Bad night & Tidal Volume Question

[Rritch]

Last night my girlfriend had a really bad night (at least for her) Her AHI was 8.2 and it looks like it was mostly related to OA's between about 4:00 and 5:00 AM (20). The other thing that I noted was that the Tidal Volume particulary during that time frame was really high. I really have not paid much attention to the Tidal Volume and I am not sure exactly what that might indicate either. I suspect that the issue was caused by her sleeping with 2 pillows last night that were propped up on the headboard causing her airway to be restricted but I am not sure if the data verify's this or not. I am attaching a .PDF of the report from last night. If someone could take a look at it and help me evaluate it a little better I would appreciate it.

[Rritch]

She slept with only a single pillow last night with it flat and her number was back down below 3. Not as good as she had been doing, but much better than the 8. I would still like to understand tidal volume better.

[zimlich]

Tidal volume is the lung volume representing the normal volume of air displaced between normal inspiration and expiration when extra effort is not applied. Typical values are around 500ml or 7ml/kg bodyweight.[1]

This is from wikipedia.

[Rritch]

Tidal volume is the lung volume representing the normal volume of air displaced between normal inspiration and expiration when extra effort is not applied. Typical values are around 500ml or 7ml/kg bodyweight.[1]

This is from wikipedia.

What would it indicate when the tidal volume numbers are really high? I have been reading about it but I can't figure that part out.

[zimlich]

I did a quick google search on high tidal volume and it seems it's more of a problem with patients on ventilators. Unless the tidal volume is significantly above 500 (sorry, I don't do well with the graphs, but the TV seems to really shoot up high) and continually above 500- I have occasional TV of 850- I would not be concerned. If it's consistently high, talk to the doctor, please. I don't know what it means. We also don't know how accurate these readings are (not to deride the software), you may want to double check with Encore.
Good luck, keep us posted.
Oh, also, is she an athlete?

[Rritch]

Thanks Zimlich, It has not seemed to be an issue since that time. And she is not an athlete.

[zimlich]

I know, it's really weird. I have nights where my tidal volume is really high at times, but averages out between 400 and 500. Is she feeling any better, any more bad nights?

[Rritch]

I know, it's really weird. I have nights where my tidal volume is really high at times, but averages out between 400 and 500. Is she feeling any better, any more bad nights?

Actually all has been going well since then.

[shutterbug sue]

She slept with only a single pillow last night with it flat and her number was back down below 3. Not as good as she had been doing, but much better than the 8. I would still like to understand tidal volume better.

Tidal volume is the amount of air breathed in and out in one breath. A lower tidal volume would mean she's taking shallow breaths, and a higher tidal volume would mean she's taking deep breaths.

Taking deep breaths makes sense if she's having a lot of obstructive apneas. Her oxygen level drops when her airway is obstructed, then when her airway opens back up she starts taking rapid deep breaths to bring her oxygen level back up again as quickly as possible.

[Rritch]

Thanks Sue, that make sense. I am trying to convince her to get an oximeter so we can monitor her O2 levels. She generally fees good and the CPAP treatment finally seems to be working so she is not to big on the idea of sleeping with yet another device connected to her.