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+--- Thread: What is PR Dreamstation trying to do? (/Thread-What-is-PR-Dreamstation-trying-to-do)
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What is PR Dreamstation trying to do? - spacewrench - 09-08-2019
When looking at data from my PR Dreamstation, I often see segments that look like I'm breathing normally, at not-max pressure, but the machine does a brief ramp-up before falling back. Why is it doing that? (See ~01:22 in these screenshots.)
[attachment=15336][attachment=15337]
RE: What is PR Dreamstation trying to do? - jaswilliams - 09-08-2019
when your breathing is all smooth and boring the Dreamstation increases pressure to see if it can improve treatment when it finds it can't it drops the pressure again. Its one of those things the Philips algorithm does.
RE: What is PR Dreamstation trying to do? - Melman - 09-08-2019
I suspect it is responding to the two hypopnea that preceded the increase. Your machine is at max pressure most of the night and you have many clustered events, probably due to chin tucking. I recommend you try a soft cervical collar to correct chin tucking. It should result in a significant reduction in events. I and many other forum members have found it to make a big improvement. See the link below for information on sizing and use. An increase in min pressure to 6 (close to the median) will allow your machine to respond faster to increased pressure needs. You will also probably need to increase your max pressure but try the collar first. An increased pressure will not overcome the restriction resulting from chin tucking.
RE: What is PR Dreamstation trying to do? - spacewrench - 09-08-2019
A collar is worth a try...I'm still getting used to the machine, and if I set the high pressure too high, it wakes me up (or I become aware of it during one of those clusters) and I can't get back to sleep. I've mostly been creeping the high pressure up, but not too fast because a full night at AHI < 10 is worth MUCH more to me right now than a couple hours at AHI < 5 (and 5 hours of insomnia!)
RE: What is PR Dreamstation trying to do? - mesenteria - 09-08-2019
Your gradual approach is by no means an unreasonable one...raising the upper pressure limit a few tenths of a cm at a time. However, the confound alluded to by Melman is a doozy; you must get a grip on any mechanism that wants to restrict flow and to cause the machine to think you're getting into trouble. If we can prevent any obvious mechanical hindrance to your airway, then what's left is going to have to respond to pressure variations or some other remedy. In that respect, a collar might be the ticket, and for the few dollars in outlay it will be worth a try.
You have no night-time stuffiness, no allergies here and there?
RE: What is PR Dreamstation trying to do? - Sleeprider - 09-08-2019
(09-08-2019, 11:59 AM)spacewrench Wrote: When looking at data from my PR Dreamstation, I often see segments that look like I'm breathing normally, at not-max pressure, but the machine does a brief ramp-up before falling back. Why is it doing that? (See ~01:22 in these screenshots.)
This is pretty interesting. Your close-up of 01:24 is in fact free of events, and the two rises in pressure of 1.5 cm over 2-minutes each is a part of the Philips algorithm. However if we step back to 12:59 we see a flow limitation followed by a cluster of hypopnea. This is a signature for positional apnea from chin tucking.
I apologize for not following your story closer, but what is the reason for the very very low CPAP pressures of 5.0 to 6.5? I would really rather see you at 7.0 to 9.0 if that is tolerable.
RE: What is PR Dreamstation trying to do? - Melman - 09-08-2019
Eliminating the clusters will also reduce the pressure increases. That doesn't mean you won't need to increase the pressure but it's why I suggest trying the collar first.
RE: What is PR Dreamstation trying to do? - OpalRose - 09-08-2019
(09-08-2019, 11:59 AM)spacewrench Wrote: When looking at data from my PR Dreamstation, I often see segments that look like I'm breathing normally, at not-max pressure, but the machine does a brief ramp-up before falling back. Why is it doing that? (See ~01:22 in these screenshots.)
The brief ramp up as you describe it is actually part of Phillips Respironics algorithm.
Although your graph is very busy, the algorithm is programmed to raise the pressure approximately 1.5cm and back down every couple minutes to determine if a higher or better pressure is needed.
Normally, these small increases in pressure are not felt. It sort of looks like a sawtooth pattern.
Your pressure setting of 5 min to 6.5 max leaves no room for the machine to do its job.
I’m all for using a narrow pressure range with Respironics machines, but in your case you need a higher minimum pressure. You have way too many Hypopneas, Obstructives, Reras, and Flow Limitations.
It’s hard to say where your pressure should be just looking at that graph, but I would set the minimum pressure at 7cm and max pressure at 12cm. Set the Flex setting to 1 or 2.
Watch for a few days, and repost. Then we will have a clearer idea of what is going on.
Also, using the soft cervical collar as Melman suggests will definitely help. This is important as we’ve seen many folk helped by this.
RE: What is PR Dreamstation trying to do? - Gideon - 09-08-2019
You also have quite a few flow limitations and RERAs. On your machine, these are best handled with pressure increases. But afte you try the collar.
RE: What is PR Dreamstation trying to do? - spacewrench - 09-08-2019
I had tried higher pressures previously (after a couple of improved nights) but found that if I woke up at all, I couldn't get back to sleep because it felt like my lungs were getting inflated (of course, they are getting inflated!). Here's a terrible night at 7-11:
[attachment=15340]
All the clusters while trying to go to sleep are me failing to switch over to automatic breathing. I couldn't stop thinking about how to breathe. After a few days of that, I went back to really low pressures hoping to get some sleep, at least, and it has mostly worked. I'm still worried about raising the high pressure, because once the machine wakes me up, that's all the sleep I get for that night. I'll raise the high limit this week; maybe I can get to 9 or so. Plus I'll have a collar by Tuesday, so maybe that will help.