Respironics Flex setting

[VTSleeper]

Last night was my first night with my PRS1 Auto 560P. I set the "Flex" setting to 3, which provides the highest relief in air pressure for when exhaling.

My question is this: Is there any reason to have the setting lower? I feel like I am missing something here.

[Sleeprider]

Flex is a comfort setting. You can try different settings and just use the one that is best for you. As you begin to get some sleep data, you may be able to correlate small improvements in your therapy (AHI) effectiveness with different A-Flex settings on the machine. For some reason on the 560 I seemed to do a bit better at a setting of 1 or 2, but everyone is different.

For now you want to use the machine at near the recommended titration setting from your sleep study and once you have a baseline, you can start to experiment with different pressure and Flex settings. I do recommend that if you have the Ramp feature turned on, that you limit its time to no more than 5 minutes, and set the minimum pressure at a comfortable level. The default 4 cmH2O and 45 minutes is a big problem for most of us.

[OpalRose]

Last night was my first night with my PRS1 Auto 560P. I set the "Flex" setting to 3, which provides the highest relief in air pressure for when exhaling.

My question is this: Is there any reason to have the setting lower? I feel like I am missing something here.

Hi VTSleeper,
Do you know what your pressure setting is?

Just an example: My pressure is set at 9 minimum.
So if I use an Aflex setting of 3- that would be an exhale relief pressure of 6.
If Aflex is set to 2, then exhale relief pressure would be 7.
And a setting of 1 would be an exhale relief pressure of 8.

The flex setting is for your comfort when breathing out, but some people have no problem with that and don't use it. On the PRSystem one machines, there is a demo you can use to see how it feels.
OpalRose

[VTSleeper]

Right now my pressure setting is 8-18, but I have yet to have my titration test.

[OMyMyOHellYes]

I keep mine set on "1" just so I can say I use it. I really do not miss it if I turn it off. I found the higher settings disturbing. On the Z-1 I think it would have been better to have a no EPR setting.

OMM

[truetopath]

Yep the flex is simply a comfort setting. On my RESMED it's call EPR. I've turned mine off after the first couple weeks and don't even miss it. Everyone's idea of comfort is different though, so feel free to tinker and use what's comfortable.

[AshSF]

Last night was my first night with my PRS1 Auto 560P. I set the "Flex" setting to 3, which provides the highest relief in air pressure for when exhaling.

My question is this: Is there any reason to have the setting lower? I feel like I am missing something here.

Hi VTSleeper,
Do you know what your pressure setting is?

Just an example: My pressure is set at 9 minimum.
So if I use an Aflex setting of 3- that would be an exhale relief pressure of 6.
If Aflex is set to 2, then exhale relief pressure would be 7.
And a setting of 1 would be an exhale relief pressure of 8.

The flex setting is for your comfort when breathing out, but some people have no problem with that and don't use it. On the PRSystem one machines, there is a demo you can use to see how it feels.
OpalRose

The Aflex setting always settles on an EPAP which is 2 cm lower than the IPAP. If you look at Aflex DOT respironics DOT com, it shows it with a graphic. This is why you need the pressure to be at least 6cm for Aflex to work (because the machine can not go below 4cm).

So all Aflex settings start out giving more than 2cm h20 relief depending on the flow rate and the setting; but by the end of the exhalation, they all settle on a pressure which is exactly 2cm less than the inhale pressure.

This is different than Resmed EPR which gives 1,2,3 cm pressure relief respectively, on settings of 1,2,3 EPR.

[truetopath]

Last night was my first night with my PRS1 Auto 560P. I set the "Flex" setting to 3, which provides the highest relief in air pressure for when exhaling.

My question is this: Is there any reason to have the setting lower? I feel like I am missing something here.

Hi VTSleeper,
Do you know what your pressure setting is?

Just an example: My pressure is set at 9 minimum.
So if I use an Aflex setting of 3- that would be an exhale relief pressure of 6.
If Aflex is set to 2, then exhale relief pressure would be 7.
And a setting of 1 would be an exhale relief pressure of 8.

The flex setting is for your comfort when breathing out, but some people have no problem with that and don't use it. On the PRSystem one machines, there is a demo you can use to see how it feels.
OpalRose

The Aflex setting always settles on an EPAP which is 2 cm lower than the IPAP. If you look at Aflex DOT respironics DOT com, it shows it with a graphic. This is why you need the pressure to be at least 6cm for Aflex to work (because the machine can not go below 4cm).

So all Aflex settings start out giving more than 2cm h20 relief depending on the flow rate and the setting; but by the end of the exhalation, they all settle on a pressure which is exactly 2cm less than the inhale pressure.

This is different than Resmed EPR which gives 1,2,3 cm pressure relief respectively, on settings of 1,2,3 EPR.

I stand corrected.

[vsheline]

The Aflex setting always settles on an EPAP which is 2 cm lower than the IPAP. If you look at Aflex DOT respironics DOT com, it shows it with a graphic. This is why you need the pressure to be at least 6cm for Aflex to work (because the machine can not go below 4cm).

So all Aflex settings start out giving more than 2cm h20 relief depending on the flow rate and the setting; but by the end of the exhalation, they all settle on a pressure which is exactly 2cm less than the inhale pressure.

This is different than Resmed EPR which gives 1,2,3 cm pressure relief respectively, on settings of 1,2,3 EPR.

Exactly right.

Much unlike ResMed EPR (which is a straightforward reduction in pressure of 1, 2 or 3 cm H2O during exhalation), there are three things going on with A-Flex.

Referring to http://aflex.respironics.com webpage:

1. A-Flex settings of 1 or 2 or 3 all provide a base of 2 cm H2O of exhalation pressure relief.

2. On top of that, and like with the other flavors of Flex (Bi-Flex and C-Flex and C-Flex+), because Flex provides Flow-based pressure relief (adds additional pressure relief proportional to how fast/hard we are exhaling), whether we use a setting of 1 or 2 or 3, the greater the rate of our exhalation airflow (the faster/harder we exhale) the more pressure relief is provided at the beginning of exhalation.

3. The higher the A-Flex or C-Flex+ setting, the more sensitive the machine will be to how fast/hard we are exhaling OR INHALING. (I think it would have been better if Philips-Respironics would have provided separate A-Flex controls for exhalation versus inhalation.)

An A-Flex setting of 3 provides the greatest sensitivity to how fast/hard we are exhaling, providing more exhalation pressure relief while we are actively exhaling. But, toward the end of inhalation, as we are finishing inhalation and the rate at which we are inhaling air reduces, a setting of 3 also causes the pressure to decrease earlier, making it harder for us to finish inhaling as much as we may like. The transition between the inhalation pressure (IPAP) and the exhalation pressure (EPAP) is more more gradual but starts earlier (too early).

With an A-Flex setting of 3 the premature reduction in pressure before the end of inhalation can be bothersome, can make us feel like the machine is trying to get us to start exhaling before we want to, before we have completely finished inhaling.

Using an A-Flex setting of 1 (instead of 3) allows the pressure during inhalation to stay high longer, making it easier to finish inhaling fully. But an A-Flex setting of 1 also results in a more rapid or sharp transition between IPAP and EPAP, which may be bothersome to some.

So the solution is obvious - just leave the A-Flex setting at 2. (Just joking.)

At the top right of the A-Flex webpage are links to explanations for C-Flex, C-Flex+ and Bi-Flex.

[chris7]

I was thinking along the same lines; I had been using FLEX=2 for a while and was amazed how comfortable FLEX=3 was. I noticed some side effects with the FLEX=3 setting:
- higher breathing rate (since the exhale happens faster, the machine seems to shorten the duration of each breathing cycle.
- higher reported AHI numbers
- tendency to hyper-ventilate and as I consequence, difficulty falling asleep.

So as much as I prefer FLEX=3 setting, it seems my sleep quality is better with FLEX=2

PS: I use the Philips Respironics and I suspect FLEX implementations vary across models