BIPAP AUTO-SV SETTINGS HELP

Banned wrote:... In a very subjective sense, the VPAP Adapt SV 'feels' more comfortable than the Auto. ...

That is also my impression. Though I only used the BiPAP Auto SV unit in the sleep lab. I found it a bit alarming how it works. Essentially, it felt as if it recognizes the pattern of breathing and attempts to help smooth that out. Thus, during the sleep study I noted several instances (after it aroused me) where I would have a breathing pattern that had several normal breaths and a deep breath or two, and so on. When I would miss a breath it would try to replicate it. This "follow the leader" approach would awaken me.

However, the VPAP Adapt SV unit appears to measure my ventilation volume. When I fail to breathe it gently increases the volume to reach the target level (based on my previous breathing pattern). Since it is being more proactive, it tends to more smoothly increase the pressure.

Again, those are just my impressions. Both machines yield the same wonderful results.

Re using one or the other machine (Bipap AutoSV vs Vpap Adapt SV).

When I 1st read about the SV type machines I was technically impressed with the Vpap Adapt SV & its use of proximal sensor, dual stage dual impeller. I had used Vpap III machines & while I liked them they whined so much my wife would never stay in the same room longer than 1 night so I back then , kept using my KnightStar PB330 a machine I did & still do, 'like very much' as being an outstanding and advanced, small, quiet, configurable device. It's only problem for me was it didn't record nightly data. The Vpap IIIs recorded the best nightly data I have ever extracted from any Bilevel but were unusable for any time due to the whine issue.

I was able to obtain a Bipap AutoSV 1st & having previously owned some other Bipap Bilevels models (Pro II, S/T Grey Model, Bipap Auto) & having had problems with most of them & their habit of switching from Ipap to Epap too early (for me), I was not at all optimistic that the Bipap AutoSV would be any better. I had come to the conclusion that the Bipap algorithm (Auto Trak) that tracked flow was not up to the mark for people who were prone to excessive nasal constriction and hypopneas but worked fine for the people without those issues.

The Bipap machines (prior to the M series) had a very clever & sophisticated 'air valve' separate from the blower motor, that could accurately adjust flow in milliseconds but the sensors & algorithms available in the early days didn't seem match its control ability. The Air Valve is still used in the expensive top-of-the-line Bipap AutoSV & Bipap Gray model. Today the sensors & algorithms seem quite able to drive it to its best effect. I would go as far as to say that in its day it had no parallel & was ahead of the sensing technology that sought to exploit it. But, the advent of newer ultra advanced composite blowers/controllers have caught up with it.

I set the Bipap AutosSV machine with Epap=10 & IpapMin=13 & IpapMax=20 & RiseTime=3 & BPM=Auto. This approximated the settings on my trusty Knightstar PB330.
From the 2nd night of use I was delighted with the machine & how it performed (1st night was a washout due to the machine's alarms that I didn't know how to override). I was so delighted that I wrote a lengthy series posts here starting from the begining of use & I am sure many readers thought I had gone to heaven & was on a terminal inside the pearly gates - I started calling the Bipap AutoSV my 'Dream Machine'. I used it pretty well continuously for about 9 months. I had the best 9 therapy months I can recall, it greatly exceeded the satisfaction I had been getting from my dear old Knighstar PB330. I noted that on a typical night the SV algorithm would go to 20 CMs about 12-16 times. This told me the machines was seeing my Peak flow drop below target quite often. My PB330 Bilevel couldn't do anything about that as it had no SV algorithm. This SV boost convinced me that many people might find they were going through the same possibly inadequate ventilation using typical bilevels as the traditional bilevels don't monitor & manage how effective your volume is they really are pre-programmed to behave a particular way in the expectation they will deliver & just do it irrespective of what your actual moment-to-moment needs are in terms of target volume/flow and the reality is these change many times in the night.

Some time later I obtained a Vpap Adapt SV. Perhaps a couple of months after starting on the Bipap AutoSV. When I got it I was keen to try it BUT could not stand it any longer then 1 -3 nights before giving up in frustration & going back to the satisfaction of the Bipap AutoSV.

My issues with the Vpap AdaptSV were:
- It caused no end of mask leaks (I was using a Mirage Ultra F/F mask at the time) -- these drove me nuts !!!
- The pressure changes were very quick & forceful, I began to think of it as the 'Respiration Nazi' -- "You will breathe the vay I tell you to breathe - You haf nooo choice"
- The machine was leak intolerant (I had heard this many times & boy were they right)

The pluses
But, the machine was sooo quiet my wife would ask if I had it on.

I put the rapid pressure cycling down to the fact that the Vpap Auto SV continuously samples the pressure at the mask (via the proximal sensing tube) & any variation it decides is needed it can deliver instantly using its new low inertia dual-stage dual-impeller blower. Then it occurred to me that anyone who had a heart condition & was having respiratory complications like Cheynes-Stokes Respiration, or some other form of erratic/periodic breathing that included centrals, this machine would sort them out come hell or high water. I suspect there are many folk with SDB who need a respiration nazi to 'assist' them in controlling their breathing !.

So given what I said above, why is it that today I tend to use the Vpap Adapt SV more than the 'Dream Machine' (Bipap AutoSV) ?

The 1st step I took after the initial frustration with the Vpap Adapt SV was to buy a new Resmed mask based on the (correct) theory it was designed to work better with the Vpap Adapt SV than the older Ultra Mirage F/F did. That was a smart decision. Because, I then found that if I persevered, the Vpap Adapt SV got better & better. Leaks came under control. But, I still do find that if I hit a period of mask leaks for whatever reason, the Vpap Adapt SV therapy goes off the rails. The Bipap AutoSV is *far more tolerant* of mask anomalies but the down side of its tolerance is that you can think it is all going very well (the data from the machine tends to support this belief) while you slide downhill & start to feel muggy. I had an episode over 3 days while using the Bipap AutoSV where my leaks were massive - a big black bar right across the chart & for 3 nights or so in a row, yet I was sure I was sleeping well & even commented in one of my posts here at cpaptalk as to how great the machine was even when leaking massively. I later had to report how wrong I was.

What I did notice with the Vpap Adapt SV vs the Bpap AutoSV is that I didn't seem to sleep as deeply as I did with the latter. But, despite this perception of light sleep, I was always able to wake early & be ready to get going. Over time, that feeling was what kept drawing me back to the Vpap AdaptSV. I was always that bit more ready to get up early while using it. It was in some ways a strange situation, I instinctively preferred the Bipap AutoSV but found I was leaning towards using the Vpap Adapt SV even is at times I got irritated by it.

A year later I would now say that I can almost not tell the difference between the machines other than the Vpap Adapt SV is still leak intolerant. I am convinced we can all train ourselves to adapt to some quirks in these machines. I can't say that I notice the light sleeping aspect anymore. It seems to me that the sleep from either is sound and similar. This conclusion about how similar they have become is a fairly recent one.

I once described the Vpap Adapt SV as being like a high quality - high performance sports car that goes exactly where you steer it & can spin on a dime. The Bipap Auto SV is like a luxury cruising car with softer steering & suspension. It is not as aggressive in its control of your breathing & is far more tolerant of leaks but, you can think all is going so well when it isn't whereas with the Vpap Adapt SV if leaks are excessive it behaves so badly you know something is wrong & are forced to do something about it (even if on occasions for me, that was to swap back to the Bipap AutoSV ).

Hope this info helps put one person's views into some SV perspective. I still enjoy them both. It is worth noting that I run the Bipap AutoSV 1 CMs higher for both epap & ipap than I set the Vpap Adapt SV to & this is because I was noticing a difference. I ran tests & proved to myself that the Vpap Adapt SV with its proximal sensor tube, was able to more accurately know what pressure was being delivered to the mask whereas the Bipap Auto SV estimates it & is usually 1 CMs lower at the mask than what the LCD says. I did these measurements with a dial manometer & anyone can repeat them. So, I set the Bipap AutoSV to Epap=11 & IpapMin=14 & left IpapMAX at 20. The pressure at the mask then matches what I am used to with the Vpap Adapt SV.

I am tempted to try experiments where I limit the SV pressure rises to say 17 CMs (IpapMAX) & see if over time that impacts the otherwise good results. I am interested in the benefits or lack of ?, from the machine going as high as 20 CMs so quickly. I certainly don't feel I notice any rapid changes.

DSM

Crowpat, One thing I guess I am thinking is that I am sure if you switched to a Vpap Adapt SV, you might feel that the 'respiration nazi' has taken over compared to the Bipap AutoSV, but for some of us, I think it can be a good thing, at the right time. I do switch between the 2 machines after a period (2-3 months) & find that is actually helpful

As promised here are the three days of charts at 13/13/13. They are not very pretty with unacceptable PB.
I can't stay at these settings - feel rotten today.
http://www.afsashoot.com/PAT1.html

CROWPAT wrote:As promised here are the three days of charts at 13/13/13. They are not very pretty with unacceptable PB.
I can't stay at these settings - feel rotten today.
http://www.afsashoot.com/PAT1.html

CROWPAT, I would suggest going back to your previous favorite BiPAP autoSV settings for just as many days as it takes you to subjectively feel as you did before these experiments. The primary purpose of this thread, IMHO, is to gradually and cautiously discern treatment patterns toward improved results. On that basis, these experiments should literally take weeks. So reader entertainment value and instant curiosity-gratification are not legitimate objectives for this thread.

With that said, the above treatment failure was a huge success. Let's put your above comment together with your observation I have below:

CROWPAT wrote:The one thing I have noticed on the BiPapAutoSV is that when my "Breathing on my Own" number is 99.9% I feel better even if some of the other numbers are not as good as usual.

Focusing on reducing an AHI of 2 down to 0 should not be our primary concern as we methodically perform CPAP, BiLevel, and SV parameter variation tests--- hoping to discover treatment patterns that make you feel better. Rather machine-scored PB and subjective assessment should probably be our primary focus in your experiments. That 99.9% spontaneous-breathing target can be helpful but sometimes misleading as well: some BiLevel users consistently or intermittently need a machine backed up rate to avoid those nights having been even worse. On that basis, your parameter variation tests specifically dealing with backup rate might cautiously explore both a wider and narrower window of control.

But we still have the majority of CPAP, BiLevel, and SV parameters to cautiously isolate and explore. As we experimentally attempt to isolate your response trends to those individual machine-parameter variations, we might start to build a useful picture of which machine-based parameters yield highest dyscontrol and following-day discomfort response rates with respect to deviation from optimum settings. Speaking of caution, I would like you to get a general health check from your doctor. And I would like you to tell your doctor exactly what you are up to. Please give him an opportunity to raise the white flag so to speak. Please give him the opportunity to raise any white flags in light of your health checkup.

At this point, CROWPAT, you might choose to abandon further CPAP modality experiments altogether, or you might choose to cautiously explore lower fixed pressure. I would not recommend exploring higher fixed-pressure since you present a very clear pattern of PAP induced central dyscontrol and characteristic following-day biologic discomfort at that setting of 13 cmH2O. The objective of exploring lower fixed pressures would be two-fold: 1) to discover the comparative benefits (if any are discovered) of "permissive flow limitation" as I have quoted near the bottom of this post, and 2) to discover if a pressure lower than 13 cmH2O might serve as a less-disruptive obstructive-addressing base pressure for your upcoming BiLevel and SV parameter variation tests.

Again, my advice is to sleep well at your previously-determined best settings for several nights. We need your subjective feeling of daytime energy and your overall subjective assessment of biological wellbeing back to that same baseline feeling that you were hoping to improve. Subjective assessment of "physical wellbeing" is probably far more key for CSDB/CompSAS individuals than those of us with ordinary OSA.

-SWS wrote:As long as sleep and respiration stay reasonable, here is rationale for exploring a lower fixed pressure (emphasis mine in red):

[u]Recognition and Management of Complex Sleep-Disordered Breathing-[/u] by Geoffrey S Gilmartin; Robert W Daly; Robert J Thomas wrote: Avoiding Pressure Toxicity
Patients with complex disease are sensitive to positive airway pressure, and usually flow limitation cannot be eliminated without worsening periodic breathing or inducing central apneas. An immediate worsening with bilevel ventilation may be seen, consistent with an effect of induced hypocapnia on the peripheral chemoreceptors. One approach is 'permissive flow limitation' - allowing some obstruction to persist and thus avoiding the worsening of control dysfunction.

If "permissive flow limitation" can manage to significantly reduce your PB and biologic discomfort, then a subjective assessment comparison at that point (against SV modality) is probably a worthwhile endeavor. However, there is the distinct possibility that "permissive flow limitation" via lower CPAP pressure will not sufficiently reduce your PB or biologic discomfort. If we knew the outcomes of each pressure-treatment experiment in advance, then they wouldn't really be "experiments" toward desired treatment gains.

Comments?

I recently had a full physical and all was well with me - good doctor. There has not been any change in observed arrythmias during this effort.
I have known for some time that centrals appeared when I exceeded 13. Prolonged SV use may have caused those centrals to now show up at a lower pressure.
I will go back to 12/14-22/Auto/Rise3 for a few days to get back to normal. Prior to these experiments I was at Rise 6 (max), but comments on this thread caused me to try a lower setting. Rise 3 seems to be tolerable now, whereas it as not a year or so ago.
Do you suggest trying fixed 12 once I get normalized again?
Thanks MUCH again for trying to get me right. I will report back with graphs on Tuesday AM if not sooner.

Crowpat,

Those charts are very helpful. The trending in Av peak flow & Tidal Volume are well worth noting. They should help as a benchmark for when you feel good vs bad in the daytimes. The logical answer would be that the higher the Av peak flow & tidal volume, the better you *should* be feeling. The charts with Av peak flow at 30 & Av tidal vol at around 550 look to be when you are getting best therapy.

It seems that going on straight CPAP at 13 & 14 introduces lots of 'destabilized' breathing (PB & hypopneas as well as apneas (which could be central)).

Good luck & keep up this valuable test programme.

DSM

CROWPAT wrote: Do you suggest trying fixed 12 once I get normalized again?

That is what SWS is suggesting. With concurrence of your doctor, of course.

Banned

I will do the 3 nights and then give a try at 12/12/12.

CROWPAT, if it were me I think I'd start my downward pressure search at 11/11/11---in light of what happened at 13/13/13 (pressure toxicity).

If "permissive flow limitation" worked well for all CSDB/CompSAS patients, then it would be the end-all treatment method. Unfortunately it is not. "Permissive flow limitation" apparently works well for some. At lower pressures the obstructive CSDB/CompSAS component tends to be more prominent; at increasing pressures the central CSDB/CompSAS component emerges as more prominent. The pressure treatment objectives for those two are thus diametrically opposed: residual obstructive adversity decreases as constant pressure elevates; however, machine-induced central adversity increases with pressure elevation.

So if CSDB/CompSAS obstruction worsens at lower pressures while central dysregulation worsens with higher pressures, then the question for anyone endeavoring "permissive flow limitation" is: "What are the resultant or combined severity effects of those two pathophysiologic components at some middle-zone or compromise pressure?"

If a middle-ground pressure can be found in which the convergent severity of both CSDB/CompSAS components are tolerable, then "permissive flow limitation" may be a viable treatment method. Conversely, if the aggregate or convergent severity of those same obstructive and central components remain excessive at all middle-ground pressures, then "permissive flow limitation" will not suffice as sole treatment method. Or so this layperson would attempt to cautiously reason...

CROWPAT, do you happen to have access to your titration pressure table(s) from past sleep studies?

Your command of the language and ability to communicate complex issues is superb. I understand what you wrote and thank you.
I do not have the original 2002 sleep study report and do not know if I can get it since the doctor quit practicing. I do have the 2006 and 2007 reports. I just reread them to confirm that centrals appear at 14 and obstructive apneas stop there. That confirms what you wrote in spades. I also found in the 2007 report that ASV was used for 80 minutes during that study with no OA at ASV pressure of 7; however, breathing appeared to be irregular on ASV. No PLM in either study and O saturation remained about 90% throughout the night. I used Ambien during both studies so that I could sleep

CROWPAT, as you cautiously decrement fixed pressure, your "permissive flow limitation" search should entail your own unique and currently unknown tradeoff: increasing obstruction intentionally exchanged for decreasing central dysregulation. Thus as fixed pressure gradually goes down, obstructive AHI will probably elevate.

When it comes to CSDB/CompSAS, we can't be certain that an even tradeoff ratio of one obstructive AHI component for one central AHI component occurs regarding following-day symptoms. There just might be more presently unknown physiologic factors and unmeasured symptomology at play with respect to the central of those two CSDB/CompSAS components. And there seems to be at least some vague and anecdotal evidence that outstanding central dysregulation just might be more symptomatically problematic for CSDB/CompSAS patients than an AHI-equivalent outstanding obstructive component. Sleep medicine seems to be grappling for better measurement methodology regarding both CSDB/CompSAS pathology and symptomology. That is the basis for my previous comment that subjective assessment is probably far more key for CSDB/CompSAS individuals than those of us with ordinary OSA.

Anyway, your obstructive AHI might climb or even leap as you experimentally decrement constant pressure. If your AHI leaps wildly along the way in your downward pressure search, then this portion of your parameter variation testing should be discontinued IMO. If anything at all does not feel or seem right, then once again you should simply resume your most recent-determined best BiPAP autoSV settings---even in the middle of the night.

On the other hand, you might get lucky enough to discover that as your obstructive AHI increases slightly, your following-day sense of physical wellbeing improves. If so, then you might be a CSDB/CompSAS patient for whom "permissive flow limitation" actually works. Along the way, we might also roughly discern a least-disruptive pressure for subsequent BiLevel and SV parameter variation tests.

CROWPAT wrote:No PLM in either study and O saturation remained about 90% throughout the night.

Do you have access to a recording oximeter? If not, you can get a useful one now days for under $100:
http://www.semedicalsupply.com/cms-50d_plus.htm
http://www.echostore.com/cms50d-plus.html

If your baseline SpO2 still consistently runs at 90%, regardless of your optimal or best xPAP settings, then you might ask your doctor to experimentally hold your nocturnal SpO2 baseline higher with an O2 bleed. That seemed to work well for BleepingBeauty, whose SpO2 baseline also ran low. Most CSDB/CompSAS patients manage to maintain a perfectly normal SpO2 baseline. So an O2 bleed is pointless in those typical CSDB/CompSAS cases when O2 baseline is already normalized. There is room to speculate that normalizing your O2 baseline (and thus normalizing baseline O2/CO2 ratios) just might positively affect your daytime symptoms.

SWS

This is proving a very informative & interesting process & your comments make great sense. It seems to me that for some SDB 'patients' that tuning the settings to seek ultimate daytime satisfaction & well being trumps choosing settings just to achieve scores (such as AHI & RR).

I would like to ask you to add your thoughts on the value of targeting to peak flow / tidal volume / good RR - are these values a good indicator of progress ? (allowing that each of us surely has an 'optimum' band of peak flow & tidal volume / RR that we will best benefit from).

Following this line, there must surely be a level where the nightly data is showing sub-optimal peak flow/tidal volume /RR for the given individual & there must be a level where these can be pushed too high/hard ?. If these values in particular are a critical focus, & it was agreed that balancing greater levels of peak flow / tidal volume / RR against what harm too high a level will do, what are those likely harms ? (am saying this knowing that induced centrals are a very obvious one & clearly applicable in Pat's case & too high an RR indcates other likely problems).

DSM

JohnBFisher wrote: So, more veggies and proteing and fewer carbohydrates can help. Boring, but it helps.

John,

I read a comment like this, and I shake my head. I gave up all grains, all potatoes, all starches, all sugar, except for the ones contained in properly prepared (homemade) yogurt, fruits, and vegetables which are not mega-carb over eight years ago.

My diet? The Specific Carbohydrate Diet, created by Elaine Gottschall. It saved my life.

And I assure you that my food is not boring. Grains and potatoes are what's boring. Not meats, fish, vegetables, spices, and fruits. Oh, and I can, and do have pizza... made with an almond flour crust, or, if I want to go lighter, a pecan souffle bread crust, and without a sugar-laden commercial tomato sauce. Yum!

dsm wrote:your thoughts on the value of targeting to peak flow / tidal volume / good RR - are these values a good indicator of progress ? (allowing that each of us surely has an 'optimum' band of peak flow & tidal volume / RR that we will best benefit from).

Following this line, there must surely be a level ...

That's not a "must surely be" type assumption for CSDB/CompSAS in my mind...

The measurement implication of what you propose seems to entail that: 1) transient-domain CSDB dysfunction itself is primarily a function of sustained ventilatory characteristics, and/or 2) transient-domain CSDB dysfunction is primarily reflected by those sustained ventilatory rates and averages.

I don't think either happens to be the case for CSDB/CompSAS transient-domain dysfunction. I do think those ventilatory rates and averages type benchmarks you mentioned work very well as primary feedback variables for sustained ventilatory problems---the likes of certain CSA, hypoventilation, COPD, etc.

And I also think contemporary medicine tends to rely on sustained ventilatory measurements more heavily for sustained ventilatory conditions than CompSAS/CSDB---which is in all likelihood an inherently chaotic disorder. In other words, I don't think science can consistently rely on "optimum" ventilatory-parameter sweet spots when it comes to avoiding chaotic CompSAS/CSDB. But I suspect practitioners tend to recognize that all relevant non-transient domain parameters should at least be kept in their respective "normal" ranges to avoid the worsening of chaotic respiratory dyscontrol.

Hence my comment about CROWPAT's 90% SpO2 baseline. That's one rate or average parameter that just might be worth a closer albeit perhaps experimental look by the doctor.

You two are WAY above my understanding of CSDB, but I appreciate all of your comments and information.
Do either of you have experience with the oximeters at the links above? My previous experience with oximeters was not good - very uncomfortable to have them on my finger. Newer versions use a strip taped to the finger that is much less confining and far more comfortable.
My conclusions from above: Lower pressure that yields more OA and little if any CA may be good and result in better "feeling". It sounds logical and I am more than willing to try anything to get there. I sincerely doubt that supplemental oxygen is necessary in my case as O readings have been good whenever I used an oximater day or night. I am willing to pay for one to help diagnose and remedy my situation, but don't want to buy something that is so inherently uncomfortable that it will further disrupt my sleep. Comments?