Difference between BiPAP and ASV

The sleep clinic told me that BiPAP is more suitable for me than an ASV machine as the BiPAP detects when I am not breathing and only breathes for me when I need it. Apparently the ASV machine is a type of CPAP and less suitable as it does not do this.

Can anyone comment on this?

ASV is for people with more central events than obstructive. Bipaps are for those with obstructive events that need an especially high setting that a regular C or Apap can't handle.

I think someone does not know what they are taking about.... The Bipap treats with pressure the ASV is a very expensive machine that treats on a breath by breath basis pushing pressure high when needed leaving it low when not. However to Quailify for ASV you need to fail CPAP and BiLevel


The BiLevel does not detect your breathing on a breath by breath basis and applies pressure all the time on inhale but it can have a larger difference in pressure between inhale and exhale to make it more comfortable for the user to exhale


For some users the increased difference between inhale and exhale makes the central apnea worse

Jas_williams wrote: ↑

Sun Apr 01, 2018 6:24 am

I think someone does not know what they are taking about.... The Bipap treats with pressure the ASV is a very expensive machine that treats on a breath by breath basis pushing pressure high when needed leaving it low when not. However to Quailify for ASV you need to fail CPAP and BiLevel


The BiLevel does not detect your breathing on a breath by breath basis and applies pressure all the time on inhale but it can have a larger difference in pressure between inhale and exhale to make it more comfortable for the user to exhale


For some users the increased difference between inhale and exhale makes the central apnea worse

Well I was given a ticking off and told "I do know what I'm doing"...

Thanks for the clarification though. I am going to see where the adjustments with BiPAP take me. They are going to get a download from Respironics ahead of my next appointment in six weeks.

Chalkie wrote: ↑

Sun Apr 01, 2018 3:16 am

The sleep clinic told me that BiPAP is more suitable for me than an ASV machine as the BiPAP detects when I am not breathing and only breathes for me when I need it. Apparently the ASV machine is a type of CPAP and less suitable as it does not do this.

Can anyone comment on this?

Bullshit.

She/he has it backwards.

Read what it says the AirCurve 10 ASV will do and what the AirCurve 10 ST will do.
Your current machine is the Respironics equivalent of the the AirCurve 10 ST
https://www.resmed.com/us/en/consumer/p ... entilators

Your current machine will treat centrals when set properly but it won't/can't auto adjust or respond to anything you do.
It makes you breathe whether you are breathing on your own or not at the rate that it is setup to make sure that your breathe.
Your current machine is a fixed pressure bilevel machine with a back up rate set to whatever and it's going to make you inhale and exhale per that rate whether you are doing it on your own or not.
It cannot adjust what it does to your breathing and hold off on forcing you to breathe if you are doing it on your own.

I pointed you to the ResMed equivalents because their product descriptions are a little clearer.

I know you are in the UK and they do things a bit differently over there but over here in the US we have a little not so nice saying....he doesn't know his ass from a hole in the ground. That's a fairly apt description IMHO of your sleep nurse.

ASV is a 'ventilor' pap system. They told me bipap OR cpap won't force me to breathe..it waits for me.

ASV forces you to take a breath.

Jas_williams wrote: ↑

Sun Apr 01, 2018 6:24 am

I think someone does not know what they are taking about.... The Bipap treats with pressure the ASV is a very expensive machine that treats on a breath by breath basis pushing pressure high when needed leaving it low when not. However to Quailify for ASV you need to fail CPAP and BiLevel


The BiLevel does not detect your breathing on a breath by breath basis and applies pressure all the time on inhale but it can have a larger difference in pressure between inhale and exhale to make it more comfortable for the user to exhale


For some users the increased difference between inhale and exhale makes the central apnea worse

I have suspected that. I had the Dreamstation (since May of 2017) set to bipap. I have had horrible AHI numbers the whole time. I have called repeatedly and had a sleep study last August where they could not resolve my centrals. I set it on my OWN to straight CPAP...and my numbers have gone down. Not gone all the way, but lots better. I suspect the lower pressure on exhale just wasn't enough.

Thanks for the link, Pugsy.

Looks like I will have to try to get BiPAP to work before I think about pushing for another machine,

From what you have told me before I understand I can probably get this machine working for me if it is set up right and leaks managed better- right?

Under the NHS you can't just choose another clinic.

Barb (Seattle) wrote: ↑

Sun Apr 01, 2018 8:40 am

ASV is a 'ventilor' pap system. They told me bipap OR cpap won't force me to breathe..it waits for me.

ASV forces you to take a breath.

There are bipaps/bilevel machines that will act like ventilators and force you to breathe whether you do it or not.
They are special bipaps/bilevel machines though...they have what is called a back up rate that will time the breaths whether you do it or not.

So think of it this way...bipaps without a back up rate (what I call plain bilevels) and bipaps with a back up rate that will force a person to breathe and thus do act like a ventilator.

ASV isn't the only type of machine that has a back up rate and will force a person to breathe. What happens with the ASV machine is the machine only forces the breath if needed and the patient isn't breathing enough on their own.
ASV machines will auto adjust as needed....those other bilevels with a back up rate are fixed rates...nothing auto adjusting about it and they will make you breathe per whatever back up rate has been set.

So people need to understand that not all bilevel devices will act like ventilators...some will and some won't....and not all are auto adjusting of those that will act like ventilators.

Chalkie wrote: ↑

Sun Apr 01, 2018 8:51 am

Looks like I will have to try to get BiPAP to work before I think about pushing for another machine,

From what you have told me before I understand I can probably get this machine working for me if it is set up right and leaks managed better- right?

In theory this current machine will indeed treat the centrals and breathe for you but I am not all that familiar with this exact model that you are using to see what sort of tweaks can be set to get the job done.
I know the basics of your machine but not how each little setting can be set to take care of your problem.
All I know is what they are doing now isn't working out so great.

Ideally this sort of tweaking would be done in an in lab setting with a tech in attendance and doing the fine tuning.
The beauty of the ASV....with it's auto adjusting ability...it is a lot more forgiving when the settings are just spot on perfect.
With your current machine the settings have to be spot on perfect or it won't work....and obviously your settings aren't spot on.

And yes...the leaks are an issue but not the whole issue.
Give the Amara View a go and see what happens.
And let's see what setting changes were made or are going to be made and see if they help or not.
Give the new settings and new mask a trial 3 or 4 nights and then send me your data again. Let's see if things are improved or worse.

Chalkie wrote: ↑

Sun Apr 01, 2018 3:16 am

The sleep clinic told me that BiPAP is more suitable for me than an ASV machine as the BiPAP detects when I am not breathing and only breathes for me when I need it. Apparently the ASV machine is a type of CPAP and less suitable as it does not do this.

Can anyone comment on this?

I'm with Pugsy, *Bullshit*,.. and ignorance or lies.

BiPAP is a trademark for ANY AND ALL of the Respironics *BILEVEL* machines... including their ASV.

Aside from the pedantics of "BiPAP" is a trademark, not a type of machine,

Bilevel is a catchall name for a whole bunch of machines, any that have different and separately adjustable inhale and exhale pressures. there are simple bilevels, auto bilevels, timed bilevels, ventilator bilevels, bilevels that treat a variety of conditions from COPD to central apnea. (there are like 9 different bilevel machines in the Resmed s9 lineup... only one of which was an ASV).

In short, your sleep clinic person that is telling you that load of bullshit is either ignorant, or lying.

The philips respironics ASV machine is called the "DreamStation BiPAP autoSV Servo-ventilation system" ... ask your sleep clinic to explain that one.

Again, to summarize... "ASV" is a TYPE of Bilevel (bipap)

Barb (Seattle) wrote: ↑

Sun Apr 01, 2018 8:40 am

ASV is a 'ventilor' pap system. They told me bipap OR cpap won't force me to breathe..it waits for me.

Some "bipaps" can force you to breath. there are many kinds of 'bipap' machines, INCLUDING the ASV.

Chalkie wrote: ↑

Sun Apr 01, 2018 3:16 am

The sleep clinic told me that BiPAP is more suitable for me than an ASV machine as the BiPAP detects when I am not breathing and only breathes for me when I need it. Apparently the ASV machine is a type of CPAP and less suitable as it does not do this.

Can anyone comment on this?

If you have a Respironics BiPAP S/T machine, it will have a backup respiratory rate. If you don't breathe at all or try to breathe below the set rate, the machine will force a breath at the set backup rate and inspiratory time until you spontaneously breathe again above the set rate. At all other times, you are the one in control, but the pressure support (difference between IPAP and EPAP) is augmenting your breathing, making the machine do some of the mechanical work of breathing.

The problem with the S/T, if complex sleep apnea is the main issue, is that it is a "dumb" machine; it will do what it's set to do and only that; it cannot auto adjust. With the S/T and a set backup rate, you can hyperventilate which is the opposite of what you want and will probably cause more central apneas. You would need a skilled technician to basically hone in the exact settings required on an S/T but you still can't account for changes in the patient in any given night of sleep. The ASV is "smart" and will prevent the over and under shoot of minute ventilation by monitoring you breath by breath and adjusting to your needs on the fly, every time you use it.

The Respironics ASV is a way more complex and advanced BiPAP since it is an auto servo-ventilator. It can do a heck of a lot more than the S/T. Comparing it to a CPAP in terms of functionality is outright wrong.

To learn more about why ASV is used and what it is, I actually recommend skimming through ResMed's titration protocols guide, as it is more in depth and recently updated:

https://www.resmed.com/us/dam/documents ... er_eng.pdf

To sum up:

All ASV machines are bi-level machines (BiPap is a Respironics term for bi-level.)
Only some Bi-Level machines are ASV machines.

A BiPap machine switches back and forth between inhale pressure and exhale pressure when you initiate a breath. If you neither inhale nor exhale (central apnea), it will wait until you do (but record the event.) As a side note, it may be set with a substantial difference between pressures and comes as either a fixed pressure machine or as an auto-adjusting machine.

A BiPap S/T machine is a bi-level machine with a back-up rate. It will switch back and forth between inhale pressure and exhale pressure when, either you initiate a breath or you fail to do so as fast as the back-up rate. It appears from the literature that the BiPap S/T is an auto-adjusting machine. It is not clear if the machine can also be set to AVAPS mode in which it can act as a ventilator.

Provider setup menu
Therapy settings
Mode CPAP, S, S/T, T, PC
CPAP 4-20
AVAPS (not available on BiPAP S/T)

A BiPap ASV machine is an auto-adjusting bi-level machine with a back-up rate and the ability to become a ventilator. It will switch back and forth between inhale pressure and exhale pressure when, either you initiate a breath or you fail to do so as fast as the back-up rate. If you fail to initiate a breath 'soon enough', it will begin increasing the pressure differential topping out at min-EPAP/max-IPAP and continue to do so until you initiate a breath at which point it resumes the 'normal' pressure you had before.

Thankyou everyone who has taken the trouble to post these detailed explanations.

It seems clear that the consensus is:

(a) My machine can work for me but needs to be set up just right
(b) It is more sophisticated than some Bi-Levels but not as sophisticated as the ASV

I think this will take time and a patience and I have another appointment in early May for review.