APAP vs VPAP Adapt SV

[babydoss]

What is the difference between the APAP & VPAP Adapt SV?

Thanks, Lee

[rested gal]

Lee, in a nutshell, this is my non-medical understanding....

The VPAP III ASV (used to be called CS 2) was originally developed to normalize breathing for Congestive Heart Failure (CHF) patients who had Cheyne-Stokes Respiration (CSR). CSR is a breathing pattern that waxes and wanes regularly; each waning phase finally resulting in a central apnea, then the pattern starts over again.

The Adaptive Servo Ventilator (ASV) machines like the VPAP III Adaptive SV and the BiPAP Auto SV ("HeartPAP") are primarily for treating the central apneas associated with Cheyne-Stokes respiration, or for treating Central Sleep Apnea (CSA) if that's the main sleep disordered breathing problem rather than Obstructive Sleep Apnea (OSA.)

Autopaps are for a different purpose entirely. An APAP "auto-titrates" (varies the pressure as needed) for people with OSA (Obstructive Sleep Apnea.) Autopaps do not attempt to "treat" central sleep apnea. Autopaps try to avoid increasing pressure when faced with a possible central apnea.

[dsm]

Lee,

Another POV in addition to RG's comments.

An Auto delivers one pressure for breathing in and out, but it can vary that pressure up or down.

It varies the pressure up if the sleeper's breathing starts to show signs of apneas. Autos are suited for people with obstructive apnea (not centrals or Cs breathing). If the apneas appear to be fading it will lower the pressure again.

The Autoset CS2 (used to be called the VPAP Adapt CS) works quite differently in that it sets a baseline for respiration (using airflow data) and if the sleeper starts to drop below 90% of the currently tracked basline for respiration, the machine will take over ventilation by increasing pressure & (IIRC (If I Recall Correctly) adjusting BPM (breaths per minute)) .

The Autoset CS2 tries to ensure the sleeper maintains a consistency in their respiration. It was one of the 1st machines to come to market as general purpose passive/active ventilator that attempts to correct apneas before they occur / as they occur (Autos try to pre-empt apneas but it can be a hit and miss effort for them).

DSM

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

[rested gal]

Lee, I hope christinequilts notices your topic. She actually uses the VPAP III Adapt SV.

[christinequilts]

This was something I was working on to sort of describe the difference between BiPAP ST & Adapt, since I'm one of the few to have extensive, hands on experience with both. I found I had to define how the various xPAPs work, in the basic sense of what they target as far as treatment to really see the progression. I know there is a lot more to autoPAPs & such, and how they work are described much more extensively by other posters who use them regularly, but hardly anything on how BiPAP ST or the new VPAP Adapt SV work.

Please also realize I should have been in bed over an hour ago, so excuse any typos and understand I'm open to add relevant facts and make other edits as needed...especially on the time frame for how quickly autoPAP & autoBiPAP can change pressures.

Let's start with strait up CPAP, the most basic of xPAP therapy. It blows a predetermined pressure that splints the airway from collapsing as a result of an obstructive event. The same amount of pressure is provided the entire night, whether or not the person needs it. It prevents events before they happen, and if set at the correct pressure for the individual, almost all obstructive events will be prevented. It makes adjustment in airflow to maintain correct pressure at all times, as do all xPAPs; but for the most part, I think we can say its main concern is if its on or off.

An autoPAP works similar to a strait CPAP, in that it uses pressure to hold the airway open, preventing obstructive events before they even have a chance to occur for the most part. It adjusts, within the pressure settings given, so the user can have more time at lower pressures, only spending time at higher pressures when their breathing pattern indicates obstructive events are likely to occur. Its my understanding that autoPAP's adjust their pressure fairly slowly, over several minutes and do not make rapid, drastic changes. They are pretty much equal to preventing obstructive events as strait CPAPs, before the event even starts. On the simplest level, we can think of autoPAP's as being primarily focused on monitoring changes in airflow to predict possible obstructive events.

Regular BiPAP or BiPAP S (Spontaneous) has two pressures levels, IPAP for inhale and EPAP for exhale. It works similar to strait CPAP, in that the pressures are set based on titration results. Used to treat OSA, the pressure works much the same as strait CPAP, except that it changes from higher IPAP to lower EPAP SPONTANEOUSLY as the patient inhales and exhales. If the patient doesn't trigger IPAP by inhaling, it will remain at the lower EPAP pressure. The advantage for some, is the reduces pressure on exhale makes breathing easier and more natural and there is less tendency to swallow air. In addition to OSA, it can also be used to treat other various respiratory disorders and in some people with CSA. It is usually as effective at preventing obstructive events by splinting the airway, as strait CPAP and autoPAP, if set to the correct titrated pressures. On the simplest level, we can think of it as being focused on changes in airflow related to inhalation & exhalation.

AutoBiPAP, is a combination of an autoPAP and a regular BiPAP, used in the treatment of OSA. It spontaneously changes between IPAP and EPAP, based on the users inhalation and exhalation. At the same time, it also adjust the over pressure ranges, within preset limits, up and down, so the user may spend more time a lower pressure settings, only increasing pressure ranges as needed when the breathing pattern indicates obstructive events are likely to occur. We can think of this as being focused on both airflow changes related to inhalation & exhalation and monitoring changes in airflow to predict possible obstructive events.

In terms of apnea, all of the previous xPAPs are primarily used to treat predominantly obstructive sleep apnea. The next two types of xPAPs are used to treat predominantly central sleep apnea and are much more complex. Up to now, we've been talking about a physical blockages, 'plumbing issues' as this article aptly puts it. With central events, you get into a lot more complex issues, using the same articles analogy, 'electrical problems'. I am more familiar with central issues, as my diagnosis from the beginning 3 1/2 years ago was severe CSA, with over 60 centrals per hour. More recently, Complex Sleep Disordered Breathing (CSDB) was added, as my centrals events have never been well controlled with BiPAP ST, leading to numerous other issues with my sleep.

BiPAP ST, like the regular BiPAP S, will SPONTANEOUSLY change pressures from IPAP to EPAP, as the user inhales and exhales. It switches to a TIMED back up mode, based on a predetermined number of BPM (Breaths per Minute), if the user does not breath so many times per minute. In TIMED mode, the BiPAP ST is in control of switching from IPAP to EPAP though as soon as the user begins to make any effort to inhale or exhale on their own, it switches back to SPONTANEOUS mode. A lot of people are mistaken that in TIMED mode, it is breathing for you- its not; its only attempting to give you a push to breath. It cannot force air into or out of your lungs, it can only assist you. Some people with central apneas are better at taking the hint then other, so while it make work while for some, it may not for others. Another difference between how the other various xPAP's treated OSA is that they prevented the events from ever happening for the most part; a BiPAP ST's TIMED mode cannot do anything to prevent a central apnea before it occurs. The goal is not prevention as much as it to stabilize breathing, which the SPONTANEOUS changing in pressure rhythm can do to some degree for some people, which is why regular BiPAP S can sometimes be used for people with CSA.

While TIMED Backup Rate is needed in some cases, it can cause issues too. It assumes at 12 breaths per minute, each breath will be exactly 5 seconds long. Okay if you take a few 4 second breath cycles, but don't push your luck and try for those 6-7 second breath cycles. Backup rate should be set a few BPM lower then your average resting BPM, but an average is just that, an average- sometime you might breath more times per minute & sometimes less. If the Backup Rate is set too low, it may not provide enough support. Its a delicate balance, which works fine most of the time, though it can feel like a Drill Sargent shouting orders at you to breath at the rate he wants you to- not fun in the middle of the night, and can disrupt sleep and breathing stability in some sensitive individuals. A BiPAP ST doesn't care how much you breath each breath cycle either, as long as you inhale and exhale on schedule. So a user could be meeting the BPM quota, but what if they are only exchanging 25% of the air they should be? The machine is happy, thinks everything is fine, but the users body thinks otherwise.

In simplest terms, a BiPAP ST is still focused on changes in airflow related to inhalation & exhalation, as the BiPAP S was, but also focuses on the number of times you breath per minute, switching to TIMED mode if necessary in an attempt to trigger breathing. Definitely more complex then any of the other machines we've looked at so far, but still lacking some finesse to really deal with all the issues related to CSA or CSDB for some users, though some people with CSA and other central related issues do very well with BiPAP ST. I happened to one of them who didn't work great for, it let me thread water the past few years, but never fully addressed my sleep related breathing disorders. Prior to the Adapt, I could not sleep without my BiPAP ST at all.


The ResMed VPAP Adapt SV is technically a BiPAP ST, and could be thought of as almost a autoBiPAP ST....but its more then that- Auto Servo Ventilation. I've been using it for 5+ months & am stilling trying to figure out what the 'magic dust' is that allows it to work so well for me. It has 2 levels, like you would expect with a BiPAP, but they are not static, not even in relationship to each other or through an inhale or exhale. It has a backup rate, like you'd expect with a ST, but its not preset, its based on your breathing history for so many minutes prior; though it does also have a 'failsafe backup rate' of 15 BPM, if it doesn't have enough data points to use. The easiest way for me to describe how it works is to use my own prescription- EEP 9 (akin to EPAP or minEPAP on autoBiPAP), minimum PS (Pressure Support) 3, maximum PS 10, which means its basic operating pressure is going to be 9+3 or 12/9, but can go up to 9+10 or 19/9. Unlike autoPAP and autoBiPAP, which make gradual pressure adjustments, it can pretty much go from 12/9 to 19/9 in one breath cycle if need be, returning pretty much to 12/9 for the next breath cycle. It sounds like a dramatic change, and very anti-intuitive with everything we hear about needing to avoid to high of pressure to avoid pressure induced centrals but it doesn't feel as dramatic as it sounds & definitely works for me personally.

The Adapt focuses on not only how many times a user breaths per minute, but also on how much air they exchange in each breath, and is the first xPAP to do so. It monitors a users Minute Ventilation (MV), which is BPM x Tidal Volume (TV, air exchanged in a single breath) and sets a Target MV, based on the users recent history. It will make changes in the inhale & exhale pressure and the length of breath cycle to guide you towards the Target MV, whether your current breathing puts you above or below it. So unlike other BiPAP, where the pressure stays the same across each IPAP and EPAP respectively, it may give me 9.0-11.0 or even more (haven't noticed it going up as much on the on screen, live data) as my exhale pressure, changing throughout one breath. During one inhale, it might go from 12-19, especially if it senses me not inhaling. Its changing pressure support microsecond by microsecond, not over several minutes or more as we saw with the other autoPAPs. The Target MV is always changing, as its based on your own history. It can be fun for a couple minutes to attempt to match your MV to the Target MV, until you realize its a moving target and akin to chasing your own tail-lol.

So why does it work exactly- that's still a little fuzzy, the 'magic dust' component I mentioned. CSA and CSDB are extremely complex disorders and its a machine built to match. It is very good at stabilizing unstable breathing of central events for some people, when all else has failed. Its almost scary sneaky, uncanny, in how it can get me to breath, even if I try to hold my breath it has me inhaling before I even realize it; the same goes for trying to breath through my mouth with a nasal mask on. So if its that great for centrals, what about obstructive events? It doesn't do much and the the base pressure, or EEP, has to be set above were obstructive events would be cleared (or in my case, where I was comfortable, based on several years pressure on BiPAP ST). If we go back to the Drill Sargent analogy with the BiPAP ST at times, the Adapt, to me, feels like a graceful ballroom dancer who sweeps you off your feet. Dancing on air is an apt description, as is having someone reading your mind & giving you what you need before you realize you need it. If anyone can't tell, I love my Adapt, especially since its the first thing that's been able to normalize not only my breathing, but also my sleep on many levels neither my sleep doctor nor I anticipated. I think having more Stage 3/4 sleep in my Adapt titration then in 4 previous PSG's combined can give a glimpse at what it can do in some cases of extremely complex sleep disorders.

The Adapt has its drawbacks- price and insurance coverage are two cannot not be overlooked. It is equal price wise to regular BiPAP ST and has the same basic requirement for documentation of medical necessity. Its not widely used and not all sleep doctors & sleep labs are familiar with it, or set up to titrate it. It is very picky about which masks are used with it, limited to 4 of the 5-6 ResMed masks being approved and able to pass a Learning Circuit which much be run any time something is changed in the circuit. It also uses a specialized hose, with an external sensor line.

[dsm]

Christine,

That is a very good bit of work.

Very readable & hits the salient points well.

DSM

[rested gal]

Thanks for the great information, Christine!

Beautifully written, clear explanations.

Definitely a "bookmark this", "save this", "link to this post" keeper!

[bookwrm63]

I agree RG. It's nice to see it all laid out so clearly and concisely on one page.

Mary

[christinequilts]

I need to go back and clean up some typos...they are so much more apparent in the light of day like so many things. I'll see if I get any time time today, otherwise tomorrow.

[babydoss]

Christine, you are SOOOOOOOOOOO good!! DSM & RG are too though...

Lee

[Sherri_Baby]

Wow....that's great!! From now on when people ask me this, I'm going to refer them here...lol! The only thing I could equate it to is its the only machine allowed to think for itself....your explanation is much better!

[Guest]

So if its that great for centrals, what about obstructive events? It doesn't do much and the the base pressure, or EEP, has to be set above were obstructive events would be cleared (or in my case, where I was comfortable, based on several years pressure on BiPAP ST)

Does this mean the vpap does not work for obstructive apnia, or will it work but it would require a higher pressure than you are comfortable with?

Jim.

[christinequilts]

Does this mean the vpap does not work for obstructive apnia, or will it work but it would require a higher pressure than you are comfortable with?

Basically your EEP pressure, which is your base exhale pressure, or EPAP in regular BiPAP terms, has to be set high enough to clear the obstructives. Or rather your EEP + minimum Pressure Support (the minimum difference between your lower exhale and higher inhale pressures (EPAP & IPAP in regular BiPAP terms) has to be set to clear obstructive events well enough during titration. The Adapt doesn't treat obstructives much differently then a straight CPAP would- its the centrals that it focus on eliminating with its adaptive servo technology.

[Guest]

thank you for the reply.

I am going to see the dr. tues on the followup to my sleep study.

During the study they used a cpap. Initially it had a ramp up so I did not notice the pressure before falling asleep with it. But when the tech woke me up to have me lay on my back, I could feel the pressure and had problems exhaling. Basically I could not get back to sleep with it at pressure, and had breathing problems.

So I have been doing some research this week to see what alternatives there are. It seems that the Adapt is the most advanced as it uses the philosophy of having the machine conform to the user instead of having the user conform to the machine.

Jim.

[Lubman]

Christine

I think you should go through it and correct it to your satisfaction.
It is a very clear comparison of what otherwise is confusing -- to users
and to non sleep specialist MD's as well.

DSM hit upon some of the ideas why the Assist SV works in the early portion of the 30 plus page Central Sleep Apnea and Assist AV post.

The dual internal design obviously sets up a control loop.
Also the machine must have quite a bit of processing power.

Now if ResMed would get FDA approved some better reporting indices
so that it makes a bit more sense to users -- which I hope is in the works,
but don't know.

Minute Volume is a bit tougher for one to understand than other reporting approaches.

Thank you
Lubman