HYPOPNIAS - ARE THEY CENTRAL OR OBSTRUCTIVE EVENTS?

[spottymaldoon]

Probably I am responding to the leak question ineptly. I shall attach the plotted leak rate for the night as, certainly, 60 is very high.

As I understand it, there can be three sources of leak in an otherwise properly set-up system:
(1) The designed-in leak due to the purge/vent arrangement (which I understand is to flush out CO2?)
(2) Mask-to-face seal leak
(3) Leak via the mouth(!)

For me I am learning to control (3) because I am a veteran mouth-breather - last night was pretty successful.
In the old days people used to recommend mouth-breathers to tape their mouth shut but that sounds dangerous if there is a nose blockage - any comments?

https://drive.google.com/file/d/0B1ZlKa1...sp=sharing

[spottymaldoon]

There is no scoring for lazy diaphragm. Except perhaps in the brass section of a band.

And, your leak rate is too high.

Haha!

Leak-rate has been re-stated, thanks.
Spotty

[cpetku]

Be careful in assuming the machine really knows what is going on when it scores an event. For example in the attached chart
   
the machine says I have a Hypopnia at 5:16:25 and it's assumed to occur while I was asleep. But if you look closely, my breathing pattern changed at 5:08:22. It became quicker and the shape went from flat topped to more rounded then back to flat topped and slow then rounded and faster again at 5:10:10. From careful observations of several weeks I know the faster and rounded waveform indicates I was awake and thus the breathing pattern should not be attributed to AHI.

Now if the machine had seen a 10 second gap in breathing between the slow and fast breathing patterns it would have indicated an OA or CA which caused the wake event and that would most definitely be scored in the AHI.

But, if there is a fast rounded breathing pattern with a 10 second gap it typically means I was awake and held my breath for a short period in which case it really doesn't count...

The best indicator for me that there's a problem worth looking at is if SPO2 drops at the same time as the scored event. Since I started using a machine I've eliminated drops below 85%, so I'm sure this is helping. I also haven't wanted to take a cat nap on the way into or at the office while using the machine (not quite 100% compliant due to nose bruising).

While not included in my posted chart, the SPO2 reading also shows increased saturation slightly after 5:10:10 and nothing significant at the time of the Hypopnia...

[spottymaldoon]

Be careful in assuming the machine really knows what is going on when it scores an event. For example in the attached chart

the machine says I have a Hypopnia at 5:16:25 and it's assumed to occur while I was asleep. But if you look closely, my breathing pattern changed at 5:08:22. It became quicker and the shape went from flat topped to more rounded then back to flat topped and slow then rounded and faster again at 5:10:10. From careful observations of several weeks I know the faster and rounded waveform indicates I was awake and thus the breathing pattern should not be attributed to AHI.

Cpetku - this kind of data presentation is extremely interesting; I had no idea the modern machines could do all this - having a way to measure the amplitude and frequency of breathing - and even the ability to look at the waveform - then, even combining this with SPO2, surely means we are very close to making the apnea/hypopnea diagnosis very reliably in the home setting. And of course nobody demonstrates their normal sleep pattern in a lab environment.

You mention hypoxia levels of "below 85%" - some experts have said such levels are extremely dangerous. From your own measurements, how low have you gone in the past?

[PaytonA]

Cpetku,.

From what you have posted, I can not reliably tell if the waveform is flat topped or rounded. I am also not sure if one can reliably tell from the waveform if one is asleep or awake.

Best Regards,

PaytonA

[cpetku]

Cpetku,.

From what you have posted, I can not reliably tell if the waveform is flat topped or rounded. I am also not sure if one can reliably tell from the waveform if one is asleep or awake.

Best Regards,

PaytonA

Sorry for the low res.

Flat (probable flow limitation whenever I'm asleep and muscles are relaxed)
   

Rounded (normal morphology: typically awake)
   

Also note SPO2 is increased in the "Rounded" version.

This is just my interpretation based upon an obsession with the data....

[PaytonA]

Cpetku,.

From what you have posted, I can not reliably tell if the waveform is flat topped or rounded. I am also not sure if one can reliably tell from the waveform if one is asleep or awake.

Best Regards,

PaytonA

Sorry for the low res.

Flat (probable flow limitation whenever I'm asleep and muscles are relaxed)


Rounded (normal morphology: typically awake)


Also note SPO2 is increased in the "Rounded" version.

This is just my interpretation based upon an obsession with the data....

What you are displaying is what my impression of sleep (flat) and awake (rounded) flow rate patterns are. Thanks for the clarification. I saw the flat but could not make out the rounded in the other charts I was looking at. Could be my old eyes.

Best Regards,

PaytonA

[cpetku]

Thanks for the clarification.

PaytonA

So Payton sincee you asked (PM) here's the another interesting way to look at CA/OA logged events to understand how the machine scored them. Just zoom in tight on the x-axis

CA - pressure wave from machine is basically equal on both sides of the 0 reference
   

OA - pressure wave from machine is offset indicating a blockage
   

Awake CA - These should be discounted as the nervous system was not acting in a closed loop with response to C02 Levels (yes I'm an engineer)
   

Again this is my interpretation from looking at many wave forms very carefully and deciding what the machine is doing, not from a specification of the equipment.

[Mark Douglas]

Cpetku,.

From what you have posted, I can not reliably tell if the waveform is flat topped or rounded. I am also not sure if one can reliably tell from the waveform if one is asleep or awake.

Best Regards,

PaytonA

Sorry for the low res.

Flat (probable flow limitation whenever I'm asleep and muscles are relaxed)


Rounded (normal morphology: typically awake)


Also note SPO2 is increased in the "Rounded" version.

This is just my interpretation based upon an obsession with the data....

Great info! I shall sit and relax and read for awhile today and save that graph as a baseline and see how it compares to night time. I wish I had the skill to write code that would make such a comparison for me and therefore identify awake patterns in my sleep data.