420E Problem--Pressure Cuts Off

Geocom · Post by **Geocom** » Wed Feb 08, 2006 12:39 pm

Recently, I have started having a problem with my 420E.

From time to time, when I inhale deeply, the pressure just cuts off, it stops in its tracks, and then, of course, I am left gasping for air. After a couple gasps, the pressure starts up again and I can begin to breath normally. It seems to happen in clusters of four or five at a time. It also seems to happen just after I roll over or move around.

I have checked the sensor hose and it is not obstructed in any way. My mask doesn't leak and all my connections are tight.

Has anybody experienced this? Anybody have any thoughts on how I can fix this problem.

snork1 · Post by **snork1** » Wed Feb 08, 2006 2:31 pm

Just recently my new 420E left me gasping on a couple of occasions for a pretty significant chunk of time until I turned it off and restarted. And this was with all tubes hooked up, and mask in place. Looking at the software, it shows a really odd set of readings for that time with it going ALMOST "flatline" on the readings, but at a lower than the lowest pressure setting, and showed zero leaks and zero incidents.

I would take it back to the DME, but its only happened a couple of times and I can't get it to repeat at will, so I figure they will just look at me like I am crazy and say its all my fault....somehow.

I am keeping an eye on it though. I hope this isn't some new 420E defect that is surfacing. Anyone else have odd problems with the 420E starving you out?

rested gal · Post by **rested gal** » Wed Feb 08, 2006 4:39 pm

snork, I think you use the Aussie heated hose, right? Does your heated hose use a piggyback connector? Reason I ask... I know of at least two people who have had a problem with their 420E cutting off when using the piggy back connector with the heated hose.

When I ordered a backup heated hose for my 420E, I had them NOT send the piggyback...to send me just the older connection style for use with a Radio Shack DC adapter, which I already had. Just in case.

geocom wrote:From time to time, when I inhale deeply, the pressure just cuts off, it stops in its tracks, and then, of course, I am left gasping for air. After a couple gasps, the pressure starts up again and I can begin to breath normally

Neither of the 420E's I've used have ever turned off while in use. Tonight I'll try some deep breaths while the machine is running to see if that happens.

Guest · Post by **Guest** » Wed Feb 08, 2006 5:37 pm

It has happened to me too, I think I could recreate it if I wanted to.

It seems as though if I take a really big and sudden deep breath the machine will do it .

For instance if I'm exhaling and suddenly take a deep inhalation before the exhale is done, It has to be a sudden and extreme change in the breathing pattern.

I never really though much of it, The machine comes right back on after about 4 seconds.

I always thought the machine was reacting to the sudden extreme change in breathing, it doesn't shut off, it just seems to "reset" and start flowing
air again.

snork1-logged out · Post by **snork1-logged out** » Wed Feb 08, 2006 5:41 pm

rested gal wrote:snork, I think you use the Aussie heated hose, right? Does your heated hose use a piggyback connector? Reason I ask... I know of at least two people who have had a problem with their 420E cutting off when using the piggy back connector with the heated hose.

When I ordered a backup heated hose for my 420E, I had them NOT send the piggyback...to send me just the older connection style for use with a Radio Shack DC adapter, which I already had. Just in case.

geocom wrote:From time to time, when I inhale deeply, the pressure just cuts off, it stops in its tracks, and then, of course, I am left gasping for air. After a couple gasps, the pressure starts up again and I can begin to breath normally
Neither of the 420E's I've used have ever turned off while in use. Tonight I'll try some deep breaths while the machine is running to see if that happens.

As a matter of fact i do use the heated aussie hose with piggyback connector. I had planned on this being my travel setup and keeping the weight and bulk down by only needing one power supply. It would be a MAJOR bummer to need to use two heavy power supplies.

I wonder if I can just up the size of the one power supply? I notice the one from Radio Shack from my previous Remstar setup is about twice the size of the one that came with the 420E. I didn't bother to check out the rating difference between the two....which I need to check out when I am home. maybe that oversize Radio Shack supply can carry more load? What are the odds?.....

Old Firehorse · Post by **Old Firehorse** » Wed Feb 08, 2006 9:04 pm

This 420e behavior has happened to me on several occasions. I don't use a heated hose or a heated humidifier. This may be a glitch. Then again, this may be by design. In a past thread there was speculation that this may be how the 420 reacts to certain irregular breathing patterns---hyperventilation specifically. All AutoPAPs must by design cope with "irregular breathing" patterns (that are apneic in nature, incidental to apnea, or even induced by CPAP). The Remstar Auto, for instance, employs its own patented "variable breathing controller" that was discussed here extensively.

In yet a different thread just a few weeks/months ago I pondered whether this was a designed response by the 420e to hyperventilation. My thought was that only a few seconds of CPAP pressure turned off would increase CO2, thereby lending an advantage to hyperventilation. I think in that thread it was mentioned that since CO2 is not measured by the machine, then this would not be an appropriate response. CO2 measurement would not necessarily be a prerequisite criteria for a tactical short-duration CO2 increase administered by the algorithm. As long as a few seconds of CPAP pressure being turned off amounted to no actuarial risk whatsoever, then CO2 measurement/titration would not at all be prerequisite. Hyperventilating patients do not measure or titrate when breath into a paper bag for a short burst of CO2 retention.

It was also mentioned that the 420e was designed to treat apnea, not hyperventilation. True. Yet all autopap algorithms detect and respond to certain incidental non-apnea breathing conditions if they are statistically significant enough and can be affected by the algorithmic response. In the case of hyperventilation, a significant albeit not very large percentage of patients will hyperventilate. During sleep onset, CPAP-related anxiety or even general anxiety can actually induce hyperventilation, which in turn can induce O2-related central apneas. In recap, those particular central apneas are related to a high O2/CO2 ratios, which were caused by hyperventilation, which in turn originated from anxiety. This is, of course, not the only hyperventilation scenario that might occur while a patient is hooked up to CPAP.

So... is this a 420e glitch or is this a designed 420e response to certain "irregular" breathing patterns. I really don't know to be perfectly honest, but I for one have yet to rule out the latter possibility. If it is a designed response, I'm not even sure that all perceived or detected hyperventilation patterns would receive this particular response. It is an interesting response, and it seems to happen when many of us inhale suddenly and deeply.

Back to Ladder Company 58's pasture for an aged bale of alphalpha...

ozij · Post by **ozij** » Wed Feb 08, 2006 10:24 pm

It seems to happen in clusters of four or five at a time. It also seems to happen just after I roll over or move around.

Since it happens when you move around - could you be jiggling the machine's electric connector? The plug in the back of mine is not very firm, and under certain conditions even a light touch can disconnect the machine, without necessarily pulling the plug out.

Snork The second power supply I have is really not that big or heavy. It's a wall wart, about 7.5*4.5*2.5 cm, not one of those variable power ones. Not much of add to the other things when traveling.

O.

john5757 · Post by **john5757** » Thu Feb 09, 2006 1:49 am

I do not think that the machine should turn off while in use regardless of any programing. Another possibility does this machine has a auto turn off when you normally take the mask off? If this is true, could taking a deep breath at a certain time foolthe machine to think that the mask is off? I am not familiar with this machine and I am just educating a guess.

rested gal · Post by **rested gal** » Thu Feb 09, 2006 2:26 am

john5757 wrote:Another possibility does this machine has a auto turn off when you normally take the mask off?

No, the 420E does not have an automatic turn off when a mask is removed. What it will do, though, is sense such a large sustained leak that it will drop down to its lowest pressure and run that low pressure until the mask is put back on. But it's still running and blowing air at the very low pressure. It doesn't turn off completely when a mask is removed.

Geocom · Post by **Geocom** » Thu Feb 09, 2006 6:08 am

Rested Gal to the rescue!

Indeed, it is a problem with the heated hose with the piggyback connector and the 420E.

After reading Rested Gal's post, I did an experiment with my heated hose plugged in, and with the heated hose unplugged. With the hose plugged in, the machine would stop when I inhaled deeply. With the hose unplugged, the problem went away. I repeated this several times, getting the same result each time.

Since this problem only started once it got cold here in Virginia, I suspect static electricity may be the culprit; but that's only an intuitive hunch.

What does this mean? If you use the heated hose with the piggyback connector and the 420E, and you have this problem, you should contact Don at Sleep Zone. His email address is don.fischer@optusnet.com.au

Once again, Rested Gal saves the day!

Old Firehorse · Post by **Old Firehorse** » Thu Feb 09, 2006 6:41 am

After reading Rested Gal's post, I did an experiment with my heated hose plugged in, and with the heated hose unplugged. With the hose plugged in, the machine would stop when I inhaled deeply. With the hose unplugged, the problem went away. I repeated this several times, getting the same result each time.

Indeed, a glitch and definitely not a programed response to variable breathing of any kind. Which gets me to wondering about mine. I have nothing else piggy-backed onto mine and very clean A.C.. none the less, it must be a case of intermittently glitchy A.C. or a marginal power supply in my cade. Thanks so much.

Guest · Post by **Guest** » Thu Feb 09, 2006 7:58 am

I think this old thread explains the "cut-off" problem very well.
Nev

Joined: 23 Apr 2005
Posts: 16
Location: Queensland, Australia
Posted: Sat Jul 23, 2005 9:43 pm Post subject: Aussie Heated Hose

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I bought a heated hose with my 420E before days of the the piggyback cable.

I recently asked SleepZone about the possibility of an upgrade cable, and whether it would overload the 420 power supply.

SleepZone assured me that using the piggyback cable would not overload the 420E power supply. They don't make un upgrade cable so I got my local TV repairman to make a Y cable with the right size plugs and socket for me. So now I can use the heated hose transformer while I'm at home an turn the hose off separately, but take the Y cable when travelling and save space and weight by leaving the transformer and 4-point switched power board at home.

I think however that there may be several different 420E power supplies depending on where you buy it. Mine came from Tyco Australia and is Powertech MP3240 100-240V input, 12V 4A output. As the machine itself only uses 0.75A at 20cmH2O and the heated hose uses 1 amp, there's power to spare.

The 420E manual I got says the power supply module is a Class II power supply with output 13V 1.85A, but it has a sticker pasted under that saying:

"CAUTION - TYCO AUSTRALIA authorises the use of one of the following power supplies:
. Powertec MP3240 ... as above ... this power supply is standard for use in all regions;
. Egston N2GFMW rated at 13V 2A for use in Europe only (optional)"

The sticker is pasted over the words in the original manual:

"Power supply provided with the device Egston N2UFMW 24W 13V or ANAM TA2412 24W 12V."

24W at 13V would be 1.85 amps and 24W at 12V would be 2 amps so the total of 1.75 amps for the hose plus the machine at full speed would still be within the rated output of these power supplies, but not by a great margin.

You might ask the guys at SleepZone to reassure you that using the piggy back cable with the power supplies issued in the USA or other countries is really OK.

Nev

Machine	Mask