[Pressure] New cpap user and guessing at machine settings

[Tsunami]

I was diagnosed with mild sleep apnea, my sleep study AHI was 10.  I have been using a cpap machine for about 5 months with mixed results.  The pressure setting originally prescribed based on my sleep study was 7.  That worked for a while (AHI usually less than 5)      and then it didn't, the AHI events started to climb.  Based on what I have learned on this site I have reset to a pressure range (see attached screenshot).  Any advice you have on interpreting the OSCAR graphs with respect to my pressure settings is appreciated.  I do not feel newly energized since starting this therapy, just a bit less tired than I used to. So I am looking to optimize my use of the machine.  Thanks.

[PeaceLoveAndPizza]

Do you have a copy of your sleep study showing the AHI breakdown? If so please post the summary and redact your personal information. If not, any idea if you had centrals during the sleep study? Any information on meds taken or other medical conditions will be helpful as well.

Let’s go back to a baseline setting to get started.

Mode APAP
Min pressure 7
Max pressure 15
EPR 1 full-time
No ramp

I know it is lower than where you are today, but I want to see if those centrals are pressure or EPR related. I suspect it is flow limitations driving up the pressure, but I cannot see the FL graph. Also, please read the link in my signature on “Formatting OSCAR charts”. It would be helpful to see those specific graphs on a single screen.

Once you get a night with those setting's folks here can help dial things in further.

[Tsunami]

Thank you. Attached is the results of my sleep study, it was an at home study.  The study in the hospital was to determine the pressure to use.  I will reset my machine according to your suggestions and post a result in a couple of days.  And I will review your instructions on formatting the graphs.

 I am on blood pressure meds, a low dosage of lisinipril, and some vitamins.    

[PeaceLoveAndPizza]

Did your sleep doctor explain why they put you on a standard APAP and not a bilevel? With 50% of your apnoea’s being central, I wonder what their logic was for doing so. I understand that the study showed you had an AHI of ~5 for OA and ~5 for CA, which I imagine they considered not needing a more capable and expensive machine.

An AHI of 10 is considered mild, but centrals are difficult beasties to treat without the proper machine. I suspect a bilevel with trigger control would solve the CA issues, but we will do the best we can with what you have available. It may necessitate a chat with your doctor if we cannot find something that works for you.

[Tsunami]

I have not seen a sleep doctor, I live in a place where doctors are not abundant.  My sleep study was ordered by a nurse practitioner.  The results were read by someone I never met.  My PCP relayed the report to me with the pressure recommendation.  I have asked for a referral to a sleep specialist (the local ones are also not doctors) but have been told there is a very long wait.  So while I wait I have been trying to set the machine myself.  I suspect many people are in a similar situation, thus the busy traffic on this website.  Thank goodness for this site.

[Tsunami]

    Here is last night's data, the machine was set to the values you suggested.  Note that I suffer from insomnia so am awake a lot.  I wonder if the clear airway events are just tossing and turning when awake?  Also, I can't seem to get the leaks to zero, am on my second mask and going to try a third soon.  My med tech claims the leak rate is so low it doesn't matter, what is your opinion?  Finally, I wonder at the ahi values for people who are awake a lot at night but still hooked up to the machine, can the number have any value since they are supposed to be a measure of obstruction while asleep?

[PeaceLoveAndPizza]

I agree with the med tech about your leak rate not being an issue. Sound like you have one that is a good’un. Most of the leaks are not enough to be concerned at the moment. Your I:E ratio is good, as is your tidal volume. 

My takeaway from the chart is that your minimum pressure should be 9 and a max pressure to start should be 12. EPR seems best at 2, though I think a night or two using EPR=3 would be a worthwhile test to see if it cleans up the remaining flow limitations. If not, then staying with EPR=2 is still in an acceptable range. With your insomnia, I do not think having your max higher than 12 will help much and in fact may work against you. 

Keep in mind low AHI does not equate to quality sleep. Look at either chart for the flat flow rates, that is what we are trying to achieve. Looking at the latest chart and ignoring the 2nd and 3rd sessions which look to be more awake than sleep breathing, you can see the median pressure is around 10. On the first chart it is also around 10.

If you would like to try an experiment, here are two settings to give a whirl. The first is a fixed setting and the second is a smaller range.

Setting #1

Mode CPAP
Pressure 10
EPR 2 full-time (or EPR=3 to test it)
No ramp (unless you truly need it)

Setting #2

Mode APAP
Min pressure 9
Max pressure 12
EPR 2 full-time (or EPR=3 to test it)
No ramp (unless needed)

Both are leaning a bit towards the higher end of your range. We will not know if EPR=3 will trigger more centrals until you try it. Depending on how things go and the response of the centrals, we can adjust from there. I would still not rule out a bilevel, but for now let’s focus on what we can control with pressure and a bit of EPR.

Thanks for hanging in there as we tweak things further. I know how frustrating it can be.

[SarcasticDave94]

I would strongly suggest, that if you do not have the full sleep study, that you should request it. This even applies to your at home test.

I see they indicate 23 Obstructive and 22 Central Apnea, others as mixed. This tells me your CA is a present issue needing therapy. ASV is the best answer in this case.

Your current ongoing CA is in the treatable level, but they'll possibly always be present, causing consistently inconsistent trouble. If the CA are a thorn, you'll need to demand CA be treated.

[Tsunami]

I have a report from each sleep study. The report doesn’t have any graphs or data in other forms, like tables.  Would the full result also include data?

[SarcasticDave94]

It might, if you're willing, post the rest that goes along with the above attachment. Worst is it doesn't help and you can remove it from your attachment area within the Board.

However with just what I've seen, CA are an issue that the best answer is ResMed AirCurve 10 ASV.