Why won't my AHI go down?

[lawdognellie]

I've been on CPAP, then APAP and Now BiPAP. I have my Bipap set at a min min EPAP 10, max IPAP 20, Bi-flex at 3 and PS at 8. My AHI is consistently between 4.5 and 5.5, which puts me in the mild apnea category even with my machine. I upped the max IPAP to 25, to see if I still needed a higher pressure, but it usually ends up at approximately 19.5/17.5, but occasionally (when I had a cold) went to 20.5/18.5. Any idea why my AHI is still so high? Leak rate for my mask is consistent with the manufacturer's specs at that high of a pressure. I've tried mouth taping and there was no change, I changed masks 4 times and no change. Anyone have any thoughts on this? I feel like I've run out of variables to change....

Sarah

[kteague]

Sarah, I'm not a bi-pap user, but just asking in general... when does your data show your events are happening? If I lay awake with my mask on either at bedtime or in the morning, I will see apneas and hypopneas during those times and don't consider them legitimate. When awake I tend to cough a lot and breathe thru my mouth. I don't know how that affects what the machine reads, just have observed recorded events when I was semi awake. Hope you find your answers.
Kathy

[ozij]

Very good point by Kathy.

The AHI numbers used after PSGs (more than 5 = mild apnea) refer only to times when you are asleep - sleep being diagnosed by your brainwaves. If you're awake part of the time that could explain the results.

Another possibility:
I'm not sure I understand the pressure results you're reporting - but if those are IPAP/EPAP results, then what I understand from them is that your EPAP is too low - and that is apparently when those residual apneas are occurring.

But don't take my word on that - let's wait till some one with more Bi-PAP experience chimes in.

O.

[lawdognellie]

I'm not awake for any of it. I have an uncanny ability to fall asleep within 5-10 min. I can't even use the ramp feature because I fall asleep too quickly. According to my multiple sleep studies, including a MSLT, my sleep latency is 94% (which is really high I'm aware). Needless to say, there is very little time that I actually spend lying down and am awake. (P.S. I'm not narcoleptic b/c although I fall asleep really quickly, I don't go directly into REM). My AHI is still really high when I exclude the data from the 1st and last hour the machine is going. Just wondering why?

Sarah

[Snoredog]

interesting.... using PS=8 and it still drives up EPAP to the PS "minimum" of 2 cm.

That tells me the events seen by the machine that drives up pressure is apnea or snoring.

IF the events being seen by the machine were Flow Limitation or Hypopnea, then you would see IPAP be driven up and EPAP remain low taking advantage of that PS=8 setting.

However if EPAP was allowed to come up faster you may not have needed as high of IPAP pressure.

My suggestion:

Leave IPAP Max=25, lower PS setting to 4, it will pull up EPAP sooner (and also pull IPAP down sooner if sleep settles).

Do you have EncorePro? What does it show on the daily report that makes up that AHI? what is the OA indice on average? Where does those events begin along the time line?

How does the AHI on Bipap compare to AHI on CPAP or on the Auto?

If you have the Encore Pro, I would study the daily report and look for what makes up that AHI and when it happens. do you have any NR's showing up? Flow Limitation showing on the reports? What happens if you sleep on your side? what pressure is needed there vs supine?

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[Guest]

please sleep on the left not on your back(supine) position ....first point.
more later....

[Banned]

Hi lawdog,

This one is a no-brainer. You will need a Resmed Adapt SV set at 10/6 to improve your AHI.

Cheers

Im not a medical professional either. In fact, my sleep-lab doc said he would never prescribe a ResMed Adapt SV for me. Some doctors really suck!
Machine: ResMed Adapt SV
Mask: Quattro FF
Humidifier: None

[track]

Any idea why my AHI is still so high?

4.5 to 5.5 averages to 5 which puts you in the normal range or at the very worst the very lowest end of mild apnea. It's certainly not something to be classified as "so high" or concerned about from what I have read on this board.

I focus more on my AI and don't worry too much about those HI that routinely put me around 4.5 to 5.5. As long as my AI is below one and my AHI is around 5 give or take a little, I consider it pretty good.

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CPAPopedia Keywords Contained In This Post (Click For Definition): AHI