Ovmeadows Therapy Thread: Flow Rate, Flow Limit and Other Issues

[ovmeadows]

Thanks.  Will try your recommendations tonight maybe several.  I'm weary of the higher pressure, fear mask leaks, dry eyes and dry mouth.

[coutherino]

I understand. Have you considered using a nasal mask? It would likely be much easier to manage leak in combination with tape.

If you are not able to due to an issue like a deviated septum, or chronic congestion, I completely understand. But if not, I would definitely recommend giving one a try if you haven't already.

[ovmeadows]

Easy breathe is either "on" or "off" mine is "on".

Forgot to replace my SD card last night, a rare event.  Device did show it was on fot 6 hrs and 15 min AHI of 0.50.  Feel like I had yet another restless night.

Do you have a recommendation for a nasal mask.  I have tried one a few years ago but got the sore nose (began CPAP 2017).

[coutherino]

No worries. I'm sorry you had another restless night. I won't be able to tell if the changes actually did anything until I can see the waveform, though. 

Still, that might just be one part of the problem. You said you were restless again. Can you explain what specifically you feel keeps you from getting a solid night of sleep? What is it about the pressure that bothers you? Is the pressure too intense when inhaling? Is the pressure too difficult to exhale against? Does the higher pressure make the mask uncomfortable? Do you wake up multiple times a night for no apparent reason? Is it mainly related to the other things you mentioned in your previous post, such as leak, dry mouth and eyes? Understanding what specifically bothers you will make it easier to make recommendations.

Do you have a recommendation for a nasal mask.

Sure. I'll list some below.

Dreamwear Nasal Cradle (not the pillows version)
AirFit/AirTouch N20 (AirFit is silicone, AirTouch is memory foam)
AirFit N30
AirFit N30i

I can't recommend the Dreamwear enough, but that's just what I use and not everyone may like it. If you do choose one, finding the right size is going to be the most important thing, obviously. There should be size guides you can print out online for all of these.

[ovmeadows]

Still, that might just be one part of the problem. You said you were restless again. Can you explain what specifically you feel keeps you from getting a solid night of sleep? What is it about the pressure that bothers you? Is the pressure too intense when inhaling? Is the pressure too difficult to exhale against? Does the higher pressure make the mask uncomfortable? Do you wake up multiple times a night for no apparent reason? Is it mainly related to the other things you mentioned in your previous post, such as leak, dry mouth and eyes? Understanding what specifically bothers you will make it easier to make recommendations.

"Can you explain what specifically you feel keeps you from getting a solid night of sleep?"  I believe I have "arousals".  I'm neither asleep nor awake.  At times I'm comletely awake after 2 or 3 hours sleep, not always bath room related but since I'm awake I'll go.       High pressure makes it hard to exhale and causes freguent "mask farting".  I've somewhat learned to deal with dry mouth and dry eyes.  

The last 2 nights have gone better:  
             

[coutherino]

Your individual breaths look better, but it's just one image and probably doesn't tell the full story. It's difficult to read the data with that much leak constantly waking you up and disturbing your breathing. If I have one recommendation right now it would be to fix that at all costs. The mask you currently have clearly isn't working, and I'm not sure there's anything you can do to fix it. You likely need a different mask entirely, and given how high your pressure is I still recommend a nasal. I'm sorry there isn't much else I can offer you right now, but at least you know what you need to fix. And it certainly is fixable. Dry mouth/eyes isn't something you should have to learn to deal with. It's possible for CPAP to be comfortable, or at least comfortable enough to be free from those things.

[ovmeadows]

How should I interpret the flow rate difference in graphs A and B?  MY sleep quantity and quality leaves something to be desired. 

   

[ovmeadows]

I would conclude from the attached screenshot for 8 Dec 2024 that it takes very little flow limitation to cause some level of sleep disturbance or at least graph anomalies.   How does a PAP user find the cause of irregular but small flow rate?  Does it even matter?

   

[G. Szabo]

Your 0.15 flow limit is higher than the accepted threshold, indicating your setting is not optimal. I suggest increasing both the minimum and maximum pressure by 1 cm.

As for the wavy pattern and its relation to flow limits, my understanding is that the flow limit is primarily deducted from the shape of the individual inhalation peaks, and it is not strongly correlated with the actual height of the peak. Suppose the peaks are smooth and close to sinusoidal. In that case, the flow limit (FL) figure is low. The FL figure cannot warn the user when nice inhalation peaks appear, but the inhalation is restricted (i.e., insufficient air intake). For instance, this is the case when someone starts showing the symptoms of nasal congestion. In the initial period,  the height of these nice inhalation peaks starts to decrease, and simultaneously, the oxygen saturation drops. But there is no FL increase reported. Because of the lack of oxygen, the patient eventually uses higher inhalation effort to compensate, which leads to this wavy pattern. NB the congestion is only an example I experienced,  but there can be other causes of the reduced airflow with seemingly perfect inhalation peak shapes.
       

[ovmeadows]

How can I have 0 AHI but have many Oscillations?  5.55 hrs of sleep is not enough to make me feel well rested in the morning.