[CPAP] OSCAR confusing me with leaks/apneas

[godletmesleep]

Hello, recently started CPAP therapy after an extremely long battle with my insurers.

I ended up settling on a DreamStation Auto CPAP, details to the right.

Regarding the mask, it's a ResMed P10, and the 4cm leak is 20 L/min, and the 20cm is 49 L/min per the ResMed manual.

OSCAR is able to calculate the difference between normal leaks and excessive leaks, however, regardless of what I set my preferences to it insists that an excessive leak is anything over 13 L/min. Which has brought an extreme amount of confusion, as although my RERAs/Central Apneas were the primary source of my studies those have entirely dissipated under the 7cm prescribed pressure.

Getting around 5 to 6 AHI, I haven't figured out how to exclude periods where I was awake from this. These events seemingly kick-off as leaks are dissipating, I taped my mouth for last night to see if that resolved the AHI issue and it reduced it by around a single point.

I cannot determine if I am having actual leaks of concern or not though, due to the excessive leak issue with OSCAR and my unfamiliarity with all these graphs. I have combed through many forum posts and Wikipedia articles here on ApneaBoard yet I still cannot find any solid answers.

I've attached the previous night's log below as you guys prefer it (hopefully). I was awake until around 3:10 AM as seen on the report.

Thanks for the help.

[staceyburke]

The pressure is raising because you have positional apnea. And no amount of pressure can help. 

Positional apnea is when you cut off your own airway by the position you are sleeping in. It is commonly called chin tucking. When ever your chin drops to your Sternum you are cutting off your own airway. 

It can be as simple as sleeping on your back or using to high of a pillow. You can chin tuck on your side sleeping in a fetal position. 

What ever it is you need to find a way not to get into that position. 

If you just can’t, you will need a collar. I have a link in my signature (bottom of the post). Many people have this problem and have solved it with a collar.

[godletmesleep]

Huh, honestly didn't think of that. Is there any specific way to tell that it's positional apnea?

Also, would the positional apnea explain the leaks that I'm seeing on OSCAR?
Dunno how to fix the total leak discrepancy either, but I imagine that is related to the DreamStation.

[Melman]

I agree that your main problem is positional apnea. See the following link http://www.apneaboard.com/wiki/index.php...onal_Apnea

The most common solution is a soft cervical collar as explained in the link below.

Positional apnea is probably not the cause of leeks. See the mask primer below for suggestions for dealing with leaks.

[staceyburke]

On a Phillips pay attention to the bottom line on the leak chart. Getting above the dotted line shows a large leak. I can’t tell much about the leaks other it is not caused by mouth breathing. You are going to have to experiential and see what helps. USUALLY it is over tight or the wrong size. 

As far as positional apnea, look for clustered events in either the “O” or “H” row (2 or more close together) shows positional apnea.

[godletmesleep]

Thank you for the help with the positional issue, I did not notice this part of the Wiki earlier. I imagine that goes with the drowsiness, which is getting better but I'm still working off.
I'll definitely look into it and update as needed.

On a Phillips pay attention to the bottom line on the leak chart. Getting above the dotted line shows a large leak. I can’t tell much about the leaks other it is not caused by mouth breathing. You are going to have to experiential and see what helps. USUALLY it is over tight or the wrong size. 

As far as positional apnea, look for clustered events in either the “O” or “H” row (2 or more close together) shows positional apnea.

I've had to add all of these to attachments as I haven't met the new member threshold just yet.

I've noticed that OSCAR calculates the Total Leak and the Excessive Leak Rate, my main concern is that the numbers aren't adding up to what I've put in preferences or what ResMed specifies for that mask.

The expected leak rate is around twenty liters per minute at 4cm, I've placed the manual's pressure-flow curve for the P10 in the preferences area of OSCAR. This same calibration can be found in the leak area of the Wiki.

However, as you can see, a leak rate of 13 and a total leak of 26 does not add up to the expected leakage. Which is the natural leakage at 8cm of pressure: 29 liters per minute.

Would this be an indication of a faulty mask or the DreamStation not properly interpreting the leak rates? They Wikipedia does recommend a 5 L/min margin of error, but that still puts it many liters below what it should be: Around 11 to 16 L/Min. I could be missing something here, I just felt the leak rate was a bit higher than expected.

Thank you for all the assistance.

[godletmesleep]

Here's an update following last night's discussion, I tried to tuck a pillow underneath my neck to see if that would help. I found it came loose as I moved throughout the night. 
I also found my mask coming loose more, almost coming off completely in the middle of the night as seen in the leak chart, it's falling forward due to the strap being too loose so I am going to try and tighten it some tonight. Still having the OSCAR problem mentioned above.

I woke up, and still feel, more tired than previous nights on CPAP therapy, don't know if taking 5mg of melatonin would've been responsible for that or possibly even me attempting to wane off caffeine. Could be a mix with of the two, if not three including the AHI, things.

Does this report still look consistent with positional apnea? I bought a Futuro cervical collar that I will try tonight and see if it helps.
I'm a side sleeper so I am unsure if there are specific positions or methods that would make positional apnea appear.

If there's anything else of concern that I haven't noticed, please let me know.

[staceyburke]

Yes you have positional apnea. Please take a look at the link for a collar at the bottom of the post

[godletmesleep]

I have bought the Futuro Cervical Collar that was mentioned in the Wikipedia article, I will follow the instructions and see how it goes.

Thanks for all the help so far.

[Gideon]

A correction, OSCAR does NOT calculate the leaks, it simply reports them. It reports what the manufacture put on the SD card.