[Symptoms] 11 months into CPAP but brain fog persists (and returned)

[Sleeper49]

   

Hi, I've been trying to desperately figure out why my brain fog has returned after 11 months of CPAP. I started with AHI 21, and after 7 months, my AHI dropped to the range of 0.2 to 0.5 each night. Things seemed to be on the mend.

Recently, my brain fog started to return despite my AHI dropping to 0 on several nights. I also replaced my mask headgear and nasal pillow, but the brain fog persisted.

Hence, I am wondering if my flow limitation is the issue. From what I've checked of my past OSCAR data, the flow limitation hovers at 0.15 (95%) and 0.30 (99.5%).

Symptoms of brain fog in the day include forgetfulness, inability to hold more than 2-3 things in the mind at any point of time, and unable to recall key events that happened yesterday. At work, I have to repeatedly write down people's comments, lest I lose track of the thrust of the conversation. Some daytime sleepiness has returned too.

Any help would be appreciated! Attached a screenshot of a recent night's sleep.

[G. Szabo]

The best way to reduce the flow limit is to increase EPR and set it to 3. To fully benefit from this, you should also increase your minimum pressure to 7 cm. 
You should also turn the ramp off.

[Sleeper49]

Thanks. My EPR was already at 3 before this, and I bumped min pressure up from 4 to 7 about a week ago. However, I've been getting slight headaches, and there's minimal impact to my flow limitations (95% flow limitation went down from 0.16 to 0.10).

Any suggestions?

[OpalRose]

Hi Sleeper49,

An updated or current chart would help us help you.

[DaveSkvn]

Hi Sleeper49,

The following is speculation so feel free to ignore it. I've been on CPAP for years (with continuing daytime sleepiness) but only discovered OSCAR last week so I'm still working through this stuff. 

Oscar shows that my sleep is in a poor state even with AHI being recorded between 0.5 and 2.5. In my case during sleep there are considerable "Flow Limits" recorded, the respiratory rate (number of breaths per second) rises x2.5, the tidal (per breath) volume drops but the volume of air per minute stays the same. In short it seems I'm more "panting" than breathing. I currently believe I have OSA (mainly when on my back) and UARS (when on my side).

For a YouTube overview of UARS, google "Vik Veer Upper airway resistance syndrome".

With OSA, the airway blocks, breathing stops (flow goes to zero), the "blood oxygen" drops  which wakes you up.
With UARS, the airway remains open but restricted, "blood oxygen" does NOT drop but it requires a great effort to breathe resulting in unrefreshing sleep.

You seem to have a lot of flow limits (about half of mine?). What is your respiratory rate at that time? Its supposed to be about 12 breaths per minute. If it goes much above 20, its unusual. As you can see I head up towards 50. My "minute vent" remains broadly constant but when I start breathing fast, the tidal volume drops. Does your "minute vent" remain constant / tidal volume go in opposite direction to the  respiratory rate?

   

If you look between 02:00 and 02:30 I was awake with the CPAP on. That's what I would like the rest of the trace to look like...

Hope you find this helpful.