Automatic Pressure

[Clemeng00]

I started using my RESMED C8 AutoSet 11 in July 2008, and have found it excellent with a set pressure of 8, after a visit to my sleep Physician I had to take my machine and have it reset to Automatic Pressur of 4 - 20 and this works well but during the night I have to turn it off and back on again as the higher pressure makes the full face mask leak. Can I adjust the upper pressure to say 16 as a trial ?

Many Thanks:[/font]

[zonk]

Hi Clemeng00 and welcome
Whats the 95% percentile pressure and leak reported on the machine screen

[trish6hundred]

Hi Clemeng00, I would like to take this opportunity to say Welcome! to the forum. Unfortunately I am unable to help you with your question but keep checking back, I'm sure there are others that will be able to help you.

[SuperSleeper]

Hi Clem... welcome!

I would say if you're relatively sure that your prescribed pressure is somewhere between 4-16, it would be okay to set your auto's range to those numbers, roughly. But, generally the closer the ranges, the better the machine will work for you.... so it may be beneficial for you to narrow those ranges slowly over time.

Assuming your machine gives you an AHI reading on the screen, you can also tweak your settings to minimize your AHI levels.

Here's a page that gives some basic instructions on how to come up with optimum pressure(s) for your machine:

http://www.apneaboard.com/adjust-cpap-pr...re-on-cpap

Granted, the above webpage is primarily for constant-pressure CPAP machines, but some of the concepts and safety points apply to auto-CPAP users as well.

If your machine tells you what your 95% pressure is with your current range settings, it's probably best to set it up so that your lower number is perhaps 1-2 cmH2O below your 95% pressure and the higher number is perhaps 3-4 cmH2O above that. Then you can slowly make incremental changes to both numbers if need be, experimenting with the numbers to minimize AHI.

If your "95% pressure" is 10 for instance, this is the value exceeded during the selected range for 5% of the time. So, if (for example) 10 is your 95% number, you may wish to start off with a low range of 8-9 and an upper limit of around 13-14 cmH2O of pressure. See how that goes and adjust one or the other based upon your new 95% numbers and the resulting AHI numbers after the adjustment.

[zimlich]

I think that would depend on why the doctor (it was his idea?) set your auto at 4-20. He might be trying to titrate you. All the above advice was good. You might want to check your numbers to see why it is going so high. When I set my auto to 4-20 the pressure kept going up, but my AHI did, too. Look at the AHI and how your pressure is running.
An old remedy for mask leaks, if you need the higher pressure is to use Macks silicone earplugs to make a better seal. It's not too time consuming. Take some of the earplugs (from most drug stores) rub them in your palms until soft, fashion into a strinp the size of a pencil and place around the perimeter of the mask or where it's leaking. Because our facial oils get on the silicone you have to redo every night. I simply take the silicone off the mask (you will not get every bit), roll into a ball, repeat the next night. I found it works well. I'm on an ASV and my mask is leaking at higher pressures so I'm going to have to start using the silicone again.

[Tommy C]

I'm on an ASV and my mask is leaking at higher pressures so I'm going to have to start using the silicone again.

Hi Zimlich,

Questions:

1) Does your ASV exhale breath pressure drop down to zero pressure - or capable of going even negative if tweaked?

2) Let's say that someone had JUST OSA with no CSA symptoms mixed in. Do you think your ResPro ASV machine would do as good a job in the mixed mode (CSA and OSA - ASV operation) as a standard ResMed S9 operating in the straight CPAP auto mode - when treating only OSA?

ie, I am wondering if the ASV in the mixed therapy auto ASV mode is so optimized for the CSA part that the OSA performance is not as good. Or maybe the ASV is so sophisticated that it deals with whatever comes its way optimally?

The reason I ask is because I cannot seem to tolerate breathing against any back pressure without having suffocation feelings. A negative, intuitive exhaust pressure seems like a possible solution for me if I am prescribed for only OSA. I have a constant CPAP now and its a bear for me. Even dropping down to 7 cm affects me the same way, so an S9 might not even do it with a 3 cm drop from max. I need close to zero exhaust pressure. Understand what I mean?

Tom

[Sleepster]

The reason I ask is because I cannot seem to tolerate breathing against any back pressure without having suffocation feelings.

Usually a BiPAP is prescribed for this situation.

[Tommy C]

Usually a BiPAP is prescribed for this situation.

Sleepster,

Is your BiPAP capable of going to zero exhale pressure or even negative? What happens to your overall treatment if you go that low but keep the positive inhale the same?

I imagine it depends on if the throat opening structure collapses under a negative exhale pressure or not, correct?

Tom

[Sleepster]

The lowest pressure setting is 4 cm. I don't know why, but this is the lowest setting we see on all CPAP's and BiPAP's.

The lowest I've ever set it on is 7 cm. Originally I went from a CPAP at 13 cm to a BiPAP at 13 cm / 8 cm. This caused a huge jump in my OA index, which was tamed when we lowered the pressures to 11 cm / 8 cm.

[Clemeng00]

Hi Clemeng00 and welcome
Whats the 95% percentile pressure and leak reported on the machine screen

It's 11.6 and I can't find any leak reported !

Many Thanks