ResScan CPAP Reporting Software (OLD version: 5.5) [Archived Discussions]

[RonWessels]

There have been a few threads recently where "proper" auto-CPAP pressure limit settings have been discussed, although I can't find them back on quick search.

Having your lower limit pressure set to a viable treatment pressure, rather than say mindlessly left at its lowest setting of 4, is important for various reasons. It is also important to have your upper pressure limit setting to at least somewhere near the maximum pressure that successfully treats your apneas most of the time. Personally, I am of the opinion that setting the upper limit to 20 is the (eventual) way to go. If you trust the auto algorithm, the argument goes that the machine will not try to use a pressure higher than what is necessary for your treatment, so how much over this value your upper limit value is set to is moot. But if you do actually need a higher pressure for effective treatment, why not let the machine provide it?

[orcaporca]

There have been a few threads recently where "proper" auto-CPAP pressure limit settings have been discussed, although I can't find them back on quick search.

Having your lower limit pressure set to a viable treatment pressure, rather than say mindlessly left at its lowest setting of 4, is important for various reasons. It is also important to have your upper pressure limit setting to at least somewhere near the maximum pressure that successfully treats your apneas most of the time. Personally, I am of the opinion that setting the upper limit to 20 is the (eventual) way to go. If you trust the auto algorithm, the argument goes that the machine will not try to use a pressure higher than what is necessary for your treatment, so how much over this value your upper limit value is set to is moot. But if you do actually need a higher pressure for effective treatment, why not let the machine provide it?

This make sense to me. But can you explain what effect a low minimum setting will have on performance? Is it noe possible to use the same arguments as for setting the max up to 20 (that the auto algorithm will take care of it? I am completely new to this, so I am just trying to understand the different settings.

[RonWessels]

There are a few issues with a too-low minimum pressure.

The first and most obvious is that, if your pressure starts off too low, you will be spending what would otherwise be quality sleep time experiencing apnea events until the machine ramps up to a viable pressure.

The auto-set algorithm has the concept of "untreatable apneas". If it detects that you are experiencing apneas and they don't go away after raising the pressure by 3 cmH2O, it considers the apneas "untreatable" and reduces the pressure back down again. This is supposed to prevent "runaway" pressure increases that would otherwise happen with apneas that do not go away with increased pressures. I suspect intentionally holding your breath while rolling over, for example, would be an example. So, if your minimum pressure limit (and therefore starting pressure) is more than 3 cmH2O below a viable treatment pressure and you happen to immediately experience apneas rather than pre-apnea symptoms (flow limitation, snoring), it may be that your machine does not actually reach a viable treatment pressure.

[kittyhawkchild]

I have downloaded the software and put in my card but cannot get it to work. Neither can my husband.

[stanlee1963]

I have downloaded the software and put in my card but cannot get it to work. Neither can my husband.

Go back and follow the directions exactly. Download ResScan on your computer. You will be able open your cards information on your computer the first try. There's no need to download program on the card. I was reading my first nights sleep 5 mins after the install. I'm sure you can too. :-)

[SkyWinder]

I have downloaded the software and put in my card but cannot get it to work. Neither can my husband.

Download and INSTALL. How did the install go?

[stanlee1963]

Definitely need to install.

[vsheline]

The auto-set algorithm has the concept of "untreatable apneas". If it detects that you are experiencing apneas and they don't go away after raising the pressure by 3 cmH2O, it considers the apneas "untreatable" and reduces the pressure back down again. This is supposed to prevent "runaway" pressure increases that would otherwise happen with apneas that do not go away with increased pressures.

Hi Ron,

Very interesting. Can you share with us where this is documented or explained?

I wonder whether the concept of "untreatable apneas" might apply only to the original AutoSet algorithm.

The new "enhanced AutoSet algorithm" which was released about 3 years ago with the S9 series of machines now specifically identifies both Central Apneas, which are untreatable by increasing the pressure, and Obstructive Apneas which need higher treatment pressure. I think the enhanced AutoSet algorithm would not reduce the pressure if obstructive apneas don't go away after a pressure increase of 3.

Thanks,
--- Vaughn

[Paptillian]

The auto-set algorithm has the concept of "untreatable apneas". If it detects that you are experiencing apneas and they don't go away after raising the pressure by 3 cmH2O, it considers the apneas "untreatable" and reduces the pressure back down again. This is supposed to prevent "runaway" pressure increases that would otherwise happen with apneas that do not go away with increased pressures.

Hi Ron,

Very interesting. Can you share with us where this is documented or explained?

I wonder whether the concept of "untreatable apneas" might apply only to the original AutoSet algorithm.

The new "enhanced AutoSet algorithm" which was released about 3 years ago with the S9 series of machines now specifically identifies both Central Apneas, which are untreatable by increasing the pressure, and Obstructive Apneas which need higher treatment pressure. I think the enhanced AutoSet algorithm would not reduce the pressure if obstructive apneas don't go away after a pressure increase of 3.

Thanks,
--- Vaughn

I think Ron's remembering this thread: http://www.apneaboard.com/forums/Thread-...2#pid41092

Perhaps the use of the term "auto-set" is not a good one since it may be confused with Resmed's "AutoSet."

There's still no documentation (to my knowledge) that Resmed's algorithm does this. So far we only know that Respironics has this 3 cmH2O pressure limit for "non-responsive" events, though according to the article there is an override if the machine thinks that the events are obstructive.

I think Respironics does this NRAH test to determine central apneas, whereas Resmed relies on Forced Oscillation Technique (FOT).

I think both algorithms will raise the pressure happily all the way to the set limit when the events are not central.

[Sleepster]

Neither ResMed nor Respironics makes available the details of their APAP algorithms. All we get is marketing hype.

I hope that as CPAP therapy becomes more common someone will crack their codes and find out what these algorithms really do.