Sierra

Yes, that is really severe sleep apnea with an AHI of 120, and it really needs to be treated. There are a few things that can impact comfort and acceptance of the CPAP.

First is the mask used. There are many different types and manufacturers. Which masks has she tried and what does she not like about each one? I may be able to suggest some alternatives.

The second is the adjustment of the machine for comfort. What brand and model of a CPAP is she using. Do you know what the pressure settings are? What are her main complaints about using the machine? I may be able to suggest some improvements in the setup of the machine.

This may or may not be relevant, but let me tell two stories.

We have a trailer and sometimes camp off the grid. For that purpose I bought two 12 Volt DC to 24 Volt DC inverters made by ResMed - one for my wife's S9 and one for my A10. My inverter worked fine but my wife's didn't. After returning the inverter three times I did some electrical measurements to see what was going on. I essentially measured the current draw as my wife's inverter was tripping out on overload shortly after the machine started up. What I found out was that both my machine and my wife's machine with both the humidifier and heated hose were drawing the same current. And, more interesting the current was switching on and off. It seems the heated hose, or humidifier, or both do not used a modulated current draw. It is simply switching on and off to control temperature and humidity. The short story is that the current draw is very uneven, and I am convinced that there is a design error in the inverter made for the S9, but the A10 is fine. Relevant to your problem however is that even though I never felt the heated hose as warm, it certainly was drawing current, as was my wife's S9. And the other point is that it is not constantly on. It seems to cycle on and off.

Since that time the heated hose for my A10 basically failed at the mask end. The flexible rubber connector seemed to overheat and turn gooey. I replaced the hose and it is fine now. But the point again was that the hose appeared to be passing current. I suspect there was a bad connection inside the mask end connector that was causing the connecter fitting to get warm or hot, but I never noticed it. And this new hose is the same as the old in that I never feel the hose itself getting warm. But. I leave the temperature at 81 F (27 C), and never adjust it higher or lower.

This all said it is very hard to check to see if the hose is working if you only have a home 110 volt version of the power supply. I was only able to do it in my trailer setup because I could measure the current going to the inverter as the wires are exposed on the 12 volt side.

What blood pressure medications are you taking other than furosemide?

FWIW, I don't notice my A10 heated hose getting noticeably warm, but I do believe it is working. I keep the temperature settings at the default of 27 C or 81 F. I also keep the humidity control on auto.

I am afraid that I don't know enough about an ASV to give you any advice. @CyrusManz here uses an ASV and may be able to help you. Hopefully he checks in.

I would ask your doctor about using Indapamide instead of furosemide to control blood pressure and edema. Indapamide is a long acting drug that is taken once a day. Furosemide is short acting and the effect is immediate and only lasts a couple of hours. Some information here:

Indapamide

I am not aware of being able to troubleshoot the problem any more than you have done. I think I would talk to your supplier and try and get them to accept a return and replacement of the machine with a new one. Your screenshots should be useful in verifying that the pressure is not being held constant, and in fact is dropping for no reason. I am just guessing but the machine pressure control system may be programmed to use flow as an anticipatory input to determine when to increase the fan speed. When flow goes up the pressure will tend to drop if the fan speed does not increase. Possibly a defective flow transmitter would contribute to the pressure dips.

You also have your S9 data to show that it is not your health problem and the S9 works well when the A11 does not. My wife has a S9 machine which has been displaying the motor life exceeded warning for about a year now, but it keeps on ticking. That is good because the on line supplier of machines in Canada seem to have no stock of new machines.

On further point. When you move the green vertical cursor line left and right on the screen with the mouse you can read the exact value of the variable in the top left of the graph. This is useful for seeing how low the mask pressure is going during these events.

From what I can see on the one you zoomed in further it appears the mask pressure drop happened on a reasonably normal increase in flow. I am thinking there may be an issue with the machine's response to increasing flow and maintaining pressure. If you post more screenshots it is helpful to put the cursor on the event of interest and that should draw a vertical green line that goes from graph to graph so you can relate correlate each graph more easily. This is much easier for you to do as you can move the cursor back and forth sideways to compare multiple different events.

The event near the left of the top image at 1:37:30 would be interesting zoom in on. It appears to have multiple drops in pressure while the flow rate is reasonably normal. But the exhale (down) flow rate seems to have a lot of noise on it. One possibility is that the flow rate sensor is not measuring flow reliably and that in turn is affecting pressure.

You could also search the S9 graphs to see if there is anything similar in them. If not, that would seem to eliminate you and the way you are breathing as a source of the disturbance.

Just of interest that squiggly line in the middle of the bottom graph is the machine pulsing the flow to test for the type of apnea you are having. If it is obstructive the cycle up and down in pressure is more extreme. And if it is an clear airway or central event then the wave in the pressure line will be narrower. This event did not last 10 seconds so it was not flagged. the next event lasted longer and did get flagged as an OA event.

That helps a lot. One issue I see, but unrelated to your problem, is that OSCAR is reporting that you are in fixed pressure CPAP mode on the A11, but the graphs clearly show it is in Auto APAP mode. Must be a bug in OSCAR. I still use Sleepyhead. I believe OSCAR is supposed to be compatible with A11, but it appears is is not fully...

What I see unusual in the A11 graph of the mask pressure is that there are times when the mask pressure drops very low, below the minimum pressure of 4 cm that it is supposed to always maintain. See the screenshot below where I have highlighted the areas. It may be worthwhile to expand out some of those areas and see what may be happening first. It's possible that it is a chicken and egg situation. Are the deep breaths causing the mask pressure drop, or is the mask pressure drop causing the deep breaths?? You might see that if the time scale is expanded out in one of these. The one at 1:37 seems to be the worst.

These machines are designed to always maintain a minimum of 4 cm of pressure. It is possible that this particular machine is defective and cannot respond quickly enough to dropping pressure. Depending on where you got the machine it may be hard to convince them of that possibility. They may respond to a screenshot clip showing in detail what is happening.

One other thought I had was that you may want to try setting the machine to a fixed CPAP pressure to see what happens. That may let the machine respond better to quick deep breaths. Not sure, but it is easy to try. I would suggest a fixed pressure of 8 cm based on your data that you posted. Then it may have to be fine tuned up or down to get an acceptable number of OA events. But, 8 cm should be close. This is a bit of a work around to the underlying issue though if the machine is defective and not responding quickly enough.

You don't seem to be using the Ramp feature. If you want to try it, I would suggest setting the Ramp Time to Auto, and the Ramp Start pressure to 7 cm if you want to go with a fixed CPAP mode of 8 cm. That should be comfortable to go to sleep. The Auto ramp feature hold the pressure at the ramp start pressure until it decides you are asleep and then ramps it up to the set pressure of 8.

Hope that helps some. I would be interested in seeing a screenshot of that event at 1:37. It may tell what is happening first.