Pressure limit of apnea treatment?

turbosnore · Post by **turbosnore** » Fri Jul 17, 2015 4:24 am

I wonder if Respironics' APAP machines have pressure limits like ResMed machines have?
I also wonder that about ResMed's S9.
S8 doesn't raise the pressure over 10 cm H2O in case of apneas, and for S10 the limit is 12 cm H2O.

Julie · Post by **Julie** » Fri Jul 17, 2015 4:29 am

Almost all C- or Apap machines (apart from bilevel or ASV ones) have a pressure range of from 4 to 20. If yours was set by a DME in the past, it doesn't mean you have to leave it there - we all change our pressure settings routinely (when we feel there's a point to it, using software to track progress overnight and see what's going on). If you need help to do that, or get free software, let us know (in this thread please).

turbosnore · Post by **turbosnore** » Fri Jul 17, 2015 4:39 am

I'm not talking about the settings, but the algorithm.
From AirSense 10 Autoset manual (For Her):

Treats apneas up to 12 cm H2O and continues to respond to flow limitation and snore up to
20 cm H2O.

Maybe the limit for non-"for her" is still 10 cm H2O?

chunkyfrog · Post by **chunkyfrog** » Fri Jul 17, 2015 5:34 am

No.
Your machine may be set for a maximum of 10, but you can change that from the clinician menu.
I believe the 12 limit in the for her algorithm refers to the one breath response.

turbosnore · Post by **turbosnore** » Fri Jul 17, 2015 5:42 am

Thanks.

chunkyfrog · Post by **chunkyfrog** » Fri Jul 17, 2015 6:01 am

All cpap and apap machines have factory set limits of 4-20.
If your machine will not go higher than 10, it has likely been set by a tech where you got it.
The settings can be changed at any time on the clinician menu.
If you need the clinicians manual, others here have a link.

Pugsy · Post by **Pugsy** » Fri Jul 17, 2015 6:35 am

There was a lot of discussion about the old A10 (not the AirSense machines) algorithm found in the S8 machines years ago when the S8 was the latest and greatest.
People thought that the machine in auto mode wouldn't go above 10 cm or adequately treat their OSA. It isn't true though because the machine would still increase the pressure above 10 in auto mode when there were still the usual flow limitations and snores present (with or without an apnea)...it just wouldn't respond to an apnea without the usual warning signs coming along with it just in case that apnea was central in nature since central apneas won't have snores or flow limitations with them.

Then ResMed came up with the S9 machines and the ability to differentiate between obstructive and central apneas so they redid the auto adjusting algorithm and it no longer has that restriction above 10 cm pressure since it knows if the apnea is central or not it can respond or not and not.
Note the Exception is the S9 Escape Auto...it has the "old A10" algorithm in it which is another reason to avoid it

Now we have the AirSense 10 machines...the For Her AutoSet apparently has a version of the old A10 algorithm in the special for her mode that isn't available on the other regular AutoSet.
It will still respond to apneas that have the usual warning signs (snores and FLs) over 12 cm or snores and FLs by themselves. It just won't respond to an apnea that doesn't have the accompanying warning signs.

Hope this helps. I got the sense that was what you were wondering about. If not, please clarify and I will try again.

turbosnore · Post by **turbosnore** » Fri Jul 17, 2015 9:02 am

Pugsy: That was exactly what I was wondering.
Thanks.

Pugsy · Post by **Pugsy** » Fri Jul 17, 2015 9:26 am

Back when the S8 was the latest and greatest there was a lot of panic from people using or wanting to use the auto mode when they learned of the A10 algorithm. They thought that the machine wouldn't/couldn't ever go above 10 cm and wouldn't do a good job treating OSA that required pressures over 10 cm.
That causes unnecessary panic among people who didn't understand the algorithm.
Most people when having an obstructive apnea will also have the usual accompanying warning signs (snores or FLs) so the machine would still respond.
Some people might just have the airway close up quickly and without warning signs and those people might have a potential issue if the pressure needed to go over 10 cm. There were ways to get around that limitation for those people. Either use cpap mode at whatever pressure is needed to get the job done or simply set the minimum a little higher than 10 to have a more optimum base pressure.

I think this 10 cm thing was where a lot of people got the idea that centrals were a greater possibility once someone passed this threshold and we have the concern about complex central apnea being a real problem likely to pop up.
In truth while it is possible that higher pressures can be the trigger for complex sleep apnea it isn't something that is a given that has a high risk. Complex sleep apnea can come about even with really low pressures too. I have seen it happen to people who are seeing as little as 6 cm triggering the centrals and 5 cm might not.
And I have seen it where any pressure (even a minimum of 4) will trigger complex sleep apnea.
10 cm isn't the magic number that people used to think it was. It can happen at any number

Last I read only a relatively small % of people who begin cpap therapy with no history of centrals will develop complex sleep apnea as a response to cpap pressures. Maybe 10 to 15% of the people depending on what you read. Lots of people are using pressures in the upper teens and even into the 20s and they don't have any more centrals than is considered normal. If it were that common then we would be seeing a lot more people using bilevel ASV type of machines than we do.

tedburnsIII · Post by **tedburnsIII** » Sat Jul 18, 2015 6:18 pm

Sclark08 · Post by **Sclark08** » Wed Jul 22, 2015 4:49 pm

My Resmed S9 Vap tops out at 25

Jay Aitchsee · Post by **Jay Aitchsee** » Wed Jul 22, 2015 6:09 pm

Algorithm
Another reason to ditch the S8 and get an S9 or Airsense 10, aside from not having to fuss with ResScan and card readers

turbosnore · Post by **turbosnore** » Thu Jul 23, 2015 12:05 am

Jay Aitchsee wrote:Algorithm
Another reason to ditch the S8 and get an S9 or Airsense 10, aside from not having to fuss with ResScan and card readers

They were very hard to get 2008.

palerider · Post by **palerider** » Thu Jul 23, 2015 12:22 am

turbosnore wrote:
Jay Aitchsee wrote:Algorithm
Another reason to ditch the S8 and get an S9 or Airsense 10, aside from not having to fuss with ResScan and card readers
They were very hard to get 2008.

not so hard to get now, though.

Pressure limit of apnea treatment?

Pressure limit of apnea treatment?

Re: Pressure limit of apnea treatment?

Re: Pressure limit of apnea treatment?

Re: Pressure limit of apnea treatment?

Re: Pressure limit of apnea treatment?

Re: Pressure limit of apnea treatment?

Re: Pressure limit of apnea treatment?

Re: Pressure limit of apnea treatment?

Re: Pressure limit of apnea treatment?

Re: Pressure limit of apnea treatment?

Re: Pressure limit of apnea treatment?

Re: Pressure limit of apnea treatment?

Re: Pressure limit of apnea treatment?

Re: Pressure limit of apnea treatment?