Different Pressure Settings - Similar Result - Wondering Why

Hi All

For the past couple of months I have been changing my pressure settings every 7 to 10 days on average, with a view to finding the best pressure for myself. Over that time the leak rates have been pretty consistent at about 43 l/min, and apneas and hypopneas have usually been spaced out over the night, often with one or two hours or more with no events. The "Command on IFL" is turned off. Snoring is zero or just one or two.

Sandman tries to count central apneas and hypopneas, how successfully I cannot be sure, so I have included them in my report below.

Pressure .............. Obstructive.........Central........Total..............Av. Pressure

....8-13..................1.5...................1.5............3.0..................8.6
....9-13..................1.2...................1.3............2.5..................9.4
..9.5-13..................1.5...................1.4............2.9.................10.0
...10-13..................1.5...................1.3............2.8.................10.6
10.5-13.5................1.1....................1.5...........2.6.................11.4
...11-14..................1.2....................1.6...........2.8.................11.6
...11-14.5................1.4....................1.7...........3.1.................11.7

From my testing so far it would appear that 10.5-13.5 is best for obstructive sleep apnea; 10-13 best for central sleep apnea; and 9-13 best overall.

But for OSA there is only a difference of 0.4 between them, and for CSA a difference of 0.4, and overall a difference of 0.6.

Obviously we are all trying to find the best pressure, but from the above it would seem that, at least for me at the present time, there is very little difference in the results I am getting.

There may well be some factors I am missing, not aware of, or just do not understand. So if anyone can cast some light on this, please help out if you can.

Thanks

cheers

Mars

Did you log your sleep quality? Length of time asleep? Number of awakening? Average pressure?

Sandman's C/A is based on Indu Ayappa, PhD, Robert G. Norman, MS, RRT, and David M. Rapoport, MD, FCCP

http://www.chestjournal.org/content/116 ... nsion.html

When the Sandman does identify a central apnea, it is one for sure.
However, is misses more than 30% of centrals -- none for some people, all for others.
And we know not all people's central apneas are accompanied by discernible cardiogenic oscillations.

http://www.chestjournal.org/content/116 ... .large.jpg

So,I'd set the machine at 9-13.

O.

[quote="ozij"]Did you log your sleep quality? Length of time asleep? Number of awakening? Average pressure?

Yes, I got all of the above. My length of time asleep (or I should say being on the machine) varies between 5.5 and 7.5 hours a night. Even though I am still tired after only 5.5 hours sleep my head is clear. The number of awakenings has now started to go down to 1 or 2 a night, whereas earlier on it could be 3 or 4. So I am now sleeping longer in 1 session than I used to do. I have attributed this to getting used to the therapy, rather than anything else, but that may not be true.

I will amend my original posting to include average pressure. I also need to look at it before I can respond to what you say further.

Thanks for helping, Ozij, once again. If you continue to do this I will run out of thanks in the English language, and have to start using Aussie colloquialisms.

Many thanks

Mars

PS My original report got left justified, which made it hard to read. My solution to that worked, but I wonder if there is a better method.

ozij wrote:

When the Sandman does identify a central apnea, it is one for sure.
However, is misses more than 30% of centrals -- none for some people, all for others.
And we know not all people's central apneas are accompanied by discernible cardiogenic oscillations.

http://www.chestjournal.org/content/116 ... .large.jpg

So,I'd set the machine at 9-13.

O.

Hi again Ozij

So I take the reported centrals seriously. Therefore 9-13 sounds good to me.

Would there be any value in continuing to experiment with a few more different pressure ranges? I was also thinking about trying different pressures using the non-auto cpap feature and a fixed pressure.

And, of course, eating a banana every time I woke up.

What do you think.

cheers

Mars

Mars wrote:Would there be any value in continuing to experiment with a few more different pressure ranges? I was also thinking about trying different pressures using the non-auto cpap feature and a fixed pressure.

Fixed pressure is always worth trying ... -set the min. to equal the max, and you'll get all the APAP reporting goodies, without the APAP pressure changes. Set on CPAP, the Sandman's predecessor (the 420E) doesn't give the details screen ; which it does when the min.=max. and the mode is APAP.

And, of course, eating a banana every time I woke up.

As long as you don't tell kopoloff...
...on a far more serious note: for me one of the blessings of CPAP is the ability to wake up, turn over, snuggle down and keep on sleeping. No more sweat baths, heart bangings... so, I would consider a bannana a major sleep disruptor...

O.

Hi Ozij

Thanks for your latest input.

I will leave off auto testing now, and just do some fixed pressure testing on 11.0, 11.5, 12.0, and 12.5 to finish off my investigation. I spent last night on fixed pressure 11.0, and the result was -

Obs AHi 1.0
Cnt AHi 0.7
Total 1.7

I noted that my leaks were down, but will get more data to find out if this is significant.

quote from Ozij - on a far more serious note: for me one of the blessings of CPAP is the ability to wake up, turn over, snuggle down and keep on sleeping. No more sweat baths, heart bangings - end quote

Sounds good to me, maybe I will start eating all my bananas before I go to bed

It is nice to start getting a bit of relaxed clarity regarding my cpap therapy, as it is the cornerstone of me dealing with all my other physical problems, not to mention my ability to think well. So far it has been about 6 months on cpap therapy, and I must have spent about 2 hours a day at least on the Forum. Now the results are coming through.

Many thanks, Ozij for all your help.

cheers

Mars

PS In relation to my original question if I can assume that different pressure settings can produce very similar results, then I guess I must look to other factors which might affect my treatment, such as leaks, how I feel, how many times I get up in the night, the state of the nation etc.

Mars, you're in good hands and I'll be interested in your updates on fixed pressures. I've got a good feeling! Dori