Great numbers! Could be better?

I have finally hit the 0.05 or lower AHI for quite a few nights. I have always had low obstructive apnias and high hypopnias around 10-12. I increased my pressure by one (from seven to eight) and kept the upper number the same (14). Now I have had very low (1-2) to 0 hypopnias and higher obstructives (as many as 9). Do I need to do something with the upper number? I'd really like to see both low to zero . I don't understand a lot of the numbers on the charts but have always been below 3.0 AHI. I'm striving for as low as possible. Any suggestions would be most welcome.
Thanks for any help!

Hi Bonnie,

I believe you're still running Encore Pro and MyEncore, aren't you?
(If so) What does Encore Pro look like in regard to where your pressures go during the night?
If it shows that you're not getting to 14, I would lower it to the highest number you get to or even one lower....if it's not spending much time there.
I would also be inclined to experiment with the lower numbers, too. Maybe going up one cm at a time and let it stay there for at least a week at a time.
Also, in my opinion, you shouldn't rule out trying it at a single pressure (CFLE mode) to see what happens with that setting. Maybe at 9 or 10?
You should be able to see from your Encore Pro charts where most of your hypopneas are occurring. If they're at the lower pressures, they it might be that you need to bump it up a bit. Don't be afraid to experiment to find your optimum setting.

Best wishes,

Den

Thanks , Den...I'll try your suggestions.

Bonnie:

I've spent the last hour trying to find an article I read when all this started for me back in January, but have had no luck. From what I remember of the article, there seems to be a body of evidence that links (at least in some people) hypopneas with REM sleep and dreams. That is, when dreaming, it is not uncommon for there to be brief shallow breathing episodes. The dreams do not have to be bad dreams, either. The studies were not directly related to apnea, but rather looking at sleep states and specifically REM sleep. It was noted incidentally that many participants consistantly had shallow breathing episodes when in REM sleep, along with the customary rapid eye movements. Participants were healthy male and female college students.

Since successful cpap therapy leads nearly all of us to have more REM time (and therefore more dreams) during our sleep, it may be that some hypopneas are inevitable. An AHI of zero or near it may not be possible...zero apneas, yes; zero hypops, probably not?? Anything less than five is generally considered 'normal'....could this be why?

Just some food for thought on this Labor Day.......

if your AI score increased as a result of a pressure range change, I would go BACK to prior settings. You want to see lower AI even if HI remains higher >5.

Under most cases (not all):

Increasing the Min. pressure should reduce the number of HI's seen*
Increasing the Max. pressure should reduce the number of AI's seen.

*Increasing the Min. or floor pressure would normally reduce the number of hypopnea seen ...unless that is the machine is misreading you and scoring central hypopnea as obstructive events then the reverse would be seen. Too much pressure results in higher central events, so lowest pressure should be used to avoid them.

AI (apnea) is the more severe event than HI (hypopnea), so your goal should always be to obtain the lowest AI score. Assuming your sleep disordered breathing "obstructive" events were left unchecked they should follow along the sequence of severity similarly to (left to right):

Normal Breathing->Flow-Limitation->Hypopnea->Snore->Apnea

If you apply cpap pressure at Flow Limitation you can delay or even prevent the following events. If pressure is not enough that flow limitation will turn into a hypopnea, if pressure remains too low that hypopnea can turn into snores. Snores happen on in-hale (not exhale) where a low pressure condition exists, this is ideal conditions for the tongue to fall into the back of the throat or the airway collapse which results in the follow-on apnea. You don't have to follow the above pattern as you can go straight to an apnea event.

Knowing that snore nearly always precedes an apnea many autopap manufacturers like to use the snore as the pressure increase trigger. Eliminate the snore you eliminate the follow-on apnea? Only fallacy in that thinking is when snores are palatal snores. You can have snores generated by the cpap air flow itself flowing over the soft palate, increasing pressure can increase the frequency of the snores causing the machine to increase pressure actually making the condition worse or even triggering "central-hypopnea" if you are suspect of those events (consult your last PSG, look for indication of CA & MA's).

There is a fine line one needs to walk when increasing the bottom floor pressure and Max. pressure(s). If your HI score didn't go down from increasing the floor pressure then lower it back down as those extra HI's you are now seeing are most likely central hypopnea being scored as obstructive.

bonnie:

how can you have an ahi below 3.0 with nine obstructive apneas? the ahi is your apneas plus your hypoapneas, so it makes no sense. or am i not understanding something?

as snoredog is telling you, this is not a good thing you are doing. your treatment is becoming significantly less effective as you are trading hypoapneas (the lesser offense for apneas (the greater offense.) given the choice, it would be better to have hypoapneas. but zero on both fronts may be unrealistic.

caroline

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

Caroline,

The AHI is a per-hour averge of events, so 9 events in a three-hour period would be a 3.0 AHI. Four (4) events over an 8-hour period would be a 0.5 AHI. So, it all depends on how much sleep she's getting. I don't THINK she was equating the nine apneas with the 3.0 AHI.
Also, I don't think it's a "bad" thing she's doing by searching for her ideal settings. If some numbers go up (or down) you have to weigh the options and either go back or try some different settings. It's not realistic to have very low numbers night after night, so you have to look at a number of night's of data. Also, what's "low" for one person may be "high" for another person.


Bonnie,

I agree with Snoredog, if you ARE seeing higher numbers at your new settings, you might try going back to your old settings and see if they revert back. Also, how many nights have you been using the "new" settings?

I would still recommend at least TRYING a fixed pressure for a period of time and see what that does.

Den

Caroline,
I used the "as many as 9" for an example. Some nights it's 5 or 3 or 7 .For example one night I had 10 OA and 3 HI for 1.6 AHI, one at 7/6 for 1.6 AHI, one for 5/3 for 1.0 AHI (according to My Encore). And I did have 3 nights last week with 0 hypopnias. Maybe I'M missing something????



Snoredog wrote

There is a fine line one needs to walk when increasing the bottom floor pressure and Max. pressure(s). If your HI score didn't go down from increasing the floor pressure then lower it back down as those extra HI's you are now seeing are most likely central hypopnea being scored as obstructive.

Snoredog, My HI did go down when I went from 7 to 8. During my sleep study there were no indications of centrals.


Since starting treatment a year ago I have never gone above 3.0 AHI. The higher numbers may be due to other circumstances? I guess I'll have to monitor more closely. A lot of the times I check my readings being in a hurry and look at the total AHIs, if they are low, I must be OK.

Botom line is after having 377 episodes (91 hyponias and 286 OA) in 3 3/4 hours sleep during the sleep study to what I have at present is I do feel blessed to be sleeping as well as I am.

Thanks for the responses, I will continue to strive for lower OAs

Bonnie -

Do the change in your numbers correspond to a change from your swift to the hybrid?

- roberto

Roberto,
I have not used the Hybrid as a night time mask yet as I haven't gotten it to work very well yet, still lab ratting it.

Bonnie--

What I was missing was that my machine just gives AI and HI and total AHI, not raw numbers, so i incorrectly assumed yours was the same.

caroline