseCrusher]

In order to understand your data you need to view it using different time frames. I look at the whole nights data to get a general trend, then narrow the time down to 60 minute segments, and finally run through it again at 10 minute segments.

When looking at 10 minute segments you can pick up lost signal artifacts.

I consider desaturations below 90% significant, so you can adjust the line that shows up at 88% by going to the options icon (the one that has the wrench and screwdriver on it) and changing the value from 88 - 90.

After looking through the data, go to the oximetry report and review the information there. Of particular importance are the total events, the basal SpO2 % and the time spent below 90%. Each desaturation event is identified on the O2 part of the graph with a grey bar that runs the duration of the event. The pulse events are also identified, but the grading seems to relate to almost every movement you make while sleeping. My cardiologist suggested changing the trigger to 15 beats change over 30 seconds to review the data for something that may be related to a cardiac event. I think the Holter monitors use something similar to signal that it is time to record what is going on with your heart.

96% is a good target average for SpO2 for ages 30 - 60 in "normal" people, with the low value not exceeding 90%.

Here is an article that goes into all of this.

http://chestjournal.chestpubs.org/conte ... 2/625.full

In particular, pay attention to the typical saw tooth pattern of O2 levels during apnea. You can play with this a little by exhaling, then holding your breath while wearing the oximeter. Typically your pulse rate will initially drop, then shoot up as you struggle for breath.

I agree that sudden spikes, either up or down, are artifacts. The oximetry report will also give you a value for artifacts. You can track the artifact value to get an idea of the quality of the data. Oximetry units try to minimize artifacts from finger movement, but many times the algorithm they use is "less than perfect." Flat line segments are normal, but since the body is in dynamic motion all the time, you don't expect to see flat lines all the time.

After reviewing several nights data, you may also be able to identify when you are in deep sleep and when you are in very light sleep or awake. An EEG is better suited for this, but you can get an idea from the O2 levels.

In general, when using xPAP therapy that is effective at removing the obstructions, your O2 levels should stay above 90% all of the time. Obviously different people have different issues, but in general your body will function better if you have enough O2 in your blood.

[snnnark]

I followed the steps for including an image, but it's not working or I missed something...

Did you surround the link with the Img brackets? [img ][/img ] No spaces after the img. The link goes inbetween the ][

[M.D.Hosehead]

Thanks, HC.

[secret agent girl]

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[snnnark]

It seems that flickr has changed their way of working and unless you specify that we can download (or in this case cpaptalk.com) then we can only go to flickr site to view your pics!

For example i can post the thumbnail


but not the big pic because you have reserved copyright!

[DreamOn]

snnark, if you change the "s" in your http: link (right before ".jpg") to "d", then a larger image shows:

All Night:


In other words, you had "http://farm6.static.flickr.com/5210/533 ... 0e7c93b82f_s.jpg" for the thumbnail, and it's "http://farm6.static.flickr.com/5210/533 ... 0e7c93b82f_d.jpg" for this larger image. You can also substitute with "z", "b", "s" or "m" and get other sizes/resolutions. (Don't ask me how I figured that out, because I don't know! )

Here's the other oximeter chart -- One Hour:

[HoseCrusher]

Questions, questions, questions, that seems to be the best way to learn.

The gray line indicates that the oximeter lost the signal. This can trigger an artifact as the unit tries to re-establish the signal. Also, artifacts occur when you slide your finger inside the unit. The best way to learn the difference is to visit with a medical professional that is familiar with these units and go through a few data print outs. Most of your questions should be answered by doing this.

My cardiologist is very interested in my data. He outlined what he thought was important and my sleep doctor and respiratory therapist agreed. After learning this information, I then began searching on what I could find, and their ideas seem to be well founded.

The sensitivity and specificity comment was referring to using oximeter studies instead of full blown sleep studies. The oximeter study is much cheaper and can be done at home. That particular study found that oximetery data and sleep study data were strongly correlated when the sleep study scored AHI > 25 events per hour. Unfortunately, as the AHI events dropped the sensitivity of oximetry also dropped off. With obstructive sleep apnea being classified as having an AHI > 5, oximetry is not sensitive enough to work there. However, as the AHI increases, oximetery sensitivity increases, and if the AHI > 25 it may take the place of a sleep study.

On your graph it is a little hard to see the various sleep stages, but it looks like you quickly went into a deeper stage of sleep, then at about 23:20 you came out of that deeper stage to a lighter stage of sleep. You can see a similar transition at around 28:40. If you do some recording during the day you will be able to sort your patterns for wakefulness out. One of my startling discoveries was that my average O2 level drops while I am driving. I now practice breathing exercises while I drive to keep my O2 levels up. The drop was not great, but I think I need to be as alert as I possibly can be while driving. My levels are normally around 96.5% and while driving this drops to around 94%.

I find that I get similar readings from my ring, middle, and index fingers, and I use all of them in rotation to avoid getting sores on my skin. Some people have fingers that aren't as uniform. In that case you need to hook up an ECG and see which finger gives comparable data to the ECG.

The pulse waveform is called a plethysmograph. You can estimate profusion from it, along with some information on how well each pulse is performing. Here is an article on this and a search will bring up a whole lot more.

http://en.wikipedia.org/wiki/Photoplethysmography

And here is another with some rather poor quality examples. Still they serve well to illustrate some of the differences. They show rate changes and the plethysmograph also shows rhythm differences. I refer to these as the chair, the echo, the picket fence, the alps, and the normal rolling hills. Not very technical, but my cardiologist understands them and knows what they relate to.

http://www.amperordirect.com/pc/help-pu ... graph.html

Unfortunately, the plethysmograph wave form is not recorded so you have to watch it in real time. Still, it adds more information as to what is going on. However, while informative, it is not as good as an ECG.

After my sleep study I was sent home with a machine set wide open (4-20) on APAP. I adjusted the pressure and dialed it in based first upon my oximetery data. Once I had a pressure that eliminated the obstructions and I had no desaturations below 90%, I then began looking at the machine scored AHI values. While I haven't heard from my sleep doctor after going over the results of the sleep study, my cardiologist and respiratory therapist are very interested in my SpO2 data reports. My cardiologist has asked me to drop off an SpO2 report of an average night once a month. When we get together for an appointment he pulls them out and we go over the data. I see my RT about once a month to complaine and replace my failed LX hose. I show him a report and we speculate on what improvements to consider.

One caution involves the accuracy of these units. I recommend comparing the results you see with those used by paramedics or in the hospital. These units are supposed to be checked prior to shipment, but you never know. I loaned my unit to my cardiologist while he was on weekend duty. He checked it out for me against the units in the hospital and let me know that is was very accurate.

As you can tell, I think the pulse oximeter is a very important part of figuring out how well your xPAP therapy is working. Proving that you have eliminated the obstructions to breathing lets you focus on other things if you find that you aren't jumping out of bed hitting the floor at full speed every morning feeling totally refreshed.

[secret agent girl]

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[secret agent girl]

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[HoseCrusher]

My experience is different. I don't suffer from the "classic" symptoms of sleep problems either, but I haven't experienced any changes and still bounce out of bed ready to go even when using xPAP.

My wife tells me that I no longer stop breathing while sleeping, and that I no longer snore. I have noticed that my O2 levels don't fall below 90%, and by adding a very small amount of sea salt to the water in my humidifier I no longer notice morning nasal congestion.

The biggest change I have noticed is that I no longer get up in the middle of the wee hours of the morning to pee. I had a discussion about this with a urologist and he thought that the obstructive sleep apnea may have been arousing me to wakefulness. In my somewhat groggy state the only thing that made sense to me was that I had to pee, so I would get up and go. I don't know if this is what is going on, but at some level it makes some sense.

I would suggest that you try to figure out how you can raise your average O2 levels for the night, and how to eliminate desaturations below 90%. It looks like your average was around 93% for the data you have posted but you can check your report for the actual value. A reasonable target to shoot for is around 96% at elevations close to sea level. If you starve your body of oxygen, your sleep quality goes down.

Just as there are many things that effect sleep, there are also many things that effect oxygen levels. Some people don't get a good signal because of the length of their fingernails, or they may use a fingernail polish that interferes with the performance of the unit. At the other end of the spectrum is vascular trauma like a broken finger or a blood clot. It is a puzzle that you can figure out on your own, but enlisting the help of a medical professional speeds the process along. I am very happy that I was able to "hire" a cardiologist that takes the time to not only look out for my well being but to also explain and share his medical knowledge with me as I try to figure out the best path to take. In my book he gets "Employee of the Year."

[secret agent girl]

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