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Interpreting 20 minute periods of low pressure shown in SleepyHead - Printable Version

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Interpreting 20 minute periods of low pressure shown in SleepyHead - tfield98 - 02-25-2016

I'm one of the lucky ones. Moderate (AHI 15) before my Resmed.

Now, two months using CPAP, my AHI is considerably below 1, usually about .2

Question: For fun I'm looking at my data in SleepyHead. In the attached image, there are several 20 minute periods when my mask pressure drops significantly.

I'm assuming these are part of the normal sleep cycle. Is that right? Are they REM sleep or something?

What about the pressure drop during the two RERAs? Related somehow?

Are there other patterns in Sleepyhead data (either pressure or other parameters) that make for interesting reading for someone with a general interest in the field?

For example, I can see how fast I fall asleep. And I can see that my sleep breathing is shallower and faster than my waking breathing.

But, what else might be fun to spot?

Tom

[attachment=2194]


RE: Interpreting 20 minute periods of low pressure shown in SleepyHead - Sleeprider - 02-25-2016

The mask pressure drops correlate perfectly with machine pressure drops. If you want constant, just increase the minimum pressure. It appears you're using a relatively low maximum pressure in combination with an EPR of 3 which effectively gives you a pressure of 4/7 (EPEP/IPAP) when your machine is at its maximum pressure of 7.4. that is most of the night, and it works well. But when the machine pressure drops to 6, the mask pressure follows, and in once case you had a hypopnea.

This is really simple. Set your machine to fixed pressure at 7.4 with your EPR at 3, and those dips will go away. There is no reason to use APAP at that low pressure anyway.

RE: Interpreting 20 minute periods of low pressure shown in SleepyHead - tfield98 - 02-26-2016

(02-25-2016, 11:05 PM)Sleeprider Wrote: The mask pressure drops correlate perfectly with machine pressure drops. If you want constant, just increase the minimum pressure. It appears you're using a relatively low maximum pressure in combination with an EPR of 3 which effectively gives you a pressure of 4/7 (EPEP/IPAP) when your machine is at its maximum pressure of 7.4. that is most of the night, and it works well. But when the machine pressure drops to 6, the mask pressure follows, and in once case you had a hypopnea.

This is really simple. Set your machine to fixed pressure at 7.4 with your EPR at 3, and those dips will go away. There is no reason to use APAP at that low pressure anyway.

Hi, Sleeprider,

Thanks for the feedback.

I guess I was mistaken. I figured that the decrease in pressure must have been from my entering a different sleep state and the machine detecting that the pressure it provided could be decreased.

I'm rather new at this. And, I suppose this has been a topic of discussion here. But, I don't feel qualified to decide what adjustments to make to my CPAP machine. I'm sure you have a lot of experience, but the changes you suggest I'll discuss with my MD.

I'm happy with just a few events a night.

Thanks again.


RE: Interpreting 20 minute periods of low pressure shown in SleepyHead - Sleeprider - 02-26-2016

No problem. Your treatment is excellent, and I don't see any reason to make any changes. Just remember when you are in Auto mode, the pressure may float between the minimum and maximum CPAP pressure settings. This will be reflected in the mask pressure. What strikes me, is that your machine is holding steady at your maximum set pressure. Normally, we would suggest a higher maximum pressure because the machine is apparently responding to something in its algorithm that suggests you need higher pressure than the maximum pressure setting allows; however with nearly zero events, it's not very compelling to make any changes. As long as you feel good and are benefiting from the therapy all is good. Don't hesitate to ask any other questions you might have.

RE: Interpreting 20 minute periods of low pressure shown in SleepyHead - trish6hundred - 02-26-2016

Hi tfield98,
WELCOME! to the forum.!
Much success to you with your CPAP therapy.

RE: Interpreting 20 minute periods of low pressure shown in SleepyHead - tfield98 - 02-26-2016

(02-26-2016, 10:36 AM)Sleeprider Wrote: ...because the machine is apparently responding to something in its algorithm that suggests you need higher pressure than the maximum pressure setting allows;

Interesting. In fact, after a few weeks of use, I was having some problems with nasal mask leaks so my MD lowered the maximum pressure from 8 to 7.4. Seems like a miniscule change numerically. That may explain it.

I'll ask him about it next time we talk.

Thanks again.

And to anyone struggling with their new CPAP machine, "hang in there!" In addition to all the helpful advice you get here, for some of us (including me) it just takes time for our bodies to get accustomed to a new regimen like this. But, the body and mind are remarkably flexible. So, give it time! :-)

Tom