ST Mode waking me up

[neoberg]

Hello,
I am prescribed for bipap ST mode (17/21). I've been using it for the last week and seen a big improvement about my sleep overall (though I lowered the pressures a bit). But I have an issue with the "T" mode: sometimes it wakes me up with the timed pressure. Yesterday I tried using the S mode but looking at the data today, I definitely need the T part. Is there anything I can do about this? Are there any settings to optimize further to improve comfort?

My device: s9 vpap st with ivaps

[OpalRose]

Hi neoberg,
Welcome to Apnea Board!

Since you already use OSCAR, we need to see a screenshot of the daily page to better advise.

Use the links in my signature line to guide you. Take a screenshot using the F12 key, then use the attachment feature to post some data here.

[Sleeprider]

Let me guess. You had too many central apneas and your doctor prescribed the ST instead of ASV. Most common mistake we see on the board. Oscar data will give us settings and efficacy, but the ASV is for central and complex apnea, while the ST is for COPD, pulmonary disease and neurological dysfunction.

[neoberg]

Let me guess. You had too many central apneas and your doctor prescribed the ST instead of ASV.  Most common mistake we see on the board.  Oscar data will give us settings and efficacy, but the ASV is for central and complex apnea, while the ST is for COPD, pulmonary disease and neurological dysfunction.

Yes, I think your guess is correct. I'm attaching the screenshots from 2 different days. One is with the ST mode. The other one is from the night I tried the S mode.

   

   

[SarcasticDave94]

If this should have been ASV to treat CA, nothing else compares. You need to discuss with doc that the ST machine isn't comfortable and isn't treating you. It's still one of the made to AVOID CA and not effectively treat. Yes the Timed section is supposed to make you breathe when a CA is ongoing but ASV acts faster in a better way to really treat CA. Convince doc the ST machine isn't the right one.

[neoberg]

If this should have been ASV to treat CA, nothing else compares. You need to discuss with doc that the ST machine isn't comfortable and isn't treating you. It's still one of the made to AVOID CA and not effectively treat. Yes the Timed section is supposed to make you breathe when a CA is ongoing but ASV acts faster in a better way to really treat CA. Convince doc the ST machine isn't the right one.

Thank you for the reply. 
I don't have any medical insurance that covers the PAP therapy so I bought the device on my own after the titration. So I can switch to another device if it's "really" needed without convincing the doctor. But as a first step I'd like to try to fix my issue using the device I already own because they are not cheap
I don't think S/T is not treating me. My sleeps improved noticeably since the day 1. I'm down from 60+ AHI to between ~2-6 with almost half of the prescribed pressures. I'm more than happy with the current state especially when compared to my sleeps without the device but trying to optimize the experience.

[SarcasticDave94]

OK in that case, stick with ST mode and adjust it to be as comfortable as you're able. S mode won't be capable of helping the Central aspect.

[Sleeprider]

Let's go over your settings with the ST and try to make them as good as possible. The ST allows for spontaneous breathing but switches to IPAP when a spontaneous breath does not occur at the rate set. You appear to have your rate set at 12 bpm. The triggering of IPAP may remind you to take a breath, however you are only using 4-cm pressure support, so there also needs to be some spontaneous effort, and the triggering of inhale pressure is often enough to remind you to take that breath, even if you are asleep. Your results in ST mode was actually pretty good. Rise time is a setting to adjust how quickly the machine transitions from EPAP to IPAP. The lower the setting, the faster the pressure rise, and the higher setting is a slower transition. Mainly this is for comfort. Ti Min is the minimum amount of time that IPAP pressure is sustained, and for people with central apnea, I like to see a setting of 0.7 or more rather than the default 0.3. This allows enough time for the lungs to fill before pressure cycles back to EPAP. Your results on ST mode are okay, but we might be able to optimize. Again, the ST is not ideal for central apnea which is apparent in S mode. We can experiment some with lower EPAP pressure and with different levels of pressure support as well as the Ti Min and other settings.

Pages 37 to 39 of this document describe the recommended uses of your ST, the settings, titration protocol and some ideas of how this works. You might also like to read from Page 28 to learn how the ASV differs from your machine. https://document.resmed.com/en-us/docume...er_eng.pdf

[neoberg]

Thank you for the detailed reply.
My current settings are defaults other than epap/ipap pressures and resp rate. My titration results were 17/21 but I decreased it to the values shown in the screenshots because 17/21 was too uncomfortable to fall asleep.
So should I start by increasing the ti min? From what I’ve read in the document you linked, it seems like I might also play with lowering the sensivity settings a bit because sometimes I find myself fighting with the machine to cycle.

[Sleeprider]

Exactly. You should be able to feel the difference between settings, and choose what to keep or not based on your perception of comfort, and perhaps efficacy. No titration test I am aware of attempts this fine-tuning, but it is there if you know how to use it and are willing to trial and error for best results. This does not change your prescription to the degree changing your pressure does, but it can make the therapy much more tolerable. We're here to answer any questions you have as you work through this.