420e waking me up on high pressure

dangst · Post by **dangst** » Fri Feb 03, 2006 9:29 pm

My new 420e (with humidfier) is giving me some hassles. The main problem I have is that the pressure seems to keep building on itself until the point that it wakes me up. When I am awake the pressure can still be on the maximum and the air is whistling out of my mask. I thought if I was awake it should be back at a much lower pressure as I am alive and breathing OK ! In order to reduce the pressure I have been turning the machine off and then on again. And the process begins again. I can therefore have 3-4 'sessions' a night. My doctors prescription was for 10 to solve my very severe OSA. I have the machine set at 12 max with 0.5 increments. Minimum is the default 4. Max on demand is 10. I did nothave this problem with autoset Spirit 7 that I was trialling for a couple of months. I chose the PB420 because on paper it looked excellent and it's portability was a good factor.
Any suggestions for this tired Aussie ?

rested gal · Post by **rested gal** » Fri Feb 03, 2006 9:47 pm

dangst, do you have the Silverlining software so you can look at your 420E's detailed data? If not, I'd like to send you a PM about that, but you'll need to be registered on this site for PM's to work.

In the meantime, if you are able to access the clinical menu on your machine, try experimentally turning off IFL1 for a few nights. Leave IFL2 on.

Here's a thread explaining why I'm suggesting that as an experiment:

Mar 16 2005 subject: Question to SWS Re: 420E

And this:
Jan 11, 2005 subject: Bman: Spirit Overnight Indices

Topic started by -SWS accidentally logged in as "Guest".

Even though that topic starts out talking about the ResMed Spirit autopap, the topic moves quickly into a very thorough discussion about the PB 420E autopap's IFL1 and IFL2 triggers. It's a "many pages topic", so keep turning the pages!

____________________

For informative posts containing sound info about how autopaps work, check out the old posts by -SWS:

Links to -SWS discussions

My edit: Sorry, just noticed that you are, indeed, registered. PM on the way to you.

rested gal · Post by **rested gal** » Fri Feb 03, 2006 9:56 pm

I thought if I was awake it should be back at a much lower pressure as I am alive and breathing OK !

All autopaps take time to move back down slowly, even if you are awake and sitting up on the bed breathing normally and watching the dial.

They are supposed to move down slowly. Otherwise, they could be jumping up and down like a yo-yo while you sleep, causing disruptions from abrupt pressure changes.

The machine doesn't know if you are awake or asleep, so it goes about its business of reducing the pressure ever so gradually, testing what's happening along the way. Seems like an undue length of time if you're watching the dial. That old "the watched pot never boils" adage, ya know.

P.S. I'd bring the minimum pressure setting up considerably from "4". With your prescribed pressure of 10, I'd put the minimum at least up on 6 or 7...better yet, 8. But I'm not a doctor!! That's just what I'd do.

Guest · Post by **Guest** » Fri Feb 03, 2006 10:09 pm

Thanks for those links -- very useful. Some of the description is identical to my situation: To Quote:

As both you and UKnowWhatInSeattle mentioned, IFL1 can over-trigger in response to flow limitation runs and consequently run away with pressure. I am aware of four posters now who have experienced this (you might be the fifth). Those 420e users all seemed to do okay by turning IFL1 off using the Silver Lining 3 software.

Perhaps the best way to tell if flow limitation runs are causing IFL1 to over-trigger would be to look for these three tell-tale signs: 1) excessive numbers of flow limitations, 2) clusters or clumps of these flow runs on a vertical line-up with pressure hikes, and 3) once the pressure elevates, it tends to stay near or at the maximum pressure most or all of the time (throughout the night).

The experiment other 420e posters in this situation have tried was to turn off IFL1, then observe the over-pressure go away while still maintaining an excellent AHI. Of course, when making pressure experiments on your AutoPAP you would ideally get your doctor or therapist in the loop. However, it does sound as if your machine needs to be set up correctly to accommodate your breathing pattern, and my hunch is IFL1=off just may be your fix.

With my earlier Spirit 7 rental I was on a base of 8 but was swallowing so much air that the clinic put it down to 6, and the situation improved. I may well take it up a smidgen. Will also book in for a chat at the clinic.

I do have the Silverlining software and have been paddling around in it looking at the last 8 days of results. The manual is so unhelpful -- a very black box approach. No expanation of what is going on or why and how you might trouble shoot.\

I thought I was registered on this site for PM. I've only just joined up but have been cruising it as a reader for a few days.

elliejose · Post by **elliejose** » Sun Feb 05, 2006 6:41 am

I have the Remstar Auto and experience the same thing. I've asked both MD and DME and neither have an explanation. If I don't go to sleep soon after I don my gear, the pressure will be to whatever is the highest pressure I have it set for (be it 16 or 20). If I awaken in the night or in the morning (and want to take another nap) and don't go directly back to sleep the same thing occurs. Like you, I sometimes turn it off and back on, but not until I think I am ready to go to sleep or it just goes right back up again. However, if I leave it high and do go back to sleep without starting over, it usually is at a lower pressure when I awaken again. BUT I also have had my elderly aunt to tell me to "wake up, you're snoring!" when I am not even asleep (just relaxed). So, my opinion is that maybe it is possible that even when I am just relaxed and awake, the tissue in the back of throat does its thing and closes the airway. Don't really know. Just know that it also happens all the time with me, so generally now I just ignore it, unless the pressure bothers me.

rested gal · Post by **rested gal** » Sun Feb 05, 2006 12:06 pm

elliejose wrote:So, my opinion is that maybe it is possible that even when I am just relaxed and awake, the tissue in the back of throat does its thing and closes the airway.

There's absolutely no question that can happen, Josie. While sitting right here at the computer, I can deliberately let my throat relax to the point that all of a sudden it slams shut and there's no way for me to take a breath in.

That's the way I eventually experimented for finding what bottom pressure I wanted to set for my autopap - lying in bed with the autopap going, trying various straight pressures and deliberately and consciously letting my throat relax until I found a pressure that would keep it open. That pressure was 8 or 9. Since we relax even more in sleep than we ever can "deliberately", I have my low pressure set at 10.

In effect, I'm using my autopap as a straight cpap machine. But I still like having an autopap since the machine does occasionally (not often, but enough to make "auto" worthwhile) use other pressures between the 10 - 16 range I have set.

What range have you set for your machine, Josie? And what was your prescribed pressure from your sleep study?

One other thought - have you ever been diagnosed with GERD (acid reflux)? Or think there's a possibility you might have undiagnosed "silent GERD"?

The throat being bathed in acid during the night could cause the machine to use higher pressures in a futile attempt to push swollen tissues more open. Swollen tissue (unlike collapsed tissue) is "un-pushable." Especially if the acid bath causes vocal cord spasms. See loonlvr's saga:

Nov 05, 2005 subject: SUCCESS AT LAST-GERD,420E, PRILOSEC AND BENADRYL

chrisp · Post by **chrisp** » Mon Feb 06, 2006 6:36 pm

Look for a tiny drop of water in the pressure sensor tube. That will also make it run away .

:twis ted:

Snoredog · Post by **Snoredog** » Mon Feb 06, 2006 9:02 pm

Its been awhile, but I thought 1FL came set to OFF by default?

Guest · Post by **Guest** » Tue Feb 07, 2006 5:41 am

dangst here...I turned off the IFL1 a couple of days ago and it seems to have done the trick -- first night was a bit erratic, but last night was spot-on. Slept really well all night, no pressure run-aways. I have sent details to my equipment supplier and pehaps he or PB's techos can shed some light onto the problem. I think this 'solution' is a must try if you have runaways on the 420e.

For Snoredog, IFL1 came turned on with my machine.

I'm still not quite sure what I have lost by turning it (IFL1) off. Can anyone explain its function in plain english ?

Guest · Post by **Guest** » Tue Feb 07, 2006 8:41 am

Snoredog wrote:Its been awhile, but I thought 1FL came set to OFF by default?

No, it comes to you from the factory preset ON.

dangst · Post by **dangst** » Thu Feb 23, 2006 2:34 am

Since I started this topic I have been experimenting with different set ups. The results are most encouraging. What I have done is the following:

turned off the IFL1
Set the maximum on 13 (my prescription is 10)
Kept On demand at 10 - the factory setting.
raised the minimum and initial pressures from the default 4 to 6.5.
tightened up the straps on my Ultra Full face Mirage

The equipment supplier contacted Tyco (PB makers) technicial support and they said to pull the little tube up towards the mask a couple of inches. (I did)

The combination of all these things seems to be coming together & I'm starting to like the result -- no runaways, max pressure is staying within the range.

I'm still getting a few apneas and am recording acoustical vibrations here and there, and the machine is a bit noisy after the Resmed Spirit 7.

Thanks to the various information from forum members! Especially Rested Gal.

420e waking me up on high pressure

420e waking me up on high pressure

IFL1 turnoff seems to work