Is my CPAP machine catching all my apnea events?

[fs12]

Hi all,

It's been a few months now that I've been using my CPAP machine. After some mask struggles and such, I now feel pretty good about my mask and set-up.

However I've noticed over the months of looking at my SleepyHead data, that there appear to be some apnea events that my machine doesn't flag. I turned on the user flag option, but of course the machine still thinks my AHI is doing well. I've posted some examples from last night that are all fairly standard for what I'm seeing most every night. Are these really apnea events that I should be worried about? Or am I being overly paranoid?

I also don't understand why sometimes the machine flags Flow Limitations, that don't seem any different on the graph to me than anything else I see...

Any thoughts would be greatly appreciated.

Thanks!




Full Night View:
   



User Flags:
   

   



No Flag:
   



OA Flags from machine:
   

[Walla Walla]

The machines arn't perfect and they miss an event or two at times. The AHI is only made of the OA,H, and CA events. It doesn't include user flags or flow limitation events.
Speaking of flow limitation events don't feel alone. I don't know anyone who knows what Respironics uses as a guide line for a flow limitation event. On the Resmed machines they don't use events but put the flow limitations on a flow chart. It at least gives you some idea of whats going on. For reference Respironics uses a 40% reduction in flow over 10 seconds for a hypopnea event.

[tedvpap]

What you are showing is that you still have a little untreated obstruction but it is not terrible. Raising the min pressure a little more would help address those. I would try 12. Only you can decide if it makes your sleep better.

[fs12]

Thanks both for your insight!

Would a Resmed machine catch more of these events? My worry is that what seem to me to be apnea events aren't caught by the machine, and thus the auto pressure isn't increased in response...

I tried to up my auto pressure a few weeks ago to minimum 12 and had an AHI of 1.7 over three nights. Tried it again last night and got 0.35. Much better, but still some of this type of erratic breathing.


   


Or am I just overthinking all this, because I really like looking at data?

Thanks for your help!!

[Walla Walla]

There is always going to be erratic flow from time to time. Holding your breath while turning over will cause it as well as grunting and coughing. Your never going to get a perfect flow all night. Remember an Obstructive event is 10 seconds long and 80% flow limitation and a Hypopnea is between 40 and 80% flow limitation for less than 10 seconds. A clear event will be no flow at all for at least 10 seconds. Anything less than those 3 and it's not an event.

[DeepBreathing]

Or am I just overthinking all this, because I really like looking at data?

That's very likely the case. Your AHI reading is commendably low, and the events you've highlighted are all very short duration. Trying to chase the elusive zero is the way to insanity.

On the other hand, your flow chart and inhale/ exhale times show a small deficiency in exhale time. You'd normally expect exhale to take up to twice as long as inhale, but it's the other way round for you. As you are ready to sleep, try consciously to slow your breathing, make it even and consistent with exhale slightly longer than inhale.

[fs12]

Thanks for the info WallaWalla. Knowing that is actually really helpful.

Looking at the data in more detail, it seems a lot of the "events" I'm seeing are in the 5-8 second range, so that's why they aren't being flagged by the machine. I do turn over every so often in the night, so maybe it's more attributable to that.

Thanks DeepBreathing! - I had a hunch that maybe I'm just reading into things a bit too much, but it helps to get validation on that... My AHI has been 1.5 or less for the last month, so I'll just be thankful that the PAP therapy seems to be working well for me.

I wonder if the low exhale time is related to not using the EPAP/Flex setting? Exhaling doesn't bother me as I'm falling asleep, but I wonder if it is harder for me to exhale when I'm asleep. I had tried the Flex setting early on but didn't tolerate it well - the difference in pressure did not feel to react quickly enough to my inhale/exhale. Perhaps I'll try it again, now that I'm more used to the machine and see if it makes a difference.

Thanks for the help and suggestions! Much appreciated.

[gwc2795]

I am wondering why your IPAP and EPAP are the same? The first chart showed the median for both to be 11. Is this because it is a dreamstation?

[Walla Walla]

I am wondering why your IPAP and EPAP are the same? The first chart showed the median for both to be 11. Is this because it is a dreamstation?

It's because flex is not being used.

[fs12]

Yeah, I wasn't using the Flex setting, as I had a really rough time with it when I tried it early on in therapy. I tried it again last night and it worked decently well. Going to give it a few nights to see how things settle in.

Bumping the minimum pressure to 12 has helped again. My average AHI for the past three nights is 0.78.

Thanks for everyone's help!