Don't turn CPAP minimum too high? Is tech's REM idea valid?

[Java Time]

Note: SleepingUgly had a concern that my subject line of "Don't turn CPAP minimum too high, you may not reach REM", may unintentionally mislead someone into lowering their CPAP minimum. I don't want that to happen , so I'm re-naming this thread "Don't turn CPAP minimum too high? Is tech's REM idea valid?"

Update from Java Time 11/22/2011 - from the comments below you will see there is agreement my sleep tech was WRONG, please don't lower your minimum CPAP pressure due to this thread!




Now that everyone has their seat belts securely tightened, here is the Original Post from 11/21:
During the CPAP Titration portion of my split night study, I had total sleep time of 108 minutes

From the doctor's report "CPAP was initiatied at a pressure of 6 cm of H2O with exploring done up to 9. The patient had difficulty initiating sleep but then achieved 1 episode of REM sleep while on pressures of 7 and 8 cm of water pressure in supine position."

Based on the above, the sleep tech who was going over my sleep study data told me "since you didn't hit REM during the time you were at 9 cm of H2O, it is possible you may not be able to reach REM sleep above 8 cm of H2O". He did also mention "the sleep lab was only allowed 3 hours for the titration study and you only slept 108 minutes, so that may be why you didn't hit REM above 8cm"

At my 40 day appt, my sleep doctor didn't mention anything about this concern. The doctor did ask if I ever woke up due to high pressure (I went as high as the mid-teens occasionally according to my SD card). I told the doctor I didn't think I had woke up, I didn't even use the ramp feature with my 8 minimum, and I felt pretty good.

After hearing this and looking at my data, my doctor said "The patient had improvement but continued to have obstructive hypopneas and, therefore, a clear optimal PAP pressure was not discovered and it is most likely greater than 8 cm of water pressure." and changed my minimum up to 10 cm of H2O.

Like many of you I am doing some mild experimentation with adjusting my minimums.

Personally, I don't think I am having any issues, but it did make me wonder...
1) Is there any potential truth to what the sleep tech said about possibly not reaching REM above 8 cm of H2O?

2) If I do go high enough to interfere with my REM sleep, I'm assuming the only way I'd know is because I would feel less rested over time?

3) Have any of you ever heard of someone who had to drop their minimum pressure due to this REM issue?

[Pugsy]

split night study, I had total sleep time of 108 minutes

I don't think it was pressure that limited REM... I think it was simply running out of time. In the best of circumstances first REM onset during the night normally will not happen until 90 to 120 minutes after sleep onset. After first cycle of REM occurs and the sleep cycles start to repeat then REM starts occurring sooner and for longer durations till the wee hours of the morning when we happen to have more REM time.
See Hypnogram here just below the kid and you will see how REM cycles come and go.

Once your events are control effectively then you won't be waking during the night as much and waking up messes with the sleep cycles because most of the time we have to start all over. This is why frequent wake ups are unwanted. They mess with the normal cycles and thus mess with restorative sleep.
Get your events under control, you will sleep better and REM will come no matter what pressure.

http://en.wikipedia.org/wiki/Sleep

[rested gal]

During the CPAP Titration portion of my split night study, I had total sleep time of 108 minutes

From the doctor's report "CPAP was initiatied at a pressure of 6 cm of H2O with exploring done up to 9. The patient had difficulty initiating sleep but then achieved 1 episode of REM sleep while on pressures of 7 and 8 cm of water pressure in supine position."

Based on the above, the sleep tech who was going over the data told me that the sleep lab was only allowed 3 hours for the titration study and that since I didn't hit REM during the brief time I was at 9 cm of H2O, it is possible I might not reach REM sleep above 8 cm of H2O.

I'm not a doctor or anything in the health care field, but if that is an accurate statement about exactly what the sleep tech said, I think that's one of the dumbest things I've heard of a sleep tech saying. That's a very good reason why some sleep techs should never go over the data with a patient after a sleep study, or volunteer their opinion about what might, or might not, have happened... or might happen in the future.

Only three hours allowed for titration time, and only a "brief time" at a pressure of 9 during the titration ... not surprising that you perhaps had simply not yet cycled into REM a second time when the titration ended.

What a thing for the tech to say!! That tech should consider putting tape over his/her own mouth each time a study is drawing to a close!

[Java Time]

Only three hours allowed for titration time

Actually, it was worse than that. I had total sleep time of 108 minutes, because I didn't sleep for a large portion of my alloted "3 hours!"

if that is an accurate statement about exactly what the sleep tech said, I think that's one of the dumbest things I've heard of a sleep tech saying

Yes, Rested Gal, you did understand what I was told . The sleep tech very clearly said that "since you reached REM at 7 and 8, but not at 9, it is possible that you may not be able to reach REM sleep above 8 cm of H2O

In his defense, he did also mention it was a short time, and that since I did reach REM briefly during the "diagnostic portion" I might have been less likely to get back into REM easily.

I'll take it from your response that my sleep tech was getting creative with his analysis!

[DoriC]

Only three hours allowed for titration time, and only a "brief time" at a pressure of 9 during the titration ... not surprising that you perhaps had simply not yet cycled into REM a second time when the titration ended.

Of course, RG makes perfect sense to me. You might have reached the REM cycle again if you had slept long enough at 9cms.

[rested gal]

I'll take it from your response that my sleep tech was getting creative with his analysis!

That's one way to put it.
However, I wouldn't call it "getting creative." I call it "displaying stupidity."

In his defense, he did also mention it was a short time, and that since I did reach REM briefly during the "diagnostic portion" I might have been less likely to get back into REM easily.

ROTFL!! Nothing he could say could justify his thinking something as stupid as this: "since you reached REM at 7 and 8, but not at 9, it is possible that you may not be able to reach REM sleep above 8 cm of H2O" -- much less taking it upon himself to say such a thing to the patient after the study.

[SleepingUgly]

Ugh. Maybe you should change the subject of this thread lest someone breezing through thinks that's actually a true statement.

[Java Time]

Ugh. Maybe you should change the subject of this thread lest someone breezing through thinks that's actually a true statement.

Agreed, I changed the subject line and added a disclaimer to the beginning of the Original Post. Thanks for catching that, I didn't intend to mislead someone into messing up their minimum settings!

[tmorris]

How can anyone be correctly diagnosed at a 3 hour Sleep study? I had to sleep 8 hours the first night, and 8 hours with cpap the second night. This way, they have more of an idea of what's going on with you

[Java Time]

How can anyone be correctly diagnosed at a 3 hour Sleep study? I had to sleep 8 hours the first night, and 8 hours with cpap the second night. This way, they have more of an idea of what's going on with you

With my insurance, they prefer a "split-night" study. I was told that if my first "diagnostic" portion of the night had enough breathing events, they put you on a short 3 hour "titration" portion.

My understanding is if I would not have had enough events during the "diagnostic" portion, I would have been allowed to sleep through the night and my doctor would have looked at the results. At that point my doctor could have requested a 2nd night, like you had, on the "titration" study.

They do this to save money, but also because it saves you one extra night in the sleep lab.

I agree that they can't dial your numbers in correctly in what for me was only 108 minutes of sleep.

However, it's not all bad. The doctor sent me home with an automatic machine and after 30 days adjusted my pressure based on what he saw from 30 days worth of data in my own bed. For me, these new pressure settings seem to be working okay.

For me, the split-night sleep study worked. Although as you read in my original post, the sleep tech had some creative interpretation of the data. Fortunately my doctor was better informed.

[Lizistired]

For the cost and inconvenience of a second night in a lab, it makes sense to get an auto and a good idea of what your minimum should be and go from there. If insurance companies push it, maybe that will become the standard. The doc could order another study if abnormalities were found.