Sudden Change to AHI After Dreamstation Firmware Upgrade

[RWhipkey]

Has anyone else noticed a change in AHI after upgrading Dreamstation APAP firmware.  I upgraded my Dreamstation APAP to 1.14 four days ago.  After 8 months of consistent AHI results, the last four nights have produced significantly different results.  My AHI's have increased from an average of .80 to 2.20 literally overnight.  Most of the increase has been in hypopneas.  Strange.  I tried to go back to 1.11 to see if the AHI fell again as quickly, but 1.14 specifically does not allow the installation of earlier firmware editions.  Anyone have any thoughts?  Is 1.14 actually that much more accurate than 1.06?  If so, perhaps I need to tweak my pressure range from 8.00-12.00 to 8.50-12.50.

[Walla Walla]

Unless they changed how they count Hypopneas I don't think there'd be a difference as far as the firm ware. It's possible they decided to count Hypopneas at 30% obstruction instead of 40% but I doubt it.

[Sleeprider]

I think your best bet may be to tweak pressure upward. It will be interesting to see if anyone else has a similar experience. Since you are using a pressure range, does your data suggest any difference in median and 95% pressure?

[RWhipkey]

Hi Sleeprider

No, median remains at 8.00 and 95% at around 9.50.  Maximums have only been around 10.7.  Is strange, isn't it?  Could just be a several day blip, but awful coincidental.  Perhaps I should wait a few days until I tweak to 8.5-12.5.

[Dawnstar]

This is curious. They could have changed the AHI scoring algorithm. The 1.1.0 to 1.1.1 change supposedly improved the detection of Flow Limitation events (unless I'm recalling incorrectly). 

My unit is on 1.1.0, and it's clear that in Auto mode, certain vibratory storing patterns can trigger pressure changes upward to preempt Apnea events, they could have done additional changes that might have changed how the machine pressure adapts.

But it could be a random, coincidental spike, monitor and let us know if it continues.

[Fedman]

Last January I upgraded from a PR System One to a Dreamstation.  Prior to the upgrade my AHI was under 1.  With the Dreamstation my AHI shot up around 2.5.  I was using a pressure range of 8-12 on the System One and left it the same for the Dreamstation and I noticed that the bulk of my events were hypopneas.  I let it go for a couple of weeks to see if it would settle down but it didn't so I raised my minimum pressure to 8.5.  That did the trick and my AHI immediately dropped back down to under 1.  Slight raise in pressure may work for you as well.

[SnoringInOregon]

My DreamStation has a cellular modem installed. Is it possible for my DME to update the machine's firmware over the air without my knowledge?

Does SleepyHead log the current firmware version? Is this displayed anywhere? In the Daily screen, If I hover my mouse over the text that says "Philips Respironics DreamStation", it changes to "Model 500X110". Is the 110 merely a coincidence or is that perhaps the firmware version?

[Walla Walla]

Look under the My Provider section on your machine it will list the current firmware there.

[RWhipkey]

Update

I did change my pressure range to 8.5 - 12.5 last night.  AHI immediately fell back to .49.  I can't believe that this is just a coincidence.  RERA, however was 1.47, and my prior RERA average had been around .45.  I'm not too concerned about RERA, however, because I don't believe its totally accurate. Even if it was, my RDI would be 1.96, and under 2.00. I'll keep my range at 8.5 - 12.5 for 10 days or so and report back.

Rick

[Walla Walla]

Looking at the instructions for installing the latest firmware the is nothing changed as far as therapy. What has happened is they have installed a password device into the firmware. This is to allow DME's to lock you out from changing settings. So the push is on to stop all you rebels from getting a good nights sleep. Anything to increase the profits and control of DME's.

No way would I do them a favor and download this for them.