Tech pre-determined pressure of 5. Does this make sense?

RosemaryB · Post by **RosemaryB** » Mon Apr 16, 2007 5:35 pm

I'm going to post both my sleep studies. I think the tech may have made a mistake. During the titration study, she kept me at 4 until I hit REM, then she put it up to 5. She told me in advance that this is what she planned to do. It seems atypical to me.

It did take my AHI from 20.3 down to 0.5, but I still have plenty of arousals, as noted on the other post. I'm just trying to understand, if given the sleep study you see below, this made sense.

Any observations would be greatly appreciated. I'm posting the original sleep study first and the titration study second. (Sorry about the poor quality/sizing of the images, I'm very new at this.

Original Sleep Study

(sorry about the variation in sizes, I've never done this before)

Titration Study

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CPAPopedia Keywords Contained In This Post (Click For Definition): Titration, AHI

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CPAPopedia Keywords Contained In This Post (Click For Definition): Titration, AHI

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CPAPopedia Keywords Contained In This Post (Click For Definition): Titration, AHI

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CPAPopedia Keywords Contained In This Post (Click For Definition): Titration, AHI

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CPAPopedia Keywords Contained In This Post (Click For Definition): Titration, AHI

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CPAPopedia Keywords Contained In This Post (Click For Definition): Titration, AHI

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CPAPopedia Keywords Contained In This Post (Click For Definition): Titration, AHI

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CPAPopedia Keywords Contained In This Post (Click For Definition): Titration, AHI

Snoredog · Post by **Snoredog** » Mon Apr 16, 2007 5:51 pm

(very hard to make out), but the very bottom graph is the one that tells the story (along with the data in between).

Looks like you need 5cm pressure to get better quality of sleep. When you you look at the graph at the very bottom on the left, that black solid line is the pressure you were at, when it goes to 5cm things really settle down.

That is what you want to see.

RosemaryB · Post by **RosemaryB** » Mon Apr 16, 2007 6:01 pm

Thanks, Snoredog. The graph I have in front of me is not very much better, though I imagine someone who reads them all the time could make it out. (I resized it and got it a little clearer)

Does anyone know what the S and R notations mean?

SleepySandy · Post by **SleepySandy** » Mon Apr 16, 2007 6:42 pm

RosemaryB wrote:During the titration study, she kept me at 4 until I hit REM, then she put it up to 5. She told me in advance that this is what she planned to do.

I'm hoping Rosemary can repost that last graph so we can see it better because I don't understand why a titration study would do just 2 pressures, particularly since that's what the tech said she planned to do. I don't see how anyone can plan a pressure ahead of time.

Like Rosemary, my titration study had no CAs, OAs, or Hs at a pressure of 5 but my tech took me through 6, 7, 8, 9, 10. I don't understand stopping at 5.

Can someone explain why 5 would be the pre-planned pressure and why the tech wouldn't have gone above 5 during the study?

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CPAPopedia Keywords Contained In This Post (Click For Definition): Titration

RosemaryB · Post by **RosemaryB** » Mon Apr 16, 2007 7:09 pm

OK, Sandy, I'm working on how to get a better quality graph for that last image. I hope to have a better one soon.

SleepySandy · Post by **SleepySandy** » Mon Apr 16, 2007 7:41 pm

This is a larger version of the last graph Rosemary posted. It's the best it can be.

rested gal · Post by **rested gal** » Mon Apr 16, 2007 8:40 pm

RosemaryB wrote:Does anyone know what the S and R notations mean?

My guess is S=Supine (on your back), and R=Right Side. The positions you were sleeping in. That line looks like it's labeled "Pos", which I think means "Position."

lmmo · Post by **lmmo** » Tue Apr 17, 2007 1:20 am

[quote]Can someone explain why 5 would be the pre-planned pressure and why the tech wouldn't have gone above 5 during the study?

During a titration at our lab the cpap pressure would be increased 1 cm h20 for snores, 2 cm h20 for obstructive apneas and 1 cm h20 for hypopneas. Sleep techs are hoping to see REM/supine to titrate effectively. It typically takes a higher pressure for REM/supine. This might be what the tech meant?? The pressure would not be increased if there were no more apneas or snores. Perhaps the study discussed above, the pressure may have been increased for snoring only. This would usually be documented in the tech notes.

Slinky · Post by **Slinky** » Tue Apr 17, 2007 2:19 am

Thanks for dropping in, Immo!!! And for shedding some light on the question.

SleepySandy · Post by **SleepySandy** » Tue Apr 17, 2007 2:23 pm

lmmo wrote:During a titration at our lab the cpap pressure would be increased 1 cm h20 for snores, 2 cm h20 for obstructive apneas and 1 cm h20 for hypopneas. Sleep techs are hoping to see REM/supine to titrate effectively. It typically takes a higher pressure for REM/supine. This might be what the tech meant?? The pressure would not be increased if there were no more apneas or snores.

This is finally starting to make sense.

I would like to ask some questions about Rosemary's study in comparison to my own.

This is my titration study table of pressures:

I clearly had no events with pressures 5, 6, 7, or 8.

Here's my hypnogram:

As I now understand it, the tech took my pressure up because of my snores which were clearly happening under all of the pressures.

I have a PDF of Rosemary's hypnogram and can zoom in to see the labels more clearly. It lists:
SpO2%
HR,BPM
CA,sec
OA,sec
MA,sec
HYPO,sec
POS
LegMvt,sec
arousal,sec
Stage
IPAP,cmH2O
EPAP,cmH2O

No entry for snores. That's a bummer.

So, the assumption is when she got to 5cm there were no snores (we already know there were no events) so there was no reason to raise the pressure. By comparison, I had snores so my pressure was continually increased.

Do I have it right?

Sandy
data geek who needs to understand everything

lmmo · Post by **lmmo** » Wed Apr 18, 2007 12:44 am

Yes, you are lucky to see the snores on your histogram. We do not count and record snores. We do document the snoring and increases of cpap on our tech notes.
Your assumption would probably right. She probably did not snore therefore, not needing an increase.
I wear cpap myself and I have found wonderful insight here. I do like to offer some info if I can. I do not infer to be in anyway giving medical advice.

RosemaryB · Post by **RosemaryB** » Wed Apr 18, 2007 2:43 pm

Thank you, Sandy, Rested Gal, Slinky, Immo, and Snoredog. I certainly understand this much better than I did at the start.

Tech pre-determined pressure of 5. Does this make sense?

Tech pre-determined pressure of 5. Does this make sense?

Thank you!