CPAP machine says I only use it for 2-3 hours when I'm working graveyard shifts?

[TinyTot87]

Hello,

I'm a shift worker who works 12 hour days that rotate between early mornings and graveyards once a week. To give you an idea, I work 4 day shifts from 5am to 5pm one week with 4 days off, and 3 night shifts from 5pm to 5am the following week with only 3 days off.

Whenever I'm on nights, my CPAP Air Sense 11 machine always says that I only use the machine for 2-3 hours when I'm asleep. Given that I sleep for about 6ish hours, that number isn't possible. It should be reading for 7-8 hours but every night set I work, it only shows me using it for a couple of hours. I don't take the mask off when I sleep so I'm not sure why it's showing such grossly inaccurate readings. My only guess is that because I'm working nights, it throws the machine off completely to have me use it during the day. Still, that doesn't quite explain things either. I've been thinking of emailing the clinician about it but I wanted to see what everyone else's thoughts or experiences are when using the CPAP machine when needing to sleep during the day. I am using it when I'm asleep for a lot longer than the machine says that I am. Only on one set did I use the machine for half the amount of time that I have it on during my night set because I feel asleep before putting it on lol. I meditate before I roll over to go to sleep so I must've been so tired I passed out before hand. I did put the mask on once I woke up though. But that's the only time.

I'm not worried at all as I know how long I'm actually wearing the mask for and I am waking up feeling as rested as one can be with short turn arounds for sleep (I feel more awake than I used to but some days still struggle on the final shift. My phone won't let me take a screenshot or upload a photo because the files too large. But yeah it's showing way less time with me using the machine than what I'm actually using it for.

[Pugsy]

When you sleep past NOON (or whatever the machine thinks is noon) then the usage data gets reset or in your case split.
All ResMed machines start a new day of recording at Noon.
Your usage hours is going to still be there but just on a different day since the usage hours get split at noon.

[D.H.]

Yes, the last poster got it right. Based on most people's sleep/wake pattern, each day begins at "noon."

To prove this is the problem look back. I think you'll find a more normal number of hours for past days. However, if your sleep pattern is very irregular, you might find short hours on some days and excessive hours in others.

[chunkyfrog]

Look at your averages over the last month, and you will see your sleep time looking realistic.
That is the usage amount your provider will see.
Each early afternoon and the following morning will count as one "night".
Weird, but it adds up.