Sleepyhead / Leaks / Obstructive

If I were saying this to a bright four year old looking at a sleepyhead chart~~~
... would these two statements be true?



1) When you quickly look at the Flow Rate graph, the gray areas are areas where your mask was leaking.

2) There will be no obstructions reported during these gray times.



~~~and if 4 year old asked, we'd say ...
"there still could be some therapeutic benefit, we hope, even in those gray areas"



Thank you for confirming / correcting this insignificant little part.

Grace~~~ wrote:2) There will be no obstructions reported during these gray times.

Possibly.
There might be no obstructions reported because none happened even in the face of a big leak. Big leaks may or may not allow the airway to close.
It depends on probably a lot of factors with the amount of big leak being probably primary factor. There are worsening degrees of bad leaks.
I have had leaks just barely into large leak territory with no flags. I am fairly certain that nothing happened because I have had leaks deeper into large leak territory and saw some event flags.
So you can indeed have events get a flag in the gray area...I have had it happen to me and I was over 30 L/min deep into large leak territory when it happened.

Great to know, Pugsy. Thank You.


~~~I will *out* myself.

*I* am actually the four year old.

Now that I know it's possible I will dig back through my data and find an example.
(I only looked back about 45 days.)

I don't want to address the leaks.
I am in a committed relationship with my mask and don't want change. LOL

Grace~~~ wrote:"there still could be some therapeutic benefit, we hope, even in those gray areas"

I don't often get large leak (gray area). When I do, I zoom in on the wave form. It always shows normal breathing. My assumption is the machine maintains enough pressure to prevent any events. So, the large leak is not horribly large. I would be interested to hear what your waveform looks like during periods of large leak.

Yes. Thank you ChicagoGranny. That makes sense.

ChicagoGranny wrote:I would be interested to hear what your waveform looks like during periods of large leak.

You got me to thinking and wondering so I did some digging and it took a bit to find some really big leaks to look at.
Most of mine barely make it over 24 L/min but I finally found a couple where the leaks were really big and well over 30 L/min.
I wanted to see what the flow rate looked like in the face of a really big leak.

I found one that shows just what appears to me to be normal asleep breathing and one where I had a hyponea flag pop up during the large leak.
So we know that even with a really big leak if an event happens it can get a flag...only thing is that I can't see why it was flagged a hyponea. I sure didn't see any change in the flow rate but maybe it just barely made that 40% reduction to earn a hyponea flag and it just doesn't show up on the graph to where we can see it.
I did a quick scroll through some flow rate during large leak and I never spotted anything that looked like it should have been flagged but wasn't.

Pugsy wrote:only thing is that I can't see why it was flagged a hyponea.

Agreed. One would think if it was going to flag a hypopnea during that LL, it would flag one at about 4:29:00 or 4:30:25. The one it did flag at 4:29:25 looks like what they call in football a late flag.

ChicagoGranny wrote:Agreed. One would think if it was going to flag a hypopnea during that LL, it would flag one at about 4:29:00 or 4:30:25. The one it did flag at 4:29:25 looks like what they call in football a late flag.

You know maybe the late flag was the result of the large leak affecting the sensors a bit?????
I had to hunt to find a flagged event during a large leak in the 30s or more. I will keep an eye out and see if I can spot any more deep in large leak territory.
I don't count 28 L/min as deep in LL territory.
At any rate...I think these machines do a lot better sensing when deep in large leak territory than they are generally given credit for.
I still won't tell people to pooh pooh off really large leaks though...just in case.
Better to play it conservatively.
Now leaks up to 30 L/min on a ResMed machine...I will pooh pooh those off. If the machine can still be fairly accurate over 35 L/min then it for sure is accurate at 28 L/min.

FWIW: ResMed (AS 10) does NOT score a length for hypopneas - your decision where it started and where it ended. (SH puts the marker on the END and it makes every Hypopnea and RERA 10 seconds long)

If I had to guess the obstructed breath that earned the scoring was the one at 4:29:08.
But we will never know if the Hypopnea didn't last over 1 minute and the scoring (besides the 2 clearly obstructed breaths during that) was earned due to the reduction in measured flow as a result of the leak.

ResMed really does suck regarding diagnostics - but they make up for that with therapy success.

Pugsy wrote:I think these machines do a lot better sensing when deep in large leak territory than they are generally given credit for.

Yes, I came to the same conclusion. Some weeks ago, I started looking closely at my waveforms during the infrequent times SH shows LL. The waveforms showed inhale/exhale and usually at normal level. That gave me a bit of mental comfort that the machines do a good job of treatment at higher leak levels than I thought previously.

Guest wrote:ResMed (AS 10) does NOT score a length for hypopneas

What you mean by this is not clear to me. I would think the machine has to count to 10 seconds before scoring a hypopnea.

that might be true - at least for resmed it is 10 seconds.
In ResScan Hypopneas and RERAs are just markers - without any length attached to it. In SH it always shows 10 seconds.

At least with the AirSense 10 (any beyond) series ResMed does no longer tell you how long those 2 events have been - might be just 10 seconds - or minutes - your guess is as good as any.

Have you heard of the invisible ships phenomenon, cited in several new-age books and movies? It goes like this: When Captain Cook/Columbus/Magellan (depending on the version of the story you're hearing) arrived at the coast of Australia/Cuba/South America, the native people completely ignored them, presumably because huge ships were so alien to their experience that "... their highly filtered perceptions couldn't register what was happening, and they literally failed to 'see' the ships."

I'm pretty sure that is all 'debunked' now but it is still how *I* feel when looking at sleepyhead.

I am not even certain what 28 L min and 30 L min really are?

Like Pugsy, I did go back and look for flags in my grayed out leak areas. So far I haven't found an example but I saw several weird examples where all of a sudden in the middle of the gray leak it is not gray for just enough seconds to get a flag and then turns gray again?

I also followed ChicagoGranny's advice and looked closely at my wave forms. But I fear I may be missing invisible ships?
The wave forms looked good to me? They sure just looked like normal breaths? But again, my uneducated eyes could be blind to what is meaningful to others?

My AHI for the year is right at 1. So obviously I have lots of nights when it's below 1. And I feel good and I like cpap. However, I am vaguely concerned that I could do better and that my AHI may be artificially low due to my leak issue.

Last night I raised my minimum pressure from 9.2 to 9.4 after not changing anything for 357 sleeps. I woke feeling not as good as normal. (psychosomatic probably.) However, my AHI last night was 0.26 which is super good for me.

I only raised the minimum because it was instant and easy and fixing my leak issue and understanding sleepyhead better is hard.

I haven't always been so mentally lazy.

There's a lesson here somewhere.
I think I'll leave it at 9.4 for a few days.




Oh, also ... I was in the hospital last week under anesthesia and telling the anesthesiologist how I was given the cpap but not a single doctor has ever discussed anything with me and I never had a sleep study and I know everything I know from this cpaptalk site.

(So they got very nervous and didn't want to get involved or hear about it )

I asked them to please watch me closely while I was under. She told me when I awoke that I was a "shallow breather" and that I went below 90 in oxygen. But then she slipped out of the recovery room and clearly didn't want to get involved. Just wondered what anyone else would make of the phrase "shallow breather?".

Grace~~~ wrote:I feel good and I like cpap

You should unplug Sleepyhead and take the rest of the year off.

Too true.

I think it's just comforting to feel like there is anything I have control over.
Even if it's just my autoset

I could work on the problem of not having a back-up machine.
That would no doubt be a better use of time.

~~~those little breath wave forms are just so seductive though?
Like they could give me the answers to the universe if I could just understand their language!

Grace~~~ wrote:~~~those little breath wave forms are just so seductive though?

Fascinating that technology has evolved to the point this is available in our homes for $500 or less. When I tell a friend that I can see every inhale and exhale I took (or didn't take) during the night, they are incredulous.