New machine, doubled AHI - what could be cause?

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DKinAA
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New machine, doubled AHI - what could be cause?

Post by DKinAA » Tue Jun 21, 2022 12:27 pm

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!

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Respirator99
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Re: New machine, doubled AHI - what could be cause?

Post by Respirator99 » 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.
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Pugsy
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Re: New machine, doubled AHI - what could be cause?

Post by Pugsy » Tue Jun 21, 2022 8:51 pm

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.
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chunkyfrog
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Re: New machine, doubled AHI - what could be cause?

Post by chunkyfrog » Tue Jun 21, 2022 11:14 pm

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 . . .

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Dog Slobber
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Re: New machine, doubled AHI - what could be cause?

Post by Dog Slobber » Wed Jun 22, 2022 6:22 am

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.

DKinAA
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Re: New machine, doubled AHI - what could be cause?

Post by DKinAA » Tue Jun 28, 2022 2:35 pm

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!