PB420E IFL1

"Most" of the 420e users in my house (1 out of 1) had to turn IFL1 off for aforementioned reasons.

Snorque, I'll be out of town for the next week (starting way too early tomorrow), but if you have software issues, PM me and perhaps we could meet up (being a semi-local and all).

WillSucceeds caution is well placed - the warning bears repeating:
People shouldn't change the defaults unless they definitely know what they're doing.

I'm sure Snork and loonlvr know, but there are many unknow beginners reading this forum - people who change the IFL1 write about it, those who don't are probably silent - they might in fact be a silent majority....


O.

Well said O. I'm sure that the default is the correct setting for most. We are probably mostly hearing from the abnormals (like myself!) in this case. I may have had a situation that was a combination of my unique breathing pattern and mask leak.

The upside of APAP therapy with the control capabilities of the software is that an educated user can tailor their own treatment. The downside would be the case where someone who hasn't made the investment to get educated starts making guesses as to how their machine should be set up. So, you're right, O, caution needs to be exercised in this area.

Jim

loonlvr wrote:How can it not be true if it "SEEMs" to him this is the case. He did not use a definitive statement. And add me to those who shut it off and immediately got better results. Of course, it will take a week to see whether its a fluke and a 1 nite occurence. But i'm hoping.

Yes, I was VERy careful to say "seems". I am also running "blind" at the moment, without the ability to look at and analyze my actual results, so I can only go by "feel".....which is back to my point that I can't believe they don't give patients the monitoring capability more freely.

And I DO feel justified about whining about my APPARENTLY DEFECTIVE machine. Sure its nice having an autoPAP, but getting rid of that whine has been like stopping whacking yourself on the forehead with a hammer...you only realize just how bad it is until after it stops. No wonder I have been still having a suprising amount of day time drowsiness, in spite of everything working correctly and all the numbers being good. Having my sleep disturbed by an exceptionally noisy machine has been disturbing my sleep.

I took a noise pollution class many years ago in engineering school. One of the points I remember was that the sound frequency of a mosquito is exceptionally disturbing to us humans. And thats pretty much the frequency of the noise coming from my Remstar Auto. The 420E seems to be a slightly lower frequency.

I hear ya!

ozij brought up the most pertinent post by -SWS regarding IFL1.

For your reading pleasure, snorkster, here's some more invaluable info -SWS wrote about the other two "advanced" settings on the 420E:

WillSucceed, IFL1 as a trigger corresponds to the Silver Lining response graph entitled "runs", which is abbreviated nomenclature for "flow limitation runs". Several flow limited breaths are scored as a "run". The IFL2 trigger will correspond to the Silver Lining response graph entitled "Hypopneas + FL". IFL2 is described as a trigger for "flow limitations with amplitude decrease" and "amplitude decrease" is a term most often used in sleep science to describe "hypopneas".

That "IFL1" trigger was always present in PB's two previous AutoPAPs (418A and 418P). It simply has a new name, "IFL1" on the 420e to make room for their brand new trigger called "IFL2". On both old and new PB AutoPAP models, apnea and hypopnea triggers are mandatory.

Some people mistakenly believe "IFL2" to be a hypopnea trigger, but it is not. Rather it is a very unique trigger for flow-limited breathing patterns that are concomittant with "amplitude reduction" or hypopneic breathing waveforms. That is apparently a manifest sleep disordered breathing condition for which PB specifically wanted a "tailor made pressure response". Note that design-wise all three of these parameters might have been algorithmically automated based on sound pattern-recognition criteria. As you see new models of AutoPAPs come to the market place, bear this in mind.

That third adjustable parameter is really best thought of as an AutoPAP pressure-response "safety limit" or "safety cap" to help in the avoidance of pressure induced central apneas (which can easily escalate in some patients, manifesting in a condition referred to as "runaway" central apneas). This "command on apnea" setting is defaulted at 10 cm on the 420e. That 10 cm default limt has very sound statistical basis across the apneic patient population with respect to air pressures at which central apneas are known to manifest in significant numbers.

There are only two scenarios that I can think of in which a therapist would need to adjust this "command on apnea" parameter: 1) significant occurences of pressure-induced central apneas at or below 10 cm (in which case the patient might ultimately require a BiLevel machine specifically designed to "treat" central apneas), or 2) a patient requiring more than 10 cm pressure to reactively (not proactively) clear his/her obstructive apneas and that patient shows absolutely no signs of inducing "runaway centrals" at those higher "apnea responsive" pressures.


That quote was from the thread:
Jan 11, 2005 subject: Bman: Spirit Overnight Indices

Thanks for the more in depth explanation RG!

IF I am reading this correctly and in light of my doctor telling me to "ignore hyponeas" in MY CASE, it sounds like indeed turning off the IFL1 is the correct thing to do...in MY case.

Of course once I get the software and can carefully analyze the overall results, combined with how I feel, then I can be much more sure of the decision.

Interesting that as patients we are in general expected to exercise much more caution and thoroughness than the actual sleep doc, the average DOCTOR probably not even knowing a IFL1 setting exists much less figuring out what the setting should be, yet that is who the trigger was aimed at. Pretty sad how little effort sleep docs are putting into their career in general.

loonlvr wrote:

How can it not be true if it "SEEMs" to him this is the case. He did not use a definitive statement.

The thing that worries me about the statement that snork1 made

But the bottom line for us users is that quite a few people, it SEEMS like MOST on this forum, find the PB420E seems to get "stuck" at high pressure if that setting is ON.

is that it gets read as a definitive statement, even if it was not intended to be one. Frankly, I think it IS intended as a very definitive statement that was, perhaps, said inappropriately.

New users of this forum are quite likely to see the comment as being other than just one persons opinion, they are likely to see it as having significantly more weight than it should have. As I go back and look at threads about the IFL1 trigger, I don't find MOST users complaining about it being a problem. Lots of talk amongst users wanting to understand it, but not many that talk about needing to adjust it. I'm worried that new users would act on this statement, or think that they are having a problem, even though they don't know what they are doing. I think that people new to treatment have enough anxiety without the fire being fueled by an off-hand comment about "MOST" users needing to adjust this trigger.

So, I commented that I see the statemant as untrue with strong feeling. It certainly does not SEEM to me that MOST on this fourm find the PB420E to get 'stuck' at high pressure if the IFL1 is on. Further, despite the intent, I worry about the impact that the statement can have.

So, yell at me if you want. I just think we need to be careful about what we say in our efforts to help one another.

Thanks, Willsucceed, for catching me on my overenthusiastic albeit misguided overstatement. Since none of us are the trained professionals we depend upon, its nice to have enough sharp people to catch us when we overstep our bounds and don't look at the big picture, or miss something.

In my rush to throw out my opinion, I did not point out a number of assumptions that I made before I would even consider TRYING it with the switch off, which includes actually having runaway pressure, and having hypopneas be an apparent non-issue for me (according to a doctor) based on oxygen desat numbers, and my plan to verify the difference of having the switch off or on with software readouts from the machine. (as soon as I can get the RIGHT cable and software from my trained professional support staff).

I still think we have better odds "guessing" than through the "professionals" that don't even know the machine HAS a software switch...of any kind. Heck, my DME and doctor would be lucky to be able to find the switch on the humifidier...... and they would certainly NOT want to be "bothered" by having to figure out what that switch SHOULD be for me. Sad as that may be.

But you are correct. "Proceed with caution" is a good suggestion. Maybe I need to add a full set of disclaimers as my tag line.

Snork1
I can't agree with you more about the "professionals" who should know more about these machines than we do but, sometimes seem to know less. Absolutely without doubt, if it were not for the clever folk on this forum, I'd be in big trouble even now as my sleep quack wanted me at a pressure of 15 --my autopap, which I fought for after learning about autopap on this forum, says I only need 8 most of the night. I honeltly don't know what I would have done if it were not for the education and support that I received (and still receive) from folk on this forum.

It is because this forum is so valuable to all of us, especially when we are new to treatment, that we must be so cautious. Your comments, Snork1, are as valuable as anyone elses; all of us need to keep making sure that our comments are balanced and fully explained.

Thanks much!