Pauses during exhalation?

[nk3125]

Hi everyone!

I've been on CPAP/Bilevel for the past year or so to treat my mild OSA/UARS (AHI 2.5, RDI 10.6, but likely undercounted due to no REM sleep during my WatchPAT PSG). Unfortunately, I haven't been able to get where I'd want to with my treatment, so I've been going through my data in OSCAR. To be honest, I'm really grasping at straws at this point.

I noticed a bit of a strange pattern that I didn't really see documented elsewhere on the board (but it's possible my search terms weren't quite right). During some exhales, I'll start out with a normal exhale, which will then cease or dramatically decrease flow, only to resume exhalation after a few seconds. Looking through my logs, I've seen these happening a few times per night.

Last night, my machine flagged one of these as an obstructive event, which I thought was a bit strange:

   

I've attached the rest of my OSCAR charts from the night as well.

Any ideas what these could be? If it wasn't for the resumption of exhalation, I would say mouth exhalation or palatal prolapse, but I don't think it quite makes sense for the palate to prolapse and then flap back into the correct position. Typically, there's no leak reported by the machine during these events. I've tried increasing EPAP to eliminate these events with no such luck.

Thanks for everyone who takes a look, I really appreciate it.

[Dormeo]

Bear in mind that everything above the zero line is the rate of airflow during inhalation. So you didn't exhale as the rate of airflow dropped to 0 part of the way through your inhalation. You just stopped inhaling (and then started again). I think what we're looking at is compatible with an OA.

[nk3125]

Thank you for taking a look! Do you think the dip below the red line into exhalation is some kind of artifact? Or just a continuation of the obstructive event that occurred during inhalation?

I chose that particular example because the machine did flag it as an OA, but typically my machine isn't flagging these events -- I'm guessing due to the duration, as I do see FOT pulses on a handful of them. I included a couple more examples here as well that have less of an obstructive inhalation.

[G. Szabo]

The tiny blip on the exhalation curve is not an artifact; it is quite common, so you should not be worried about it. 
It is not a palatal prolapse. Although the movement of the soft palate might be involved,

[staceyburke]

IF you have had other like that but not flagged - it was not at least 10 seconds to be classified.  I have how apnea is classified at the bottom of the post.  Again, they need to be 10 seconds or longer to be classified as a H or O event.

[Sleeprider]

All the events you have provided a zoom image of are breath-holds. You take a breath and physically obstruct your airway to hold it causing the momentary blip into exhale, then you exhale at the end of the event before resuming breathing. This is commonly seen when someone moves in their sleep and holds their breath as they roll over.

[nk3125]

Stacey, that makes sense.

Sleeprider, that's an interesting idea. I went back to one of my earlier OSCAR days where I had my Wellue SleepO2 on as well (admittedly, it was earlier last year when my SleepO2 was still reading O2), and in the readings where I could see the similar pattern, there was some movement associated with it. Maybe I'll see if I can get my SleepO2 working again and try to get some additional data.

I went back through my data for last night (the graphs I posted earlier), and I noted somewhere around 24 of these breath-holds during the 7.5 hour session, sometimes lasting 2-3 seconds and others lasting up to 10 seconds (hence getting the OA flag that I mentioned).

Now I knew I was always a bit of a kinetic sleeper, but even that seems a bit surprising to me. So I might need to do some additional research as to what else could cause that...but hey, at least it's something different to investigate!

If you have any ideas, I would be open to any suggestions.

Thank you everyone for your help so far

[Sleeprider]

Lots of things can cause short duration breath-holds. For example swallowing. After seeing so many charts over the years and trying to interpret "why", I can read the flow chart like a musical score, and I often "sing" the notes I see. There are many ways to get to these brief breath-holds with a late expiration release.