Riddles in the dark

General Discussion on any topic relating to CPAP and/or Sleep Apnea.
Rise
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Riddles in the dark

Post by Rise » Fri Oct 12, 2012 11:34 am

[reference original SpO2 graph inquiry here viewtopic.php?f=1&t=82064]

Picked up a pressure sensor and A/D box

Results as expected

There are also places where it looks "flattened" if you zoom in but I need to tweak the A/D converter settings to get a cleaner waveform to be sure.

Image

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Julie
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Re: Riddles in the dark

Post by Julie » Fri Oct 12, 2012 1:47 pm

Are you asking a question? Looking for help?

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Slartybartfast
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Re: Riddles in the dark

Post by Slartybartfast » Fri Oct 12, 2012 1:59 pm

Looks like Cheyne-Stokes pattern to me. But what do I know. Run that by a sleep doc/pulmonologist to be sure. It can be a sign of congestive heart failure, so don't let it slide.
The flat-topping could be airflow obstruction, preliminary to snoring which may be preliminary to an obstructive event.

http://en.wikipedia.org/wiki/Cheyne-Stokes_respiration

http://www.google.com/imgres?imgurl=htt ... m=1&itbs=1

Guest

Re: Riddles in the dark

Post by Guest » Sat Oct 13, 2012 10:35 am

Sorry, intented as an update but incomplete.

Yes, looks like CSR and that's linked to scary things, but I'm reasonably healthy other than being tired and feeling foggy (I think)

I'm more inclined to suspect over-robust co2 response and instability triggered by arousals, but I don't currently have eeg visibility. There are more channels on the data acquisition box though and I'm working on that.

The sleep lab called back after my partial post attempt above so I have an appointment soon for a consult. Will see what they say...

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Slartybartfast
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Re: Riddles in the dark

Post by Slartybartfast » Sat Oct 13, 2012 10:46 am

If that's a typical pattern, it's one thing. If that pattern appeared during REM sleep, or a period characterized by disordered breathing then it's most likely innocuous. EEG would be nice to have.

Rise
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Re: Riddles in the dark

Post by Rise » Sat Oct 13, 2012 1:23 pm

It happens a lot, sometimes the bulk of the night, but it's not the only pattern. Sometimes it's quite stable.

I don't think[\i] I'm dying, at least not at any particularly accelerated rate. Tired of feeling fogged and funky, but whether sleep breathing or even sleep has anything to do with it is an open question, one which I want backed into a corner as quantitatively and independently as possible. It seems plausible, but with any complex system it's easy to infer causation where something is actually an effect or entirely independent.

Fascinating to have insight into such things, even if they are somewhat vexing.

Rise
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Re: Riddles in the dark

Post by Rise » Mon Oct 15, 2012 7:19 am

Woke up with a headache feeling like crap again

Blood sugar 85 (94 and 95 the last two times I checked pre-breakfast)

BP 140/90 (fairly standard these days, not great but not interesting differentiating today from yesterday)

Not a good night for nasal flow, but of course I didn't wear the spO or resp monitors


Maybe I should just wear the monitors all the time and the universe will be forced to leave me alone because I'm watching...

Rise
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Re: Riddles in the dark

Post by Rise » Mon Oct 15, 2012 11:10 am

From a more stable portion of the same night -

As I understand it, these would seem to reflect restricted flow(?)
Image
Image
Image

More normalish
Image

Is there any kind of recognizable signature for where a restriction occurs? I know I have nasal issues (septum/turbinate), and I know I have intermittent issues elsewhere but I didn't think they were frequent.

I'm getting mixed signals from my reading on the applicability of xPAP for nasal issues and centrals. Some seem to suggest some potential benefit, others less so.

Thoughts?

Thanks in advance

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Slartybartfast
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Re: Riddles in the dark

Post by Slartybartfast » Mon Oct 15, 2012 11:27 am

Most of us are used to seeing airflow, rather than pressure, so I might be all wet:

Assuming that your pressure chart is essentially the same as flow, the pattern would appear to indicate severe flow restriction. The peaks which rise rapidly, then flat-top are consistent with inspiratory flow restriction, while the peaks that stair-step down, looking somewhat like a chair with the back to the left side, indicate expiratory flow restriction. There's a fairly regular stairstep rise that you can see on the chart that _might_ be your pulse. If it is, that's pretty cool.

Below is a pretty typical pattern for me. Looks like a dull sawblade. Or a school of sharks playing follow-the-leader.

Image

1041
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Re: Riddles in the dark

Post by 1041 » Mon Oct 15, 2012 11:38 am

Can you show us a graph of a good night?

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Slartybartfast
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Re: Riddles in the dark

Post by Slartybartfast » Mon Oct 15, 2012 11:40 am

Windaq looks like a useful application.
http://www.dataq.com/products/software/acquisition.htm

Rise
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Re: Riddles in the dark

Post by Rise » Mon Oct 15, 2012 1:04 pm

That recording is actually from a fairly good night. Wish I had made the effort to hook up last night, although there does seem to be a very real element of "observing the system alters the system" in play, either that or "the universe loves irony", not sure which.

I went through the log again looking for 'clean' waveforms and at first selected the same one as before. Looking more thoroughly I believe this is +/- what it should look like
Image

On further search, I found this - http://www.aastweb.org/resources/focusg ... rotech.pdf, which I missed previously.

It looks like the above isn't exactly prototypical but is at least a reasonable approximation of 'normal'.

Note:

"QUESTION 10: What does a hypopnea look like?
Hypopnea is defined as airflow decreased below a given percentage of the
“surrounding baseline” and may also require the presence of some degree of
oxyhemoglobin desaturation or arousal. Typically, a flow reduction of 25 – 50% should
be seen in order to score an event as a hypopnea. Scoring for both apnea and hypopnea is
often subjectively determined, but the event duration should typically be at least 10
seconds. In the scoring of hypopnea one might wish to keep in mind the nature of the
relationship between the NP airflow signal and true flow. The nasal cannula actually
records the square of airflow. Thus, a NP airflow signal that is 50% of the surrounding
baseline is actually 70% of the surrounding flow. A NP airflow signal that is 25% of
surrounding flow is actually 50% of the actual airflow. A typical hypopnea is shown in
Figure 8.4. Note, in addition to an amplitude reduction there is a marked change in shape
with prolongation of inspiratory time."

See link for accompanying graphics. So the earlier waveforms would seem to be restricted but given the relationship between pressure and flow, not severe. (I assume the graph from the xPAP machine is from a mass airflow sensor?)

That periodic 'bump' is interesting, quite possible it is a pulse artifact.

Windaq took a bit of reading the manual to get used to, and I'm used to working with software, but once you get it sorted out it seems to work well. I really wish my amplifier chips would get here - I want EEG...

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JohnBFisher
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Re: Riddles in the dark

Post by JohnBFisher » Mon Oct 15, 2012 1:36 pm

Rise wrote: ... Woke up with a headache feeling like crap again ... BP 140/90 (fairly standard these days, not great but not interesting differentiating today from yesterday) ...
The problem is that that is high blood pressure. It WILL over the course of time cause serious damage. By the way, if you have those awful headaches in the morning, it's probably a sign that you have untreated sleep apnea (obstructive or central). This leads to unmanageable high blood pressure - medication won't touch it. The down side of ignoring it is that damage will occur. For example, if you take Ibuprofen (or any other NSAID) to tackle the headache with the high blood pressure, it WILL damage your kidneys.

I could not get my doctors to pay attention to my central apneas. Unfortunately, due to Ibuprofen use and the resulting high blood pressure that medication would not handle, it damaged my kidneys. I now must pay close attention to my diet, blood glucose levels, and the overall state of my kidneys. With the proper xPAP therapy, my blood pressure is now controlled with medication. I also am going onto insulin pump therapy to try to keep my blood glucose levels as close to normal as possible.

But dang! You don't want to be in the same mess that I now face .. So, PLEASE pay attention to those morning headaches!!

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Slartybartfast
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Re: Riddles in the dark

Post by Slartybartfast » Mon Oct 15, 2012 1:37 pm

Where and how are you measuring pressure? It might be the location of your pressure sensor is responsible for that particular pressure waveform. CPAP machines measure pressure/flow at the machine, so there's plenty of elasticity between there and the old shnoz. Therefore my waveform and yours might both be OK.

To expand on what JohnB said, I, too, had high, unresponsive blood pressure. Nothing would treat it. My GP was perplexed. UNTIL I asked for and got a sleep study and got on the hose. Now I'm down from 145/98 to about 115/75 and I'm not on any meds.

Only thing that changed was the CPAP machine.
Last edited by Slartybartfast on Mon Oct 15, 2012 1:43 pm, edited 1 time in total.

1041
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Re: Riddles in the dark

Post by 1041 » Mon Oct 15, 2012 1:42 pm

How long have you been having non-restorative sleep? Do you wake up a lot at night?