Bman: Spirit Overnight Indices

[wading thru the muck!]

Hi SleepyGuy,

It's my understanding that the Spirit is very sensitive to moisture in the circuit. If you have this condition it may be causing back pressure that is being interpreted as a hypopnia (just a guess). I would consider having your upper limit increased to see where you might go since you said you spend a lot of time at the max. It may be that your max is set right at your required pressure but it wouldn't hurt to bump that number up a little to be sure.

Are you able to use the Vista without leaks? I have not heard good things about the Vista. If you have large leaks that may also be causing some of the problems you've encountered.

Sounds like when you can keep the mask on you've been doing well.

[-SWS]

I understand (from Rested Gal) that the 420E allows for some tweaking of the machine for those people who are shallow breathers. I think this is the "flow limitation" stuff. How does one know if one is a 'shallow breather?'

If I recall correctly Rested Gal had vast numbers of what the 420e registered as "flow runs". These flow runs caused her 420e to peg out at top pressure because they were vast in numbers, completely unresponsive to pressure, yet still managed to somehow trigger a pressure response from the 420e. Rested Gal had to turn off IFL1 and rely on the remaining 420e triggers (including mandatory triggers) to yield effective therapy. My guess is that since Rested Gal knows her own daytime breathing patterns exceptionally well, she probably surmized that her shallow breaths were the likely culprit causing IFL1 to over-trigger on the 420e. That's a really good guess in my estimation, but there are other possible causes as well.

Can you offer any comparisons/suggestions regarding the 420E vs. Spirit in terms of adjustablility?

The 420e has three notable adjustable parameters the other models do not: 1) IFL1 (flow limitation runs), 2) IFL2 (individual flow limitations that are concomitant with hypopneas), and 3) command-on-apnea. Those first two are optional triggers that jointly yield four unique combinations of treatment. That last one is a pressure response "safety cap" toward the avoidance of central apneas. Contrary to popular myth, command-on-apnea is the 420e's primary means of avoiding central apneas. With a sensitivity rating of 62%, CA detection via measuring cardiac oscillations is but an augmentary method. With the command-on-apnea setting at its default of 10 cm, most patients will not pressure-induce "runaway" centrals. However, cardiac oscillation detection will catch 62% of any and all central apneas that happen to sneak under that 10 cm safety cap. So I would characterize the 420e as a good out-of-the box AutoPAP with all its default settings. It has three additional adjustments the Spirit does not have that can either get unknowledgeable patients in big trouble, or knowledgeable therapists a great edge toward patient-specific customizations for those patients who happen to be "statistical outlyers".

By contrast the ResMed Spirit is intended as a "best statistical fit" machine that offers therapists fewer adjustments toward statistically anomalous patients. I can think of two seasoned CPAP veterans on TAS who own both the 420e and the Spirit, yet rely on the Spirit for more effective treatment. I know of one or two here who have tried the Spirit but prefer the 420e. It's important to realize that each AutoPAP model has its algorithmic strengths and weaknesses that will match up differently against individual patients across the apneic patient population. Since cortical arousals are never measured by AutoPAPs, it's even possible to achieve great obstructive (and central) sleep indices on AutoPAP brand "xyz" at the expense of too many pressure-based sensory arousals----and yet sleep and feel much better on AutoPAP brand "abc" which yields marginally higher sleep indices, yet fewer pressure-based cortical arousals. Even this latter effect cannot be generalized from one or very few patients here with respect to the entire patient population. However, this does demonstrate one very important reason that a subjective assessment must be factored in as well as sleep indices.

Just my 2 cents here. I have a Spirit autoPAP with a Mirage Vista mask. It's set for a range of 4-9.

I rarely have an AHI of more than 4 and the AI is rarely higher than zero. But when I get up in the morning I find that the machine is almost always at the maximum. Often it rises to this level after less than an hour. I don't understand why when the number of events is so low.

The machine will register hypopneas when I'm awake and have been breathing normally! I don't understand this either.

So far, I have been unable to sleep more than four hours with the machine since my nose has a tendency to close off when doing so. I'm going to try a nose pillow mask for this and check with my doctor for other options such as surgery.

But I have no complaints about the Spirit AutoPAP itself. It is masks and other things that I am checking into.

The Spirit is very proactively pressure-agressive regarding flow limitations (as likely precursors to both hypopneic and apneic events). Likely your swollen nasal passages (which are, after all, flow limitations) are trigerring the Spirit to sustain high pressure. This is pretty much what the Spirit does in response to condensation in the sensor line as well: it mistakenly detects condensation as a flow limitation or other obstructive event and tries to address it with pressure. With that said, you are going to have to get together with your doctor and somehow properly address those swelling nasal passages if the Spirit is to yield you treatment that is adequately comfortable.

Your AHI, AI, HI may be low, but the other two obstructive events the Spirit can trigger on are snore and flow limitation (neither of which are reflected in AHI, AI, HI).

[rested gal]

SleepyGuy, you wrote:

So far, I have been unable to sleep more than four hours with the machine since my nose has a tendency to close off when doing so. I'm going to try a nose pillow mask for this and check with my doctor for other options such as surgery.

Not to dissuade you from trying a nasal pillows interface - might do the trick for your problem. But, for stuffy nose nights, I have to put my Breeze with nasal pillows aside. ResMed's Ultra Mirage FF (full face) mask is the one I reach for on such nights, allowing me to breathe through my mouth. Just a thought.

[-SWS]

I'm no medical or health expert of any kind.... But I do think I recall someone posting that their nasal passages got swollen from CPAP air also. I vaguely remember them saying that they addressed this swelling by not only turning the humidification up (beware of rainout) but also swabbing their nasal passages with Ayr, which is a saline-based nasal gel.

I hope my vague memory has that right.....???

[WillSucceed]

Thanks, SWS for the explanation that you offered --> VERY helpful.
I think I ma understanding the IFL1 setting; could you please offer some detailed explanation of the other two settings OR is there an article or document that you are aware of that I could review?

Thanks much!

Just as an aside, do any of you find the 420E to be loud? I'm still trying to decide between the 420E and the Spirit and find that I "hear" the 420e much more clearly (and loudly) as I breath while wearing the mask. I've wondered if building a box of sound dampening (convoluted) foam to place over the 420E might help.

[rested gal]

The 420E does seem to make a slight "rev up and down" sound while one breathes. Sounding almost as if it were breathing with you. That rev up/down sound doesn't bother me, but I can see where it might be more noticeable to some and even annoying to some. It has nothing to do with what mask one uses. It is definitely an "up/down" sound that the 420E itself makes, as you breathe. Slight (to me), but noticeable.

[Irving]

The Spirit makes that sound also. LOL

[-SWS]

I think I ma understanding the IFL1 setting; could you please offer some detailed explanation of the other two settings OR is there an article or document that you are aware of that I could review?

WillSucceed, IFL1 as a trigger corresponds to the Silver Lining response graph entitled "runs", which is abreviated 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.

[WillSucceed]

SWS:
Thanks for your time and energy regarding this explanation.
On Monday, the 420E that I have been trialing goes back to the provider: I'll have to wait a few days for the data print-out. I'll bear in mind your comments as I review the printout and, hopefully, the tech will be able to explain the data to me.
I'm hopeful that the numbers from the 420E will look better than the 6-9 AHI per hour that the Spirit printout showed. I've decided that I can get used to the noise of the 420E and will purchase it if the numbers are better than Spirit. Both the 420E and the Spirit leave me feeling pretty good during the day so, if the numbers are the same, my decision will be based on features. If the 420E numbers are better than Spirit, I'll buy the 420E.

Thanks again!
P

[bman]

sws

I am surprised to see your reply

Many thanks

I am new to internet forum and also a new cpap user

I want to improve my condition and so far slowly feeling more comfortable with using cpap etc. It is certainly a challenge.

I still have a long way to go and many mountains to climb. I am fortunate enough to have your wisdom to guide me.

I am going to follow your suggestions to try my resmed autopap in various ways and I think from your explanation a trial of 420e is also warranted later on. I think I would slowly increase my upper pressure to 15. So far I am feeling a lot better and not falling asleep easily. I think higher pressure can be quite inflating the lung sometimes. One can feel some aching chest muscles in the morning. In fact I have come across a case where the person's Chest XRays showed features of COAD(chronic obstructive airway disease) ie lung hyperinlated after using CPAP. The sleep physician did not think the cpap caused this but I could not see any other causes. I guess the question is whether high pressure can cause any sinus, lung, ear or other problems. Interestingly my severe reflux is gone with using CPAP and also I have good appetite in the morning.

I was reading an article where it quoted one in 4 persons has sleep apnoea and
I wondered whether the AHI of less than 5 is a practical gold standard figure.

I do find my machine tending to run at the higher range(may be I set the upper pressure too low) and also it tends to reach the upper pressure immediately despite I am conscious breathing and looking at the machine. I wondered I have sleep apnoea too when I am awake. Ha! Anyway will be looking through your advice very carefully to experiment with my machine.

It would be nice if I can know my ideal mask, machine etc. In fact most cpap sufferers dont even know about autopaps etc in real life or join the internet forum or just give up trying them. Many persons have make the remarks of
I would rather die than using the machine.

This posting is mainly intended to say thank you. I am also quite overwhelmed with your knowlege. Feeling very lucky indeed.

[-SWS]

Bman, after you methodically and carefully increase your upper pressure to 15, you very well may need to also slowly and methodically increase your lower pressure as well. Increasing the upper pressure will allow for heavier obstructions to be properly addressed. However, in some patients increasing the lower pressure will often be necessary to proactively address incipient and/or lighter obstructive events that don't respond as favorably to reactive pressure treatment.

[bman]

sws

shocked to see an instant reply

it's Sat 2am in Oz, thanks to your constructive suggestions,

in fact I dont need much sleep nowadays, may be deprived from sleep even during my Uni days, in fact I remembered myself always falling asleep 10 minutes into any lecture

willsucceed's figure is quite similar to mine, but my pressure is slightly higher

I find that if I sleep for 1-2 hrs without the machine despite slept well with the machine for 5 hours, I actually felt worse than sleeping well with the machine for 3 hours and then not sleeping again

one other symptoms I used to have was saliva dripping from my mouth prior to treatment and I wondered whether others have similar experience

I better go to sleep now.

[wading thru the muck!]

SWS,

Thanks for your excellent explaination of the IFL1 and IFL2 adjustable parameters on the PB420E.

Could I impose on you for a little futher explaination?

What breathing pattern occurrence would require IFL1 to be selected or deselected?

Ditto for IFL2.

Thanks, you are a Godsend to the forum

[-SWS]

Must "dequalify" myself real quick, Wader. I'm just a patient (with a completely unrelated background in design and development) making heads or tails out of "sleep therapy" as everyone here is. I dread the thought of anyone reading anything written on a message board by me or anyone else as gospel. We are literally the blind leading the blind here----and it is utterly amazing that so often the information we get here is better than that which we get from the medical establishment. I would really like everyone to take anything that I ever write about as potentially accurate information that is, none the less, also potentially wrong.

What breathing pattern occurrence would require IFL1 to be selected or deselected? Ditto for IFL2.

Both IFL1 and IFL2 are factory-defaulted to "on". Theoretically if any trigger's reponding algorithm were well-written, those triggers would never have to be turned off. They would detect a sleep disordered breathing pattern/condition, then act accordingly; they would also monitor the patient's response or short-term efficacy relative to any trigger's corresponsding algorithmically-based treatment, then make necessary adjustments. So the generalized answer is any trigger should be turned off when either: 1) the algorithm treats the patient incorrectly (event detection, programming, or statistical-reference error) or 2) when the machine presents the "correct" or "best" pressure by medical definition, yet the patient still responds unfavorably. So the SL3 graphical data charts are the best means of deciding on a case-by-case basis when either IFL1 or IFL2 should be turned off for most of patients in my opinion (see UARS/RERA exception below).

In Rested Gal's case, unabated pressure response to an "over-triggering" IFL1 was the case. Ideally the algorithm should have discerned that the machine was "pegging out" to her pressure-unresponsive "flow limitations" and yet it did not. Turning off IFL1 in her case was a matter of compensating for a less-than-ideal algorithmic response. Tightly swollen airway tissue that is densely packed with blood (hence swollen) is but one example of a flow limitation that would not be adequately responsive to pressure treatment. Misinterpreted shallow breaths or atypically presented incipient obstructions can easily fool any algorithm as well in my guestimation. The point is that many things can go wrong with algorithmically-based SDB detection and treatment, and Rested Gal was undoubtedly very glad that she could turn off IFL1 when things did not go well, algorithmically speaking. Generally speaking, one should be able to vertically line up both discrete and concomitant obstructive events and corresponding pressure response on the SL3 graphical charts to look for obvious problems relative to either IFL1 or IFL2 triggers. There really is no point in trying to guess or predispose a breathing "type" or pattern toward predicting a malfunction of either IFL1 or IFL2 (either trigger related or response related) in my opinion. I suggest that 420e users should assume that both triggers work unless their data and/or subjective assesment tells them otherwise.

With that said, there is another altogether "trial and error" purpose for IFL1 and IFL2 in my own guestimation. Recall that UARS/RERAS are a type of sleep disordered breathing condition which the 420e attempts to address. However, of all the obstructive airway sleep-event types or conditions, these are perhaps the least predictable and the least understood by sleep medicine. There is much disagreement within the medical community about the classification of this sleep disordered breathing condition (my hunch is that it is actually several), let alone proper pressure treatment for this type of patient as well. Some of these UARS/RERA patients seem to respond favorably to more air pressure, some respond favorably to less air pressure, while others are completely air pressure unresponsive. Patients falling in this diagnostic category are a genuine "predictive wildcard," so to speak, regarding the best pressure treatment to offer in my view. Disappointingly, AHI and other simple obstructive sleep indices do not always help to reveal exactly how well these patients sleep/feel or how well they respond to IFL1 and IFL2 triggers. However, a highly skilled therapist would be able to methodically run all four binary combinations of IFL1 and IFL2 on one of these challenging patients with the hopes of discovering which if any of those IFL combinations suit that particular UARS/RERA patient best.

[WillSucceed]

SWS:
I REALLY appreciate the effort that you put into your responses and value your insight and effort. Having said that, and please forgive me if this sounds rude, but would you please just give a simple explanation in plain, non technospeak.

In simple language, what do the 3 adjustable defaults on the 420E do and what situations might require adjusting these defaults.

Thanks!