ahi continues to drop as i lower the pressure

I'm running the machine as cpap and not apap. I'm down to a pressure of 11.5 and last night my ahi was 1.4 ( the first time i was below 2) with 0% leaks and 0% periodic breathing. When i run the machine as apap, the 90% pressure is usually around 14cm with an ahi of 14-21 and about 7.5% periodic breathing. Even when i set the range of the apap pressure with a low of 13 and a high of 20 my ahi was around 14. This seems rather odd to me since the automatic pressure should always be as high or higher than when running it as cpap. In almost a week of using it as cpap ( and dropping .5 cm of pressure each day) i never went over an ahi of 3.5. The full faced resmed mirage quattro mask still doesn't work at all - in an hour of use on cpap the other night there were no leaks but the ahi was 14. I'm wondering if the apap isn't working properly on the machine and whether i should care. I don't find the cpap any more tedious than the apap.

Please post the equipment you use in your control panel. I make it my mission to suggest to members that cpap MAY be better than apap. Some folks need and prefer apap... it's a personal thang'. Some folks respond better to straight cpap. You never know until you try it. My goal is to recogmend to each member see for themselves. In your case, I think you are changing the machine's pressure too quickly. Go a week or two before tweaking the pressure. Finding what I call the "sweet spot" takes time.

Sheriff

It is possible that with time and better sleeping (not many wake ups) that any events that were maybe getting flagged during times of wakefulness. With better sleep...less chance for awake events getting flagged.
Impossible to know for sure without looking at the software reports but often there are a large number of events get flagged at sleep onset time..awake time and those will falsely elevate the overall AHI.
This is why it is important to see the full reports and base all the ideas on a single AHI number.
Also it is possible that the reduction in pressure and using cpap mode is simply less disturbing to overall sleep and with better sleep the possible awake events are reduced.
Impossible to know for sure...at this point...less events and if you are feeling better and sleeping well, I wouldn't be concerned.

sheriff buford - i thought i do have my equipment listed so i'm not sure what you are referring to


Machine: PR System One REMstar Auto CPAP Machine with A-Flex
Mask: Swift™ FX Nasal Pillow CPAP Mask with Headgear
Humidifier: PR System One Heated Humidifier

Pugsi - I can't say that i feel any better on cpap than i did before i started being treated for sleep apnea about 6 weeks ago - actually i'd say i feel a bit worse and more sleepy during the day- some of it is from having to duct tape my mouth shut and wrap my head and jaw with sticky ace bandage material with a nasal pillow directly in my nostrils which seems to irritate them a bit. Hopefully i'll eventually find a full-face mask that works but i can't figure out why the quattro doesn't work at all since it is not leaking and i'm using the exact same pressure that works with the swift fx (luckily i bought it with the return insurance). I guess i'll have to wait until i get a PC to get any answers - what is the software i need to use for the PR 560 and where do i get it?

It would be good to know what your leak rate is and is it consistent. Some machines will take a 'face fart' as an event. Some will take 'smooshing' of the input device/mask and stopping the flow momentarily as an event. Lower pressures, in theory, should not reduce AHI, but there are anomolies with various blowers that will cause erroneous readings. Or you may just subconsciously be holding your breath momentarily due to diffulty with exhalation. There are so many explanations for this, but it goes against reason that lower pressure would cause lower AHI in and of itself.

Does the answer lie in the ratio of clear airway events to obstructive (or hypopnea) events? I.E., was the higher AHI at higher pressures due to having more CAs (whether true centrals or wake/transition events)? Isn't it true that if our pressure is too high we're more likely to start having more CAs? Just a thought.

kaiasgram wrote:Isn't it true that if our pressure is too high we're more likely to start having more CAs?

It is commonly thought that "higher pressures can cause centrals" and while for some people that may be true it isn't a given that everyone will/can have that happen with higher pressures. It can just as easily happen at lower pressures too.
Actually the percentage of people who have the appearance of centrals with any pressure (high or low) is really fairly low. Around 10 to 15 % of the people who start on cpap therapy with no history of centrals may have the centrals appear in response to pressures. Lots of people use much higher pressures and have no more centrals than they would have at lower pressures. I saw 19.61 max on my machine not long ago and zero centrals during that hour.

My gut reaction to the OP situation here...very likely the higher AHI was a product of "awake" events being flagged and as he has used the machine more and got more accustomed to it that he has spent less time awake or semi awake.
Less chance for events being flagged. Simply newbie stuff settling down but it is impossible to know for sure.

johnthomasmacdonald wrote: I guess i'll have to wait until i get a PC to get any answers - what is the software i need to use for the PR 560 and where do i get it?

I sent you a link for EncoreBasic...you may have misplace that private message. EncoreBasic is the only software right now that will work with your 60 series machine and it won't work on your Mac unless you set up a Windows environment for it. When you are ready for it again send me a private message and I will get you the link again.

Pugsy - sorry, i hadn't realized that you had sent me a pm with the info in it - i checked the folder and it was right there - thanks - I'm buying a cheap PC laptop since there are quite a few software programs that i've been unable to run on mac - thanks!

I find that my S8 and S9 both had issues with centrals out of nowhere..... and I attributed them to sudden leaks, coughing during the night, face farts from the mask, etc. I generally show one or two a week, so the liklihood of them being actual centrals is minimal. Remember that the algorithms and sensors in these machines are not perfection at the price they are selling them for.