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+--- Thread: high pressure (/Thread-high-pressure--35205)
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high pressure - Larrypac - 01-03-2022
This has happened to me 4 or 5 times now. The pressure from my Airsense 11 goes up to the maximum setting and wakes me up. I then breath calmly for 30-40 seconds hoping it will drop but it does not so I turn it off and then back on. It is not pinned to the max but hovers just below it. Shouldn't the pressure drop down pretty quickly once I am awake and breathing normally? Thanks, Larry
RE: high pressure - pholynyk - 01-03-2022
It actually takes quite a while for the machine to reduce its pressure, so hitting the off button and then starting to breathe again is your quick solution - assuming you have AutoStart enabled. Otherwise use the button to re-start.
The better solution involves downloading OSCAR and getting an SD card to leave in the machine while you sleep. Once you've imported a night's data, you can use the F12 key to create a screenshot that you can attach to a post here. There are several members here who can look at that and likely give some suggestions that will prevent the runaway pressures.
If that sounds complicated, don't fret, we are happy to guide you through the process of improvement.
RE: high pressure - sheepless - 01-03-2022
flow limitations (including obstructive events) are a primary driver of pressure increases. epr is used when tolerated to help control flow limitations. expiratory pressure (epap) combats obstruction including flow limitations to some degree. min pressure is often raised in the amount of the epr setting to maintain sufficient epap to keep obstructives down.
when I used to use apap, I would frequently get runaway pressure. much (not all) of my flow limitations are caused by my physical response to periodic limb movements (plm) which the machine can't overcome. I'm not saying you have plm but I mention as an example of why we might get runaway pressure. nothing to do but stop the flow and restart it. the pressure is disturbing, often causing leaks, sometimes aerophagia. worse, it wakes us up and requires action to stop it. alternatively, restricting max pressure can avoid this problem.
post some screenshots so others can see what's happening and give you some targeted suggestions.
RE: high pressure - SarcasticDave94 - 01-03-2022
I'm going with possible flow limit spikes but show the OSCAR and we'll be better able to help.
RE: high pressure - Ratchick - 01-04-2022
What the others have said. It takes longer to drop than it does to go up. Is it ACTUALLY the pressure waking you, or could it be the events that are pushing the pressure up that are waking you? We'd really need to look at OSCAR to see what's happening, though, as others have said.
RE: high pressure - Larrypac - 01-04-2022
Here is last night's data. Obviously I did not sleep well. The high pressure wake up was about 11:40
RE: high pressure - Ratchick - 01-04-2022
Yeah, you have clustering of events and flow limits which are maxing your pressure. Normally just for flow limits the answer would be EPR but you already have that on full time at 3. I wonder if instead you're having positional apnea AKA chin tucking? I'm sure someone better at this than me can have a look and let you know.
RE: high pressure - OpalRose - 01-04-2022
The clustering of Obstructives in the early morning hours is what positional apnea looks like, but since we don't see that throughout the night, it's probably just SWJ (sleep-wake-junk)
From the Wiki:
Sleep-Wake-Junk - Clusters of apnea and hypopnea events concentrated mainly around periods of sleep-wake transition. In general Sleep-wake-junk (SWJ) is not regarded as "real" since they do not occur during periods of sleep, but may be during semi-awake periods or "dozing".
You do however have Flow Limitations throughout the night. Also Hypopneas and Reras. At the time you mention, 11:40, line this up the FL and Snore graph... you will see what's driving your pressure up.
You are already using max EPR, so a slight pressure change may help combat some of these issues.
Your median pressure is currently at 9cm, so try moving your minimum closer to that. Start with 8cm. Also, would like to limit the max pressure a bit, because FL and snores will drive that pressure up to whatever you have it set to.
So, the goal is to narrow the pressure range. (8cm minimum, 14cm maximum)
Keep EPR AT 3.
Note: I don't know what your other nights look like, but the cluster of apnea in the morning hours is from chin tucking. Watch that doesn't occur more often.
RE: high pressure - SarcasticDave94 - 01-04-2022
For the clusters, you can try a thinner pillow or use the pillow you have to tuck a corner between chin, chest, shoulder. Failing that, a soft cervical collar may be needed, if this becomes an actual need.
Since EPR is already at 3, to combat flow limits you'll need to increase Min pressure. Try 8 which is 1 click up from the current 7. Remember with EPR 3, 8 will drop to 5 on exhale as your lowest.
RE: high pressure - desaturator - 01-05-2022
It would be great if these machines could just shut the pressure off if you wake up. Do any of them have such a feature? I often wake up with the pressure at maximum. I'm satisfied that there's a good reason for it being at maximum, but it doesn't serve any useful purpose (so far as I know) when I'm actually awake.
Last night it was freezing in the bedroom, and I really didn't want to have lean out and switch the machine off and on again. Yeah, first world problem, I know.
Best wishes, DS