ResMed Adapt SV vs. Respironics Auto SV

[Snooze_Blues]

My second sleep study is Thurs, Mar 6. Depending on what occurs after I (hopefully) fall asleep, I may be titrated on an ASV machine.

In the last week I've read several threads on the ResMed VPAP Adapt SV and the Respironics BiPAP Auto SV doing Google searches (for "adapt sv" OR "auto sv") here on cpaptalk.com. I then created a list of features, advantages, and disadvantages for the two machines, but there was no clear revelation or winner based on superior technology since there is so much speculation and my own lack of understanding.

My conclusions can be distilled down to:

1. Both machines may or may not have unique strengths that may or may not work better for my particular issues; and

2. I don't know enough about either machine to pick one over the other regarding efficacy, even if I understood my condition completely, which I don't; and

3. I'll probably just surrender to 'the force' and accept either ASV machine (if) recommended by the sleep doctor or lab and hope they know what they're doing, because they likely know more than I.



( For those interested, here's my Pro /Con list. Comments, additions, and corrections are welcomed. ):



Purpose: Compare Adaptive Servo Ventilation (ASV) Machines

ResMed VPAP Adapt SV

Features:

Algorithm senses and calculates on both Respiratory Rate and Tidal Volume (same as the Respironics BiPAP Auto SV?).

Advantages:

Learning circuit might allow larger choice of (third party) humidifiers.

Static pressure tube sensing at mask may provide more accurate breathing data.

Leak rate table may allow more accurate measure of flow rate and hypopneas.

Dual impeller reduces possible harmonic induced algorithmic confusion.

May be better for those with lots of central and mixed apneas and CSDB (like me).

Optional ResLink data module seems superior to EncorePro (but I'm unfamiliar with it).

Disadvantages:

May not allow use of my 10-foot hose.

May not allow use of my DIY Repti Heat Cable hose and mask heater.

Mask selection. ResMed Quattro Pro alone is 100% design compatible. (Is this true?)
These masks are approved, but (anecdotally) with reduced efficacy:
Vista
Ultra Mirage
Mirage Full Face Mask Series II
Ultra Mirage™ Full Face Mask
Activa
Liberty (per SAG)

Respironics BiPAP Auto SV

Features:

Algorithm senses and calculates on both Respiratory Rate and Tidal Volume (same as the ResMed VPAP Adapt SV?).

Advantages:

Mask selection. Theoretically, all masks are equal. I can use my current mask!

Simpler hose selection (no extra little attached static tube needed) allows:
a. My 10-foot hose; and
b. My DIY 10-foot Repti Heat Cable hose and mask heater

Uses EncorePro, with which I'm already familiar.

Disadvantages:

Anecdotal reports suggest continuous maximum pressure events may occur, possibly due to inability to distinguish between mask design leak rates vs. accidental leaks.

Q. Could large leaks, or intermittent leaks with extremely varying L/min values, confuse the algorithm and compromise therapy?

Q: Could water (rain-out, condensate) in the hose, which makes that "weird hollow bubbling" or "gurgling" sound after a couple hours of operation, create weird pressure fluctuations that might be interpreted as "choppy breathing" and confuse the algorithm? I'm speculating based on my Respironic's M Series Pro CPAP machine, which consistently fails to shut itself off in this condition when I remove my mask. The "gurgling" condensation seems to trick the M Series into thinking I'm still at the other end of the hose. Of course, being set at 6 cm H2O may be part of that particular problem, too. Perhaps this is not a factor since the Auto SV algorithm is "flow based" and probably responding to "minute ventilation" measurements. Still, it seems like there could be some complications with dynamic vs. static pressure or other unknown variables when utilizing the main hose to do the work of supplying air plus providing the sensing mechanism with feedback.

[dsm]

[quote="Snooze_Blues"]

<snip>


Algorithm senses and calculates on both Respiratory Rate and Tidal Volume (same as the Respironics BiPAP Auto SV?).

### As far as I can see, both can track rate & volume (minute ventilation) - it is what they do with the data that may differ a bit.



Advantages:

Learning circuit might allow larger choice of (third party) humidifiers.

### I don't know that this matters

Static pressure tube sensing at mask may provide more accurate breathing data.


### I believe that to be true but there is debate about its value

Leak rate table may allow more accurate measure of flow rate and hypopneas.

### I did and still do believe this, I think SAG may disagree


Dual impeller reduces possible harmonic induced algorithmic confusion.

### I believe the dual impeller (one at each end of the motor shaft), does more to eliminate whine than anything plus allows the impellers to be built for rapid acceleration (low inertia high acceleration)

May be better for those with lots of central and mixed apneas and CSDB (like me).

### I agree with this based on the excellent input from SAG RG SWS

Optional ResLink data module seems superior to EncorePro (but I'm unfamiliar with it).

### Reslink is a great little add-on but is far too expensive if the SpO2 unit is included. But the data from it is the best.

Disadvantages:

May not allow use of my 10-foot hose.

### That wouldn't bother me

May not allow use of my DIY Repti Heat Cable hose and mask heater.

### Yup

Mask selection. ResMed Quattro Pro alone is 100% design compatible. (Is this true?)

### Not really sure

These masks are approved, but (anecdotally) with reduced efficacy:
Vista
Ultra Mirage
Mirage Full Face Mask Series II
Ultra Mirage™ Full Face Mask
Activa
Liberty (per SAG)

Respironics BiPAP Auto SV

Features:

Algorithm senses and calculates on both Respiratory Rate and Tidal Volume (same as the ResMed VPAP Adapt SV?).

### I believe so

Advantages:

Mask selection. Theoretically, all masks are equal. I can use my current mask!

### Again, I believe so


Simpler hose selection (no extra little attached static tube needed) allows:
a. My 10-foot hose; and
b. My DIY 10-foot Repti Heat Cable hose and mask heater

Uses EncorePro, with which I'm already familiar.

### I expect the data gathered is more traditional (AHI with AI & HI) but I'm not certain.

Disadvantages:

Anecdotal reports suggest continuous maximum pressure events may occur, possibly due to inability to distinguish between mask design leak rates vs. accidental leaks.

### I have read of a few users posting about the machines going to max more than once

Q. Could large leaks, or intermittent leaks with extremely varying L/min values, confuse the algorithm and compromise therapy?

### I believe it could

Q: Could water (rain-out, condensate) in the hose, which makes that "weird hollow bubbling" or "gurgling" sound after a couple hours of operation, create weird pressure fluctuations that might be interpreted as "choppy breathing" and confuse the algorithm? I'm speculating based on my Respironic's M Series Pro CPAP machine, which consistently fails to shut itself off in this condition when I remove my mask. The "gurgling" condensation seems to trick the M Series into thinking I'm still at the other end of the hose. Of course, being set at 6 cm H2O may be part of that particular problem, too. Perhaps this is not a factor since the Auto SV algorithm is "flow based" and probably responding to "minute ventilation" measurements. Still, it seems like there could be some complications with dynamic vs. static pressure or other unknown variables when utilizing the main hose to do the work of supplying air plus providing the sensing mechanism with feedback.


### Really don't know re this

[StillAnotherGuest]

Well, my head still hurts from banging my head against the wall trying to convince people that the Earth isn't Flat, so I'm going to jump on the Santa Maria and sail off in a different direction.

The first thing I think you should do is fix that abyssmal sleep efficiency (37% titration, 59% diagnostic) you have there. You need to get up to 74% just to be at the upper limit of "poor", and at least 85% to start being "acceptible". Now, while some reductions in sleep efficiency can occur because of "Lab Effect" (Omigod! This is a LABORATORY and all those WIRES!!) it usually amounts to only a few %. VERY rarely will a person who puts up a 59% sleep efficiency in the lab be doing 99s at home. That can't be "assumed" to be the case, and if you were going to "assume" anything, you would assume that if somebody's doing 59% in a lab, they're doing maybe 70% at home.

These numbers are correct?

Diagnostic
Slept 137.0 mins of 233.0 min recording.

Titration
Slept 158.0 min of 421.0 min recording.

That means your PSG was 654 minutes (~11 hours) long?

Anyway, there's a bunch of different kinds of central sleep apnea, such as Complex Sleep-Related Breathing Disorder and Cheyne-Stokes Respiration, and these are cyclical in nature. Central begets central. ASV should fix these.

There is periodic breathing associated with altitude, and I don't know how that would respond.

There is periodic breathing with sleep-onset, which is considered to be a normal phenomenon, and not (normally) of long duration.

There is another type a central apnea, post-arousal central. An arousal causes a brief period of hyperventilation, then the body responds with a central apnea. The arousal is abnormal, the response is not. In these cases, you fix the arousal, not the apnea. These are more isolated instead of cyclical. ASV will not help these.

Also, you got this huge pile of Stage 1 sleep and CSDB tends to be more of a Stage 2 phenomena. CSDB tends to disappear in REM, but since you didn't have any in diagnostic, that tidbit is of no help.

Anyway....

It is not clear to me that you are even an ASV candidate yet. ASV works by breaking the cyclical characteristic of these various forms of CSA. If those centrals are not cyclical, then ASV is just an awful expensive comfort measure (assuming that it would even work. AdaptSV is not very Wake/Stage 1 - transition friendly).

SAG

_________________

CPAPopedia Keywords Contained In This Post (Click For Definition): Titration, Arousal, CSA, Altitude

[Banned]

SAG & dsm,

The 'Additional Comments' on Snooze's profile say 6cmH2O. If that is his inspiration pressure the Adapt SV would only go as low as 4 + 3 = 7cmH2O. Any thoughts?

Banned

[dsm]

SAG & dsm,

The 'Additional Comments' on Snooze's profile say 6cmH2O. If that is his inspiration pressure the Adapt SV would only go as low as 4 + 3 = 7cmH2O. Any thoughts?

Banned

That 6 CMS is so low I can hardly seeing it matter.

Where the SV machines appear to shine (as I learned this week) is in holding epap CMS steady while varying the Ipap up & down as needed to clear central & rythmic breathing 'events' (in the vpap SV, this configurable gap between epap & min ipap must be at least 3 CMS - in the Bipap SV it appears can be as low as 1 CMS (but I need to check))

I can now visualize this in relation to someone experiencing centrals - the machines can aggressively ventilate the user back into line using the fluctuating Ipap. In the Bipap SV that fluctuation can be set to a massive swing. In the Adapt SV it can't be set nearly as high.

If someone were on a normal cpap of 6 CMS the SV machines might be too powerful & aggressive.

But if the person listing their setting as 6 CMS has an auto, then 6 CMS may be the low setting ?

6 CMS just seems sooo low to me.

DSM

_________________

CPAPopedia Keywords Contained In This Post (Click For Definition): CPAP, auto

_________________

CPAPopedia Keywords Contained In This Post (Click For Definition): bipap, CPAP, auto

[Snooze_Blues]

Well, my head still hurts from banging my head against the wall trying to convince people that the Earth isn't Flat, so I'm going to jump on the Santa Maria and sail off in a different direction.

Wherein lies your frustration?
a. Self-diagnosis for newbies 101
b. I'm a hammer so all problems look like nails
c. If it costs more, it must be better
d. A voice told me I'm a disease and genocide vector for American natives
e. I'm a compulsive self-stimulator
e. All of the above
d. None of the above

The first thing I think you should do is fix that abyssmal sleep efficiency (37% titration, 59% diagnostic) you have there. You need to get up to 74% just to be at the upper limit of "poor", and at least 85% to start being "acceptible".

59% pre-titration is accurate, but the 37% during CPAP titration may be skewed. I was apparently discombobulated around wake-up time. Wanting to get the most out of my sleep study dollar, I lay there stubbornly for hours waiting for more sleep for them to record, practicing advanced meditation techniques and Patanjali's Yoga Sutras in the clock-less, light-less, sleepless, transcendent fog of a semi-conscious drowse, waiting for a bedsore to tell me it was time to greet the day. My wife called the lab several times to see if they'd killed me while I interacted with several shifts of friendly lab technicians.

These numbers are correct?

Diagnostic
Slept 137.0 mins of 233.0 min recording.

Titration
Slept 158.0 min of 421.0 min recording.

That means your PSG was 654 minutes (~11 hours) long?

Yep. I got my money's worth, but I missed breakfast and they couldn't offer lunch since the cafeteria buffet had closed. Stepping out of my Skinnerian box into intense 1pm sunlight nearly caused a migraine. My celebrity pick-up plan was in shambles. I stood outside the lab in jammies for half an hour waiting for Mrs. Blues. I discovered later that to sooth the angst of the unexpectedly long wait, Mrs. Blues resorted to shopping therapy, likely why she didn't answer my calls.

Anyway, there's a bunch of different kinds of central sleep apnea, such as Complex Sleep-Related Breathing Disorder and Cheyne-Stokes Respiration, and these are cyclical in nature. Central begets central. ASV should fix these.

There is periodic breathing associated with altitude, and I don't know how that would respond.

I live at 700 feet above sea level. No altitude involved here.

There is periodic breathing with sleep-onset, which is considered to be a normal phenomenon, and not (normally) of long duration.

There is another type a central apnea, post-arousal central. An arousal causes a brief period of hyperventilation, then the body responds with a central apnea. The arousal is abnormal, the response is not. In these cases, you fix the arousal, not the apnea. These are more isolated instead of cyclical. ASV will not help these.

Good to know. Since no Cheyne-Stokes or other periodic breathing and no PLM or RLS are mentioned in my summary, what else might induce such arousals? There's an occasional wet dream, but I see no problem there.

Also, you got this huge pile of Stage 1 sleep and CSDB tends to be more of a Stage 2 phenomena. CSDB tends to disappear in REM, but since you didn't have any in diagnostic, that tidbit is of no help.

That day was atypical. I rode a 24-mile organized bicycle tour in unfamiliar, gnarly hills, at a slightly higher pace than normal (hey, people were watching) that left me a bit more fatigued than my normal 16-mile pleasure ride (might explain increased sleep levels 3/4), the entire lab experience was weird, and having no clock or sunlight queues confused me. When I finally asked what time it was, they said 12:45. To which I replied, "AM or PM?" I really had no idea, so to insure enough recording time I "gutted it out" after any legitimate need for sleep had long passed.

Anyway....

It is not clear to me that you are even an ASV candidate yet. ASV works by breaking the cyclical characteristic of these various forms of CSA. If those centrals are not cyclical, then ASV is just an awful expensive comfort measure (assuming that it would even work. AdaptSV is not very Wake/Stage 1 - transition friendly).

SAG

I'll have to ask if their initial impression of "underlying disorder is central sleep apnea" mentioned in my summary, can be further characterized as to type (if still present).

I'm hoping no cyclical central apnea events are observed tonight. At 6 cm H2O, I don't need comfort measures, but I do ramp 5 minutes to take the edge off the initial micro-blast. Plus, I'm a notorious tight-wad and having studied economics, I realize that the most expensive things in life are FREE, like insurance coverage of PAP machines.

[Snooze_Blues]

I forgot to mention my motivation for comparing the two ASV machines.

If my sleep doctor or lab specifies "(generic) ASV" on my prescription, I was hoping to have some informed input on machine selection.

[dsm]

Here is a set of Qs & As (from Respironics) in regard to the Bipap SV ...

In particular they state ...

Q. How does the algorithm operate?

A. The algorithm is based on flow. Using proven RI technologies such as Digital Auto-Trak, the flow signal is analyzed and a target flow is calculated. If the patient reaches the flow target, the device does not offer any additional pressure support. If the patient does not reach the flow target the device will dynamically change pressure support breath to breath.

*************

Q. Does the BiPAP autoSV operate like an Auto CPAP or Auto Bi-level device for treating obstructive events?

A. No – The device does not have an auto-titrating algorithm to alleviate obstructive events. The innovative algorithm was designed to treat complex apnea and periodic breathing. The obstructive component of SDB is treated utilizing a clinician adjustable CPAP or BiPAP pressure level.

(#DSM# The above means that the OSA part of a patients SDB is treated by raising EPAP during titration, until the OSA is resolved - no auto algorithm is applied (like is in the Bipap Auto). Then the next step is to titrate the irregular breathing so that gets addressed).

*************

Q. Is it necessary to titrate these patients?

A. Yes. To treat the complexity of this patients as well as establish a baseline CPAP or BiPAP pressure for OSA, an in lab titration is necessary.

*************

Q. Which type of mask I can use with this device?

A. The BiPAP® autoSV™ can work with almost every mask type. However, controlling unintentional leak is very important for the algorithm to work effectively. If a patient presents with higher than expected leaks, move them to a full-face type of mask.

*************

Q. How long does it take before the patient’s periodic breathing is stabilized?

A. After 2 – 4 cycles of periodic breathing the patient’s breathing pattern is typically stabilized.

*************

Q. Which modes are possible with the BiPAP® autoSV™?

A. BiPAP® autoSV™ is intended to be used as an auto-servo ventilator. However a variety of therapy treatments are available utilizing the 3 different pressure settings on the device. (EPAP, IPAPmin, IPAPmax). With these three pressure settings the device can be set to deliver CPAP, CPAP with autoSV, BIPAP and BiPAP with autoSV

(#DSM# The auto in the above means Auto SV & not Auto Cpap - Auto SV regulates the patient's flow, Auto CPAP/Bipap regulates cpap or epap/ipap pressure based on detected apnea events)

*************

Q. Is it possible to use BiPAP® autoSV™ patients with COPD, OHS and NMD?

A. The BiPAP® autoSV™ is designed to treat complicated breathing patterns in sleep patients. Nevertheless, utilizing the 3 different pressure settings and a standard backup rate of 4 -30bpm, the device can be set similar to that of a standard S/T device. The ASV algorithm is not able to assure a volume which would be most beneficial for these types of patients.

*************

Q. Is a Bi-level S/T device better for these patients (COPD, OHS and NMD)?

A. A Bi-level ST device would be better for these types of patients. Experience with the VPAP adapt on these patients showed that over time the device can not treat them as well.

*************

(2 Qs skipped) ...

*************

Q. Can an identified candidate w/ Complicated Breathing Patterns, Central, and/or Mixed Apneas or Periodic Breathing (CSR), be put on the device w/o coming into the sleep lab?

A. If the CPAP or BiPAP pressure is already determined in lab, the patient can be put directly on BiPAPautoSV. To assure that the patient is being properly treated it is a good idea to download the SmartCard data after 7-10 days.

*************

Q. What settings should be used in this case?

A. For the set up of these patients it is advisable to use the CPAP or BiPAP pressure from the “old” unit,set the IPAPmax 10cmH2O above the CPAP or BiPAP pressure and set the back up Rate to Auto.

*************

Qs skipped

*************

Q. Will BiPAP autoSV utilize Encore Pro and is an upgrade going to be necessary?

A. Yes – The BiPAP® autoSV™ does utilize Encore Pro v1.8, an upgrade available currently. A special reporting for the SV is available.

*************

DSM


Ref = http://bipapautosv.respironics.com/faq.aspx

[dsm]

This is a question aimed at SAG or SWS or anyone confident they can explain it.

The question is that Respironics say they base the Bipap SV therapy on 'flow' where as the Adapt SV is said to be based on 'Volume and rate'.

What I am trying to work out is just what the difference is in meaning. When Respironics say flow, my mind short on any other detailed explanation, interprets this as CMS setting. When Resmed say Volume & rate, I interpret this as minute ventilation and breathing rate.

In the Q&A from Respironics + the Bipap SV manuals, they state that the 'rate' can be set to Auto and that the machine when in SV mode, can be set in either 'Bipap SV' or 'Bipap AutoSV' mode. I am taking the 'auto' to mean automatic breathing rate. What is difficult to work out though is what the auto rate really means.

Does it mean there is some tracking of the breathing rate, if yes, does anyone know what it is (we have it said that the Adapt SV tracks volume & rate for the prior 3 minutes).

Thanks DSM

[-SWS]

The question is that Respironics say they base the Bipap SV therapy on 'flow' where as the Adapt SV is said to be based on 'Volume and... <snip>'.

Right, Doug. Resmed samples & targets minute volume. Respironics samples and targets peak flow. That amounts to Resmed sampling and targeting more points on the inspiratory curve. By the way, that's the real reason for wanting a proximal sensor tube: inspiratory curve-slope measurement becomes more accurate. Resmed works with curve-slope while Respironics does not.

Respironics works with only one data point per inspiratory cycle: peak flow. Respironics isn't working with curve slope when measuring only peak flow. Therefore Respironics does not need the proximal tube to accomplish its entirely valid low-level technical objectives. There are advantages and disadvantages to either approach in my way of thinking. And the minute volume versus peak flow sampling difference alone should account for different efficacy patterns across target patient populations.

In the Q&A from Respironics + the Bipap SV manuals, they state that the 'rate' can be set to Auto...

When set to auto mode, Respironics will calculate a running average of F (or respiration rate) to use as an "automatic" backup rate. You can see how that approach differs from a traditional fixed or "manual" backup rate.

By contrast the Adapt SV uses common or typical "CSA-variant" profiling criteria to calculate an automatic F target toward a sliding ASV backup rate. However, if signal/algorithmic processing toward determination of that flexible F fails, then a fixed backup rate of 15 prevails.

Again, two different design-and-treatment approaches that should also account for differences in efficacy patterns across target patient populations.


[edit described below]

[dsm]

SWS,

Once again thanks for sharing your very comprehensive knowledge of this very technical area.

I can see the point about the proximal sensing. The multiple sampling of the Insp curve does make sense to me in light of how the Vpap SV is said to provide therapy & monitor the sleeper.

The Bipap SV also looks interesting to me because there are so many variables to play with. As said earlier, that can be both a blessing and a curse (to me a blessing).

The titration process for both also makes more sense.

DSM

[dsm]

PS,

Re the availability of the 'new' Vpap SV, the new machine hasn't yet been released here in Australia. An enquiry here today suggests it will be released with in a few weeks.

Respironics have released here in Australia, the Bipap SV (previously we couldn't buy the Bipap Pro, Pro II, or Gray S/T locally).

So we here have the choice (for those that want either) plus we Aussies don't need a prescription to get one. But, as one might gather from recent discussions on both, fiddling with the settings on either machine is no simple exercise.

But I am interested in the comments made by Resp, that standard Bilevel titration data can be used to set up the Bipap SV. Epap won't be any different but Ipap set up will. I am not sure if they are being bold & brave or that it is a non issue.

DSM

[-SWS]

Thanks for that info, Doug.

Also a correction of one of my earlier statements about sampling:

Respironics samples only one data point per inspiratory cycle: peak flow.

That was bad word choice on my part. I really should have worded it more along these lines:

Respironics works with only one point per inspiratory cycle: peak flow.

A semantic hair worth splitting, since they really data sample all the way up and down that curve to derive a peak flow value.

[dsm]

SWS,

I don't suppose you know what data the Bipap SV collects - because it is not like the Bipap Auto (as I once presumed) I am inclined to think it is more like the S/T at data recording.

The S/T provides CMS settings, MV (in detail), Breathing Rate (in detail), AHI (not in detail, just the average for the entire night).

Tks

DSM

[StillAnotherGuest]

By the way, that's the real reason for wanting a proximal sensor tube: inspiratory curve-slope measurement becomes more accurate.

I am of the belief that the proximal pressure pressure line only serves to calculate system resistance during Learn Circuit and then monitor for disconnects (Low Pressure Alarm). I have attempted to employ dsm's testing methodolgy (wearing AdaptSV to bed with the proximal pressure line isolated and having my wife stay up all night with a notepad and a "torch") but the only result I got was that I woke up with a "Ray-O-Vac" logo on my forehead and a beam of light coming out of my navel.

Will use alternative testing methodologies tonite.

SAG