Mask change?

[lonigan]

Can simply changing masks cause much of  a change in events and AHI?

I had a second sleep study on the 1st of the month and started it using my nasal cradle and a couple hrs into it the tech came in and changed me to a full face (F30i) because my leak rate was too high(too much mouth breathing despite the chinstrap - I suspected the same because quite often I have dry mouth in the night). They were testing for ASV and I could feel the pressures were higher than I was normally using.

They recommended I change to ASV so afterward I decided that if those pressures were causing excessive leaks in the study they would probably do the same thing after I switch machines. I changed to the F30i and have no problems with it and have basically zero leaks and no dry mouth. I sleep side to side and this thing works great and i get a good seal all night - I prefer this one to the nasal one now that i have the correct size mask.

I've noticed that since changing masks my AHI jumped from about a 8 avg to around a 14 avg in the 2 weeks since. There are a lot more snores and OA's flagged also.

Before, I was on a nasal cradle with a chinstrap and now just the mask with no chinstrap.

With the nasal mask I was on a constant pressure of 7. I left the pressure the same after changing but changed the setting on the machine to full face. I was hoping it would compensate.

Only thing I can guess is this pressure is too low now and the snores and OA's (higher flow limitations also) are because I ditched the chinstrap. Yes? NO? Any guesses. If so maybe a 9 or 10cmH2O? I was on a low pressure because of high centrals and the first study recommended that pressure. I tried that and also 9 and then 7-9 with no changes in AHI using the nasal mask thus the second sleep study. I've only been on constant 7 with the full face mask.

I don't really need to chase it too much as I have an appt to change machines in late oct but was just hoping to maybe optimize it a little better in the meantime.

Suck it up til Oct or tinker? I'm good with either. Its all a learning experience

here's a random day before changing

   

and last night

   

[staceyburke]

You have 3 problems.  First you are having positional apnea.  You can see positional apnea where either H or Oa events are clustered together.  Getting rid of as many as you can will lower your AHI.  Positional apnea can NOT be controlled by pressure changes.  You have to find out what position you are getting into and cutting off your own airway.  Have you changed your sleep position?  Sleeping on your back?  Using more (or new) pillows?  These things can cause positional apnea by chin dropping to your sternum and cutting your airway.  Think of it of a kinked hose – nothing can get through – you have to unkink the hose…

IF you can’t make a simple change like changing to a flatter pillow helps then you will need a collar.  I have a link to collars in my signature at the bottom of the page.  It shows people who are not wearing a collar and the SAME person wearing a collar.  There is a huge difference between the two.

2nd problem is you need to have EPR on full time and set to 3.   This will help the flow limits that are high.  Flow Limits stop you from getting into deep sleep and can wake you up.  Flow Limits are apnea just like O and H events but they are not long enough to be an O or H. (at least 10 Seconds)  Flow Limits are NOT counted in you AHI.

3rd are leaks, any time you record Large Leaks your cpap can not give enough pressure to stop apnea and it can not recognize apnea when they happen.

[Jay51]

In my experience, changing mask types did change my AHI scores (and leaks also).  

A plan may be to experiment with both higher pressures and lower pressures now with the new mask; and also experiment with both with your chinstrap on and off.  You can post OSCAR results also.

[lonigan]

Thank you

I start off on my back for an hour or hour and a half and then transition to side. left and right, switching back and forth what seems like every 40ish minutes to an hour and then the other side. That is the same before and after switching masks. The only difference being the mask and chinstrap. Before switching my OA was 0.2 and hypopneas most likely around a 1-2. Everything were centrals. The first sleep study concluded with the recommendation of the constant pressure and 0 EPR. Those changes brought my index down but not below 5 so they ordered the 2nd study.

Leak rate now is pretty much 0, the only large leak spikes I see every night are due to an itch around my nose or mouth and i break the seal to scratch then the leak goes back to 0.

I was curious about the increase in OAs and H's being due to the chinstrap or mask or combination of the two. just wasn't sure if the chinstrap alone was what was keeping the OA's down when i was wearing it. I don't particularly like it. am willing to try the collar for those I suppose.

thanks again,
tim

not sure which oscar data to post
I just didn't know if it was worth chasing pressures for a little over a month or just grind through it and then dial in the ASV settings.

PLM index was over 130 this time around so I plan to talk to primary care about that issue as well.

[lonigan]

The recommendation is for BiPAP ASV EPAP 7-15cmH20, pressure support 5-18cmH2O (still trying to read up on and learn that stuff). Was also wondering if those higher pressures would negate the need for a collar (or chinstrap) and still keep the obstructive index down

[lonigan]

Time for a cervical collar I think.

the first hour or so is the only time spent back sleeping the rest is side. 

   

[SarcasticDave94]

Yes, the collar will help with the clusters of events.

Let us know when you get that ASV. I think your suggested pressures will be a bit lacking, even before seeing an OSCAR from you using that machine. The EPAP and PS ranges look a bit too spread out, adding up to a too high IPAP Max.

We'll help you get it dialed in pretty quick, or your money back.

[lonigan]

Still learning terminology and my morning headache may be affecting things but do those numbers mean the IPAP range is 12-33cmH2O?

That recommended range is the same as what they titrated me at and they had an AHI of 7.3 - no wonder

My legs were kicking and spasming like I stole something most of that night so maybe that was the best they could dial in with the amount of sleep i had.

   

[SarcasticDave94]

Yep you got it right. The problem is the numbers can be input and saved, but the ResMed ASV will physically stop IPAP Max at 25. No big deal though, as my own ASV setup for 2 years was Max IPAP 27. EPAP was 7-12, PS 3-15 (default). So my only real edit was EPAP Min. on the ASV Auto mode.

The benefit of settings that exceed IPAP 25 is the ASV can choose to add either more EPAP or PS, and can switch as necessary.