For ASV...does flex or humidity OR restlessness affect AHI??

Does the flex or humidity settings affect AHI numbers? Also being restless or tossing and turning, will that affect the AHI numbers.

My reason for asking is even with the new ASV machine (been about 3 weeks) I am still having about 9-13 AHI every day. My centrals are around 1 or so, my OAs are around 2 ish, but the hypopneas seem to be the issues that is always the highest number.

I have my flex on 3, my humidity on 1 (I live in the desert, very dry, but didn't like higher humidity for some reason). I toss and turn a lot, probably due to arthritis and getting stiff in one position.

I am just wondering what I can change?

Does flex or humidity or restlessness affect AHI?

In a word ... Yes. If you are restless you are more likely to be awakening just a little bit and falling back to sleep .. though sleep state transitions are known to impact your AHI values.

Too much flex also impacts the AHI (can increase the hypopneas).

Too much and too little humidity can also increase hypopneas.

Also, three weeks is a short amount of time for your body to fully adjust to ASV therapy. I think most of us find that our AHI numbers drop after a couple months. It takes time to retrain your body on how to breathe. ASV will do it. But it takes several weeks .. not just three. So, it should get better in another three or four weeks.

Hope that helps.

jjlady wrote: Also being restless or tossing and turning, will that affect the AHI numbers.

Definitely. If you are restless and remember awakenings with tossing and turning then it is possible that the machine is flagging some awake stuff as apnea stuff and that awake stuff messes with overall numbers. The awake stuff has to be removed out of the equation (mentally usually). Like the time I was awake with extreme nausea for about an hour and I did lots of tossing and turning and that hour had over 20 events get flagged and I know for a fact I was awake.

For some people the Flex setting does seem to make a difference in AHI. You would just need to try different settings to see if it does for you. It doesn't for everyone. In fact I once did an experiment where I turned my AFlex off and my AHI went through the roof and my sleep was horrible. Other people do better with it off. There is no right or wrong setting when it comes to Flex settings because we all have individual needs. Flex exhale relief isn't as much of a dramatic drop and Resmed's EPR is. Instead it is flow based. If you breathe more forcefully then your 1 setting might be a greater reduction than someone else who breathes more shallowly with a setting of Flex at 3.

Anything that affects comfort and sleep can affect AHI and also affect how you feel.

Even if I was on CPAP for 2 months prior??? I feel like I am sleeping well, except like I said I tend to turn a lot to relieve stiffness.

JohnBFisher wrote:Does flex or humidity or restlessness affect AHI?

Also, three weeks is a short amount of time for your body to fully adjust to ASV therapy. I think most of us find that our AHI numbers drop after a couple months. It takes time to retrain your body on how to breathe. ASV will do it. But it takes several weeks .. not just three. So, it should get better in another three or four weeks.

Hope that helps.

jjlady wrote:Even if I was on CPAP for 2 months prior???

Yes, the ASV machines are entirely different animals to have to get used to. Someone who has been on cpap therapy for years could very likely have some adjustment time when switching to ASV machine.

jjlady wrote:My centrals are around 1 or so, my OAs are around 2 ish, but the hypopneas seem to be the issues that is always the highest number.

JJ,

I am experiencing the same thing - hardly any OSA and centrals, but many hypopnea flags.

Could you post the breath-by-breath flow rate chart of some of your hypopnea events? I'd like to take a look at them.

If your OSA and CA events are few, the hypopneas may be so minor that maybe it's just over-sensitive software flagging going on.

I have both an older PR Advanced SV and a new Resmed Adapt ASV. I can't see the detailed breathing flow data in the older PR, but my Adapt shows these hypopnea breathing events to be so minor that I cannot understand why they are flagged at all. My breathing continues right through them with almost full ventilation.

I can also see residual Cheynes-Stokes in my breathing, left over from potential centrals after ASV treatment. No big deal.

I'm wondering if these ASV machines are yelling "fire" about hypopneas when there is nothing to really worry about.

Anyone else notice this?

Tom

As to the toss and turning, usually this is how it happens, I kind of come up from a deeper sleep feeling stiff somewhere and turn over or move/stretch parts of my body, but usually I don't come up fully, and usually fall back to a deeper sleep in maybe 10 minutes or so....those are the good nights. I usually do this maybe 3-4 times a night. On those nights I feel like I slept good overall but in fact come up from a deep sleep like I said 3-4 times during the night. My husband says I turn like a turkey on a spit (constantly turning!), I don't notice that!!

I'm convinced that Flex and EPR are trial and error things. They help some, and hurt some.

Pugsy wrote:

jjlady wrote:Even if I was on CPAP for 2 months prior???

Yes, the ASV machines are entirely different animals to have to get used to. Someone who has been on cpap therapy for years could very likely have some adjustment time when switching to ASV machine.

Exactly. I had been on CPAP and BiPAP for about 20 years before I started ASV therapy. It took me about three months to fully adjust to ASV therapy. It's a beast of a different color!

jjlady wrote:As to the toss and turning, usually this is how it happens, I kind of come up from a deeper sleep feeling stiff somewhere and turn over or move/stretch parts of my body, but usually I don't come up fully, and usually fall back to a deeper sleep in maybe 10 minutes or so

Hi jj,

First I want to thank you for your post. I hadn't thought about Flex for a long time. My primary machine is the same as yours. When I first got my doc's settings, he had the Flex set at 1. I did a LOT of experimenting with the pressures which resulted in me being extremely satisfied with my therapy; however, I ignored the flex for four months:

First 4 months: Flex 1
Next 2 months: Flex 0
Last Night: Flex 2

Since from beginning therapy I have never had difficulty breathing against pressure (current Min EPAP: 12.5). After about 4 months, one night I turned the Flex off. Apparently the setting of 1 had had such a minimal impact on my breathing that I couldn't tell the different, so I left it off for the next two months - until last night.

Your above description of "partially awakening" is very similar to my experience, BUT what I often found was when I was attempting to go back to sleep my breathing pattern was "not acceptable" to the ASV and it would continuously do pressure pulses. As often as two or three times per night I would have to turn the Bi-PAP off and back on to enable me not to have to "fight" the ASV and to get back to sleep.

After reading your post yesterday, I decided to reconsider the possible impact of the Flex on my sleep and I set it to 2. I realize that one night "does not a trend make," but I did not experience the awakening a single time.

archangel wrote:I'm convinced that Flex and EPR are trial and error things. They help some, and hurt some.

I agree with archangel, but I may have made an "invalid assumption" and will now experiment with settings of Flex Settings of 2 and 3.