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Lower AHI when using HME filter
I have been using CPAP for just over one year with varying AHI results. For the last six months my AHI average has been 9.61 with 8.35 being clear airways according to Sleepyhead. I use an Airsense 10 machine set at 16. I use my humidifier set a varying settings. When I travel or go away for a weekend I leave the humidifier at home and use an inline heat moisture exchange (HME) filter instead, rather than shulp my gallon of distilled water. The last two times I have done this my AHI was below three each night. The ratio of clear airways to AHI remains about the same.

I wonder if I should just continue to use these filters instead of the humidifier. Does anyone have any explanation for this or comments?
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Here's a guess...
Your apnea is mostly CA. You put in the inline heat moisture exchanger and get better numbers.

It's possible that you experience pressure induced CA. Putting the inline heat moisture exchanger may increase the flow resistance and lower the pressure delivered to you. The was these machines work, airflow is always toward the mask -- even when you exhale. Your exhaled breath is added to the vented air from the mask. So, the pressure drop due to flow through the inline heat moisture exchanger is always there; and it peaks during inhale.

You might do better with an auto machine set slightly lower. Autos do not raise pressure on CAs; but do so on snore, flow limitation, Hypos and OAs.
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Whatever the reason it's certainly worth figuring out--now you know that you can reduce your ahi significantly through some kind of pressure adjustment. I would imagine that you will feel much better is you can consistently replicate the ahi 3--or less!
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It's hard to say whether the inline filter is helping AHI, or masking the sensors from detecting events. It might be helpful to see daily data comparison of with and without the filter. I agree with Just Mongo, you are using a relatively high pressure, and experiencing predominately CA events. You might realize significant improvements by lowering that pressure incrementally until obstructive events become more common. I would suggest you do this without the inline filter, since we don't know how that might affect the machines sensing of events.

You may want to add to your profile, or this thread, the specific model of Airsense 10 you are using. If it has data, it is probably either the Elite or Autoset. The machine model will influence your options and what we might recommend. In addition to fixed pressure at 16, are you using EPR?
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My Airsense 10 is the Autoset model and I have my EPR set at 2. In the past I have tried reducing EPR to one which increased my AHI. A couple of months ago, after I saw my sleep doctor I adjusted my settings to automatic and set the pressure from 10 to 16, then a few weeks later from 12 to 16. In both cases my AHI went up significantly. When set to automatic my 95% pressure was in the 14.2 range.
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Thanks for posting the additional details. You have done everything I would have suggested, so, good work! The AHI is apparently really stubborn, but fortunately, it's more CA, which might be a bit less stressful. This raises the questions whether you have consulted your doctor, and is he/she satisfied with this result, and whether you are comfortable and sleeping well enough that this is acceptable? Given what you've tried, about the only thing I can think of to resolve near a 10 AHI of CA events, is a bilevel or ASV upgrade. You're borderline to qualify, but that may be the next step. I'm pretty sure the next progression would be bilevel without ASV, and it seems you benefit from pressure support based on your experiments with EPR.
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I wanted to add one thing, going back to your original question. I think if you enabled the UA events in Sleepyhead, you might find the CA events are replaced with UA events. These are unidentified, and are real events, but the machine cannot identify whether they are CA or OA; and I think that may be the masking from the inline filter. I don't know this for certain, but strongly suspect it.
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What is the inline Heat Exchange filter? I am a new Autosense 10 user and am getting ready to travel with it - do you not use the humidification chamber because it is a nuisance to carry?
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[Image: 51jGlWvf6fL._SX522_.jpg]

I personally would not recommend it.
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So, last night I turned off my EPR to see if that would help. My AHI remained about the same, but my CAs went down and HAs went way up. Apparently my CAs just moved down the chart to HAs. I think I'm gonna try to just lower my pressure a bit tonite and see what happens.
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