Incorrect Encore Pro AHI Index?

Guest · Post by **Guest** » Fri Aug 18, 2006 6:51 am

I'm wondering whether Encore Pro (and My Encore) are reporting incorrect AHI values whenever large leaks occur.

When large leaks occur, my Remstar Auto never reports any apnea events (in another posting, this was described as a "feature" - my interpretation of the posting). However, when the AHI is computed, the total apnea events are divided by the total blower hours - not the blower hours less the large leak hours. As a result AHI indices are deceptively low whenever large leaks occur.

Am I missing something?

Sleepless in St. Louis · Post by **Sleepless in St. Louis** » Fri Aug 18, 2006 7:26 am

Just a guess, but I would think that a sustained large leak would compromise the machine's ability to adjust to your apeneas. How can it measure your breathing with all the background noise. So it does nothing, according to its built in programming. Or the leaks are not big enough to trigger SDB events. How are you feeling with the therapy is the key question, in my mind. If you're not feeling too good, I would think you'd need to work on getting those leaks under control before worrying about what the machine is measuring. My 0.03 (inflation you know).

Tim

greyhound · Post by **greyhound** » Fri Aug 18, 2006 9:01 am

Clearly, there's a need to improve the leak situation. However I would think that if there's a period when the machine can't determine whether an apnea event occurred, then that period shouldn't be part of the AHI calculation.

I wonder what Derek's thought would be on the "correct" AHI calculation.

wolftracker · Post by **wolftracker** » Fri Aug 18, 2006 10:14 am

The question is how is this affected by the hybrid mask

the mask has a naturally high vent rate that is registered as
a leak

so the ppl who are saying there ahi is way down
may only be seeing the results of a high leak

not a true reduction in ahi ...

what say the experts????

to much of a nee bee to know
hmm

Guest · Post by **Guest** » Fri Aug 18, 2006 10:16 am

wolftracker - This question refers to the Encore Pro/My Encore AHI calculation. It's not restricted to the hybrid

oldgearhead · Post by **oldgearhead** » Fri Aug 18, 2006 11:21 am

I've been curious about the accuracy of the RemStar leak numbers.
Why? I have 6 weeks of CL2 leak data, followed up by 6 weeks of Hybrid leak data. Both of the numbers are about the same (41.0 LPM @ 8.6 cm/H2O).

41.0 LPM at 8.6 cm/H2O is very close to the Hybrid's 'Passive Exhalation Port Flow'. I have not perceived as many CL2 leaks as Hybrid leaks. So,
why doesn't Encore Pro report lower 'leak' numbers for the CL2?

wolftracker · Post by **wolftracker** » Fri Aug 18, 2006 11:35 am

my numbers for leaks on the CL2 are much lower
in both encore and myencore

my hybrid numbers are much higher and i dont feel
any leaks anywhere