420E Strange Behavior

On several occasions I have seen my 420E drop to a low pressure as if a large leak was present and then go up towards the high end of my pressure and sit there even though I am breathing and my Activa mask has no apparent leaks. One time recently I was awake before this started and it seemed that taking a deep breath all of a sudden set this in motion. I actually couldn't get to the panel fast enough to see if it rebooted or just was behaving like a large leak, but seconds later it came right back from this low or off state and went a couple of CM higher than my base pressure and sat there. I continued to take several breaths and waited a bit and it wasn't coming down. I shut the machine off and turned it back on and it behaved properly again. I have seen this type of behavior happen at least 4 times since I had this machine. I have had it for almost a year. Has anybody else ever seen this behavior ? Does anybody have any thoughts on this ? Thanks in advance.

Which mode is the machine on? What pressure or range?

Do you have the software? What does the software show? Has this ever happened when you were asleep, or only when you were awake and just turned it on?

Your profile shows you have Respironics equipment - I assume it has to be updated.

O.

Hi,

I use it in APAP mode, range 14 - 18. I can't tell exactly which days because I didn't note then down at the times and I been having some challenges with parallels, Vista and SL3. I downloaded the data tonight and looked at it for the whole time period in there and nothing stands out. My numbers usually are between 14 - 15.5 cm. My apnea is really bad and without pressure I will wake right up fairly rapidly. It never has happened when turning the machine on. Usually after 6 to 7 hours I will usually wake up when pressure is dropping and half asleep pressure will rise and be higher than normal. Only early this week was I already awake and took a deep breath and this set it off, I was slightly more awake this time so I observed the deep breath made the pressure drop immediately and while I tried to lean over and look at the display the pressure rose to 16.5, 17 and 17.5 and I watched this while breathing expecting it to go down. It didn't so I power cycled it after a bit of observation. I have both a 420 and an Mseries. I like the 420 because mine is quiet. With the 420 I show very few Apneas, but I see lots of runs and some hypopneas.

Thanks

My answer is a qualified yes.

1. On one machine, the machine's sound changed, ther pressure dipped way below minimum to about 1.5 or so as I was falling asleep. It was very frightening, and showed clearly in the SL3 data. The machine was under warranty, and I had it replaced. It never happend before, nor did it happen on my new machine.

2. When awake and taking forceful breaths (in and out) in "testing mode" so to speak, I can see the pressure go up, or down - not dramatically.

What happens when you're awake is not a reliable indicator of what happens when you're asleep - so the pressure not dropping when you're awake doesn't mean much.

I suggest you make sure to track your data nightly - and if the pressure ever drops below the minimum - without you having a leak - that's a malfucntion and the machine should be replaced. If you're sure this is what is happening (when you're asleep) then maybe you shouldn't even wait.

Howvever, you may be waking and responding to an apnea caused by the pressure being too low. Try setting the Initial presssure at what the machine gives as you recommended 90%. This will keep it from dropping too fast to the minimum, and will bring it up to the initial very quickly if you're below it. By setting minimum to equal the initial as it is probably set now, you're basically setting the machine to slow response when going up, and faster when going down - not something you want when your minimum is less that the recommeded.
Therapy will start for a while at your initial pressure, and the pressure will drop when the machine figures it's safe to do so. If your (new) initial is too high for comfort, use the ramp.

Also, check to see that your power supply is plugged in firmly on both sides. The machine side of the power supply plug has a habit of working out, and jiggling when you toss and turn - and you get sudden, surprising interruptions when that happens.

O.

Next time it happens check how hot the power transformer is getting, if it is hot to the touch it may be getting ready to go south on you.

Make sure your filter is clean on the back of the machine.

Make sure the smaller clear hose is connected on the machine securely.

Thanks Guys Do any of you have a clear definition of initial and minimum. I read the PB manual. I thought initial was what the machine went to when you turned it on and interpreted minimum as the lowest you were ever going to permit the machine to go. If initial has ongoing relevance, why would the machine go lower than initial ? I am a bit confused and even initially reading the manual I don't think it was that clear.

Do any of you have a clear definition of initial and minimum.

viewtopic.php?t=30201

O.

On the 420e the Power Supply is on th limit at high pressure settings, a better power supply can help, it did on mine.

Billy

Thanks to all, I had my 420e replaced and the new one hasn't misbehaved yet. I will try the power supply replacement if the problem occurs with the new unit.

Thanks for the update, Brian. Good luck in your further therapy.
O.