assistance with analyzing cpap data

[jentlesoal]

Hello members,

I'm hoping someone on the forum can help me interpreting the data from my Philips Dreamstation 1. I'm using the Dreamstation 1 with nasal CPAP nasal pillows. Although I have been using the unit faithfully for over 5 years, sleep quality is poor and sleep has NEVER been restorative. This lead me to see if the CPAP data can provide answers as to why the sleep quality has not improved with CPAP.

Below are screen shots from one night. The same abnormalities in this sleep session, are common to some degree every night. To summarize the abnormalities; there are reduced flow rate, abnormal waveform (expiratory pressure seems to be reduced when compared to inspiratory pressure), and reduced tidal volumes, often in the 200s. My tidal volume reference value should be 580. This is occurring with normal respiratory rate, so the abnormalities do not appear to be deep sleep or rem sleep related.

Questions:

1. What causes a reduced flow rate?
   
2. What causes a wave form that is not symmetric? In my data, it appears that the pressure is longer on the inspiratory effort, and shorter on the expiratory effort. Am I correct that both lengths should be equal?
   
3. What causes low tidal volume with normal respritory rate? The basal tidal volume for my height and weight should be approx 580. The data shows my tidal volume average is 380 over the past year and often dipping the single digits and often 100-200 through the night. Is that normal, and if not what does that suggest?
   
4. Am I correct, that these metrics appear to indicate nocturnal hypoventilation?
   

Thanks everyone/anyone for reviewing my post and providing any feedback!

[Jay51]

I have been diagnosed with hypoventilation, and you possibly could have it.  But it is too early to tell.  

Your flow rate graph from a pretty far distance in the upload you provided looks like the tops are a little bit pointed.  Probably some flatness to them also.  

Could you please upload images of the regular OSCAR that shows your pressures, and all of the important information so you can get much better suggestions as to how to proceed?  

I went back and looked at your old posts, but they did not have the tidal volume included on them or other important information.  

Thank you very much.          Organize your OSCAR Charts

[jentlesoal]

Hi Jay,

Thanks so much for the reply. I was able to download my lateset stats, which are attached.  Please let me know if you need the screen shots as well. Im just trying to find some answers and improve my sleep qlaity, and sincerialy apprecaite your opinon.

Thanks again!

JS

[Phaleronic]

Hello jentlesoal

I use a similar machine (dreamstations), it is a good machine and actually in my years of trying different makes and models (and vendors) it's one the better ones, if you take apart the motor air chamber it has a much more robust motor than the other vendors (and you can use flex/epr without having to increase pressure or lose apnea/hypopnea control) so you're on the right track. Please change the flex mode to cflex or cflex plus, and set min pressure to 11cm (your 95 percent pressure is right around that). A-flex does not work quite as well.

Also please disable ramp and if you are able use F12 in the daily tab to save a full screenshot and attach it here.

I will check out your first group of charts now.

[Jay51]

You are welcome JentleSoal.  It looks like you are in APAP mode with 8 min 15 max.  With a flex set to 3.  I must admit I am not an expert on this machine.  There are some experts on this particular machine that may be able to give you much better suggestions.  

Your flow limitations data is still missing.   That is important.  Also, your median, min, 95%tile and 99th%tile numbers are missing also.  They are usually seen just above the statistics that you posted on the left hand side of your OSCAR chart. 

No worries.  We are getting there.