Why does cpap ramp, even when not on?

I have my minimum pressure set to 7 on my Airsense 10. I turned off the ramp feature shortly after starting to use the machine early last week, since I just wasn't getting enough air at the starting pressure of 4 set up by my DME. Even though I turned it off, the level stays at 7 and creeps up very slowly for about 12 minutes. It normally isn't a big issue; but if I am running around too much before going to bed, I am not getting as much air as I would like early in the session. I would think that the machine could tell that I am sucking harder than it is putting out; but perhaps, it only increases if I am not sucking hard enough. I don't understand what the auto feature is looking for to modify the pressure setting. It sure seems like it is ramping

My median air pressure has been around 8.5 to 9.0. My 95% max pressure is usually around 11. Is there any reason to not just increase the starting pressure to 8, since the machine is never at 7, unless I take the mask off and restart?

MVPinBoynton wrote: ↑

Sat Oct 27, 2018 10:52 am

I have my minimum pressure set to 7 on my Airsense 10. I turned off the ramp feature shortly after starting to use the machine early last week, since I just wasn't getting enough air at the starting pressure of 4 set up by my DME. Even though I turned it off, the level stays at 7 and creeps up very slowly for about 12 minutes. It normally isn't a big issue; but if I am running around too much before going to bed, I am not getting as much air as I would like early in the session. I would think that the machine could tell that I am sucking harder than it is putting out; but perhaps, it only increases if I am not sucking hard enough. I don't understand what the auto feature is looking for to modify the pressure setting. It sure seems like it is ramping

I don't really understand what you're saying... could you rephrase. (I don't like to guess at what people mean, because if I guess wrong, and tell you to do something, it might be the wrong thing.)

MVPinBoynton wrote: ↑

Sat Oct 27, 2018 10:52 am

My median air pressure has been around 8.5 to 9.0. My 95% max pressure is usually around 11. Is there any reason to not just increase the starting pressure to 8, since the machine is never at 7, unless I take the mask off and restart?

No, there's no reason not to set a higher minimum pressure. Go ahead.

No reason in the world that you can't change the starting minimum from 7 cm to 8 cm if you want to.
You just happen to feel better with more air movement. Happens to lots of people. I know people who prefer 10 cm starting just for comfort even though technically they might not "need" that much to hold the airway open.

palerider wrote: ↑

Sat Oct 27, 2018 11:02 am

I don't really understand what you're saying... could you rephrase. (I don't like to guess at what people mean, because if I guess wrong, and tell you to do something, it might be the wrong thing.)

It was a bit jumbled. What I tried to say was that I don't understand why when I don't have ramp on, the machine stays at the minimum setting for a while and still creeps up very slowly to my median level. I would have thought the machine would increase the pressure quickly if I was sucking harder and needing more air.

It doesn’t do much for when you’re sucking for more air to adjust: just when you’re NOT sucking for more air does it respond to the flow blockage, and it doesn’t jump to fix the cure one, but to try to prevent future ones.

If you want to not feel like you’re starving for air while awake, you’ll need a higher starting pressure.

The ramp is designed to transition you from e.g. 4 (the machine default low) to your prescribed setting of e.g. 9 cm more slowly than you'd reach 9 without using the ramp - in other words you'd immediately be 'at' 9 when you put on the mask and started to breathe. If the machine doesn't respond by rising (presumably with ramp 'off') then at that time you apparently are breathing adequately for the machine and only in however many secs or mins later does it sense a need to rise, whether to 9 or beyond, in reaction to apneas or just your attempting to get more air in.

Thanks for the info. I have raised my minimum and looking forward to another night of great sleep.

The machine doesn't increase the pressure just because you feel the need to suck more air.
The machine is designed to respond to the physical changes in the airway requiring more pressure.
Just because you feel the need for more air doesn't mean the machine senses the same need.

MVPinBoynton wrote: ↑

Sat Oct 27, 2018 11:09 am

why when I don't have ramp on, the machine stays at the minimum setting for a while and still creeps up very slowly to my median level. I would have thought the machine would increase the pressure quickly if I was sucking harder and needing more air.

The simple answer to that is "pull the data, and look at the charts in Sleepyhead".

Every time you see the pressure increase, look down the charts for a flow limitation, snore, hypopnea, or apnea. Those things make the pressure increase.

And when you do that, you'll see how irregular your awake breathing is.

Got it! Thanks for the info.