420E more sensitive to pressure changes than Spirit?

Janelle · Post by **Janelle** » Fri Jan 14, 2005 7:42 am

Since I have received my 420E, I've noticed that I'm recording higher pressure readings than I did with the Spirit I used for the first 3 weeks. With the Spirit my highest pressure reading was 12, with the 420E it was 14.5 last night and climbing. I pushed the middle button and it reset to ramp level of 6. I might add that the reading stayed at 14.5 even after I was awake for 15 minutes. Does this mean that the machine is not functioning correctly?

I usually average about 10.5 during the night

I'm calling my RT this morning, but I'm not sure she'll know anything. I do have an appointment with my Sleep Dr. the end of the month to go over my "titration study" --the first 2 weeks with the Spirit, but I don't think I should wait that long to address this.

-SWS · Post by **-SWS** » Fri Jan 14, 2005 7:58 am

One of those AutoPAP algorithms is likely reading and responding to your breathing patterns better than the other. One way to tell would be by comparing the overnight data from each AutoPAP's overnight chart as well as comparing how you subjectively think you sleep and feel with each machine. A third and perhaps better method would be to correlate detailed sleep event occurences and pressure responses charted by each AutoPAP against equivalent events during any PSG sleep study that you might have had.

This is going to be best sorted out by your sleep doctor and RT working together in my opinion.

Janelle · Post by **Janelle** » Fri Jan 14, 2005 8:09 am

I have noticed I sleep better with thte 420E, so I think I am getting better therapy with it than the Spirit. Since I don't have the software for the 420E (got it from the DME and they don't get software from PB since they order direct) I can't see any overnight figures. And the 420E doesn't give you any information like the Spirit does without the software.

wading thru the muck! · Post by **wading thru the muck!** » Fri Jan 14, 2005 9:09 am

Janelle,

You can purchace the software for $99 from cpap.com

Link: PB420E software

It's well worth it to see how your numbers are and also to show your Doc/RRT how the machine is working for you.

Lots of Data available including monitoring leaks which is something the RT can only do if they sleep in the same bed. HA!

Janelle · Post by **Janelle** » Fri Jan 14, 2005 1:19 pm

I'm in the process of obtaining the software and I called my RT today who is going to talk to the CPAP expert there and try to get copies of my first CPAP Titration study and see what they can find out, then will get back to me.

rested gal · Post by **rested gal** » Fri Jan 14, 2005 7:15 pm

hi Janelle,

You mentioned:

I might add that the reading stayed at 14.5 even after I was awake for 15 minutes. Does this mean that the machine is not functioning correctly?

I used to wonder why, if I woke up in the morning with an autopap registering, say 12 (when the low was set for 8 ) and I lay there watching the number for several minutes, seeing no drop off in pressure at all...why??? Why was it not moving back down to the minimum pressure set, when I was obviously awake, being still, and breathing easily?

Later I found out that when these machines go up to prevent or clear an event while we're sleeping, they are designed (I think...I may state this wrong) to stay up at that level for a built-in amount of time - not just jump back down the instant the event is cleared. I suppose that is to make sure the event conditions really are prevented or that the event really has been taken care of. Also, to prevent sudden jumps up and down in pressure - yo-yo'ing up and down that could be just as disturbing to sleep as actual events are. I think (again, not sure) that they are designed to allow pressure to go up more quickly than it will come back down. All in the interests of treating you smoothly, rather than jerkily, as the pressure gradually works its way back down, checking on your breathing periodically as the pressure creeps back down. Giving itself time to make sure it's "ok" to come down a bit more. That whole process of coming back down could last... what (somebody techie?) five minutes per cm or per half a cm, perhaps? Ten minutes per cm? I dunno. But I do think it's supposed to be gradual and somewhat slow...the coming back down.

That said (and perhaps said wrong! lol) fifteen minutes seems longer than usual for an autopap to stay up at a higher pressure while the person is wide awake. If you were just guessing "15 minutes", perhaps you watched it less time than you thought. One or two minutes of laying there watching a pressure sit on 14.5 while you are awake can seem a lot longer than it really is. The old "A watched pot never boils" adage - kinda' in reverse.

If you ever do really time it, Janelle, and it stays up there, say, 10 full minutes with not the least "first slight step back down", then I'd wonder if it was a faulty machine.

Janelle · Post by **Janelle** » Fri Jan 14, 2005 9:19 pm

This does make sense to me that the pressure would be programmed to remain at that level. I dont know the architecture of apneas or other similar events, but I suppose they could come in like "machine gun" fashion, one right on top of another and if the pressure were going down it would take that extra time to go back up, possibly missing an event.

I noticed too, that the information on the ResMed Spirit says it does not work as accurately with small tubed masks (such as the Breeze), and since this is what I was using during the trial period, except for the last week after the titration study, I wonder if this is also one reason for the lower reading on it versus the 420E. I am now using a Swift, which has a hose nearly the same diameter as the APAP hose and larger in diameter than the Breeze hose, in addition to the 420E having that pressure sensitive small tubing inside the hose.

WillSucceed · Post by **WillSucceed** » Fri Jan 14, 2005 9:35 pm

The Spirit allows you to tell it what type of mask you are using. If you buy a ResMed mask, it will say in the user manual that came with the mask, what setting to use on the Spirit.

If using a non-ResMed mask, you could try to compare the physical characteristics of the mask with those of a ResMed mask so that you would know which setting to use.

My understanding is that the Spirit does a better job "reading" the patient's individual breathing needs if it knows which mask is being used.

wading thru the muck! · Post by **wading thru the muck!** » Fri Jan 14, 2005 9:44 pm

Janelle,

Going back an re-reading this thread I'm understanding that you don't have the software for the PB420E yet? If this is the case I'll caution you not to necessarily go by what you are seeing on the LCD readout. Not to say it is not reading accurately but the better picture is to see over the course of the night what your readings were. Mine usually shows some spikes in the beginning and end of the night from mask adustments etc... Hard to say what was going on with the 14.5cm but watching the readout is not the best way to tell what's up.

Nev · Post by **Nev** » Sat Jan 15, 2005 12:25 am

I've sometimes woken with the pressure high on my 420E and tried to breathe evenly and count breaths to see how long it takes to come down. I get up to 100 or so if I do it right. If I forget to breathe regularly it takes longer. I think the machine restarts recording your breathing pattern and needs to compare a sequence of breaths with the previous sequence to make sure you are not getting a further flow limitation.

Usually I just press the reset button and go back to the ramp.

I also think that because it has the inner sensor tube it can adjust itself to a variety of masks without the need for a special setting at the machine end.

Janelle · Post by **Janelle** » Sun Jan 16, 2005 12:27 am

Update: I was watching TV tonight, wearing my mask because I was feeling a bit sleepy. Dozed off and woke up about a half hour later and my pressure was at 12. Got up did some stuff and went back to bed about 40 minutes later. Woke again at midnight and the pressure was at 16.5 (highest I have ever seen it). I sat on the edge of the bed and counted. Two minutes later it went up to 17. Another two minutes later it went up to 17.5. I then took off the mask and turned the machine off.

I think I definitely have a defective machine. Of course because it is Sunday and because the DME probably doesn't have anymore in stock I will be stuck with this one or will have to go back to renting a Spirit.

In fact I just found out I'm renting this one, when I thought my insurance was buying it, so that means a call to the insurance company on Monday!

wading thru the muck! · Post by **wading thru the muck!** » Sun Jan 16, 2005 12:38 am

Janelle,

Inspect the little pressure sensing hose inside the large hose. If is is pinched or seems as though it has a spot that may become pinched occasionally that may cause irratic pressure. I had trouble with the original hose on my 420E. It had a pinch where the small hose exited the large hose. The folks at cpap.com told me how to temporarily fix it and then sent me a new hose N/C.

Also check to see if there are any droplets of water in the little hose. This may do the same thing.

Janelle · Post by **Janelle** » Thu Jan 20, 2005 8:16 pm

I had a long talk with the Head RT at my DME this afternoon. He said the alogrithm with the Spirit and 420 are totally different and that alone might account for the various pressure readings I'm getting on the 420. He also said that the 420 will keep a pressure high for up to 5 minutes to "protect" from ending it too soon to control an event.

I have an appointment to go in an hour before my appointment next Thurs. with my Sleep Dr. for them to download everything so far on my 420, not only for diagnosing to see if the machine is functioning correctly but to take with me to the Dr.s appointment so he can have it sooner rather than later.

Hopefully I'll get some more answers to my questions.

420E more sensitive to pressure changes than Spirit?

420E more sensitive to pressure changes than Spirit?

Different AutoPAPs

Pressures

420E more sensitive to pressure changes than Spirit?