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+--- Thread: [CPAP] How quick do autosets change pressure? (/Thread-CPAP-How-quick-do-autosets-change-pressure)
How quick do autosets change pressure? - ted13 - 08-06-2023
This has happened many times…So I wake up at 6:24am this morning, mostly because of the air hissing through the seal of my mask. I’m laying on my side, zero obstructions, breathing normally (I’m awake at this point), yet still taking 9.9 - 10 cfm of air to the face for the next 15 minutes. At one point it went up to 10.2 briefly, still while I’m staring at it breathing normally.
Why am I being force fed air when there is zero obstruction?
Even if I was snoring or I was laying on my back prior to waking up, do these machines not react that quick?
I know when I’m on my side I don’t snore and breathe normally. On my back it’s a different story. I’m concerned when I flip from back to side all night this thing is force feeding me air when I don’t need it.
Resmed Autoset 10.
Pressure range 6 - 13.4
EPR full time, level 2.
Response Soft
Starting pressure 4
RE: How quick do autosets change pressure? - Gideon - 08-06-2023
How did you measure your flow rate of 383 lpm?
That is a bit high. And how did you get units of cfm.
Please post your OSCAR charts so we can see what is going on.
RE: How quick do autosets change pressure? - ted13 - 08-06-2023
(08-06-2023, 10:37 PM)Gideon Wrote: How did you measure your flow rate of 383 lpm?
That is a bit high. And how did you get units of cfm.
Please post your OSCAR charts so we can see what is going on.
My bad. The correct measurement is cm h2o and not cfm. Not sure where the flow rate of 383 LPM is mentioned?
I do have Oscar but of course the sd card was in my laptop and not in my resmed last night. I’ll get more data.
Just curious if these machines don’t automatically drop the pressure as quick as I expect them to… seeing how I was awake breathing normally for 15+ mins and it never dropped pressure below around 10 yet my minimum is 6.
RE: How quick do autosets change pressure? - Phaleronic - 08-06-2023
I didn't like apap mode on my resmed machine, so I sold it and went back to the apap mode on my ds1, but eventually I decided to try cpap mode, and it's been the best for me, you may want to try it on your resmed machine to see how you do.
RE: How quick do autosets change pressure? - ted13 - 08-06-2023
(08-06-2023, 11:13 PM)Phaleronic Wrote: I didn't like apap mode on my resmed machine, so I sold it and went back to the apap mode on my ds1, but eventually I decided to try cpap mode, and it's been the best for me, you may want to try it on your resmed machine to see how you do.
How do I figure a good starting point for pressure? Maybe start at my 95%?
RE: How quick do autosets change pressure? - OpalRose - 08-07-2023
(08-06-2023, 11:10 PM)ted13 Wrote: Just curious if these machines don’t automatically drop the pressure as quick as I expect them to… seeing how I was awake breathing normally for 15+ mins and it never dropped pressure below around 10 yet my minimum is 6.
Awake breathing often times is more erratic than actual sleep breathing. The algorithm is probably reacting to that. Pressure is also driven by Flow Limitations.
Once you show us a night or two of an OSCAR Screenshot (daily page), we can better answer your questions. The SD card must be in the Cpap while sleeping, or you will only see summary data.
RE: How quick do autosets change pressure? - Sleeprider - 08-07-2023
Ted, in the presence of a leak, the machine will flow as much air as possible to maintain pressure. CPAP pressure is practically unnoticeable, but a leak is extremely disruptive. Your problem wasn't the pressure, it is the leak. Fix the leak and the machine will quiet down.
RE: How quick do autosets change pressure? - Gideon - 08-07-2023
Basically events, snores, hypopneas and obstructive/mixed apneas cause pressure increases. When these events occur near each other they can increase pressure fairly rapidly. They also decrease just as rapidly but after a time delay. I can't remember the delay but this decrease is why even AutoSets need to be optimized. Why should an AutoSet decrease pressure to below that pressure which is below optimum? The answer is these machines have no way of knowing what optimum is. Thus we, thru analysis of the data sty a minimum that will manage most of the apnea and let the Auto mode minimize the apneas that occur above this.
FYI 10 CFM converts to 383 lpm
RE: How quick do autosets change pressure? - Millstone50 - 08-07-2023
Immediately after an OA, snore or flow limit
RE: How quick do autosets change pressure? - Phaleronic - 08-07-2023
(08-06-2023, 11:36 PM)ted13 Wrote: How do I figure a good starting point for pressure? Maybe start at my 95%?
Yes, or 90%, I'm not sure if you can use EPR with the resmed but you could try it for a night and see how you feel.