Bad sleep study titration? SpO2 drops...

palerider wrote:

raisedfist wrote:My mouth kept popping open but I wanted to keep recording the data so I dealt with it all night. I STILL feel better - probably from clearing more CO2 and apparently preventing hypoventilation from occurring. All the AHI shows up as "unclassified apneas" in Sleepyhead (0.0 for hypopnea, obstructive, clear airway). There were no large leaks reported.

how bad were the leaks?

I am going to take a closer look this evening, to correlate any leaks with the time of apnea events that were recorded. According to SleepyHead the "Large leaks" value was 0.00% or 0.10% (I can't remember precisely). But I will hone in this evening, I was in a hurry this morning to get to work.

It was more of a "wake up and gasp for a second or two" instead of a rushing feel of air or air blasting my face.

I will post a screen shot this evening. I understand the way Resmed reports on leaks is different than Sleepyhead (?).

raisedfist wrote: I understand the way Resmed reports on leaks is different than Sleepyhead (?).

where do you 'understand' that from?

palerider wrote:

raisedfist wrote: I understand the way Resmed reports on leaks is different than Sleepyhead (?).

where do you 'understand' that from?

I thought I read someone here saying that Resmed defines a large leak as anything above 24L/min.

On my Aircurve machine itself it's always stated my mask fit was a smiley face, and on Resmed Myair I've always gotten the full score (20/20) for "minimal mask leak." On all but two nights I've gotten "stars" that say no leaks. The two nights with leaks on Resmed Myair had leaks of 5 L/min and 4 L/min (and still received full score since < 24 L/min).

raisedfist wrote:

palerider wrote:

raisedfist wrote: I understand the way Resmed reports on leaks is different than Sleepyhead (?).

where do you 'understand' that from?

I thought I read someone here saying that Resmed defines a large leak as anything above 24L/min.

On my Aircurve machine itself it's always stated my mask fit was a smiley face, and on Resmed Myair I've always gotten the full score (20/20) for "minimal mask leak." On all but two nights I've gotten "stars" that say no leaks. The two nights with leaks on Resmed Myair had leaks of 5 L/min and 4 L/min (and still received full score since < 24 L/min).

Resmed says to keep leaks under 24lpm. you get a smiley on the machine if you had large leaks less than 30% of the night.

couldn't care less about the toy myair.

sleepyhead shows whatever data is on the card.

palerider wrote:

raisedfist wrote:

palerider wrote:

raisedfist wrote: I understand the way Resmed reports on leaks is different than Sleepyhead (?).

where do you 'understand' that from?

I thought I read someone here saying that Resmed defines a large leak as anything above 24L/min.

On my Aircurve machine itself it's always stated my mask fit was a smiley face, and on Resmed Myair I've always gotten the full score (20/20) for "minimal mask leak." On all but two nights I've gotten "stars" that say no leaks. The two nights with leaks on Resmed Myair had leaks of 5 L/min and 4 L/min (and still received full score since < 24 L/min).

Resmed says to keep leaks under 24lpm. you get a smiley on the machine if you had large leaks less than 30% of the night.

couldn't care less about the toy myair.

sleepyhead shows whatever data is on the card.

gotcha. I will dig into sleepyhead this evening, and post some screen caps zoomed in to show what's going on during the flagged events. thanks for putting up with my lack of knowledge.

raisedfist wrote:gotcha. I will dig into sleepyhead this evening, and post some screen caps zoomed in to show what's going on during the flagged events. thanks for putting up with my lack of knowledge.

the reason I'm asking about leaks is that typically, the only time a resmed reports a UA is either 1) it's an ASV and doesn't check to see if the apnea is central, or b) because the leak is so bad the machine can't tell what kind of apnea it is.

palerider wrote:

raisedfist wrote:gotcha. I will dig into sleepyhead this evening, and post some screen caps zoomed in to show what's going on during the flagged events. thanks for putting up with my lack of knowledge.

the reason I'm asking about leaks is that typically, the only time a resmed reports a UA is either 1) it's an ASV and doesn't check to see if the apnea is central, or b) because the leak is so bad the machine can't tell what kind of apnea it is.

that is good to know. I am anxious to get home and check. if major leaks I will have to try using my full-face mask or at the least, tape my mouth shut.

i am also going to try keeping the ipap at 20 and raising the epap to 8 - changing only one thing at a time may help narrow down the issue as well,

raisedfist wrote:i am also going to try keeping the ipap at 20 and raising the epap to 8 - changing only one thing at a time may help narrow down the issue as well,

making changes every day when trying to figure out things highlights another variable.

sleep varies from night to night, and making no changes at all, you'll have better nights and worse nights.

making changes every night is fine (in my opinion) when first starting out and trying to at least get 'in the neighborhood' quickly, but then you want to start slowing down, looking at averages between changes.

This is a situation where I would want to probably use ResScan to see what it called those "unknown" apneas.
It doesn't sound like large leaks were present for long enough for large leaking to impact name calling.
If the machine was ASV we would know why but the regular Air Curve shouldn't be dumping everything into the "apnea" basket. And it would take a lot of prolonged really big leaks to mess with the event classification and that means a large amount of time well above 24 L/min whenever those events were flagged.

It might be possible that the restrictive lung issues could be impacting the machine's ability to sense things properly though.
It is also possible that with such a high PS that the unknowns were central in nature and confused the machine.

Pugsy wrote:It is also possible that with such a high PS that the unknowns were central in nature and confused the machine.

if it were in any way pressure related, I'd think it'd be the low epap, since the apneas would pretty much have to be happening between breaths, so at epap pressure, no?

It could mean a bad study (as in not able to make a diagnosis), or it can mean that you have very severe sleep disorder(s). Based on reading the postings, it seems that we're talking the latter.

D.H. wrote:It could mean a bad study (as in not able to make a diagnosis), or it can mean that you have very severe sleep disorder(s). Based on reading the postings, it seems that we're talking the latter.

Another possibility might be inexperienced, inadequately trained, or unmotivated personnel at the sleep lab.
It is not always the fault of the patient.

D.H. wrote:It could mean a bad study (as in not able to make a diagnosis), or it can mean that you have very severe sleep disorder(s). Based on reading the postings, it seems that we're talking the latter.

or it could mean you're nattering on about crap you don't understand, as usual.

palerider wrote: if it were in any way pressure related, I'd think it'd be the low epap, since the apneas would pretty much have to be happening between breaths, so at epap pressure, no?

We are thinking in terms of what is usually seen with plain vanilla OSA and I am not so sure that we can do that here with this situation.

Though I agree...more EPAP for sure.

I was just wondering if the restrictive lung issues are in some way causing the machine to not be able to easily name the event (whatever it is) because in this situation there is something unusual and not run of the mill OSA going on.
I was just wondering if the "unknowns" are more of a by product of the machine simply not being able to sense normally due to the underlying different sort of problem going on.
We are used to "unknowns" in the face of big leak or ASV machines but maybe there is some other reason for the machine to need to use the "unknown" classification that we are not aware of.
Just thinking out loud.

At any rate...more EPAP should help and if it does...who cares what they are.

chunkyfrog wrote:

D.H. wrote:It could mean a bad study (as in not able to make a diagnosis), or it can mean that you have very severe sleep disorder(s). Based on reading the postings, it seems that we're talking the latter.

Another possibility might be inexperienced, inadequately trained, or unmotivated personnel at the sleep lab.
It is not always the fault of the patient.

my sleep tech was nice but when I told him that a previous sleep study at University of Chicago medicine hospital titrated me to 20/4 because of hypoventilation, and that it resolved everything giving me > 92% oxygen saturation and preventing hypoventilation, he scoffed and told me those pressures are basically impossible/ridiculous. in fact, the sleep report has instructions from the head of their sleep lab to only raise EPAP if discrete obstructive apneas are observed.

obviously they are not the norm, but I was kind of shocked because I have read several studies involving people with purely restrictive disease component, with no co-existent sleep apnea, and they all repeatedly said that the EPAP usually used was between 2-4, and *sometimes* an epap of 5-8 was necessary to keep the alveoli open and increase functional residual capacity.

I also am skeptical, as I spoke about earlier, that the "therapeutic settings" were clearly only used in maybe the last hour or so of data.