For the stats chasers - pressure and AHI

[symmit]

OK so over the last few weeks I've been trying to find my "ideal" minimum pressure, worked out so far it's somewhere between 8 and 10 hPa.

5 days at 8hPa average AHI 0.7, best 0, worst 1.2
5 days at 9hPa = 0.7, 1.3, 1.8
5 days at 10hPa = 1.3, 1, 1.7

So I'm going for 8hPa - anyone got any comments?!

[Sparticus]

Not enough Data, as it is starting to drop a bit at 10Pa how do you know that after a few weeks at this preasure your body will adapt and your AHI will will remain low? My advise would be to grab yourself an APAP my preasure rating through the week varies from 7.2 to 12.8 and thats within 1 week. Each night my preasure readings are different, probably why I have good nights and not bad nights. I beleive that there are too many variables. My preasure differs by 5.6 but because Im apap my machine catches this and compensates. Also with my health changing now due to not smoking my preasure could vary even more, who's to say that a night out with a few beers could send your theories out the window. If your chasing your stats then I beleive that a month on each setting would be advisable but again is it really worth messing with it?

[Berneta]

Stats

Hi Graham. After my sleep studies, I was started out at 8--they said that should be enough for me, and that my machine would kick in higher if needed. After 3 months I had my Smart Card read, and my AhI was o.5. It was all great at 8-- and had not needed to kick it up at all. In early November I tripped over the cat, tore a bunch of ligaments in my ankle and foot and was so full of stress and pain, that I was not sleeping well, In Dec I had my Smart Card read again. Still set at 8--but my AHi was 1,2 and had kicked it up to 15 a couple times when I first injured my foot. ( I remember waking up in a gale.) So stress does in my opinion have a bad effect on your stats. My foot is feeling good now, and I am walking around some without the brace/splint, as the Dr said to do. Putting it back on if it gets to hurting. So its not all the way healed up. The Dr said it might take 6 months or more to get back to normal. I will have my Smart Card Checked again in early March, to see what the AHI is doing . I don't think it hurts to check how you are doing on each level of pressure--but that may vary quite a bit over several weeks and you may need to do an average to find out how you have really done on a certain level. Of course--that is just my guess. TF knows a lot more about stats and numbers than I do. It pays to be an engineer. Good luck today. x Berneta

[Sparticus]

Agree!

Yes TF is the man for the stats. It just seems to me that to many things in our daily lives can upset the balance. Stress is probably one of the main ones. I wouldnt use a cpap because of this if I have a difference of 5.6 preasure then I would have to over-set my preasure settings on cpap which could upset my sleep.

[symmit]

Sparticus!

I'm using an APAP, just finding a comfortable and effective PMin, so it doesn't have to adjust too much.

In two months of usage I've not had it blow harder than 13.

I'm of the opinion (not sure how the professionals agree) that the lower the average pressure that is effective the better. Also my machine allows me to alter the response slope (how much it steps up by per event). There are so many variables.

What I do know is that it's working damned well, and I feel refreshed and awake all day at 8, 9 or 10. So I'm gonna stick at 8 for a while and keep checking the numbers in case anything changes.

[Tigers Fan]

All the answers are here already!

Hi symmit

Eight looks like a very good choice - for now.

Let's not confuse max pressure in an APAP with base pressure, either in an APAP or in a CPAP.

Some, like me, sleep with a high base pressure that will prevent most events and have a max pressure a tad above 90/95 % pressure - fixes a lot of events if/when they happen but not all, but you are not woken by a gale. In CPAP, of course, you have no upper protection, just a base pressure to catch most events.

Other people sleep with a wide pressure band in their APAPs, tick away at a low base pressure for most/some of the night and trust the APAP algorithm to kick the pressure up as required. I think this method best suits those on lower pressures and thus who don't get the gales at the high end max.

Also, don't forget we are talking PAP here, so nothing is straightforward. What is the perfect pressure this week and next might be too much or too little the week after or next month. So many things can affect our requirement - weight, stress, alcohol, room temperature, length of day, bodily variations and hormone levels, fitness.

How do you know if you need an adjustment? By the way you feel in the morning - not just one morning but by trend. Increase or decrease? The only way I know is to experiment - in small changes made at min four day intervals (for trend spotting).

And as everybody comes to know - the most important thing of all - RELAX. Amazing how leaks disappear when you relax about the whole thing, n'est ce pas?

TF