Auto CPAP

I wouldn't say it's immediate, but yes, the machine reacts to the airway resistance and then goes back down to a lower pressure when the resistance is gone.

Different machines have different ways (algorithms) of detecting that resistance and dealing with it. Some machines don't immediately increase the pressure, in case you are leaking, because that will only cause more leaking. But over time, the pressure will increase as it detects airway resistance, until a normal breathing pattern is resumed, or until the upper limit of pressure is reached. Then the machine will start lowering the pressure while it keeps testing the resistance to make sure your airway stays open.

There are a lot of people who can explain this much more clearly than I just did, with a lot of technical information. But the main thing is that is exactly what an auto is programmed to do.

Deano wrote:I understand that you program a low and high limit. What I do not understand is how the machine reacts to auto adjustment while you sleep?

It increases pressure in response to certain patterns of irregular breathing attempting to prevent apneas and hypopneas.

Deano wrote:...If I have a apnea while I'm sleeping, does the machine immediately react and increase pressure?

No. It responds to those identified irregular breathing patterns; now that said, the ResMed model S9 APAP responds differently than the older S8 AutoSet and I'm not sure if what I've stated covers how it responds...hafta wait until someone who knows more about that device to respond. If breathing irregularities preceded an apnea/hypop, then the APAP would already be increasing the pressure.

Deano wrote:...Does the increased pressure decrease back to the lower limit when normal breathing is restored?

Yup, the length of time to drop back varies per mfg.

Janknitz wrote:I wouldn't say it's immediate, but yes, the machine reacts to the airway resistance and then goes back down to a lower pressure when the resistance is gone.

Different machines have different ways (algorithms) of detecting that resistance and dealing with it. Some machines don't immediately increase the pressure, in case you are leaking, because that will only cause more leaking. But over time, the pressure will increase as it detects airway resistance, until a normal breathing pattern is resumed, or until the upper limit of pressure is reached. Then the machine will start lowering the pressure while it keeps testing the resistance to make sure your airway stays open.

There are a lot of people who can explain this much more clearly than I just did, with a lot of technical information. But the main thing is that is exactly what an auto is programmed to do.

well actually you explained that in a way that made sense to me -- and i didn't know how that worked before...thank y ou janknitz....oh....does jan knit? I do....when i'm not sleepy!