Not possible to run Dreamstation auto BiPAP as an auto CPAP?

[Sibbs]

I have a new dreamstation auto BiPAP that I've been having some challenges with getting titrated properly.

I thought that in the meantime I could run it as an auto CPAP using my old settings, but was surprised to find that the clinical menu only allows it to be set as a CPAP with constant pressure – – the auto CPAP option is not available.

Does anyone have any experience or thoughts on this?

[JDS74]

I don't have access to my manual collection to see how parameters can be set.
Can you set the PS to zero?

[lilly747]

Yes you can. My VPAP bi-level is set up to run like an autoset, However your PS is different than mine so can't tell off hand how to set your PS. Someone will come along that will know: I have a Resmed. (You can get real technical and say it is not 100% the same)

[robysue]

I have a new dreamstation auto BiPAP that I've been having some challenges with getting titrated properly.

I thought that in the meantime I could run it as an auto CPAP using my old settings, but was surprised to find that the clinical menu only allows it to be set as a CPAP with constant pressure – – the auto CPAP option is not available.

Does anyone have any experience or thoughts on this?

You should be to mimic Auto CPAP with the following settings:

Set min EPAP to what you want the min pressure to be.
Set max IPAP to what you want the max pressure to be.
Set min PS and max PS both to 0. This forces IPAP = EPAP all night long. And when the machine decides that it needs to increase either the IPAP or the EPAP, these PS settings force both the IPAP and EPAP to increase together.

BiFlex can still be turned on with these settings if you want a bit of exhalation relief without having the full power of allowing different EPAP and IPAP pressures.

[Sibbs]

I have a new dreamstation auto BiPAP that I've been having some challenges with getting titrated properly.

I thought that in the meantime I could run it as an auto CPAP using my old settings, but was surprised to find that the clinical menu only allows it to be set as a CPAP with constant pressure – – the auto CPAP option is not available.

Does anyone have any experience or thoughts on this?

You should be to mimic Auto CPAP with the following settings:

Set min EPAP to what you want the min pressure to be.
Set max IPAP to what you want the max pressure to be.
Set min PS and max PS both to 0. This forces IPAP = EPAP all night long. And when the machine decides that it needs to increase either the IPAP or the EPAP, these PS settings force both the IPAP and EPAP to increase together.

BiFlex can still be turned on with these settings if you want a bit of exhalation relief without having the full power of allowing different EPAP and IPAP pressures.

Thanks for the suggestion and specifics.

If I peg IPAP and EPAP in this way with the bipap's auto pressure setting algorithm work as the auto CPAP would?

I know the rule of thumb that CPAP = EPAP, but as I understand it, it's not quite the same as intraalveolar pressure never drops below EPAP on bipap, while it does on CPAP during expiration.

[palerider]

If I peg IPAP and EPAP in this way with the bipap's auto pressure setting algorithm work as the auto CPAP would?

I know the rule of thumb that CPAP = EPAP, but as I understand it, it's not quite the same as intraalveolar pressure never drops below EPAP on bipap, while it does on CPAP during expiration.

you've got terms confused, and you should unconfuse them before you go any further.

your last statement, especially, seems to be very confused.

[robysue]

You should be to mimic Auto CPAP with the following settings:

Set min EPAP to what you want the min pressure to be.
Set max IPAP to what you want the max pressure to be.
Set min PS and max PS both to 0. This forces IPAP = EPAP all night long. And when the machine decides that it needs to increase either the IPAP or the EPAP, these PS settings force both the IPAP and EPAP to increase together.

BiFlex can still be turned on with these settings if you want a bit of exhalation relief without having the full power of allowing different EPAP and IPAP pressures.

Thanks for the suggestion and specifics.

If I peg IPAP and EPAP in this way with the bipap's auto pressure setting algorithm work as the auto CPAP would?

Yes.

The PR BiPAP algorithm will increase the EPAP for VS snores and OAs. And min PS = max PS = 0 will force the IPAP to increase by the same amount.

The PR BiPAP algorithm will increase the IPAP for FL, RERAs, and Hs. And min PS = max PS = 0 will force the EPAP to increase by the same amount.

Hence the EPAP=IPAP pressure will increase in response to VS snores, FLs RERAs, Hs, and OAs in pretty much the same way a PR Auto CPAP running in Auto will respond to them.

I know the rule of thumb that CPAP = EPAP, but as I understand it, it's not quite the same as intraalveolar pressure never drops below EPAP on bipap, while it does on CPAP during expiration.

If you have Flex turned off on a PR CPAP/APAP, the pressure never changes, even on exhalation. If you have Flex turned on, then yes, the pressure does change during expiration based on how hard you exhale.

If you turn BiFlex on, you get the same kind of (extra) pressure reduction on exhalation.

In particular, if BiFlex is turned on and EPAP = 6 and IPAP = 10, then at the beginning of the exhalation, the pressure drops a bit below 6cm at the beginning of the exhalation and is raised back up to 6cm by the end of the exhalation. The actual drop below 6cm depends on the Flex setting and the forcefulness of the exhalation. If BiFlex is turn OFF and EPAP = 6 and IPAP = 10, then at the beginning of the exhalation, the pressure simply drops to 6cm.

So if min EPAP = max IPAP = 10cm and min PS = max PS = 0, the pressure will drop a bit below the 10cm at the beginning of the exhalation if BiFlex is turned on. But the pressure won't drop below the 10cm if BiFlex is turned off.

[Sleeprider]

Sibbs, can you explain what kind of problems you're having with titration? You got a great machine that should be very comfortable and flexible in therapy, but you want to disable much of its capabilities. Why?

As far as mimicking an APAP, the settings described above should do pretty well, although I have found the auto-BiPAP to be a bit slower than APAP in changing pressure, and much slower than Resmed machines in attacking OA.

[robysue]

As far as mimicking an APAP, the settings described above should do pretty well, although I have found the auto-BiPAP to be a bit slower than APAP in changing pressure, and much slower than Resmed machines in attacking OA.

The PR machines in general are much slower to raise the pressure than the Resmed machines. And that is an issue for some people, but not for everyone.

On the other hand, the PR machines are also slower to lower the pressure after raising it, which is also useful in preventing more events.

What it boils down to is this: Every manufacturer of an APAP or an Auto bilevel has made their own decisions on both when and how the machine will respond by increasing or decreasing the pressure. You can see the implications of those decisions in the pressure curves of the various brands.

Unfortunately, there's not been much objective testing of those algorithms to determine which auto algorithms are actually "best" in terms of managing OSA in which patients. The only benchmark study comparing the auto algorithms from the various manufacturers that I've seen is this one from Sleep Review: http://www.sleepreviewmag.com/2009/09/a ... -pressure/

This article is somewhat old (2009) and the machines they tested are now 2 or 3 generations "old", but many of the decisions manufacturers made back before 2009 are still present in their current Auto algorithms.

[HoseCrusher]

RobySue, the link to the 2009 article doesn't seem to work and when reviewing the web site it seems that they are truncating articles older than 2012. Do you have the whole link or another source for the article?

[robysue]

RobySue, the link to the 2009 article doesn't seem to work and when reviewing the web site it seems that they are truncating articles older than 2012. Do you have the whole link or another source for the article?

My bad. When I copied the link, I didn't get the whole thing.

Here's the correct (and just tested) full link: http://www.sleepreviewmag.com/2009/09/a ... -pressure/

[HoseCrusher]

Thanks.

[palerider]

RobySue, the link to the 2009 article doesn't seem to work and when reviewing the web site it seems that they are truncating articles older than 2012. Do you have the whole link or another source for the article?

My bad. When I copied the link, I didn't get the whole thing.

Here's the correct (and just tested) full link: http://www.sleepreviewmag.com/2009/09/a ... -pressure/

I can't tell if that's covering the prs1 series, or the M class... I did see that it's about the older s8 resmeds (since the s9 hadn't been released yet... )

were there any reported changes between the m and prs1 and dreamstation algorithms? I know there was a big change between the s8 and s9 era.

[robysue]

RobySue, the link to the 2009 article doesn't seem to work and when reviewing the web site it seems that they are truncating articles older than 2012. Do you have the whole link or another source for the article?

My bad. When I copied the link, I didn't get the whole thing.

Here's the correct (and just tested) full link: http://www.sleepreviewmag.com/2009/09/a ... -pressure/

I can't tell if that's covering the prs1 series, or the M class... I did see that it's about the older s8 resmeds (since the s9 hadn't been released yet... )

The PR machines discussed are the M-Series as I recall. Certainly there is no mention of CA detection or of RERA detection, both of which were introduced with the PR S1 models.

were there any reported changes between the m and prs1 and dreamstation algorithms? I know there was a big change between the s8 and s9 era.

The biggest advertised difference between the M series and the PR S1 algorithms is the detection of CAs and the ability of the machine to NOT respond to them, along with RERA detection and the ability of the machine to respond to them.

I've seen nothing useful on line about the DreamStation auto algorithm or the DreamStation's algorithms for detecting RERAs and CAs. And google has not helped. The DreamStation data that I've seen posted here strongly indicates that whatever changes to the Auto algorithm are pretty subtle. If you just took the daily data graphs from an S1 and a Dreamstation and you did not have the left sidebar to tell which machine you were looking at, I don't think I'd be able to reliably pick out which is the S1 and which is the Dreamstation.

The biggest advertised difference between the Resmed S8's AutoSet algorithm and the S9's AutoSet algorithm was the introduction of the CA detection algorithm that allows the machine to NOT respond to them. The S9 AutoSet for Her algorithm introduced RERA detection and a tweaking of the main Auto algorithm to apparently make it more aggressive in attacking flow limitations. The biggest non-advertised difference between the S8 and S9 machines was in the detection of Hs. The S8's apparently over scored the Hs by quite a bit. But we don't have any wave flow data from the S8's to confirm that idea. I do remember that when I first came on here I was a brand new PAPer with a brand new S9 AutoSet, I saw a lot of posts from people who went from the S8 AutoSet to the S9 AutoSet who were worried that the S9 was underscoring Hs because their HI numbers had dropped dramatically. The RERA detection algorithm and the S9 Auto For Her algorithm was introduced when the S9's were a couple of years old and they were only available on the hideous metallic pink S9 AutoSet For Her model. That RERA detection now seems to be part of both the AirSense 10 Auto and Auto For Her algorithms, but the For Her Auto algorithm with its more aggressive response to FL is only available on the AirSense For Her mode..

Truth be told, there is NOT much out there that describes the current generation's Auto algorithms on any of the major brands of APAPs in any detail.

PR has really buried a whole lot of technical information that used to be available on their web pages. While I can still find information about Flex by googling, I can no longer find anything on their web pages that really describe anything about the Search algorithm (the pressure "pokes") or the CA detection (the pressure "pulses") or the RERA detection algorithm. Several years ago there was a lot of high quality information about both of those things readily available on their web pages.

Things are not much better on the Resmed web pages: I find lots of glitz and very little content about how even EPR with EasyBreathe when I'm poking around those pages.

[palerider]

Truth be told, there is NOT much out there that describes the current generation's Auto algorithms on any of the major brands of APAPs in any detail.

I imagine you'd have to be good at reading patents and digging around in patents.google.com

Things are not much better on the Resmed web pages: I find lots of glitz and very little content about how even EPR with EasyBreathe when I'm poking around those pages.

I have a bit of info on epr and easybreath from playing around with my Tx machine, as far as what they actually do to the delivered pressure: