GoodKnight 420E

Hello... I'm brand new to all this, and purchased the 420E thinking it would be better b/c of the autoadjusting function. I purchased it, like many of you, from cpap.com.

Unfortunately, with my pescription set at 19cm, the 420E keeps shutting down the airflow (not turning it down, but literally turning it off) as I'm trying to breathe. I wake up in the middle of the night b/c I'm suffocating through the mask with zero air pressure. It lasts for about 2-3 seconds, then the airflow starts back up 100%.

This obviously isn't working right. Any thoughts or experiences????

Sounds like the 420E is shutting off because of major mask leaks. When you wake up, are you fiddling with the mask and eliminating the leak? In any case, I think LARGE mask leaks are the cause of your problem. I don't know whether there's a setting that would let the 420E respond differently to these leaks. In any case, if you can eliminate these leaks (and I'm not talking about smaller leaks), your problem will go away.

It sounds like your 420E may be suffering from the dread "IFL1 On" syndrome. I've been using a 420E for almost 2 years now and from about day 3 I've had the IFL1 switch set in the "Off" position (using the software, but it can be done from the control on the 420E). With the IFL1 set to "On", there have been reports of not quite "runaway" pressures, but pressures that go above what they are supposed to and then don't come back down. Sooo, you might check into toggling your IFL1 switch to off and see if that helps.

Remkember, I'm not a doctor or a RT or anything resembling medically trained, just an experienced user.

Best of luck!

Kajun

There are definitely no mask leaks. I can even turn down the ramp time to zero, and then turning the cpap on with the mask held flush to my face, it still does the same thing after about 5-10 seconds of pushing 19cm air.

No leaks in the tubing either.

As for the "1FL1"... I went into the configuration, and I found an "FL 1" setting, but I could not change that at all, the up/down arrow buttons wouldn't change anything.

this is my topic. I thought I was logged in, but I see it was listing my as guest.

Unfortunately, with my pescription set at 19cm, the 420E keeps shutting down the airflow

Can you be more specific about the setting up of your machine?

What is your lowest pressure?
What is you highest?

We've had a number of reports of 420e's loosing pressure for 2-3 seconds.

viewtopic.php?t=8159&highlight=420e+shut%2A

viewtopic.php?t=6384&highlight=420e+shut%2A

And here's my rsponse on one of those threads:

That doesn't make sense to me. Nor does a CO2 "safety feature" make sense - the machine can't measure it, and is meant for treating obstructive apneas.

I would do a very very thorough check of all the electric connections, paying special attention to where the little inlet where power supply enters the machine. I had a slight problem there once with a plug that wasn't snug enough - and yes, the machine stops for a moment, without recording the stop (I was wide awake and fumbling for the humidifer switch, more than once, when I touched the power cord, and apparently nudged the plug just enough to disconnect the power)..

Could anything by touching that little round plug?
Or snagging on the cable or power supply where it connects to the electric outlet?

If all those things checked out perfect, I would consider buying a new power supply for the machine, or taking it to the DME to be checked.

Another possibility: Could you be waking up because you covered the mask's vent with the covers or something?

I recenetly seem to have stopped my Breeze's vent with my hand!

Are you sure the sensor tube is plugged in properly, and isn't getting pulled out?

Whatever it is it's not acceptable behavior from your 420E.
O.

ozij wrote:That doesn't make sense to me. Nor does a CO2 "safety feature" make sense - the machine can't measure it, and is meant for treating obstructive apneas... I would do a very very thorough check of all the electric connections

The 420e pressure response mentioned by the original poster (lack of delivered pressure) is the opposite of FL-based runaway pressure that has been suggested. I do recall that a few 420e power supplies were found to have marginal instantaneous current-delivering capabilities. On these effected power supplies, whenever the instantaneous current-delivering capacity fell short, the processor-driven circuitry was inclined to very briefly crash. Very few 420e units seemed to be affected this way if I recall correctly. And some of those 420e power supplies fell short of instantaneous current demand because heated hoses were piggy-backed, while other units fell short without any other electrical devices used in tandem. I wouldn't sum up all crashing 420e units as each having a marginal power supply, but I would personally suspect that 420e component first and foremost.

But boy was that "astray" Firehorse character CO2-crazy or what? As that poster stated, he or she really should have been called "crazy horse" regarding any kind of CO2 vision quest. The 420e has never, by design, even attempted to mitigate certain types of respiratory drive instability using accumulated CO2. While that treatment strategy is both unorthodox and impractical in certain respects, it's none the less technically feasible in my view.

Here's the basis for my assertion that it would be technically feasible albeit impractical: 1) very sound statistical limits might be established (using historical PSG and epidemiological data) between best-case and worst-case effects of CO2 accumulation on a time domain versus pressure spectrum basis (in other words, CO2 measurement would not necessarily be a requirement for technical feasibility of CO2 accumulation used for mitigation purposes---or even for CO2 threshold avoidance as a potential pathogen), and 2) while treating apnea is any auto titrating CPAP machine's primary objective, coping with yet other incidental disordered breathing patterns are secondary requirements for all standard APAP algorithms---with either pressure variation or constant maintenance being used in all documented cases. When pressure is used to mitigate breathing cessation, the low-level etiology-based and pathogenic processes are in reality never measured. Rather machine pressure and resulting patient airflow are used in all cases to ascertain efficacy.

Or restating it in another way: the machine will pressurize and even depressurize the air to varying degrees, then assess resulting patient airflow based on that delivered pressure. A CO2 factored/calculated time-domain-based cessation of machine pressure followed by measurement of patient breath (on a frequency or BPM basis) is really only an ever so slight methodological treatment extension of what has always occurred with flow-based APAP machines. Pressure has always been varied on a statistical results basis with the algorithm subsequently measuring or assessing nothing more than the resulting patient breath signal itself (this happening on an indefinite machine-iteration followed by machine-iteration basis throughout the entire sleep therapy session).

In summary, any APAP will take a variety of pressure-based actions for various incidental disordered breathing patterns that are not directly related to apnea. And, measurement of intentionally accumulated CO2 may not be a technical-feasibility requirement for any given low-risk incidental treatment objective. Measurement or titration would undoubtedly be used when CO2 is employed as a primary or key treatment technique. But CO2-based respiratory-drive mitigation on a standard apnea-targeted APAP platform sure would represent a financially unfeasible portion of R&D budget, with esoteric treatment and thus disappointing financial gain expected. Additionally such an unfeasible R&D investment would have plenty of FDA and similar agency approval pending for that incidental and extremely marginal treatment gain. Crazy horse, indeed, Ozij! .

The FL1 and the power supply can be both problems.
I uprated my power supply from a 2 Amp power supply to a 4 Amp (no aussie hose) because it would stop dead at a pressure of about 18.
The problem never re-occured.
I then tackled the FL1 problem and turned it off, the pressure didnt go above 13 after that.
Hope that helps.

Billy

In addition to the links ozij gave, here are a couple more links about the 420E shutting off for some people. I think puffing billy, ozij, and -SWS nailed it in regard to the power supply...in some cases the 420E might simply need a better power supply than what comes with it.

Feb 08, 2006 subject: 420E Problem--Pressure Cuts Off
viewtopic.php?t=6930

viewtopic.php?t=11259
Stronger power suppy for 420E -- 12V 4a

However, you said yours starts back up; and if I remember right, the 420E doesn't have an automatic start from breathing into a mask, so....dunno.

you need to contact cpap.com customer service, the 420E machine comes with a 2yr warranty, I would also suspect the power supply not having enough current to drive the machine to 19cm.

Probably fine at 10cm, you get up at the maximum pressure and I don't think that 1AMP power supply provides enough current. If you could measure the voltage with a good digital volt meter you'll probably find the voltage is also dropping to unacceptable levels.

Send it back to cpap.com, they will take care of you.

People complain about the M series adjunct power supply being so big, yes it is, it is 4AMP. It has to be large to provide the current (amps) needed to run the blower at needed pressure.

Wrong Machine: Actually it might be a good thing it doesn't run at your needed pressure, you should be on a Bi-PAP anyway at that pressure, might as well make cpap life easier. I would check with cpap.com, maybe they could help you get into a auto-bipap so you have some exhale relief at that pressure.

I wouldn't be afraid of trying the new M series AutoBipap.

https://www.cpap.com/productpage-advanced.php?PNum=2335

Don't get sticker shock, but you NEED a machine that goes to a higher pressure, at 19cm you are already at the Maximum delivery pressure of these machines, that machine will be way noisy and that pressure.

I could see if you started out at 15cm pressure and worked your way up to 19cm, then maybe that machine would be kosher, but not starting out, you are already at the limits of that machine. The new M series AutoBipap goes to 25cm (vs. the 420's 20cm limit).

You would have to read up on it, but I think the new M series Auto Bi-pap also gives you AHI information right on the LCD.

The M series (without humidifier) is about the same size as the 420.

Suggestion: Knowing the design of the M series humidifier, based upon your pressure, I highly recommend that you consider the F&P 150 Humidifier for use with the M series Bi-pap. The M series humidifier works almost too good even at the lowest heat setting, add 19cm pressure and you may just get too much moisture from it. I'd think the HC150 would be easier to control the moisture level and prevent rainout.

The Auto Bipap costs about twice as much, but look at it from a health stand point.

Another possibility is that the 420E is designed to lower to 8 when it hits 20 for more than a hour in the auto mode as a safety feature as shown on page 11 in the Clinician manual. Where you able to read the display when the machine shut down? A 01 is a major leak and a 03 is a reduction of supply voltage. It does not make sense to run the 420E at 19 in auto mode if that the starting pressure and I would run in CPAP mode. Depending on the mask type you can have large mouth leaks , I would at that pressure level. You may need a stronger machine.