Respironics BiPAP autoSV Advanced System One - AHI w/ Humidfier

[BigSkyMike]

Greetings,
I have been using a Philips Respironics BiPAP autoSV Advanced System One DS960 for nearly 3 years. About 99.9% compliant with use.

The short story is I have wildly different AHI (as reported on the device) numbers from week to week, or even day to day. By "wildly", I might have one night with an AHI of 1.5, then the next it would be 40. I discussed with my physician, but she was at a loss to explain. I did notice that when traveling, I trended far lower than when at home.

I have now narrowed the issue to really just one thing... my heated humidifier.

When traveling, I often don't bring it along. After months of trial and error, looking at weekly and monthly average AHI, I'm confident that the humidifier is causing the super high AHI readings (~30 AHI). Average weekly without humidifier is between 1-2, with it attached, >30.

Questions:
Is it all normal to experience wildly different AHI's while using a humidifier?
If no, is there a way to troubleshoot where the issue is (gasket, etc.), or should I replace the entire humidifier?

THANKS!

[Pugsy]

No...not normal for the humidifier to cause wildly differing AHI.

I don't know of an easy way to troubleshoot but replacing the gaskets as a first experiment is easy and cheap.
https://www.cpap.com/productpage/Dry-Bo ... Humidifier

[BigSkyMike]

I did plug the hose connection to determine if I could hear any leaks, but nothing. But, I've ordered new gaskets. I'll keep my fingers crossed.

On a side note, I do actually have two of the DS960 machines and both exhibit the same behavior when attached to the heated humidifier.

[Pugsy]

Any chance of nasal issues maybe confusing the machine?
When you use the humidifier....any change in nasal breathing? Increased congestion or anything like that?

[BigSkyMike]

Nothing noticeable. I just seem to prefer the warm humid air over the dry stuff. My sleep pattern seems similar too, and I do feel about the same level of "rested" with the humidifier on or off. Only the AHI is different. I've even turned the heated tube off, and the humidty level off, but left it connected... with the same "bad" AHI. So, I don't think moisture or heat is an issue at all.

[Pugsy]

you might call acbio.com and talk to someone that fixes these machines to see if he has any idea what might be going on.