Mask fit 100% but high AHI?

[dler4]

Hey there, I've been trying to find out why my AHI is always above 4 when I use my APAP machine.  Typically it's around the 4-8 range which I was told was not normal and was hoping to get some advice on what's happening here. In the following screenshot I had 100% mask fit according to my DreamMapper app but the AHI is pretty high at 6.52.  Unfortunately I don't have the option to add a 'Flow Rate' chart, I just got my SD card today and imported the results.  
   

This other screenshot is a more typical night where my mask fit is around 95% and the average AHI is even higher at 7.9. 
   

Is there anything anyone can spot that's wrong here? I'll try sleeping with my SD card in tonight so hopefully the Flow Rate will be imported too.

[Gideon]

Welcome to the Apnea Board.

Your settings are typical for initial settings. The trouble with that is they conflict with each other.
Min pressure of 4 is almost always too low, I'll guess something like 99.9% of the time. It is usually set that way because doctors think that since it is an automatic machine it will always find your optimum settings. That is not nearly correct. Once set to near what you need it will adjust for differences but it has to be somewhere near your single pressure CPAP setting. This is especially true for PR machines. (I am assuming your is not impacted by the recall) Yours is nowhere near 4. Also because you frequently having flow limits as evidenced by both your RERAs and FL events you need a higher Min Pressure.

Set your Min Pressure = 8 and then repost and we will see where you are at.

[staceyburke]

Both have positional apnea, more on the 2nd night. Positional apnea is when you sleep in a position where you cut off your own airway. 

There are no settings to help with positional apnea. You have to find a way to stay out of that position. It is also called chin tucking where your chin drops down to your Sternum. 

Sometimes it is caused by sleeping on your back or to high of a pillow. If it can not be fixed that easily then you might need to get a collar. I have a link to collars in my signature. You can see people without using a collar and the same people with collars. Huge difference. 

You can see positional apnea where there are clusters of events of O or H events (not centrals).

[dler4]

Welcome to the Apnea Board.

Your settings are typical for initial settings. The trouble with that is they conflict with each other.
Min pressure of 4 is almost always too low, I'll guess something like 99.9% of the time.  It is usually set that way because doctors think that since it is an automatic machine it will always find your optimum settings.  That is not nearly correct.  Once set to near what you need it will adjust for differences but it has to be somewhere near your single pressure CPAP setting.  This is especially true for PR machines.  (I am assuming your is not impacted by the recall) Yours is nowhere near 4.  Also because you frequently having flow limits as evidenced by both your RERAs and FL events you need a higher Min Pressure.

Set your Min Pressure = 8 and then repost and we will see where you are at.

Okay great to know, thanks! I just tested it, and at 8 pressure it feels like I need to put some effort into exhaling. Is this normal and something I just have to get used to?

Both have positional apnea, more on the 2nd night. Positional apnea is when you sleep in a position where you cut off your own airway. 

There are no settings to help with positional apnea. You have to find a way to stay out of that position. It is also called chin tucking where your chin drops down to your Sternum. 

Sometimes it is caused by sleeping on your back or to high of a pillow. If it can not be fixed that easily then you might need to get a collar. I have a link to collars in my signature. You can see people without using a collar and the same people with collars. Huge difference. 

You can see positional apnea where there are clusters of events of O or H events (not centrals).

Interesting, I'll definitely try a flatter pillow and look into a collar if it doesn't help. Thanks very much!

[Ratchick]

You get used to the pressure after a while, yes. It looks like you have A-flex on which reduces the pressure a little as you exhale. You can do a test with a glass of water. Fill it with 3 inches of water, and then grab a straw. If you can blow bubbles easily out through that straw, then that's the pressure you're breathing against - only you have a much bigger airway than just a straw. It feels weird at first, but you get used to it in time.

[OpalRose]

Unfortunately I don't have the option to add a 'Flow Rate' chart, I just got my SD card today and imported the results.  

The Respironics machines don't show a Flow Rate graph, (meant to say Flow Limitation), but it does give the Flow Limitation on the left sidebar statistics.

[Ratchick]

I'm pretty sure the flow rate chart only displays when you have full data, not just summary data. As opposed to flow limit chart which is Resmed Only.

[SarcasticDave94]

Just wanted to mention, regarding the title, don't assume that the ability to pass Mask Fit as a conclusion there won't be any Apnea events. Low mask leaks are important to proper treatment, yet other things like correct for you settings will influence therapy as well.

My experiences with mask fit has left me fit to be tied.

[dler4]

Here's an update after 2 more days of recording with a higher minimum pressure.  The first day I set the minimum pressure to 6 and the second to 7.5.  I also used 1 somewhat flat pillow for both nights.  It still seems to be in the range of my typical 4-8 AHI, though the 7.5 pressure is on the lower AHI end coincidentally or not.  Should I make any other adjustments?

       

[SarcasticDave94]

With Hypopnea being your highest event type, you should consider raising Min pressure to give your Philips Respironics more power to help. Even though this is an APAP, Respironics is notorious for being slow to respond. The fix for this is a higher min pressure.