Upping My Pressure Despite Good AHI

I am running auto 10 - 20.

Last nine days -
90% pressure was 11.9
Peak auto pressure 12.0
A few brief pressure spikes to 14.0
AHI 3.0
Events are lightly scattered = no clusters
No large leaks, leak line relatively flat

But something is just not right. I usually awaken around four hours in feeling like I am not getting enough air and it takes some time to fall back asleep and then when I awaken after eight hours I feel like I again have not been getting enough air.

I feel significant fatigue/sleepiness most early evenings.

Tonight I will take the min pressure up to 12 so it is equal to my 90% pressure. Max will stay at 20.

Comments?

Morning V
I found that at 10 to 15 pressure I felt the same, took a good look at my ahi's and noticed that all of my apnea & hypops were coming at a pressure of 10........hmmmm got me to thinking. My 95% pressure is usually at 11 sneaks up to 12 for a few minutes every night. Five days ago I set my pressure at a straight 11, and have had NO ahi's since...zero, none in five days, doesn't feel like I'm not getting enough pressure either. I usually had zeros maybe twice during a week, usually sat about 2 or 3. At pressures of 10 to 15 I was usually waking 2 to 3 times per night to go to the biffy, now at straight 11, I get up once. I'm going to keep trying this and see how I do. I think the range of pressures was waking me up when it pulsed to hit an apnea, so perhaps straight pressure will fix that component. My original machine is a straight cpap and was set to 11 but It has no data, so I had no idea how I was doing other than how I felt. Once I was able to get my auto from another member I started using a range of pressures and have been going in auto ever since. Now that I have the auto I can stay in auto or change it to straight cpap...........kinda nice to have a choice .

VVV - I also think it may be a good idea to raise the lower pressure to 12 for a couple of nights to see how you do. Also, what I've read on the forum, having a spread of 11 or 12 - 20cm is not good. Can't remember the reason why. May I suggest lessening the range to 12 - 15 (3 number range is what I do) or 12 - 16.

Starlette

VVV wrote:I am running auto 10 - 20.

Last nine days -
90% pressure was 11.9
Peak auto pressure 12.0
A few brief pressure spikes to 14.0
AHI 3.0
Events are lightly scattered = no clusters
No large leaks, leak line relatively flat

But something is just not right. I usually awaken around four hours in feeling like I am not getting enough air and it takes some time to fall back asleep and then when I awaken after eight hours I feel like I again have not been getting enough air.

I feel significant fatigue/sleepiness most early evenings.

Tonight I will take the min pressure up to 12 so it is equal to my 90% pressure. Max will stay at 20.

Comments?

I think nanwilson is pointing in a good direction here. The higher the pressue the more likely it is to make breathing unstable - as in you breath say 10 liters per minute (lpm) of air rather than say 6 lpm (my normal at 200#). Since it takes more effort to move all that air arousals are likely. As well doing so tends to wash out necessary CO2 which reduces circulation and oxygen transport. You may never awaken from all this commotion but you will feel it during the day and with the increased stress hormones (arousals) perhaps in an extra trip to the bathroom.

You want to be where very few if any AHI is present, and where your breathing does not "take off" on it's own.

May we find good sleep soon!

Todzo

I've been wondering the same thing. With my new Elan mask my AHI has been below 1 every night. But I'm not feeling great. I know this could be all kinds of other stuff, but thought maybe I'd tweak my pressure a little to see if it made a difference.

And I'm wondering if the changes in the pressure during the night are making me wake up - or give me a restless night. I tried straight cpap for about 20 min and couldn't stand it. But maybe I just need to practice.

Hi V,
I agree with the others that your spread seems too large. I would narrow it down to 2 or 3 cm. I also agree with Nan that you might try straight cpap. I've found it to be a little more comfortable (less disturbing) than apap. I used apap to find my 95% and then switched to cpap. On cpap, I've gradually reduced my pressure with no increase in AHI.

Jay

If you never ever see your pressure go beyond that max of 14 then that 20 max setting is a non issue because it never goes higher.
Lowering the maximum isn't going to change where the max goes to unless you limit it. It will go to where it wants to go and that is it up to what ever limit you set.
Having the max at 20 doesn't alter any of the usual responses at the lower pressures if you never get above 14. Now if the machine actually did try to reach the max for some reason or other (valid or not) then you might evaluate if the pressure changes themselves are the problem and not necessarily the actual pressures...like with aerophagia or simply waking up from minor pressure changes.

Just because a machine can go to 20 cm doesn't mean that it will go to 20 and if it never ever goes anywhere near 20 then it is a moot point. Heck, if the machine would go to 100 and it never got past 10 cm, it wouldn't matter if we use 20, 30, 50 or even 100 as max. The responses are based on what it does go to and not what it could go to.

That said, it hurts nothing to limit the maximum if that is what someone wants to do but unless the machine actually reaches the higher pressures and thus maybe causes some problems, it doesn't factor in to things. It has to go somewhere for it to impact anything.

Back when I was first starting to use my APAP I found that 10 cm minimum seemed to give me a consistent AHI in the low 2ish range. Below 10 and AHI crept upwards...more upwards the lower I went.
So I settled on 10 cm as base point. I did what you are thinking of doing...increasing the minimum to see what would happen and/or would it change how I felt because I also didn't feel as good as my numbers seemed to point or as good as I wanted them to be. I felt better...sort of "okay" but not great. Over a period of 6 weeks or so I worked my way up to minimum of 13. I discovered that it really didn't reduce my AHI any more than 10 cm and I didn't really feel any different. I was able to determine when I went with the lower minimum pressure around 9 cm that my AHI was in the 3 to 4 range with clusters. I discovered that when I had clusters (even with an okay AH)I that I felt less than my usual "okay". So it seemed to me that it was the clusters that seemed to have a negative impact more than the actual AHI. Once I used a suitable minimum pressure to break up the clusters I could tell that I felt better.

I don't know if your AHI of 3 happens to show any clusters but if it does and a little more minimum pressure helps break up the clusters it may show up in how you feel. Can't promise that it will but it might and sure doesn't hurt to try.

I ended up going back to my 10 minimum because at 13 things weren't really changing. No sense in using more pressure all the time if things weren't going to change.

Edit: In regards to limiting the maximum when reaching the higher pressures creates problems...like aerophagia, sleep disturbances or whatever. Those would be valid reasons and one would need to evaluate risks vs benefits thing and likely compromise just like what RobySue does. That's a whole different ball game. If Robysue had been lucky enough that her pressures never needed to go to her maximum and stayed near her minimum the maximum would be a moot point.

But if someone sleeps better with their max limited to 15 or whatever and maximum never ever even reaches anywhere near that limit it hurts absolutely nothing to limit it but opening it won't hurt anything either.

You all are giving me a lot to think about. Too bad this is not as simple as the ceiling fan in my office - lo, med, hi, reverse.

Understanding that God made us all unique and we therefore will find different solutions, let me make some specific and some generalized comments.

nanwilson wrote:Morning V
Five days ago I set my pressure at a straight 11, and have had NO ahi's since...zero, none in five days, doesn't feel like I'm not getting enough pressure either.

Nan, Any change in energy level or daytime sleepiness?

nanwilson wrote: I think the range of pressures was waking me up when it pulsed to hit an apnea, so perhaps straight pressure will fix that component.

If I can trust the EncorePro daily details chart my pressure seems to increase some minutes after an apnea or two or a flow limitation. I don't believe the pressure increases during an apnea (and maybe that is not what you are saying).

Todzo wrote:

The higher the pressue the more likely it is to make breathing unstable - as in you breath say 10 liters per minute (lpm) of air rather than say 6 lpm (my normal at 200#). Since it takes more effort to move all that air arousals are likely. As well doing so tends to wash out necessary CO2 which reduces circulation and oxygen transport.

Thanks for the comments Todzo. I am uncertain about the physics and the body response. First does an increase in pressure to say 12 cm from 10 result in much change in flow in the body? Certainly there is more washout through the vents but it would seem the body determines the flow (Roster frequently posts that the rise and fall of the diaphragm determines the amount of flow assuming the airway remains open.)?

Todzo wrote:

You want to be where very few if any AHI is present, and where your breathing does not "take off" on it's own.

I do feel like an AHI of 3.0 is too high for me but last night it was 1.2 and I still did not feel "right".

What do you mean by "breathing take off on it's own"?

Jay Aitchsee wrote:Hi V,
I agree with the others that your spread seems too large. I would narrow it down to 2 or 3 cm. I also agree with Nan that you might try straight cpap. I've found it to be a little more comfortable (less disturbing) than apap. I used apap to find my 95% and then switched to cpap. On cpap, I've gradually reduced my pressure with no increase in AHI.

Jay

Oh it is Jay of the RLS pharm thread, if I remember correctly. I should find that thread and do an update if I ever get the time. Briefly let me say "ferrous sulfate supplementation is a winner for us old guys".

My machine (set at 10 - 20 cm) will hit 14 many nights and maybe once a month 15 or a little bit higher. So if I change the min to 12 and leave the max at 20 could I expect my common range to be 12 to 14? If so I would achieve that 2 cm range some call for.

I am cautious about lowering the 20 because of that "once-per-month" happening when it hits 15+. I have never been able to tie those nights to heavy meals, late alcohol, nasal congestion or any other suspect. But I do like having 20 cm "in reserve" and feeling like it will be there to awaken me if I get in trouble. That seems to be what happens when it hits 16 or 17 - I awaken, reposition myself and do well the rest of the night.

I do remember Wulfman has a strong preference for straight CPAP. But what about all those people using EPR, Flex or BiPAP? Many of them seem to do quite well.

At this point a decision has to be made for tonight and that will be 12 - 20. More than scientific this change is driven by my subjective feelings on numerous occasions that I am "not getting enough air". The good Lord willing I can check my energy level and my data in the morning and make a decision to stay put or make another change of settings.

nanwilson wrote:My original machine is a straight cpap and was set to 11 but It has no data, so I had no idea how I was doing other than how I felt.

I wonder if, at the end of the day, an evaluation of your vigor level throughout that day is not a great way to measure the effectiveness of the therapy?

Maybe I am too old to work and travel so much. But I feel like stepping down might throw me into a quick downward spiral. Maybe a little tweaking gets me going strong again.

Thanks all,

Pugsy wrote:If you never ever see your pressure go beyond that max of 14 then that 20 max setting is a non issue because it never goes higher.

Agreed!

Pugsy wrote: Once I used a suitable minimum pressure to break up the clusters I could tell that I felt better.

I don't know if your AHI of 3 happens to show any clusters but if it does and a little more minimum pressure helps break up the clusters it may show up in how you feel. Can't promise that it will but it might and sure doesn't hurt to try.

I really would not call them clusters. But I am still thinking a 12 will prevent some of them. It seems to me that when the machine goes to 13 or 14 I am in REM. I am thinking that a necessary 14 will be reached quicker from min 12 than min 10 and will also result in more prevention of events.

But, as I mentioned earlier, science aside my decision is being driving by my feeling of not getting enough air through the interface. But it is good to have all your scientific thoughts so my feelings don't lead me too far astray.

Tweak and ye shall find,

VVV wrote: science aside my decision is being driving by my feeling of not getting enough air through the interface.

As good of a reason as any to try what you want to try. Maybe your body will "like" the stability of a little less pressure roaming and reward you with feeling better. Maybe the little quicker response will prevent potentially disruptive minor flow limitations or mini arousals and let you feel a little better. Maybe it will help and maybe it wont' but if you don't try something the answer is always "no".

Pugsy makes good points, as usual. I appreciate the in depth information and experience. Thats what Im on here for, even if i disagree from time to time with someone. Everyone is here to maximize the quality of their life.

A few comments:
--riasing your pressure can also raise your leak level, causing more AHI. Just a thought. But this doesnt come into play until 13-15. My experience is that at 15 you have to be pretty serious about clamping that mask down, and that in itself can cause other problems depending on your sleep position.

--agree also, whether you set max at 15 or 20 really makes no difference if your data consistently shows that you are not spiking above 14 anyways. The machine is only going to raise you to a certain level if it thinks you need a much higher flow. Heck, you could set it at 30 and it still wouldnt jump above 14.

--Also agree if youre making changes do them orderly and as billy murray might say baby steps. This gives you the assurance that youre not going berserk on the range, but also you can more easily track your small gradations of change more easily. If you suddenly jump significantly, you cant really intgerpret the data.

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