pb 420E users data advice needed (HELP) !!

[kev]

Can any of the puritan bennett 420E users on the board let me know what they think of this data, I always have a low number of apneas (0-7 in 8 1/2
hrs. sleep)

"apneas CA" always single digits and Hypopneas (FL) usually single digits

BUT...............................................my "hypopneas" are ALWAYS in
double digits : anywhere from 10 to 31.

And my "acoustical vibrations and "runs" are ALWAYS in triple digits,

This happens whether i'm in straight cpap mode or auto mode.
I have adjusted the machine many times and I can't get the acoustical vibrations or the runs (FL) below triple digits.

I greatly appreciate your expierence and advice

Kev

[John M]

Don't worry too much about the run data if you feel ok. If the machine is responding too agressively for you on run data, you can try turning of the "IFL1" setting. The machine may be responding too fast for your breathing style, and the higher pressures, in turn, could be causing you to breath more shallowly.

Another possibility is that the high hypopnea number (w/o Flow Limitation) may indicate that you are normally a shallow breather, but as long as your 02 saturation is ok, it is probably not anything to worry about (discuss with your doctor, though).

Even if your total hypopneas in 8.5 hours is 30 and you have, say 10 more events, then your AHI is < 5. (Not fantastic, but not bad, either.)

I suspect that you may see better hypopnea numbers if you set "IFL1" to off ("0"). Try a search on "IFL1 and 420E"--there's a lot of info posted.


-John

[ozij]

Hi Kev,
As John said, the foremost question is how do you feel?

But I do have some others:
What were your sleep study results?
How long did you try each configuration?
Which pressure ranges did you check in Auto mode?
What pressures did yo check in CPAP mode?
Are you satisified with your mask?

O.

[kev]

Thank you for the quick replies

JohnM : I will try switching Ifl1 to off to see if that helps.

OZIJ: my sleep study numbers were pretty bad, Although I only slept for just over an hour they recorded "64" events.

My pressure from the study is 13cm, so Itried auto mode from 13 to 20
with the same reults.
I tried cpap mode with pressures from 13 to 15, same reults.

I tried each method for about 10 days.

My mask is the ultra mirage f.f. mask, I don't breath well thru my nose and
they gave me the f.f. at the sleep study. I've never really had any problems with it except the few minor leaks everyone has.

I was lucky in the fact that I never really needed to get used to cpap or the mask, Right from the first night I was able to sleep with it for over 8 hours
and nothing has changed since.

I went and bought the auot machine on my own, my sleep center told me
"we don't use those machines here".

I figured why not get the best technoloy ? I cleverly hornswoggled a
script out of the sleep doc and bought the auto.

The machine they gave me sits in the closet for "back up" .

[ozij]

Hi Kev
Do you have a copy of your sleep study? Get it, if you don't have it, and see how the events were distributed . Did you have more hypopneas in your sleep study than apneas?

On the Silverlining screen:
Take a look a the synthesis report. Click on a single day, then look at the right pane. You have two columns of data on the upper left corner, one is the number, the other says "Index/h" and mean the number, divided by the hours you slept. This index is the important data. Is it the total you are telling us about, or the index?

The 420E on Auto mode does not react to "stand alone" hypopneas. It will raise the pressure in reaction to hypopnea concurrent on a flow limitation, (That is IFL2) and will raise the pressure when it identifies flow limitations (that is IFL1) but will raise pressure in reaction to a hypopnea that appears withoug a flow limitation of without a snore. So, if most of your events in the sleep study, and on therapy are plain hypopneas, you might be better off in CPAP mode, since the auto mode is useless in that case.

Waiting 10 days on each pressure change is a good idea, unless it makes things clearly worse. If you're basically a hypopnea person, then try changing your pressure slowly (even in .5 increments. which are possible on the 420e.

If you're not using a humidifier you might benefit from that too.

I'm not a doctor, RT, or anything like that, just a 6 month user of the 420e...
O.


O.

[WillSucceed]

The 420E on Auto mode does not react to "stand alone" hypopneas. It will raise the pressure in reaction to hypopnea concurrent on a flow limitation, (That is IFL2) and will raise the pressure when it identifies flow limitations (that is IFL1) but will raise pressure in reaction to a hypopnea that appears withoug a flow limitation of without a snore. So, if most of your events in the sleep study, and on therapy are plain hypopneas, you might be better off in CPAP mode, since the auto mode is useless in that case.

I'm having confusion, and not understanding this comment very well. Apologies if my questions don't make sense.

Hypopnea concurrent on a flow limitation means less air is getting through because the throat is closing, yes? no? And, the 420E reacts with a pressure increase, yes? no?

Hypopnea without flow limitation, but with snore, would mean that throat tissue is starting to lose muscle tone (getting floppy) and the 420E reacts with a pressure increase, yes? no?

I would think that by definition, a hypopnea means that flow of air is lessening because the airway is not as patent as it could be. So, what is a "stand alone" hypopnea?

[ozij]

Yes, its very confusing. I had biiiiiig trouble inderstanding the difference between a "flow limitation" and a "hypopnea".
The best way for me to understand it was via IFL1 and IFL2 in the CPAP's control screen. IFL1 shows you a graph of how a flow limitation looks - the shape of the flow over time changes. IFL2 shows a graph of how a hypopnea + flow limitation looks - different shape, and different height (volume I would guess).
A hypopnea without a flow limitation means less volume, without a change in the flow.

When the 420E encounters a hypopnea without the marks of a flow limitation, it does not raise the pressure. By the way, Resmed in The Autoset's three lines of defense also does not mention hypopneas as triggers to raising pressure. Like the 420E, " The AutoSet Spirit responds to snoring, apneas, and flow limitation". Not hypopneas. The reason, according to -SWS, (can't find the reference just now, but it was in a public communication) is that the machine has no way of knowing whether this "non-flow-limitation-related" hypopnea is the result of a partial obstruction, or a central hypopnea - so the pressure is not raised, to be on the safe side.

Hope this makes things clearer.
O.

Edited: By "stand alone" I mean with neither a flow limitation, nor a snore.
_________________

CPAPopedia Keywords Contained In This Post (Click For Definition): 420E, resmed, CPAP, Hypopnea

[kev]

thanks OZIJ : I will print your directions and try to put them to full use.


WILL SUCCEED : ALL GOOD QUESTIONS, i ALWAYS LOOK FORWARD TO YOUR POSTS !!

[WillSucceed]

WILL SUCCEED : ALL GOOD QUESTIONS, i ALWAYS LOOK FORWARD TO YOUR POSTS !!

'tanks, Kev. I appreciate your support!

[rested gal]

The reason, according to -SWS, (can't find the reference just now, but it was in a public communication) ...

ozij, perhaps here (of all places! LOL..surprised me, too!) --

May 23, 2005 subject: PB Good Knight 420E and hypopneas

[John M]

Ozij brought up a good point about mask.

I'm not a very good nose breather either, so I usually squirt one blast of Afrin in each nostril before I go to bed. I don't like the idea of sleeping with a full face mask without an adequate power back-up and/or power outage alarm.

Also, all FF masks are prone to leak significantly. This affects the way APAP's respond and makes a big difference in the way I breathe.

For example, I prefer the ResMed Vista for comfort, but it leaks like a sieve. This generally causes the pressure to ramp up (for massive leaks) and may trigger more problems (like central apneas/hypopneas). Whenever I see major leakage on the charts, my "Normal Cycles" number goes down to 75 to 85%, which means there are more "flow limitations". This may be because there is extra effort required to breathe, so my breathing generally becomes shallower. Or perhaps less inpiration/expiration is detected by the flow sensor and this is misinterpreted as a flow limitation. This is why I limit my upper pressure limit to about 2 cmH2O above my Rx and turn off the IFL1 setting.

By contrast, when I sleep with the ResMed Activa (it is virtually leak proof), I see no leaks, the pressure has a tendancy to stay much lower, and my "Normal Cycles" is almost always above 90%. However, when I use the Activa with IFL1 on, then my "Normal Cycles" number drops to the low 70's. So, I know for me, at least, that pressure increases triggered by flow limitation "runs" as determined by the 420E lead to more flow limitation runs which in turn leads to runaway pressure increases and poor overall treatment.

In summary, low leaks + IFL1 = off, leads to good treatment for me. Other than choice of mask, there are two other things that you can do to minimize leakage: (1) do not let the hose "hang" and pull at your mask--support it, somehow so that you do not feel the weight of the hose; and (2) wash your face and silicone face seal before going to bed.

[georgep]

Hi John M

I wouldn't recommend using Afrin on a long-term basis. The instructions say not to use it more than 3 days. For me, if I use it for more than 4 days it starts loosing effectiveness. On the 5th day it's pretty much useless. Then when I stop using it I get a hell of a rebound and am completely plugged up for 2-3 days. Also Afrin increases blood pressure and a lot of us have blood pressure issues.

My salvation was the Fisher and Paykel FlexiFit HC431. It comes with three size cushions and one of them fit me perfectly without any leaks. The only time I had a leak was when my pressure sensor hose got kinked and the machine went up to 19. Then it leaked like crazy. At my normal pressure of around 12 I have no problems whatsoever. I still use the nasal mask when my sinuses are clear. My doctor recommended using saline spray followed immediately by Nasacort and that keeps me clear most of the time.

[WAFlowers]

Kev, I find that if my pressure is too low I have more hypopneas and "accostic vibrations" (aka "snores"). I raised my lower number and achieve nirvana.

However, it doesn't sound like this applies to you. You've varried your pressure over quite a range with no solution. I'm stumped!