Best lower and upper pressure settings - APAP

In your learned opinions, what would be the best upper and lower settings on an APAP machine for a prescribed pressure of 9?

I look forward to your responses and thanks.

Common wisdom is 1 below and 2 above. (8-11 in your case)

However the REAL answer is whatever works best for YOU...in terms of comfort, AHI and quality of sleep. The goal is to maintain the lowest average pressure while maximizing your therapy.

Whatever works for you and enables you to get good rest. If pressure variations disturb sleep then a tight range. If you occasionally seem to have some "rogue" (worse in REM or supine) events that need a higher pressure (not the pressure responding to leaks) then a wider range if the variations do not disturb you. I discovered that with my minimum at 9 cm I tend to have some clusters of events and don't feel so good. With the minimum of 10 cm I only get a random event so it breaks up the clusters and I seem to feel better. I was titrated at 8 but won't go into that story, bad titration sleep study. I have the max wide open. I used to see 15 cm often, not so much now but the pressure variations never disturbed my sleep. If they had I would have tightened the range and just let the rogue events happen and not worry so much about them. We can't kill all the events anyway and disruptive sleep from pressure changes will make us feel worse than a random event that slipped past the defenses.

So what works for you is the deciding factor. There is no hard fast rule. Just some generalizations low enough to take care of the bulk of the events with max high enough to take care of stubborn events IF needed and IF changes don't disrupt sleep.

Many thanks - mine arrived set at 4-20 and that just seemed strange. Saw several comments in the poll that advised against "wide open." I think I'll start in a close range and go from there. Thanks again, folks, for being here.

That minimum of 4 is so low that the machine simply doesn't have time to respond to events that need an 8 or 9 pressure.
It is common for APAPs to be delivered with that 4 to 20 range though. Titrated at 9? Start with minimum of 8 and see how it goes.
Watch your reports. If you set the max at 11 watch the pressure and see if it wants to stay closer to that or the lower number. If it chases leaks, toss that part out the window and work on the leaks. If it still wants to go higher then consider upping the max a bit.
It won't take long for you to spot a workable range for your needs.

Sounds good to me - 8 and 11 it shall be. Appreciate it Pugsy and LinkC.

I am having the best results with the lower setting set AT my titirated pressure which also makes the most sense to me. I had the upper end set 4 above that but there was a week where I kept hitting the upper end and my Flow wasn't improving so I raised it to 6 above and that seems better.

Most of the time the machine keeps me at my Titrated pressure or close to it, which is where I would do best on CPAP, and when I am having trouble the machine actually guages just how much trouble I am having and reacts accordingly either giving my a little more pressure or a lot.

I have seen NO good or logical reason to set the pressure LOWER than my optimal pressure setting other than if I want to increase my chances of my airway closing more often, which I don't (and I tried it and that is what happens). My optimal pressure is the one I do best on if I have to use only one pressure, its the one where I have the LEAST amount of apneas and the best possibly pressure to keep my airway open MOST of the time. Why the hell would I want to make it any lower if on Auto? There is no good reason....

Having said that, if I was JUST Titrated at 9, I would check it by setting the machine on something like 7/8 and 12/13/14. Then after about a week, you will see what your 90/95% pressure is and know how accurate your Titration was. Once I had that info, I would go with what I said above.

GL

jimnsc wrote:In your learned opinions, what would be the best upper and lower settings on an APAP machine for a prescribed pressure of 9?

I look forward to your responses and thanks.

If your prescribed pressure is 9 cm., then set the machine to CPAP mode at 9 cm. and run it that way for a week or two and see how it works. You FIRST have to either prove or disprove that your titrated pressure was correct. THEN, after you've gathered some data for a time period......you could make the determination as to whether to experiment with other settings.


Den

There is some logic in setting the minimum pressure below your titrated pressure. Your titrated pressure is the lowest pressure that eliminated all or almost all events. But that pressure is a measurement taken under a specific set of circumstances during a single night. There may be situations, like sleeping position, that will result in your therapy being effective at a lower pressure. And, presuming that lower pressures are more comfortable, that is a good thing.

It is common knowledge here that APAPs are slow to respond to events, and that setting the pressure too low makes the time for the APAP to respond unacceptably long. But I have seen graphs where my S8 AutoSet II increases pressure by 2 cm very, very quickly. Note that it is impossible for an APAP to eliminate an event already in progress. I may be that the thought that APAPs respond slowly is based on the performance of older machines.

If you set your APAP to a tight range, keep tabs on your downloaded data. If the APAP pressure is pinned at either the min or max pressure for a significant part of the night, it's time to start inching the min down and/or the max up.

Actually, it's not a bad idea to leave the max at 20. The machine won't go there unless it senses a need to. Older APAPs had situations where the pressure would inappropriately run away to the max, so bringing the max down made sense. But that does not apear to be the case with current machines.

jdm2857 wrote: Actually, it's not a bad idea to leave the max at 20. The machine won't go there unless it senses a need to. Older APAPs had situations where the pressure would inappropriately run away to the max, so bringing the max down made sense. But that does not apear to be the case with current machines.

Jeff,
My sleep doctor actually encouraged me to leave the max at 20 and also said it wouldn't go there unless it needed to. I used to see some high pressures that I couldn't blame on chasing a leak but not so often any more. The pressure changed never bothered me either.
Seems like everyone thinks a tight range treats the events better but it is really the minimum that seems to be the most important factor. So I don't often mention leaving that wide open range because I don't want to get into a debate about the merits or non merits. I can usually get into enough trouble without adding that debate.

That said, when I do mention wider ranges I always mention if the pressure variations seem to disturb sleep. Never bothered me but it might bother someone else and maybe especially a newbie, so ..... that is why I temper what I say.

To the OP here, I started with APAP BUT I originally set it at a VERY narrow range to mimic the straight CPAP RX of 8 (in my case). I did it so that I would get the extra data that my machine offered in APAP that it didn't offer in CPAP mode. I used 7 - 8 range.
Then I watched the reports and immediately it became apparent I was maxing out all the time. The adjustments I made were gradual and I watched the reports closely. You might want to take Den's suggestion to start in cpap mode or do like I did and have a very, very narrow range to mimic cpap. Many people do better at a single level pressure. You are the one though that has to make the final decision as to what seems to work best for your needs. We are all individuals with individual quirks.

jdm2857 wrote:There is some logic in setting the minimum pressure below your titrated pressure. Your titrated pressure is the lowest pressure that eliminated all or almost all events. But that pressure is a measurement taken under a specific set of circumstances during a single night. There may be situations, like sleeping position, that will result in your therapy being effective at a lower pressure. And, presuming that lower pressures are more comfortable, that is a good thing.

It is common knowledge here that APAPs are slow to respond to events, and that setting the pressure too low makes the time for the APAP to respond unacceptably long. But I have seen graphs where my S8 AutoSet II increases pressure by 2 cm very, very quickly. Note that it is impossible for an APAP to eliminate an event already in progress. I may be that the thought that APAPs respond slowly is based on the performance of older machines.

Those are arguements FOR my point, not against it. As I posted above, I agree that checking to make sure your Titration was accurate is a great idea by setting the pressure lower, BUT this is for a WEEK or TWO, no more than that.

The problem is people read lower than Titration by 2 and then think they should just leave it there and this is advice you see other people posting, which common sense would tell you is a bad idea since it is lower than your optimal pressure which means your airway has more chance of opening (assuming your Titration was accurate). Some will argue setting it lower means you spend more time on a lower pressure, for what benefit? Again to leave yourself more vunerable. IF HOWEVER, you are somone who has trouble with accepting the pressure in the first place or are overly gassy, THEN AND ONLY THEN could it make sense to put the pressure lower and even then I question whether it is a good idea, only the charts could tell you and if it means having more apneas then that is a choice you will have to make.

Some machines respond faster than others but regardless why make it have to go so much higher, again setting the lower number at your optimal number makes the most sense. YMMV of course, not everyone is the same....

Maybe I wasn't clear, but the result of a titration is a single pressure for use all night, every night. So the titrated pressure is set at the highest pressure needed during that single night. This is in contrast to your optimal pressure requirements that can vary during a single night (due to position, REM vs. non-REM, etc.) as well as from night to night (due to congestion, alcohol use, etc.). So giving an APAP a bit of leeway to decrease the pressure may result in more comfortable yet still effective therapy. There is no single, constant optimal pressure at which to set the minimum pressure of an APAP.

jdm2857 wrote:Maybe I wasn't clear, but the result of a titration is a single pressure for use all night, every night. So the titrated pressure is set at the highest pressure needed during that single night. This is in contrast to your optimal pressure requirements that can vary during a single night (due to position, REM vs. non-REM, etc.) as well as from night to night (due to congestion, alcohol use, etc.). So giving an APAP a bit of leeway to decrease the pressure may result in more comfortable yet still effective therapy. There is no single, constant optimal pressure at which to set the minimum pressure of an APAP.

Right, but there is one Optimal pressure that works best for you on CPAP, the one that will eliminate the most apneas, your 90/95% pressure. THAT is where a lower limit set will likely serve the majority best, at least logically and it works for me I tried it many different ways and I've seen many other people say the same here in these forums.

jdm2857 wrote:So giving an APAP a bit of leeway to decrease the pressure may result in more comfortable yet still effective therapy.

And also increase your chances of your airway opening. Whatever pressure was best over a 2 week period, the one where you hovered at the most, is where I would set it, not lower. Its the same theory if you switch to CPAP and are stuck on one constant pressure, you want the one that eliminates the most apneas, no reason to make that lower when on APAP.

Bottomline like I mentioned in an above post, if you really think 1 or 2 less cm is going to help you be more comfortable and are willing to accept you might have more apneas, then that is a choice you make.

Again on the flipside, some people are also succeptible to arousals and going over a certain pressure can trigger them (however so can a big fluctuation too and if you lower your lower limit then you either increase the spread making bigger fluctuations OR you also lower your upper limit which can have its own consequences), again though I would be looking closely at charts too see and sometimes these people just end up on CPAP but this is one other scenario where lowering the lower limit might help someone to try and still use APAP (again at a potential cost, though).

The whole nice thing about APAP is if and when you experience sleep issues like you mention, REM, alcohol etc the machine will compensate and adjust upwards to help squash them, where as CPAP does nothing.

Jayjonbeach wrote:Right, but there is one Optimal pressure that works best for you on CPAP, the one that will eliminate the most apneas, your 90/95% pressure.

You are confusing terms again. 90% pressure applies ONLY to APAP, not CPAP. And it's definition has nothing to do with eliminating the most apneas. It may or may not be "the pressure that works best for you". It is simply the pressure at OR BELOW which you spent 90% of your time. While it is expressed as a singular pressure, it actually represents the RANGE of pressures between your lower limit and your 90%.

If my titrated pressure is 9 ,than i assume that number would be high enough to eliminate most events .
the important pressure is the minimum and would set it at 6 and the maximum pressure at 12 or higher as it is not important at that early stage as the most important that be able to get a good sleep with a comfortable mask as it is the key to comply with the therapy .
Leave the setting for a month and to fine tune things if need to would check the data and adjust the minimum pressure between the median and the 95th percentile ,would also set the maximum pressure slightly higher than the maximum showing on the data providing no leaks as leaks would bump it higher .