Stats from first week on apap: should I do sleep study?

[cuziamthecaptain]

For the past few years I’ve suspected I had sleep apnea. I would just feel a sense of fatigue throughout the day and a doctor told me my tonsils were 3-4x regular size. About 10 years ago I did a sleep study but the results were either mild or inconclusive.

Recently I found a good deal on craigslist for the resmed S8 autoset II (the data card, alas is missing) but I was able to get into clinical mode. I figured this could tell me if I had sleep apnea without having to do a sleep study (I don’t have good insurance, so I I’d have to pay out of pocket).

From a post on this forum about estimating cpap pressure, I estimated my ideal pressure as around 5, so I set the minimum as 4 and maximum of 9. I also used something to keep my mouth closed and made sure my mask was attached correctly.

After about 7 days, I can’t say I feel that much different. I did notice that the machine went up to 8.8 the first few days, so I changed the setting to a max of 12. After that, the machine set an average pressure of 9.5 for the remaining four days (more data below).

There any way to figure out from this if I have sleep apnea? Although the machine did automatically increase the air pressure when I was sleeping, it also elevated the pressure when (out of curiosity) I wore the mask while watching TV.

Additionally, my BMI is normal, my neck circumference is 36.5 inches, and I wouldn’t say I’m sleepy during the day (where I fall asleep just sitting in front of a TV), but I do feel fatigue where it’s difficult for me to concentrate.

It could be my diet (I do eat like I’m in still in college, though I do walk a lot each day). If I had better insurance, I’d sign up for a sleep study or at least visit a sleep doc. But is there a way to tell for sure just from the APAP machine? If someone didn’t have sleep apnea, how would the APAP machine react in terms of adjusting pressure?

Also—is there a chance I could find a specialist in the Los Angeles area who will take plight of my economic situation and maybe go over the data from the APAP with me without first insisting on a sleep study?

Thanks for any insight! – John

Data for first 7 days:
Average use: 4.5 hours per night
Average pressure first three days (when I set max at 9): 8.8
Average pressure final four days (when I set max at 12): 9.2
Average leak: .11
Average scores (I believe per hour)
Average Apnea: .15 (ranging from 0 to .5)
Average Hypopnea: 3.37 (ranging from 2.3 to 4.4)
Average AHI: 3.41 (ranging from 2.3 to 4.6)

[Julie]

Hi - I have one suggestion for you to try - if you normally sleep on your back, sleep on your side for at least 3-5 days and then see what your numbers look like... the reason is that for most, apneas are provoked on their back, but disappear otherwise, and if you're in that category, you should be ok as long as you train yourself not to sleep on your back (you can buy foam wedges to put behind you to keep you from flipping at night).

From your numbers, I'd say you don't have apnea, and I'd look first into your nutrition, and definitely into how much sleep you normally get (4.5 hrs is NOT enough for someone your age tho' I understand it may only be the length of time you wore the mask), and you should also try to keep the most regular hours possible as it can help too. '

There are many reasons you could feel tired, so don't assume it must be apnea. Good luck and come back if you have more questions.

[Pugsy]

Change the machine to cpap mode and use the least amount of pressure that you can tolerate. Hopefully 4 cm.
See if the AHI changes.
While 4 cm is still offering some therapy value and not the greatest of indicators..if your AHI is markedly higher....then the AHI you are seeing in APAP mode is treated AHI...meaning the machine is treating something.
If it doesn't change and still stays in the 3 ish range...then you may or may not have OSA and if you do we don't know to what degree.
It's nearly impossible to tell with any certainty if you do or not with just the data off the LCD screen in this situation.
We don't know if that acceptable AHI of 3 ish is because the machine did what it is supposed to do and prevent events or you simply didn't have very many.

If your AHI at 4 cm (lowest it will go) is double digit or markedly higher....then you have sort of an answer....meaning the machine is trying to prevent some of the events with the higher pressures but can't with the lower fixed pressure.

Under normal circumstances the machine won't increase the pressure if it doesn't think you need it.
But sometimes it might mistake awake breathing irregularities for Flow limitations or reductions in air flow and raise the pressure to try to prevent them.

The pressure number you are seeing isn't an average like you might think. Instead it is a 95% number which means for 95 % of the time you were AT OR BELOW that number. People tend to overlook the "or below" part of the definition.
For all we know you may have spent 80 % of the night at the minimum pressure.

[cuziamthecaptain]

Hi - I have one suggestion for you to try - if you normally sleep on your back, sleep on your side for at least 3-5 days and then see what your numbers look like... the reason is that for most, apneas are provoked on their back, but disappear otherwise, and if you're in that category, you should be ok as long as you train yourself not to sleep on your back (you can buy foam wedges to put behind you to keep you from flipping at night).

From your numbers, I'd say you don't have apnea, and I'd look first into your nutrition, and definitely into how much sleep you normally get (4.5 hrs is NOT enough for someone your age tho' I understand it may only be the length of time you wore the mask), and you should also try to keep the most regular hours possible as it can help too. '

There are many reasons you could feel tired, so don't assume it must be apnea. Good luck and come back if you have more questions.

Thanks. I'm going to try this tonight and the next two nights-- to set it as CPAP with a pressure of four.

During a past period of fatigue-- I trained myself to sleep on my side and have done so since. Also-- the reported time was how long I had the mask on. I would wake up around 4am and take the mask off because my mouth was dry and then go back to sleep. I'll see if I can adjust the humidifier settings.

As I reflect on things in my past-- maybe I've always been an anxious person and maybe that anxious energy has to come somewhere-- creating a sense of fatigue at certain points of my life. Ironically, I took to the CPAP therapy quite easily. I was always adverse to trying it-- but it wasn't too difficult for me to fall asleep.

follow up results soon. Thanks again! -- John

[cuziamthecaptain]

Okay, I made the settings CPAP and limited the pressure to 4cm.
After not doing it for a few days, it was more difficult to keep the mask on and the two days of any significant time were both around 1.5-2 hours. Nevertheless, here’s the stats:

Day 1:
Total time: 2 hours
AHI: 9.7
AI: 2.0
HI: 7.7
Leak: 0.0 leak

Day 2:
Total time: 91 minutes
AHI: 1.3
AI: 0
H: 1.3
Leak: 0.0

So on the first night, my AHI did approach 10, which I believe means mild sleep apnea? Yet I can’t say that using the machine even at the higher pressure made any concrete difference in terms of my daily energy levels or what not.

I’ve already lost weight and sleep on my side. Maybe if I use a mouth guard, breath rite strips, and maybe practiced the didgeridoo I might be okay??

[Pugsy]

The numbers off the machine don't tell us enough information...like what was the event breakdown for that 2 hour AHI?
You need 6 to 8 hours on the machine getting good solid sleep to have any idea for sure how the AHI is trending.

90 minutes with not much of an AHI....that doesn't mean anything because there likely simply wasn't enough sleep to gauge things. You may have had the mask on for 90 minutes but I bet you weren't asleep all that time.

[jweeks]

Okay, I made the settings CPAP and limited the pressure to 4cm.

Hi,

You might be running into the Heisenberg principle...any attempt to measure your OSA using CPAP might alter your OSA enough where you cannot measure it accurately.

In a sleep study, they are going to have you sleep with no pressure for a while, and then watch your brain waves and oxygen level to determine if you have OSA. While your machine can measure events, it isn't overly accurate. Also, the 4 cm of pressure might be too low to be comfortable, while any pressure level might treat enough events to skew the data.

If you had really bad OSA, or OSA that took a real high pressure to treat, it probably would have shown up during your experiment. It was a good experiment.

There is another alternative. If you can get your hands on a recording pulse oximeter, like a CMS-50E, you can try sleeping without the machine, but with the oximeter running. If the oximeter data shows drops in your oxygen levels (below 88%), then you are having events. The number and severity of events is what will be interesting. If you do see events, then you can try running again with the CPAP machine, and see if the events stop happening.

Of course, having an overnight sleep study, and having that sleep study data scored by a doctor would be preferable from a medical point of view. However, you are unlikely to hurt yourself doing this, so probably no harm in giving it a try.

-john-

[cuziamthecaptain]

The numbers off the machine don't tell us enough information...like what was the event breakdown for that 2 hour AHI?
You need 6 to 8 hours on the machine getting good solid sleep to have any idea for sure how the AHI is trending.

90 minutes with not much of an AHI....that doesn't mean anything because there likely simply wasn't enough sleep to gauge things. You may have had the mask on for 90 minutes but I bet you weren't asleep all that time.

I think part of the problem is that at 4cm, I'm not sure I'm getting enough air to comfortably fall asleep. I may take off the chinstrap, since I'm just looking for an assessment...

There is another alternative. If you can get your hands on a recording pulse oximeter, like a CMS-50E, you can try sleeping without the machine, but with the oximeter running. If the oximeter data shows drops in your oxygen levels (below 88%), then you are having events. The number and severity of events is what will be interesting. If you do see events, then you can try running again with the CPAP machine, and see if the events stop happening.

I did do an oximeter reading a few months ago that I left on all night and uploaded the data.

In my four hour assessment there was one 15 minute period where there was a dip to 98 and another dip to 88. Overall 99% of the time it was above 90%.
Per hour desaturations of 3%: 8
Per hour desaturations of 4%: 2

I've heard that the cutoff for diagnosis is 15 at 3% and 5 at 4%. However-- it appears the oximeter is prone to false negatives (where the oximeter says I don't have it when I really do).

Also-- I took the Epworth Sleepiness Scale
http://www.umm.edu/sleep/epworth_sleep.htm
And got a 2. Meanwhile scores above 10 usually suggest the possibility of sleep apnea.
As I'm typing this--- maybe I don't have sleep apnea after all. Though I should redo the cpap for more hours to be sure.

[cosmo]

Are you fatigued everyday? How many hours of sleep were you getting without cpap?

Maybe try a home sleep test kit if you want some answers? Since you don't have insurance and live in LA, you could always make a trip to Tijuana if you wanted a full lab test.

[cuziamthecaptain]

Are you fatigued everyday? How many hours of sleep were you getting without cpap?

Maybe try a home sleep test kit if you want some answers? Since you don't have insurance and live in LA, you could always make a trip to Tijuana if you wanted a full lab test.

Hmmm... I never thought of doing that.

Fatigue yes... sleepy no. Meaning, there are times when I feel I need caffeine to be productive. But at the same time I'm the type of person who could never fall asleep on an airplane or while watching TV. I don't have that much difficulty falling asleep (though again, usually only if I'm on a bed). I usually sleep about 7-8 hours each night.

[cuziamthecaptain]

Also--- figured I should ask...


If I do have a mild case of sleep apnea--- and I set the cpap at 4, what would the numbers look like for AHI, AI, HI?

Thanks guys!

[Pugsy]

If I do have a mild case of sleep apnea--- and I set the cpap at 4, what would the numbers look like for AHI, AI, HI?

Don't really know because AHI or OSA sleep severity isn't tied to pressure needs.
In other words someone with a really severe case of OSA with AHI even in the 100s might be able to have their OSA well treated with 4 or 5 cm and someone with nice minimal severity of say 10 AH might need 18 cm to afford effective therapy.

This is why we can't say for sure if someone uses 4 cm and doesn't have an exciting AHI that it means no OSA or minimal OSA because that 4 cm of pressure sometimes is all that is needed for some people and we have no way of knowing if that is the case for you. As you already found out using 4 cm is rather stifling and difficult to be comfortable with so sleep itself doesn't come easy.
Best we can hope for as an indicator is when 4 cm is used and your AHI is significantly elevated....then you have an answer to a question. A low AHI with 4 cm doesn't mean that nothing exciting has been going on but a high AHI at 4 cm is exciting.
The machine sometimes is not the best tool for determining level of OSA severity. A positive result is a strong answer but a negative result may not be totally accurate.

Same thing if someone use a pulse oximeter over night...Not everyone has significant oxygen level drops with their OSA.
So no significant oxygen level desats on a pulse ox doesn't automatically mean no OSA.

If you had recorded some REM sleep while on your side and no events (or minimal) were recorded then I would feel confident (if I was in your shoes) that as long as I stayed on my side for sleeping I would be in good shape.
The absence of any REM sleep while on your side clouds the strategy...we don't know for sure if that AHI would have stayed low on your side.
Or if your initial REM AHI had been only in the single digits...then we wouldn't be quite so alarmed but it was significant in REM sleep and REM sleep does happen (or should happen) no matter what position we sleep in.

I know what you want to believe and I don't blame you one bit but without confirmation of REM sleep while on your side giving a nice low AHI...we just don't know with absolute certainty that your OSA is strictly positional.

Here's what happened to me and I am documented much worse in REM sleep.
AHI in non REM sleep was a meager 12 per hour...not exciting at all but when in REM stage sleep I was over 50 per hour and its real hard to get a good number relative to just REM sleep because what happens is you get to REM sleep and 2 or 3 nasty events happen and cause you to wake up...breaks the cycle...so then you have to go through some time back through the other sleep stages to get to REM sleep again...and then maybe in 5 minutes another 3 or 4 events happen and then you get to wake up again and it starts all over again.
End result is a LOT of wake ups or arousals from sleep and having to start all over with the sleep cycles so a LOT of time spent in the lighter stages of sleep and minimal time spent in the deeper stages and the deeper stages of sleep is where the most restorative powers of sleep work their magic. We simply don't spend much time in REM because we wake up too many times.

Now in my case sleep position didn't make any difference but I had documented REM sleep on my back and side both...so it didn't matter. I get the diagnosis anyway.
Now you might be different and not have any apnea events at all in REM sleep on your side...but we have no measuring tool to say with any degree of certainty.

Without a sleep study where REM is documented along with side sleeping the best we have is the 4 or 5 cm setting on your machine and you need to have a chance to get to REM sleep several times during the night for it to be evaluated.
90 minutes into sleep is normally when the first REM segment comes along...getting short segments of 90 minutes to 2 hours of sleep on the machine doesn't tell us anything at all about REM sleep possibility because there simply wasn't/isn't enough time to have much REM sleep even materialize.
So you need 7 hours or more of uninterrupted sleep on the machine so that your chances of actually having substantial REM stage sleep minutes to happen and thus have the chance for any REM related evens to appear.