Had my machine changed to auto-did I do the right thing?

I couldn't get my doc to lower my pressures from the originally prescribed 17/13 after my study and titration, but I did get him to agree to change my machine to automatic. He sent the Rx to my DME and it's done. I understand that the possible pressure range is from 5cm to 25cm. I tried to get him to cap it at my old Rx of 17 but he didn't want to do that for some reason. The pressure support (which as I understand it is the difference between IPAP and EPAP was left at the default of 2-8.

I requested this in the hope that if I didn't need all the pressure I was getting that maybe less pressure would equal fewer leaks. It occurs to me though that it could go the other way and shoot up to 25 just as easily. At my "old" pressures of 17/13 when I got lucky and had a 0% large leak night my AHIs would run from 1.4 to 2.4, with most all of the events being either OAs or Hypopneas.

So I guess we'll see, but can anyone speculate as to whether my desired result of overall lower pressure will come to pass?

BTW I realize I could change the pressure settings myself but I'm trying to maintain a good relationship with this doc for the time being and my DME is nearby.

old dude wrote:Had my machine changed to auto-did I do the right thing?

Yes, if you got them to give you an Auto machine to replace your non auto machine you did a good thing for your future requirements. The auto machines can emulate a non auto, but the non auto machines will never be able to operate in auto mode.

I think that those wide open settings are inviting a big train wreck.
Not so much because of the wide open IPAP but because of the lower EPAP and thus starting pressure for IPAP.
With EPAP at 5 and PS at 2 (that's the default in auto mode on the 50 series machine and changes based on what the machine senses once you get to sleep and the apneas start trying to form) then your beginning of the night pressures will be 5 EPAP and 7 IPAP and that most likely is going to be way too low to effectively prevent the apneas from happening and you are apt to have wildly fluctuating pressures which isn't going to do your leaking problem any good either.

Pugsy wrote:I think that those wide open settings are inviting a big train wreck.
Not so much because of the wide open IPAP but because of the lower EPAP and thus starting pressure for IPAP.
With EPAP at 5 and PS at 2 (that's the default in auto mode on the 50 series machine and changes based on what the machine senses once you get to sleep and the apneas start trying to form) then your beginning of the night pressures will be 5 EPAP and 7 IPAP and that most likely is going to be way too low to effectively prevent the apneas from happening and you are apt to have wildly fluctuating pressures which isn't going to do your leaking problem any good either.

Don't know if it matters but my machine is a 760P. My understanding (which could be totally wrong) is that the 5-25 is the IPAP pressure and the EPAP pressure will lag behind that by a variable amount anywhere from 2-8 cm. Now I have NO idea how quickly the machine is capable of responding but I got the impression that if it sensed an obstruction or irregularity it would instantly go up to the pressure necessary to correct it, and likewise do the same on EPAP in the other direction. If so that would seem to prevent the scenario you describe.

But admittedly I have no idea if the machine can respond that quickly or if in fact that's even how it works.

I believe that the lower setting is EPAP min (5 here) and the upper is IPAP max (25).

The PS is the allowable difference between IPAP and EPAP. So here IPAP - EPAP
will always be between 2 and 7 inclusive.

IPAP has priority over EPAP, so if an IPAP increase would cause PS to become
greater than PS max, EPAP will be pulled up.

Similarly, if an IPAP decrease would cause PS to become less than PS min, EPAP
will be pushed down.

On the other hand, if an EPAP change would cause PS to become greater than
PS max or less than PS min, the change in EPAP will not occur.

IPAP can force changes in EPAP to keep PS within bounds. But EPAP cannot
force changes in IPAP.

As far as the low EPAP min setting discussed, an auto does not respond
instantaneously. The only way for the machine to determine how much
to increase the pressure is for it to increase a set amount and then wait
to see if events still occur. If they do, it increase the pressure again
and tests again.

There are numerous examples of users with wide pressure spreads
complaining that the pressure seems to stay at maximum for a good
part of the night. Intuition says that the maximum is not letting the
pressure go high enough and should be increased. But after increasing
their minimum pressure, they have found that the pressure no
longer gets pinned at the maximum setting.

I have a 760 also. I thought you had a 50 series machine...that's what your profile points to...but it doesn't matter...it won't do what you are thinking it will do. Trust me...I know how the machine works.

With the settings at 5/25 with PS 2 to 8...it doesn't work like you are thinking it will work. And it for sure won't respond instantly like you are thinking it will....I can guarantee you that it won't. It can't go from 5 or 7 or 9 IPAP to 17 in a blink of an eye...it just can't do it. It goes up in stages over a period of a few minutes..not seconds and it tests the airway while it is increasing.

There has to be an EPAP pressure...so that is the 5 cm...and with the PS ranging for 2 to 8 then that makes IPAP 7 cm...try it out during the day right now and you can watch the machine and it will show you what it is delivering in terms of pressure.
That's the starting point as well as where the machine will go back down to should events trigger a pressure increase during the night while asleep and enough time passes where the machine doesn't sense the need to have more pressure.

The PS range from 2 to 8...what it will be is determined by what the machine senses it needs to do. Not a bad thing to have it wide open if the EPAP is set optimally. So there's a large number of possible combinations of what might be used in terms of EPAP, PS and IPAP. I suspect that the EPAP at 5 cm is going to be a potential problem in terms of being able to get to the pressures needed to prevent the collapse of the airway. If you were using 13 EPAP and 17 IPAP...and you needed that 13 EPAP to prevent the obstructive apneas from forming...it is not going to be able to respond quickly enough to get to 13 from 5 (or really any of the single digit EPAP numbers).
Now maybe the original RX for 13/17 was over kill for a worst case scenario and you don't really need that much pressure all night long...then maybe there's a chance this lower EPAP will work.

All I can tell you is give it a try tonight and see what happens but don't be surprised if the AHI increases and you still don't have leaks under control because the pressure is going all over the place. It's hard to keep a good seal when you start the night at 5/7 cm and it seals great and then you go up to 12/18 (just an example) during the night. Simply too much difference in pressures to anticipate and fit.

Here's an example of mine from the other night. My settings were 9 EPAP and PS 4 min and 5 max and my IPAP max is 20.
Note the 2 clusters of obstructive apneas early in the night...my EPAP wasn't optimal. It couldn't prevent the OAs from materializing. Most of the time the 9 EPAP does a good job but for some reason it didn't this time.
Normally I don't need this much pressure...this is unusual for me. If you really needed 13/17....with your new EPAP you are very likely to see a bunch of clusters like mine. Now maybe you didn't need so much all the time and in that case you might do better than I think but for now I am thinking that there's a good chance you will see a train wreck on your report tomorrow...I hope I am wrong...nothing would make me happier than to be proved wrong because it means you can use a lot less pressure than you have been using and that's always a good thing.
Please note...I have never seen one of your reports so I don't know what was happening with the 13/17 you were using...I only know you were having massive amounts of large leak flags.

Pugsy I likely will not be so lucky. I'm up and down as a rule during the night so I'll likely check it and see what's going on, then switch over to my back up machine if need be. My DME requires another Rx to switch it back to straight 17/13 if this doesn't work, which I'll have to do before going out of town Wednesday for a week.

Well everybody, I tried it and the night was pretty much a disaster. Even though I only slept about 2-1/2 hours, my AHI jumped up to 5.6 from the previous night's 1.4. EPAP pretty much flatlined at 5 cm all night and IPAP hovered around 10 cm give or take. Predictably there were 0 LLs. Other details were:

Hypopneas 5.07
OA 0.0
CA 0.39
RERA 1.95
Flow limit .78
V snore 0.0
PB/CSR 2.37%

RERA, flow limit and PB/CSR have never appeared in my details before and I have to admit I don't know what they are. Given that my IPAP didn't skyrocket to the max, I think that there is potential in using the automatic setting approach. But I do agree with Pugsy and JDM that likely some tweaking is needed in the min/max pressures and also with the pressure support parameters. I am completely lost in this area so I will rely on your suggestions and give them a try. Since I'm going out of town for a few days I'll likely have the DME turn my #1 machine back to the old 17/13 settings so I'll have something that I know works and then ask for suggestions from you folks that I'll try on my back-up machine next week when I return. I went through the clinician set up screens on both of my machines this morning and feel pretty comfortable that I can change the settings if I get specific numbers to input.

Thanks all.

Well it was a train wreck but not as big of one as I thought might happen.
If your IPAP stayed around 10...that's real good news...you don't need that 17 IPAP you have been using.

If I were in your shoes and wanted to use the Auto mode (by the way FL flags are turned off in fixed mode and that's why you see them now) I would try a nice simple EPAP at 8 cm....Pressure support 3 minimum and 4 maximum and IPAP max at probably 14. That will give you a small range that will be much easier to control the leaks and still most likely be comfortable and effective.

I think that the RERAs and PB/CSR are most likely from poor sleep in general. Not comfortable with the new settings.
It's really hard to evaluate in terms of therapy effectiveness how last night went..you slept poorly so maybe the AHI would have been higher if you had slept.

Heck, if using fixed bilevel pressures...instead of 13/17....maybe try 9/13 and see how things go...it would sure be easier to manage the leaks.

At some point you may just have to take the bull by the horns and make the setting adjustments yourself....the DME can't do anything without the doctor telling them to and your doctor seems unwilling to use the auto mode in an optimal setting and for some reason thinks that the 13/17 just has to be perfect choice.

Pugsy wrote:Well it was a train wreck but not as big of one as I thought might happen.
If your IPAP stayed around 10...that's real good news...you don't need that 17 IPAP you have been using.

If I were in your shoes and wanted to use the Auto mode (by the way FL flags are turned off in fixed mode and that's why you see them now) I would try a nice simple EPAP at 8 cm....Pressure support 3 minimum and 4 maximum and IPAP max at probably 14. That will give you a small range that will be much easier to control the leaks and still most likely be comfortable and effective.

I think that the RERAs and PB/CSR are most likely from poor sleep in general. Not comfortable with the new settings.
It's really hard to evaluate in terms of therapy effectiveness how last night went..you slept poorly so maybe the AHI would have been higher if you had slept.

Heck, if using fixed bilevel pressures...instead of 13/17....maybe try 9/13 and see how things go...it would sure be easier to manage the leaks.


At some point you may just have to take the bull by the horns and make the setting adjustments yourself....the DME can't do anything without the doctor telling them to and your doctor seems unwilling to use the auto mode in an optimal setting and for some reason thinks that the 13/17 just has to be perfect choice.

Pugsy this is exactly what I needed. To be sure I understand, you suggest (in AUTO mode) setting the Min EPAP at 8 cm and the the Max IPAP at ~14, then setting the PS min at 3 and PS max at 4? And then if I wanted to experiment with fixed settings try EPAP=9 and IPAP=13 to see what happens? Not trying to be anal, I'm just feeling my way around a bit gingerly here. If I have this correct I'll give these a try next week when I return and report in.

You're 100% right about last night in that if I'd slept more my AHI would likely have been worse. I'm not a good sleeper anyway and I'm a lifelong chronic and acute anxiety sufferer, so I was kinda just laying there waiting to die based on settings that seemed to have been disagreed upon by the doc's office and the DME.

I'll tell you, it appears that this disorder is just like my diabetes in one respect: if you rely solely on the knowledge of doctors they will likely shorten your life. One has to take charge and find out what works for him or her self. The A1c levels that my GP thinks are just great would have me being an amputee is less than 10 years. And my sleep doc's opinions are all based on my one split night sleep study to start with, which I think was flawed for reasons that are another whole discussion.

Thanks goodness for groups like this one!

Yes, those are starting point suggestions as to what I might try if I were in your shoes. I have no idea how close to optimal they might be.
First of all at 13/17 your leaks have been massive for a good bit of the night and massive enough that we don't know if the lower AHI is from effective therapy or simply the machine not being able to sense any events...so that low AHI might be a misleading number.
I would need to see the detailed reports to have a better idea...but even your less massive leak nights like 33% of the time in large leak is still pretty bad...for a third of the night we don't know if the machine was able to flag events or not...above 100 L/min leak...the machine can't sense or record things. From 90 to 100...iffy...and from 80 to 90 L/min the machine probably can still sense the events...so it all depends on where the leak line goes.

So the most important thing to do is get the leaks under control first....then we can better evaluate pressure needs.
A few minutes here and there in large leak isn't the end of the world but if you have more than 10% of the night in large leak then we have to question the AHI that is shown. Like was the leak bad enough that the machine totally missed some events??? That can happen.

Since you really didn't sleep much last night...very hard to say what pressures you might need but a nice middle of the road compromise like I suggested might be enough to allow you to get the leaks under control and then we can trust the data that we see and make adjustments if needed.
That 13/17 suggestion...might be a worst case scenario for maybe supine sleeping or some REM stage sleep events.
If that is the case then maybe a compromise might be in order....either use auto mode to deal with them (and hopefully not create leak city) or use fixed mode and just allow them to happen if they are short lived and sporadic.

Well, maybe a modicum of success with my doctor has come out of this.

I tried another night with the automatic settings suggested by my doc, i.e., Min EPAP=5, Max IPAP=25 and PS= 2 to 8. And the results weren't good; my AHI was 8.6. Interestingly, the actual recorded pressure never rose over 5 and a little over 10 again all night. I attribute that to the PS settings not being correct but I couldn't convince my doc's RRT of that. I DID however convince her to approach the doc on letting me go back to fixed pressures a little lower than my 17/13, and he approved a trial of 15/11. The "successful" part is that when the RRT said she would fax the Rx right over to my DME I told her I didn't have time to get there before going out of town (true) and got her to agree to let me make the changes to the machine myself. So, if (and that's a big IF) the 15/11 setting gives good results I'll take that as permission to do a little dial wingin' myself to see if I can take pressures even a little lower. Guess we'll see what works...

My only object in lower pressure is a better mask fit without tightening it down so much my nose and face look like hamburger the next morning. The pressure itself doesn't bother me, in fact I find it sort of calming. It's just the leaks. And on those rare nights when I tighten down the mask enough to get 0 LLs, I'm normally rewarded with an AHI between 1.4 and 2.4-and of course a beat up nose.

So I'm very hopeful that a little experimenting will yield good results. I could in no way do any of this without the help and support of all of you and I appreciate it!

Well, first night on the new fixed pressures of 15/11 yielded the following results:

AHI 2.82
LLs = 0%
Hypopneas 1.01
Obstructive 0.0
Clear Airway 1.81
RERA .040

The IPAP pressure on SH's graph stayed pegged on 15 pretty much all night, but for reason(s) I don't understand the EPAP pressure line stayed at 7 even though the EPAP pressure is set at 11.

I was hoping for a little lower AHI so that I could experiment with lowering the pressure even more but I think I'll give it a week or more at this pressure setting and see where things go. It did seem a little easier to control the leaks than my old titrated pressure of 17/13. And at least the doc gave his blessing to trying the 15/11 setting.

What do you folks think?

In SleepyHead go to Preferences then the Appearance Tab and look on the right side for "use pixmap caching" and remove that check mark and see if your pressure line for EPAP shows up correctly.

Your AHI is roughly a little more than 50% Clear Airway events....remember we don't treat those with pressure using your machine.
You only had average of 1.01 hyponeas per hour...that's low enough that you could probably go a little lower on those pressure settings...probably 10 EPAP and 14 IPAP and not have a truckload of obstructive events (OAs or hyponeas) pop up.

Pugsy wrote:In SleepyHead go to Preferences then the Appearance Tab and look on the right side for "use pixmap caching" and remove that check mark and see if your pressure line for EPAP shows up correctly.

Your AHI is roughly a little more than 50% Clear Airway events....remember we don't treat those with pressure using your machine.
You only had average of 1.01 hyponeas per hour...that's low enough that you could probably go a little lower on those pressure settings...probably 10 EPAP and 14 IPAP and not have a truckload of obstructive events (OAs or hyponeas) pop up.

Well Pugsy, that did it and thanks so much! My pressure lines now show 15and 11just like they should.

You're reading my mind on trying the 14/10 settings. I'll give the current 15/11 a week or so to see if anything strange comes up then try the 14/10.