Resistance to inhalation

My numbers have been pretty good for the last few months - average AHI's in the 1.6-1.9 range and 90% pressure @ 12. However, I've noticed two things: 1) there is significant resistance from the machine when I inhale, as though it doesn't expect me to inhale very deeply. And, 2) I'm experiencing an increased number of hypopneas. Even during the day - it's like I just tend to stop breathing as though it's too much effort to do automatically. I find myself having to consciously make myself breathe! And then of course I'm short of breath, so I have to breathe more deeply and/or more quickly for a few moments. I've never had this problem before and wonder if it's related somehow to the resistance I'm feeling all night long.

Last night I got fed up with the resistance and cranked the min/max range on the machine up by 2 full steps, and changed the Cflex setting from 2 to 3. The resistance all but disappeared - but my AHI was over 6, no doubt because of increased leaks due to the higher pressure.

I guess my questions are:

1. What's causing the resistance?
2. Is it plausible that my hypopneas, especially those during the day, are related to the resistance?

I ended up changing the C-flex setting from 2 to 3 and it made a world of difference. Interestingly, I'm breathing better during the day too since I made the change.

First thing that I would do is to get rid of that mask and try a regular nasal mask like I am using or Activa or Blue by Respironics (and chinstrap), and try to not inhale VERY deeply.

avi is wrong.....Your problems have nothing to do with the mask...you have been using it for months with good data. Since the resistance problem seems resolved, I would leave everything as you have it and see what happens in a week.

Right, I see no basis on which to blame the mask. Besides, I long ago tried nasal masks & chin straps. They were some of the least effective things I've tried so far.

KSMike wrote:I ended up changing the C-flex setting from 2 to 3 and it made a world of difference. Interestingly, I'm breathing better during the day too since I made the change.

Mike,

There is a thing called "upper airway resistance syndrome", which is characterized by RERA breathing. If your RDI index was higher than your AHI during your sleep study, you might have that hiding behind your OSA. That is something I ran into...my OSA was what got me to get started with treatment, but once the OSA was treated, RERA became my primary issue. While auto machines react to OSA events, they don't react to RERA issues. The fact that turning up your pressure and increasing the FLEX setting helped might be an indicator that this might be your underlying issue. Given the pressure you are at and the FLEX setting, you might be someone who could benefit from a BiPAP machine set with fixed pressures. The higher inhale pressures help to overcome the resistance, and running at fixed pressures helps overcome the issue with auto machines not responding to RERA breathing.

Check your sleep study results, and see what it lists for an RDI. If it shows any RERA breathing, you might want to follow-up with your sleep doctor.

-john-

John, I've never even heard of RERA - so I'll do some reading up, check my last study, and look into this. Thank you!

Hmm... Bells are ringing. I need to look into this too.

Suz