Is my S9 bad?

[jobe2433]

2 years ago I had my first sleep study and diagnosed with moderate sleep apnea. I received a resmed cpap s9 with a pressure setting of 8. I noticed my pressure 95% of the time has been staying at 15. My doctor ordered another sleep study thinking something must be wrong. I had my second sleep study last night. I asked the technician how high my pressure got last night and he told me 8. Now I'm confused and wondering if my cpap machine is broken or do people sleep differently at a sleep study than they do in there own beds? Is anyone else having this issue?

[LSAT]

How do you know that your pressure setting remained at 15? Are you looking at reports? If you are running on Auto, what are your upper and lower settings?

[Mr Concerned]

I received a resmed cpap s9 with a pressure setting of 8. I noticed my pressure 95% of the time has been staying at 15.

If it is set to 8 how did it get to 15?

[jobe2433]

My first sleep doctor set my machine to run from 8 to 20 on the S9. They downloaded the software so I could monitor on my own. I am looking at reports from the S9. But in both sleep studies they told me the pressure never got above 8. The low on my current machine is 12 the high is 19. It never shows 8 as a constant number or ever.

[hyperlexis]

It could be something with the mask. In my experience sometimes FF masks change the pressure requirements upward compared to other masks.

Have you always used the qfx? Is the cushion new(ish)? Or were you on a different mask when getting the 8s and then switched to the qfx and the pressure went up?

I would do an experiment and change out the mask cushion, and maybe even the anti-asphyxia check valve flapper, and see if anything changes. I would also switch to a different mask, like a nasal mask or a pillows mask and see if that changes anything.

Is the hose still good? Leaking?

Otherwise, unless you have gained weight or have terrible allergies or something, there may be reason to have the machine inspected.

[robysue]

My first sleep doctor set my machine to run from 8 to 20 on the S9. They downloaded the software so I could monitor on my own. I am looking at reports from the S9. But in both sleep studies they told me the pressure never got above 8. The low on my current machine is 12 the high is 19. It never shows 8 as a constant number or ever.

If the min pressure setting is 12cm and the max pressure setting is 19, that would explain why you never see a pressure of 8 cm. Your machine is set to use 12 cm as the starting (therapeutic) pressure and it is allowed to increase the pressure in response to flow limitations, snoring, and clusters of two or more OAs and Hs. It can increase the pressure all the way up to 19cm, but it cannot lower the pressure down to 8 since 8 < 12.

As to why the titration study never got above 8: Some labs (probably most labs) do NOT titrate to eliminate all FLs and the human tech can distinguish between WAKE breathing patterns that look like an H or an OA or "snoring" and real Hs, OAs, and snoring that happen when you are asleep[//i] according to the EEG data. If the EEG says you're awake, the tech ain't going to increase the pressure. Likewise, the tech can hear real snoring because of the microphone. But the AutoSet cannot tell when you are awake and when you are asleep and it judges "snoring" only through a ragged wave form. Hence the AutoSet can raise the pressure in response to "false" events, whereas the human tech in the lab won't.

So who set your machine to its current settings? The sleep doc? The DME? Or you?

[jobe2433]

Thank you guys for the help! Robysue I'm sorry I did not type that right. The machine is set from 8 to 20. All my equipment is new. I've found the only mask I can use without causing huge blisters on the bridge of my nose is the Quattro FX. The sleep doctor just called me back and told me to adjust the pressure starting at 8 and ending pressure at 11. We will see how this works!

[archangle]

APAPs don't always find "THE" right pressure. Nor do sleep techs during an in-lab titration. Sometimes, you just have to tinker until you find the best guess for you. Some people find they need to set to a narrow pressure range, or even to full manual.

Me, I've always left the upper limit on 20, and the machine never seems to "run away."