advice on setting up an auto-bipap

[bob simons]

I've just been moved from an auto-pap which I've used for about 13 years to a bipap. The machine is a Respironics auto-bipap DS760 but was delivered from the clinic set to manual 17/13. I want to set it to auto-bipap and have gotten the manual from the board here (thanks!). After one week at the4 manual settings above, my AHI is under 3. I'm on a few heavily respiratory-suppressing drugs in varying amounts, and the settings above came from a new sleep study at my most drugged, to set the likely maximum pressures. I'm expecting the typical will remain near what I've been using on the old auto-pap.

Does anyone have instructions on how to set the machine for auto? I'm not at all clear on how to set the minimum, the differential and any other important settings. My last machine was a Respironics auto-pap 550 set from 10 to 16, and it tended to rattle around 12.6 to 13.

I know it's an iterative process so I'm looking for a starting point. Also looking for software advice. I started with sleepyhead 0.9.3 beta from about a year ago. I also found that I could not figure out how to get data into Encore basic 1.2 from the card. I don't want to send data to Respironics as I fear this would mean automatic liability if I was ever in a car crash. I just cant see the upside to letting this info out.

Any advice is appreciated.

[trish6hundred]

Hi bob,
WELCOME! to the forum.!
Hang in there and someone who knows the ins and outs of your machine will be along to help you shortly.
Best of luck to you with the new machine.

[robysue]

Welcome to the forum Bob!

First the easy question:

Also looking for software advice. I started with sleepyhead 0.9.3 beta from about a year ago. I also found that I could not figure out how to get data into Encore basic 1.2 from the card.

The newest stable version of SleepyHead works with the DS760. If you downloaded SH 0.9.3 a year ago for a WINDOWS machine, that version of SH should work with your new BiPAP. Plop the SD card into the computer, open up SH, and import the data in the same way you did for the APAP machine were using. Let us know if you have any problems.

If you really want Encore Basic, you need Encore Basic 2.2, which can be requested from the Private part of the forum, but there's no real need for it if you like SleepyHead.

Now for your real question:

I've just been moved from an auto-pap which I've used for about 13 years to a bipap. The machine is a Respironics auto-bipap DS760 but was delivered from the clinic set to manual 17/13. I want to set it to auto-bipap and have gotten the manual from the board here (thanks!). After one week at the4 manual settings above, my AHI is under 3.
...
My last machine was a Respironics auto-pap 550 set from 10 to 16, and it tended to rattle around 12.6 to 13.

I assume that you've got the clinical manual for your 760 machine? If not, request one from the Private area part of the forum. You get into the clinical manual in the same way you do for the 550 machine: Select "Set up" on the lcd and press both the large round On/Off button and the Ramp button at the same time until the machine beeps at you.

In BiPAP AUTO mode, the therapeutic settings for your new machine are:

• Min EPAP
  Max IPAP
  Min PS
  Max PS
  

The max EPAP and min IPAP are derived from the other settings and you don't set them up in the clinical menu.

Given your previous APAP settings, I think I'd start out by trying something like:

• Min EPAP = 10 = your old min pressure setting
  Max IPAP = 17 = your fixed IPAP pressure
  Max PS = 4 = the difference between your fixed IPAP and EPAP settings.
  Min PS = 2 = a wild guess on my part

The reason I'm suggesting setting Min PS = 2 is that on the 750 BiPAP (that I use), which is a slightly older version of the PR System One BiPAP Auto, there is no min PS setting and the min PS is, by default, equal to 2cm. And since min PS = 2 was the old default, it seems like a reasonable starting place when you have no idea what to use.

With these settings(Min EPAP = 10, Max IPAP = 17, Max PS = 4, and Min PS = 2) (and no RAMP) your pressures will work like this on the BiPAP Auto running in Auto mode:

Beginning EPAP pressure with NO ramp = min EPAP = 10
Beginning IPAP pressure with NO ramp = min EPAP + min PS = 10 + 2 = 12
Maximum EPAP pressure = Max IPAP - min PS = 17-2 = 15
Maximum IPAP pressure = 17

And at any point in the night:
min PS <= IPAP - EPAP <= max PS so 2 <= IPAP - EPAP <= 4

This means that as the Auto algorithm kicks in and starts to adjust the pressures, the following pressure combinations are possible:

EPAP = 10, IPAP = 10 + 2 = 12
EPAP = 10, IPAP = 10 + 3 = 13
EPAP = 10, IPAP = 10 + 4 = 14

EPAP = 11, IPAP = 11 + 2 = 13
EPAP = 11, IPAP = 11 + 3 = 14
EPAP = 11, IPAP = 11 + 4 = 15

EPAP = 12, IPAP = 12 + 2 = 14
EPAP = 12, IPAP = 12 + 3 = 15
EPAP = 12, IPAP = 12 + 4 = 16

EPAP = 13, IPAP = 13 + 2 = 15
EPAP = 13, IPAP = 13 + 3 = 16
EPAP = 13, IPAP = 13 + 4 = 17

EPAP = 14, IPAP = 14 + 2 = 16
EPAP = 14, IPAP = 14 + 3 = 17 = max IPAP

EPAP = 15, IPAP = 15 + 2 = 17 = max IPAP

Changing the min and max PS settings change the possible pressure combinations. The farther apart min PS and max PS are, the more possible pressure combinations there are.

If setting min PS = 2 does not provide enough pressure relief when you are still awake at the beginning of the night, you can bump the min PS up to 3. If min PS = 3, then possible pressure combinations are:

EPAP = 10, IPAP = 10 + 3 = 13
EPAP = 10, IPAP = 10 + 4 = 14

EPAP = 11, IPAP = 11 + 3 = 14
EPAP = 11, IPAP = 11 + 4 = 15

EPAP = 12, IPAP = 12 + 3 = 15
EPAP = 12, IPAP = 12 + 4 = 16

EPAP = 13, IPAP = 13 + 3 = 16
EPAP = 13, IPAP = 13 + 4 = 17

EPAP = 14, IPAP = 14 + 3 = 17 = max IPAP

Setting min PS = 4 = max PS will force the EPAP and IPAP to go up nd down together. The possible pressure combinations would be:

EPAP = 10, IPAP = 10 + 4 = 14
EPAP = 11, IPAP = 11 + 4 = 15
EPAP = 12, IPAP = 12 + 4 = 16
EPAP = 13, IPAP = 13 + 4 = 17 = max IPAP

[robysue]

And one more thing:

If you used A-Flex on your old 550 machine, I'd suggest using Bi-Flex at the same level since Bi-Flex is essentially a bi-level version of A-Flex.

If you had A-Flex turned off on your 550 machine, then you may want to turn Bi-Flex off on the 760. If you turn Bi-Flex OFF, you will then have to choose a "Rise time" setting. You will be able to test the different Rise Times at your minimum pressure settings from the Patient interface in the same way you can test the different Flex settings.

[bob simons]

And one more thing:

If you used A-Flex on your old 550 machine, I'd suggest using Bi-Flex at the same level since Bi-Flex is essentially a bi-level version of A-Flex.

If you had A-Flex turned off on your 550 machine, then you may want to turn Bi-Flex off on the 760. If you turn Bi-Flex OFF, you will then have to choose a "Rise time" setting. You will be able to test the different Rise Times at your minimum pressure settings from the Patient interface in the same way you can test the different Flex settings.

Thanks for this info. I'll start with it. my back story is that I'm on both constant 24 hours a day pain meds and as-needed meds there's a fair amount of respiratory suppression from the ER drug and less but still some from the IR (a different drug). So I went to the sleep study on the maximum amount of drugs to have a worst case number. I'm expecting the usual numbers to be much closer to what the old auto pap ran on.

A few things confuse me, including that the sleep study showed 51 centrals but they insisted that they cleared up with pressure increases, which makes sense for OSA but not central, which in fact is often made worse with increased pressure. I asked why I wasn't rprescibed the server machine if the central count was so high and they said there was no need and that centrals went away with pressure just like OSA. Does this sound plausible? I presume the study calls it OSA if there is chest movement but no airflow and no chest movement means central.

Does the AHI score include both OSA and central (and of course hypopnea)? If so, maybe they're right as improbable as it sounds.

I had ramp, and all "flex" options off as they annoyed me. I'm using a new-to-me resmed Altiva LT nasal mask which has the least leaks by far than anything I;ve ever seen before but it has a bellows between the frame and the cushion which pumps and breathes as the machine cycles the pressure. I'm aware of dislikinig that while I'm awake but it's never woken me up and I'll probably get used to it. I see a "rise" time with options from 150 to 400 ms as it switches between the pressures. I think it's se to 200 ms, which is option 2, and the lowest is 1 at 150.

Any ideas on this option?

[zonk]

A few things confuse me, including that the sleep study showed 51 centrals but they insisted that they cleared up with pressure increases, which makes sense for OSA but not central, which in fact is often made worse with increased pressure. I

Confuse me too, normally they decrease pressure if central apnea/hypopnes observed

Pain medication contain opiate causes central sleep apnea

[bob simons]

A few things confuse me, including that the sleep study showed 51 centrals but they insisted that they cleared up with pressure increases, which makes sense for OSA but not central, which in fact is often made worse with increased pressure. I

Confuse me too, normally they decrease pressure if central apnea/hypopnes observed

Pain medication contain opiate causes central sleep apnea

to ask again, goes the AHI score include both osa and centrals, essentially only measuring breathing stoppage beyond a certain limit, with no difference in the score from the cause? So you'd need the scoring of OSA, hypopnea and central apnea for the AHI number to actually mean anything beyond the overall impact, which is presumed to be equivalently scored amount the multiple causes?

In other words, without analyzing the report, which I still don't have, I don't know how the centrals were at each pressure?

[robysue]

1) AHI includes central apneas as well as obstructive apneas and hypopneas. And that's true for the overall AHI and the AHI at each pressure setting.

2) While many people with central problems do have more problems as the pressure goes up, it's not a simple relationship. And some people with central problems are lucky enough that the centrals do indeed wind up going way with an appropriate level of pressure. One reason is this: If there is less disruption of the sleep from the obstructive events because the pressure is optimized, then the sleep is sounder and if the sleep is sounder and the centrals are mainly confined to areas of unstable sleep (i.e. they are strongly correlated with problems making the transition TO solid Stage II sleep), then as the sleep becomes more stable, the number of CAs goes down. Enough CSA patients fall into this category that many insurance companies insist that CSA patients do a trial on CPAP/APAP and plain BiPAP/VPAP to see if those cheaper machines will take care of the problem before authorizing a switch to an ASV machine.

3) Rise time. You write:

I see a "rise" time with options from 150 to 400 ms as it switches between the pressures. I think it's se to 200 ms, which is option 2, and the lowest is 1 at 150.

Any ideas on this option?

You are right, the units are msec, although the connection between the setting and the time is not straightforward. The rise time is how fast the transition is from EPAP to IPAP. You can try out the different settings and see which one you like the most.

According the the clinical menu for my 750 BiPAP, the rise time settings correspond to the following times:
0 = 150 msec
1 = 200 msec
2 = 300 msec
3 = 400 msec

I've got mine set to "3" (400 msec). I settled on that choice by testing. There's a neat "real time" testing feature. If you twist the big knob to select the upper RIGHT corner of the main LCD screen when the machine is turned off and push the button, the machine will start delivering pressure (at your minimum settings) and you can turn the knob to change the setting while the mask is on your face delivering pressure. This allows you to directly compare the way the different settings feel. When you push the knob/button to turn the machine off, the last rise time setting you used is entered as the rise time setting in the set up menu.

As a general rule, the shorter the rise time, the sooner you're back to full IPAP and that means the more pronounced the blast of additional pressure is. The longer the rise time, the more "gentle" the blast of additional pressure is because it is spread out over a bit more time. Other things to consider: If you have very short inhalations, a shorter rise time will insure you get back to IPAP pressure for the whole inhalation, where as a rise time of 400msec = .4 sec may make it where a substantial part of your inhalation is done without having the full IPAP pressure to support it.

[bob simons]

1) AHI includes central apneas as well as obstructive apneas and hypopneas. And that's true for the overall AHI and the AHI at each pressure setting.

2) While many people with central problems do have more problems as the pressure goes up, it's not a simple relationship. And some people with central problems are lucky enough that the centrals do indeed wind up going way with an appropriate level of pressure. One reason is this: If there is less disruption of the sleep from the obstructive events because the pressure is optimized, then the sleep is sounder and if the sleep is sounder and the centrals are mainly confined to areas of unstable sleep (i.e. they are strongly correlated with problems making the transition TO solid Stage II sleep), then as the sleep becomes more stable, the number of CAs goes down. Enough CSA patients fall into this category that many insurance companies insist that CSA patients do a trial on CPAP/APAP and plain BiPAP/VPAP to see if those cheaper machines will take care of the problem before authorizing a switch to an ASV machine.

3) Rise time. You write:

I see a "rise" time with options from 150 to 400 ms as it switches between the pressures. I think it's se to 200 ms, which is option 2, and the lowest is 1 at 150.

Any ideas on this option?

You are right, the units are msec, although the connection between the setting and the time is not straightforward. The rise time is how fast the transition is from EPAP to IPAP. You can try out the different settings and see which one you like the most.

According the the clinical menu for my 750 BiPAP, the rise time settings correspond to the following times:
0 = 150 msec
1 = 200 msec
2 = 300 msec
3 = 400 msec

I've got mine set to "3" (400 msec). I settled on that choice by testing. There's a neat "real time" testing feature. If you twist the big knob to select the upper RIGHT corner of the main LCD screen when the machine is turned off and push the button, the machine will start delivering pressure (at your minimum settings) and you can turn the knob to change the setting while the mask is on your face delivering pressure. This allows you to directly compare the way the different settings feel. When you push the knob/button to turn the machine off, the last rise time setting you used is entered as the rise time setting in the set up menu.

As a general rule, the shorter the rise time, the sooner you're back to full IPAP and that means the more pronounced the blast of additional pressure is. The longer the rise time, the more "gentle" the blast of additional pressure is because it is spread out over a bit more time. Other things to consider: If you have very short inhalations, a shorter rise time will insure you get back to IPAP pressure for the whole inhalation, where as a rise time of 400msec = .4 sec may make it where a substantial part of your inhalation is done without having the full IPAP pressure to support it.

I was playing with sleepyhead and found that it was fairly easy to drag through a small area of the graph to expand the selection to the width of the window. It shows that the system has detail avaialable on each breath, regardless of whether it exceeds any limit. I didn't play with it to see if the expanded samples as viewed also limit the numbers to the time displayed. In other words, I was wondering if I could pick a block of time with the mouse and see the numbers for that time, and if these selections can be printed.

Is it worth the bother to try to get encore pro as a single user, and not a clinician trying to manage a practice back before my model 550, I had an earlier copy of Encore pro back before they started making it so impossible to get.

Any idea what to do regarding mask settings when using a resmed mask? Any guidelines about what to set it to? I'm currently using an Activa LT which is a nasal mask with a fairly large bellows between the frame and the cushion which makes it seal better than anything I;ve ever used but also makes it pump and breath as the pressure changes. But it's almost free of leaks.

[DeepBreathing]

I was playing with sleepyhead and found that it was fairly easy to drag through a small area of the graph to expand the selection to the width of the window. It shows that the system has detail avaialable on each breath, regardless of whether it exceeds any limit. I didn't play with it to see if the expanded samples as viewed also limit the numbers to the time displayed. In other words, I was wondering if I could pick a block of time with the mouse and see the numbers for that time, and if these selections can be printed.

G'day Bob. When you select a block of time in SleepyHead, the number of events, duration and AHI for that block of time are displayed just above the flow graph. I use a fairly long ramp period which has lots of hypopneas, so I use this method to get my "true" AHI. I don't think there's any way of printing this other than a screen dump - the statistics display doesn't change when you select blocks of time.