Update and more questions

[vancity]

Hi again.

Checking back in after a few months,
Still struggling with the machine etc after my overnight sleep study back in May. Been on CPAP for 4 years before this most recent sleep study and it was to do a titration and find a good pressure as they never did it 4 years ago.

Before sleep study 10-12 Auto and not too bad readings although I had problems dealing with the pressure.
After sleep study in May they said I only needed a pressure of 7. (?????)
Tried 7 the next night and this is what happened: ( note there are no OA's...and there usually is an equal amount of HA's and OA's )


So after that I went back to 9 using straight CPAP. I decided over the last few months I would see what would happen if I slowly reversed the pressure back down to 7. By the way, they told me that my AHI was 1.8 or so for that night of the study. Not much more info from the respirologist though as the report was not finalized. I do have another appointment Oct 7, with the sleep Dr for 90 minutes.
OK, so I went down from 9 to 8.5 ( over the last few months ) and last 2 nights was starting 8 cm. HAs and OAs were pretty well equal at 8.5 - 9 pressure, I mean never too lopsided, that is until the last 2 nights.
See charts:





Very similar to the first night after the sleep study @ 7 pressure. Note mostly a ton of HA's and hardly any OA's. Guess my question is why? Why at higher pressures ( 9 for example) I was getting better numbers but more OA's, and now at lower pressure 7-8 get mostly HA's? Add to the fact that the overnight study was 7 cm and an AHI of approx. 1.8.
Makes no sense. My machine is working fine and I even asked him if it was a difference in machines. He said "no" and pressure was pressure.

Just trying to get as much info together before I go back and see the Dr Oct 7.

Any help why this is happening would be a help.

Thx in Advance

[Julie]

I would not put too much value on one night's study results because they're often not typical of what happens at home. What I am curious about is that your avg. leak rate seems to be the same every night (32) - is that normal for you? It's a bit strange to me. I'm also curious about whether you sleep on your back, side or otherwise as that can make quite a difference to some people, often resulting in more hypopneas on your back (the classic 'worst' position for events) but suggesting you might only have 'positional' apnea if that's the case, though I'd expect to see even fewer OA's in other positions. Hopefully someone else will have some other ideas.

[vancity]

I would not put too much value on one night's study results because they're often not typical of what happens at home. What I am curious about is that your avg. leak rate seems to be the same every night (32) - is that normal for you? It's a bit strange to me. I'm also curious about whether you sleep on your back, side or otherwise as that can make quite a difference to some people, often resulting in more hypopneas on your back (the classic 'worst' position for events) but suggesting you might only have 'positional' apnea if that's the case, though I'd expect to see even fewer OA's in other positions. Hopefully someone else will have some other ideas.

The overnight sleep study is indeed one night, but because they found the pressure at 7 to work ( AHI 1. I decided to take their advice and try 7 at home. The first chart was that night. Tons of Hypos and zero OA,s. Very strange. I put it back to 9 the next night and over the last few months have been slowly working back to 7 to see if I could get the same results. My machine is at 8 now (last 2 nights) and got the similar results as the night after the sleep study. I intend to be at 8 cm for 2 weeks, to give it time.

Try to stay off my back as things are worse and sleep with a softball in the back of a shirt. ..seems to work.

Just don't know why at lower pressure ( 7-8) the OA's are much less and hypo's skyrocket.

Oh and my leak rate is pretty good, not always the same but any spike is always in the acceptable range ... with a very tight mask!

[JDS74]

I would not put too much value on one night's study results because they're often not typical of what happens at home. What I am curious about is that your avg. leak rate seems to be the same every night (32) - is that normal for you? It's a bit strange to me. I'm also curious about whether you sleep on your back, side or otherwise as that can make quite a difference to some people, often resulting in more hypopneas on your back (the classic 'worst' position for events) but suggesting you might only have 'positional' apnea if that's the case, though I'd expect to see even fewer OA's in other positions. Hopefully someone else will have some other ideas.

Julie,

I think this report comes from Encore Viewer and reports total leak, not net leak.
The Mirage Quattro has a vent flow rate (leak rate) of approx 30 with a constant pressure of 9 cm H2O, so you had essentially a zero leak rate and all you are seeing is the base level mask vent rate.

I suspect that the sleep lab didn't score the hypopneas in the same way that the machine at home did so you get an AHI of 1.8 in the lab and 9.9 at home.

You really need to get the detailed sleep lab report to find out.

[vancity]

Julie,

I think this report comes from Encore Viewer and reports total leak, not net leak.
The Mirage Quattro has a vent flow rate (leak rate) of approx 30 with a constant pressure of 9 cm H2O, so you had essentially a zero leak rate and all you are seeing is the base level mask vent rate.

I suspect that the sleep lab didn't score the hypopneas in the same way that the machine at home did so you get an AHI of 1.8 in the lab and 9.9 at home.

You really need to get the detailed sleep lab report to find out.

Yes, I use Encore Basic and have an older Repironics M series auto machine.
Possibly they used a different system at the sleep lab to score things but in the last few months at 8.5-9 cm, i was not getting that kind of HA reading...not even close.

I see another Sleep Doc Oct 7, hoping he will explain why there is such a difference between machie readouts. I know Encore Basic only records very basic info esp. in CPAP mode.

[Jeannh]

I do have another appointment Oct 7, with the sleep Dr for 90 minutes.

Wow! I've seen my pulmonologist once for maybe 20 mins, and my sleep study follow-up is 30 mins, where the nurse says he will explain the study, the insurance and all my needs. The study sayS I have an AHI of 12, and he wants me to use a past-generation straight CPAP.

Do I need a new doc? I'm starting with an APAP (even if I have to buy it myself), since insurance will make me keep it a few years. Input welcome - what I'd give for even a longer appt!

Thanks

[vancity]

I do have another appointment Oct 7, with the sleep Dr for 90 minutes.

Wow! I've seen my pulmonologist once for maybe 20 mins, and my sleep study follow-up is 30 mins, where the nurse says he will explain the study, the insurance and all my needs. The study sayS I have an AHI of 12, and he wants me to use a past-generation straight CPAP.

Do I need a new doc? I'm starting with an APAP (even if I have to buy it myself), since insurance will make me keep it a few years. Input welcome - what I'd give for even a longer appt!

Thanks

Jeannh, believe me, I was shocked when they said it's a 90 minute appointment. I'll believe it if it actually happens! Since my sleep study in May I saw a respirologist twice and I came away with not much info and 10 minutes each time. I think he was fed up with me and referred me to regular sleep doc (in the same location). Still have yet to actually see and have the sleep study/Titration explained to me.
I hope this appointment will finally shed some light on years of multiple sleep disorders i seem to be dealing with.

It's also strange that in the sleep study I took 2 Ativan to help me get past all the electrodes they glue on you. I slept through and seemed to have the best night sleep in a long time.

[Janknitz]

The study sayS I have an AHI of 12, and he wants me to use a past-generation straight CPAP.

Did the doctor actually say that he wants you to use an older generation of machine, or is the DME trying to tell you that's what he ordered. Most doctors don't order a machine in that detail. They may distinguish between CPAP and APAP, they certainly prescribe the pressure setting, but very few say "I want this patient to have an S8, not an S9" or "an M Series rather than a PRS1".

OTOH, DME's are happy to tell you that your doctor ordered THIS older model so that they can sell and older model machine at new prices. NEVER take a DME"s word for ANYTHING. Always check it out yourself.

[vancity]

Well 3rd night at 8 pressure, working my way down ( from 9 cm) to the sleep study recommended pressure of 7.
Seems to be a definite pattern here although only the 3rd night... tons of HA's and only a few OA's. Only 4 hrs sleep with mask on ( although it didn't really do much)

Why would I have almost no OA's at a lower pressure and tons of HA's????

Something seems to quite different from the sleep study and my home machine.
Makes my head hurt just thinking about it....

[JDS74]

Does Encore Basic not create waveform charts for your machine?

It would be helpful to look at what your breathing is doind when the hypopneas are happening.

Have you tried SleepyHead to see if the data is really there?

It stlii seems as if the scoring between the lab and your machine is dramatically different.

[vancity]

Does Encore Basic not create waveform charts for your machine?

It would be helpful to look at what your breathing is doind when the hypopneas are happening.

Have you tried SleepyHead to see if the data is really there?

It stlii seems as if the scoring between the lab and your machine is dramatically different.

Hi JDS74, my machine is 4 years old and records only basic data...esp in CPAP mode. I use Encore Basic, no waveform charts/breathing info. Can't use SleepyHead, at least I don't think so.
Yes the difference in the lab and at home is what's confusing the hockey sticks out of me.
Was hoping someone here had a similar situation and / or knows why OA's are reduced at lower pressures and HA's skyrocket. There must be a reason.
At 9 cm CPAP I was getting readings of 1-3 mostly every night with a 4 + AHI once in awhile.
I could leave it there but they said 7 was the pressure. Just don't know why there is such a disconnect between my machine and theirs. They were using an older Respironics, not sure of the model, but it was about double the size of my M series.

[Pugsy]

Does Encore Basic not create waveform charts for your machine?

Vancity is using a M series machine. It doesn't gather wave form data at all so even if he could use Sleepyhead it wouldn't show it.


To Vancity...
I don't know why the sleep lab comes up with such good numbers and you don't at home unless the scoring for hyponeas is maybe different than the scoring that the machine is coming up with. Meaning maybe a different amount of reduction in flow is need for their hyponeas in the lab vs what your machine is flagging.
Not to mention that sleeping in a sleep lab isn't the same as sleeping in your own bed at home.

At what setting do you feel any better or any worse if the data was not available to look at?

[vancity]

At what setting do you feel any better or any worse if the data was not available to look at?

Hi Pugsy, hard to say cause most of the time I don't feel great because of not sleeping enough or bad numbers. I was at 9cm and getting a good run of 3 AHI or less ( with more OA's than at 8 cm)
Of course even at 9cm I would have the odd night above 4 AHI or higher and at 8.5 cm the numbers started to increase but OA's and HA's were kinda equal. It wasn't until I reduced to 8 cm that I have been getting this lopsided HA events . I think it I further reduced it to 7 cm as their recommendation I would see similar but even higher HA's possible into the 10+ per hr ( as indicatated on the first chart above).

Yes I have no idea why. Is the sleep lab machine so much better than mine?
Its funny because after that night in the sleep lab, I felt better than usual. I had to take 2 ativan, to get to sleep.

I just can't understand why on my machine a lower pressure spikes the HA's and OA's seem to be a non factor.....

[JDS74]

Vancity and Pugsy

There is another explanation for the variance in the numbers. It is possible that the two machines are calibrated differently in terms of pressure.

Do you have a way of testing your machine for correct pressure?

Perhaps the sleep lab has a manometer and they could check for you.

Hypopneas and apneas are really the same thing with the apnea just a little farther on the scale of airway restriction. So as you reduce pressure, the airway has a tendency of closing down more and more until you get an apnea. The generally accepted method of treating hypopneas with CPAP is to increase pressure and that's what you're seeing. Lower pressure -> more hypopneas, higher pressure -> fewer hypopneas.

Your data does show an increase in obstructives with lower pressure. It may be that you will need to go to 10 or even 11 cm to get rid of the hypopneas. That would be a good topic for your next appointment. Do bring your reports so what you are experiencing can be seen.

[archangle]

To Vancity...
I don't know why the sleep lab comes up with such good numbers and you don't at home unless the scoring for hyponeas is maybe different than the scoring that the machine is coming up with. Meaning maybe a different amount of reduction in flow is need for their hyponeas in the lab vs what your machine is flagging.
Not to mention that sleeping in a sleep lab isn't the same as sleeping in your own bed at home.

At what setting do you feel any better or any worse if the data was not available to look at?

I believe most labs will not score a hypopnea unless there is an O2 desat or EEG arousal. The home CPAP can't see O2 or EEG, so it may flag "hypopneas" that won't show up in the lab.

I guess the theory is that that a period of reduced breathing is not necessarily a problem unless O2 drops or it disturbs your sleep.

In some sense, CPAP machine detected hypopneas may not be "real" hypopneas.