New machine, doubled AHI - what could be cause?

I used an ResMed AirSense 10 for about 6 years, but its 3G modem went off the air. I now have a new ResMed AirSense 11.
I was getting AHI consistently around 5 or less with the old machine, but in the last couple of weeks I've been getting consistently around AHI 10 with the new machine.

While there might be issues with my current medications, sleeping conditions, etc., I don't believe these have changed in the last few weeks before and after changing machines.

Is it plausible that the new machine is defective in some subtle way? How could we test it?

Is there some difference in how the new machine would be detecting events that would explain this? For example, might it be more sensitive?

Could my apnea change that quickly for no apparent reason?

I'm in contact with my sleep clinic, but thought I would ask here for any suggestions on how to pursue this.

Thanks!

Welcome to the forum.

First thing to check is the settings on the new machine - are they exactly the same as on the old? Maximum and minimum pressure, EPR, ramp.

Respirator99 wrote: ↑

Tue Jun 21, 2022 8:23 pm

Welcome to the forum.

First thing to check is the settings on the new machine - are they exactly the same as on the old? Maximum and minimum pressure, EPR, ramp.

Don't forget the AB filter being on/off. Remember the guy who said everything was set the same yet the pressure was "off" and come to find out AB filter was turned on and he didn't use an AB filter.

It's always a good idea to note and write down all settings for your cpap,
to keep in a safe place--even when it is fairly new.
Because . . . "Murphy".
I did this before my last overnight hospital stay; but neglected to note
that I like "essentials" set to PLUS--as if the hospital's tech would even do that . . .

DKinAA wrote: ↑

Tue Jun 21, 2022 12:27 pm

Is it plausible that the new machine is defective in some subtle way? How could we test it?

Is there some difference in how the new machine would be detecting events that would explain this? For example, might it be more sensitive?

Could my apnea change that quickly for no apparent reason?

It is *highly* unlikely that your apnea changed with the changing of the machine, and it's also unlikely the new machine is defective.

The most likely explanation is different settings.

If you still have the old machine, plug it in and get the settings. The compare them to the new machine.

Having said that even with your old machine, an AHI around 5 is pretty crappy. You could use some optimization, and it sounds like your sleep doctor hasn't been keeping a close eye on you.

Put an SD card in it and post some charts.

Thanks everybody for the suggestions. I found out how to access the clinical interface on both my old and new machine, and viewed and recording all the settings. After the last round of modifications from my Sleep Clinic, they all match except now instead of the previous fixed pressure it is now on automatic, as I requested, with a range that covers my old setting but allows it to be some higher. (I wanted to try an auto mode in case my optimum pressure had changed since the original sleep study). The last several nights have seen my AHI actually improve from before to now well less than 5.

So I am not sure what happened during that first couple of weeks with the new machine - according to the Clinic doctor, at least one setting did not originally transfer over correctly. But it looks all good now.

Thanks again!

I'm getting a similar thing after switching from my 5 year old 10 to an 11. My AHIs on the 10 were in the 1-2 range and the 11 says I'm up to 4-6 per hour. Same mask. I hacked into the clinical menu to check the settings, and as far as i can see the settings are the same.

I bought a SD card last weekend so I can download my results with the 11 into Oscar. I'll double check the options and update soon.

I had to update my version of Oscar to get it to read the data from the new 11 machine, but I finally got it to work. Comparing the settings, the only differences are:
Ramp auto rather than a set time of 25 minutes,
EPR level is 3 instead of 2,
Climate is auto rather than manual.

The last 30 days on my old 10 machine I had an average AHI of 1.81, with a leak rate of 3.76.
The first week on my new 11 machine I had an average AHI of 5.15, with a leak rate of 9.72.

I am puzzled! No changes in health, weight, medicines; just a new machine. Maybe the old machine really was worn out?

Otterdaughter wrote: ↑

Sat Mar 30, 2024 9:01 pm

I had to update my version of Oscar to get it to read the data from the new 11 machine, but I finally got it to work. Comparing the settings, the only differences are:
Ramp auto rather than a set time of 25 minutes,
EPR level is 3 instead of 2,
Climate is auto rather than manual.

The last 30 days on my old 10 machine I had an average AHI of 1.81, with a leak rate of 3.76.
The first week on my new 11 machine I had an average AHI of 5.15, with a leak rate of 9.72.

I am puzzled! No changes in health, weight, medicines; just a new machine. Maybe the old machine really was worn out?

The change in EPR and the change in humidity can both impact the quality of your therapy. Get them to where they were on the old machine.

I find the ramp auto very convenient, and it's always in agreement with my Polar Ignite sleep reports.
I use a ramp at about 1 cm or less than my target pressure, more for tracking purposes than for comfort.

Get this: last night, I hadn't read your reply yet, so I didn't change anything. I did tighten my mask straps up a bit because they're new too and stretching out a bit as they break in. I had some trouble falling asleep, so I got up after an hour of tossing and took a melatonin. My right shoulder was sore, so I slept on my left side (I usually don't).

My AHI last night was 0.24.

Now I'm wondering if I should change those two settings or not...!?

No sense in making many changes at once.
Stick to the changes you made, and see what happens.

If I understant correctoy, you made 3 changes:
Improved the leaks, took melatonin, slept in a different position.

Darn machine had a SD card error and only saved the stats last night, but my AHI was 2.0. That's quite acceptable, and probably due to sleeping the last part of the night on my right side.

Tonight I'm skipping the melatonin because my dreams get wilder the longer I take it, but definitely going with the left side sleeping position.