[Pressure] Help me understand EPAP, IPAP and Pressure Support

[Kahri]

I haven't figured out how to post, other than being told I'm too new to post the picture of the sleepyhead data I had from last night. I cannot see where I can post a new topic, either, so I remain at a bit of a loss.

My problem, really, is that I have no idea how the values for EPAP, IPAP, and PS interact with one another, and need to keep EPAP below 8.

I have not slept a full night's sleep in almost 4 years now while on CPAP, and getting this VAUTO working is critical, but no one around me seems able to give me information.

Sorry - admins made me delete my picture as I have to have 4 posts before I can post a photo. 

Hello. I am happy to see someone with the same machine I was just given to use one week ago: It is a ResMed AirCurve 10 VAUTO. I have high hopes.

After not sleeping more than 2 to 4 hours a night for years, and vomiting when the CPAP pressure, ranged 4.0 to 8.0, hit the value '8.0' to the point where I said if they could not do better by me, I was going elsewhere for I could not risk vomiting into my throat, mouth or mask several times a week. Exhaling against 8.0 pressure was a nightmare. I had air coming out my tear ducts, ear aches, especially in the left ear, but also the right, and even if I didn't vomit that evening, I would wake up nausous, burping, etc. for some time before I started to feel like I could eat something. Forget breakfast. I never once felt 'rested'. Doc claimed I was mouth breathing. I showed her the ripped skin where I actually taped my mouth closed to be sure of no leaks. If my mask leaked, that night I might not vomit - if my mask had no leaks, I was up due to vomit. Disgusting.

I was told I was having apneas mostly during REM sleep, and since cpap was not working for me and I was completely exhausted daily, I was finally given a drug to help keep me awake so I could leave the house, drive myself to doctors, etc, and not just be a zombie stumbling around the house. Ironically, I went and had the sleep test back in Dec 2014 to fix all this so I'd not feel horrible... but the 4-8 Cpap setting didn't help my sleep, and only made it more painful to try to get through the night.

The final straw was when over the last couple, I got sick and then started avoiding going to bed at all, for whether I slept or not, I felt the same amount of 'non-rest', and if I didn't bother going to bed, I didn't have to wake up vomiting at 2:30 or 4am in the morning - so not sleeping at all became quite attractive, but was making my health even worse. I swear I aged 10 years during those 4 non-rested years.

I rarely get to see the actual sleep doctor at this practice, only her nurse, so finally when I said I was no longer going to bed as it was useless and the vomiting had just gotten to me she says she didn't know I was vomiting. (Still don't know how she didn't know. But anyway, that seemed to have her think of better solutions.)

So, last week, after 2 more tests, I was given the VAuto. But the 'nurse' told me the exhale value would be 10!!!! She frogot to phone me the day before at our scheduled time as promised, so I was stuck trying to recall what she was saying while trying to do our appointment over the phone - even though I said I could not write anything down and could not pull over because I was on my way to a serious other medical issue (blindness occurred in one eye)  to deal with. But she championed onward. When she first told me the values would be EPAP 8; IPAP 14 (I never go IPAP that high in the past); and PS 4; I told her there must be some mistake because I vomit at epap 8. So after asking for the EPAP value to be set under 8, she gets back to me 2 days later and says EPAP will now be 10. 10?!?!? (I know. I should have left this practice years ago, but I did think early on the Dr. was trying to help me. The nurse, however, doesn't appear to recall facts well.

The nurse could not tell me coherently what PS was and how it worked... 
Was PS INCREASE EPAP if IPAP increased? 
Would PS SUBTRACT the value of 4 from the EPAP value of 8 so it would be at 4 and I'd not vomit? 
Where's she get the EPAP value 10 from?
Like, was PS a value to lower EPAP if I got sick? Would it react to vomiting?
Was PS instead subtracting from the IPAP value of 14 and that's why the prescription said EPAP 8 but she's saying it's 'really EPAP 10"?

She told me many contradictory things, and I realized she simply didn't know. I asked for a call back from the house tech, but stil have not heard. Ended up with the machine Friday, vomiting that night and the following night.

So, I phoned the DME. They didn't know and said the clinician could tell me. (She clearly could not.)
So I got on here and have been hunting. I did dig in and change settings because the first 2 nights on settings EPAP 8; IPAP 14; PS 4; I was up vomiting in the night the first 2 nights, and frankly after a week of no answers, I am desperate. I even tried reviewing docs relating to the ResScan, but that doesn't explain how PS works, either. And with ResMed telling me THEY didn't know (I needed to ask that nurse... who doesn't konw), I am stumped.

So, last night I set the machine at PS 2.8 over 5.0-14 (cmH20) 
[PS 2.8 over EPAP 5.0 and IPAP 14.] 
What I was HOPING it meant was that my EPAP of 5.0 would not go above 5.0 pluse PS value 2.8 == 7.8 (so I'd be forced to exhale against a value of 7.8 at worst.)

I woke a couple times due to an itchy nose, but other than that 'slept' 6:59 hours with an AHI of 0.8.
No air shooting out my tear ducts; no pressure in the abdomen - no burping, no nausea, no voming
No pain in my ears, no headache. Pretty amazing. 
Still don't feel rested, but I also don't feel like the walking dead - AND at least I don't feel attacked. 
Now to figure out what these settings really mean. I'm supposed to be seen in 60 days. No way was I going to harm my abdomen for 60 days nightly aerophagia.

I know PS does different things for different machines. (ie Respironics does not do things exactly as Resmed does in the way their machines work.)

What I want to know is how can I ensure I NEVER hit an EPAP greater than 7 ever again so I can go to sleep and never vomit in the future? My 'nurse' had no idea, nor did the DME, and I'm running out of ideas.

If IPAP indeed needs to really be 14 (it was 11-something max in sleep testing), and I'm certain EPAP needs to be LESS THAN 8 (not 'more than' 8, as I wish the value was EPAP MAX, not EPAP MIN), then what in the world is PS and what value of PS might be safe? 
If my EPAP is 4, and my IPAP is 14... would a PS of 10 keep the machine from killing me with EPAP values greater than 7?

I've never posted anything regarding this in the past, and I'm going to hope the attachment comes out ok. I used the 'Snipping' tool on my Windows 10 64-bit machine to grab SleepyHead page for last night.


Thank you so much for any help you can give me.

[Sleeprider]

Kahri, I'm going to have this thread move to your own thread, then we can go through the details of posting a new thread and using Attachments to post images instead of linking images hosted elsewhere. Links in my signature describe organizing charts and posting attachments. You are using an Aircurve 10 Vauto, so I will help you understand your pressure settings.

In Vauto mode pressure can vary to meet your changing needs. At EPAP 5.0, PS 2.8 and IPAP 14, your pressure starts at 7.8/5.0 and can increase as high as 14/11.2. PS is fixed and is added to EPAP to produce IPAP. We can use the settings to accomplish a variety of therapy and comfort goals. EPAP controls obstructive apnea, and pressure support is for comfort to make breathing easier and treat flow limitations, snoring and hypopnea. Once we see your data we can probably get all of this done quickly and easily.

If you want to keep IPAP in the 5-8 range, just add PS to the maximum EPAP to limit IPAP. If 2.8 PS works then set max IPAP to 10.8, and you will get EPAP 5 to 8 at PS 2.8.

[Kahri]

Kahri, I'm going to have this thread move to your own thread, then we can go through the details of posting a new thread and using Attachments to post images instead of linking images hosted elsewhere.  Links in my signature describe organizing charts and posting attachments.  You are using an Aircurve 10 Vauto, so I will help you understand your pressure settings.  

In Vauto mode pressure can vary to meet your changing needs.  At EPAP 5.0, PS 2.8 and IPAP 14, your pressure starts at 7.8/5.0 and can increase as high as 14/11.2.  PS is fixed and is added to EPAP to produce IPAP.  We can use the settings to accomplish a variety of therapy and comfort goals.  EPAP controls obstructive apnea, and pressure support is for comfort to make breathing easier and treat flow limitations, snoring and hypopnea.  Once we see your data we can probably get all of this done quickly and easily.

If you want to keep IPAP in the 5-8 range, just add PS to the maximum EPAP to limit IPAP.  If 2.8 PS works then set max IPAP to 10.8, and you will get  EPAP 5 to 8 at PS 2.8.

You're telling me that with an PS as tiny as 2.8, it STILL pushes up the minimum EPAP to 7.8? There's no way to just let EPAP run at 4? or 5 or at least less than 8 without hosing up IPAP?

I never asked to keep IPAP in the 5-8 range.
I want to keep  EPAP in the 4-7 range ideally. and would LOVE to keep EPAP at a value less than 5, actually.

But I'm hearing all sorts of stories about PS raising EPAP or PS raising IPAP, or PS should not be greater than 6, let alone 12. I was told setting PS to values higher than 7 could cause central apneas. I'd like to avoid that new horror.
I'm not sure what 7.8/3 means. I'm guessing you mean 'pressure' in that sentence is EPAP, and that it's not 7.8 divided by 5... or is it? or do you mean EPAP would run between the RANGE of 2.8 at the lowest up to 7.8 at the highest, which means PS does push epap higher and it is not my friend. If my 'pressure' is EPAP and it can run as high as 11.2, I think I'll be hospitalized from the aephagia that I cannot tolerate at 8.

No one seems able to tell me how PS affects EPAP.
Nor how IPAP is affected, if at all, by either PS or IPAP.

HJere's the question presented a new way:

IF 
1. I want EPAP to remain NEVER HIGHER than 7 

AND

2. I want IPAP LESS THAN or EQUAL TO 14 so as to STOP going higher than 14, but start as low as my body needs it.. .say even 4 or 5, 
 
3. and I have no clue what PS is supposed to do to keep my EPAP LOW LOW LOW LOW LOW LOW LOW so I don't get hurt
then what are my settings?
What is the IPAP value? (I assume 14)
What is the EPAP value? (I have no idea but I never want it to hit '8' as I have done enough damage to myself on CPAP 8)
What is the PS value? (God only knows that PS is supposed to do to LIMIT EPAP TO LESS THAN 7 or 8)

Do I have the wrong machihne?

Thanks!
I can post pictures, but not until I hit 4 postings, which is a shame for one picture might have explained this better than I am explaining it.

[Gideon]

Edit a reply and look below at the section titled "Attachments"  You will then choose a file, a screenshot from your computer.  Attachments are allowed, links are not.

With the VAuto machine that you have 

Bilevel pressures

• The AirCurve 10 device assists spontaneous breathing by cycling between two pressures in response to the patient flow.
  
• The inspiratory positive airway pressure (IPAP, or the sum of EPAP and the pressure support level) assists inspiration.
  
• The lower expiratory positive airway pressure (EPAP) facilitates exhalation comfort while providing a splint to maintain an open upper airway.
  
• The difference of the two pressures—pressure support (PS) level—contributes to patient comfort.
  

VAuto mode
In VAuto mode, the AutoSet algorithm automatically adjusts pressure in response to flow limitation, snore and obstructive apneas.

Min EPAP, Max IPAP and pressure support in VAuto mode
Pressure support allows you to set the difference between inspiratory and expiratory pressure and is fixed throughout the night. Min EPAP and Max IPAP settings allow you to restrict the delivered pressure ranges in which the AutoSet algorithm can operate.

The EPAP and IPAP will vary across the session according to the patient’s needs. It responds to snoring, apneas and flow limitation of the patient’s flow curve.

Min EPAP and Max IPAP can be adjusted to limit the upper and lower delivered pressure limits.

For VAuto settings 
EPAP means Min EPAP
IPAP means Max IPAP
PS (Pressure Support) is the difference between the actual EPAP and the actual IPAP

The VAuto algorithm automatically adjusts pressure in response to flow limitation, snore and obstructive apneas.

The Min EPAP is the lowest pressure the VAUTO will apply
The Max IPAP is the highest pressure the VAuto will apply

at any point in time the actual IPAP will be the actual EPAP plus the PS/Pressure Support  (IPAP = EPAP + PS)

There are other settings but these are the main ones.

[thibaulthib]

Hi1

Just helping you reach your 4 postings :-)

I had to move from CPAP to VPAP 2 weeks again, Sleeprider and other members on the forum such as Matt helped me a LOT to understand IPAP and EPAP. I would recommended you to take a look at my post, then post sleepyhead screenshot in yours, and we can help.

My post: http://www.apneaboard.com/forums/Thread-...-some-help

Thibault

[Kahri]

Edit a reply and look below at the section titled "Attachments"  You will then choose a file, a screenshot from your computer.  Attachments are allowed, links are not.
REPLY: I could not post with even a smiley face, as the post only went through after I deleted it. It didn't even like the ":" plus ")" (a manual smiley face) for as soon as thiat appeared, I could not post. I never posted any link. I selected a static file from my computer folder for various pictures and files related to BiPap and posted that. But this is post #3, so one more and perhaps I'll be able to post something more useful.
END

With the VAuto machine that you have 

Bilevel pressures

• The AirCurve 10 device assists spontaneous breathing by cycling between two pressures in response to the patient flow.
  
• The inspiratory positive airway pressure (IPAP, or the sum of EPAP and the pressure support level) assists inspiration.
  
• The lower expiratory positive airway pressure (EPAP) facilitates exhalation comfort while providing a splint to maintain an open upper airway.
  
• The difference of the two pressures—pressure support (PS) level—contributes to patient comfort.
  

REPLY: But with my aircurve settings of Epap 8, Ipap 14 and PS 4, if your formula is correct, my numbers will never add up, for 14 does not equal 8 plus 4 (12)
Since I get sick at that high exhale pressure I must get it at least down to 7 - and lower if possible, so using your formula the only way I can get low epap and high ipap is to have I = E+P being 14= 7+7. But if PS can raise EPAP, I'm in trouble.
Ironically, with straight CPAP of pressures adjusting from 4-8 continusouly, if my cpap pressure hit 8, I was up clawing at my mask as I was about to vomit into it. I don't know how to make it any more clear how horrible is is to exhale against a pressure of 8. I do recall getting through nights with pressures 4,5,6,and 7. But not if it hit 8.
END
VAuto mode
In VAuto mode, the AutoSet algorithm automatically adjusts pressure in response to flow limitation, snore and obstructive apneas.
REPLY: I do have it in VAUTO mode, but have no idea how it 'adjusts' if I ever do have an apnea... does IPAP yank up EPAP? or PS, or does EPAP yank up PS or due to PS. I have no idea. So yeah, I know this units is supposed to react, but I keep going back to the same problem - what numbers for I, E, and P do I set so that I never get ill at total expiration pressures 8 or more? Do i have to set a NEGATIVE value to PS? like PS -7?
END
Min EPAP, Max IPAP and pressure support in VAuto mode
Pressure support allows you to set the difference between inspiratory and expiratory pressure and is fixed throughout the night. Min EPAP and Max IPAP settings allow you to restrict the delivered pressure ranges in which the AutoSet algorithm can operate.
NOTE:But it does NOT allow me to restrict how large Epap will get. It only lets me set a bare MINIMUM. Is there no way around this?
END
The EPAP and IPAP will vary across the session according to the patient’s needs. It responds to snoring, apneas and flow limitation of the patient’s flow curve.
REPLY: how does "it" respond? By shoving EPAP up to where I'm vomiting? How does it let IPAP go up and EPAP remain below 7?

Min EPAP and Max IPAP can be adjusted to limit the upper and lower delivered pressure limits.
I need the settings on EPAP to be reversed... I don't need an EPAP MIN setting... I need an EPAP MAX setting. I need to put a CEILING on EPAP to protect myself.
END

For VAuto settings 
EPAP means Min EPAP
IPAP means Max IPAP
PS (Pressure Support) is the difference between the actual EPAP and the actual IPAP

NOTE: I'm really sorry if I appear like I havn't bothered to read my owner's manual or countless pages on the internet to try to figure out how to save myself from pain, but still get a therapeuitic inhale value so I can get well. Again, Yes, I have read all these terms repeatedly in many different locations. But in no location that RESMED provides does it say I=E+PS. Nor does it say that Ipap will pull Epap value up if IPAP goes up, or that PS will pull Epap values up, o that PS will pull IPAP values down, or anything about how any alogrithm works.
And Yes, I did ask my 'sleep nurse', but she was unclear as to how it worked. I never thought getting a bipap machine would make it so impossible to ascertain good settings. I cannot use CPAP, but if I cannot understand this machine, how am I ever going to get well. I don't trust this nurse to ever understand this RESMED machine, although they only prescribe resmed machines, so I'm really leaning so heavily on this board for help. I hate to think that if I cannot get to the bottom of this here, I'm going to have to hire yet another doctor to explain how VAUTO works and how to protect myself from vomiting in my sleep.
END

NOTE: So with my 14I, 8E, and PS 4 settings It should have been 7 for PS to get all the way from Epap 7 to IPAP 14, which I was told was not the case - I still don't know which value dominates.
Is the order of primacy - does one value rule them all? Does Ipap rule all and PS is just a rod hooked up to EPAP and IPAP so if IPAP goes up, it could drag Epap dangerously high? Is there any point where I'm safe? what is the alogrithm?
I, E, PS so the PS is just kind of bouncing round but doesn't push epap higher nor pull ipap lower?
or
E, PS then I , so that if Epap raises itself to some other value because, what, I cannot exhale?, then it shoves PS higher and shoves IPAP higher?
I know all the terminology, I need someone to plug in the numbers that leave me with values under 8 so I stop damaging my insides as I cannot exhale against 8 without pain and or vomiting.
END

The VAuto algorithm automatically adjusts pressure in response to flow limitation, snore and obstructive apneas.

NOTE:WHat *IS* the alogrithm. That's my point - Is the alogrithm having PS pusing the EVAP ever higher? Can this alogrithm function whjile still alowing me to avoid damage through aerophagia, or Epap, or IPAP. WHat is the alogrithm so I can put numbers in and get some sleep tonight without risking harm.
If this machine is just built to harm me, I'd like to know now so I can change it to something that will not constantly harm me through high EPAP values, but I've been at this 10 days now, and I just cannot seem to get an answer as is it even POSSIBLE to have an EPAP below 5,6,7 and still have an IPAP hit 14. Will I get central apneas if I have to put PS at some number over 10 , but won't a high PS just affect just the EPAP - and have it work against my attempts to exhale? I have had my throught close up trying to shove air out of my lungs against a torrent of air. I cannot be the only one with aerophagia.
END

The Min EPAP is the lowest pressure the VAUTO will apply
The Max IPAP is the highest pressure the VAuto will apply

at any point in time the actual IPAP will be the actual EPAP plus the PS/Pressure Support  (IPAP = EPAP + PS)


NOTE: I was told that was *not* the formula. But iot might be for some Respironics product. Just not Resmed. I read the manual cover to cover when I got it. I read a ton on resmed.com and elsewhere. I did at first believe it was the simple addition problem you point out. BUt...When I phoned the DME, they said it was NOT IPAP=EPAP+PS, but they could not tell me what it WAS. And for someone with this aerophagia problem, why in he world would I want to make sure that any night the machine sense I need more Ipap pressure, that it would wake me up vomiting with EPAP pressures over 8? Why is there no max ceiling on EPAP for those of us who cannot take the damage? Mine is not I+E+PS originally. It was set at 14=8+4. And we all know that match is not correct. Perhaps you are thinking of some other machine, and not the resmed aircurve vauto? or perhaps my DME has misled me?
END:.
There are other settings but these are the main ones.
NOTE:Thank you, I have investigated the other settings as well, but for now, I'm just trhying to deal with these 3 big ones. I'll worry about breath lengths and volumes, etc all once I can sleep without threat of pain, but actually also get some RESTORATIVE sleep for the first time in 3.75 years. Not being able to heal effeciently is really causing me a whole ton of problems.
END

NOTE:Unfortuantely, I cannot stay awake longer in hopes of an answer, so I'm going to have to sleep with the settings I have it on and hope it is doing me some good. I will check back in tomorrow, but I am still stunned at how incredibly convoluted it is to just get a straight math question solved with Resmed.
If I do find out through other hospitals, doctors, whatever what the real calculations are, I'll let you know. meanwhile, I'm hoping someone could tell me, once and for all, what to do with the settings I was given.

Simply:
if IPAP is 14,
and
EPAP is 5 (to steer clear of aerophagia.) 
THEN, What value must PS be ???
Thank you.

---

Seriously, that is the shortest way I can presesnt it. I've read all the manuals and probably know more than most about all the internal settings as well. All I want to know is:

Simply:
if IPAP is 14,
and
EPAP is 5 (to steer clear of aerophagia.)
THEN, What value must PS be ???

Going to bed. Perhaps to get some restorative sleep if I'm very very lucky.

[thibaulthib]

IPAP - EPAP = PS

So 14 - 5 = 9. If this is the PS you are having right now, I guess it blows in your face because it is very high! You should lower it to 4 as a start, either by increase EPAP to 10, or lowering IPAP to 9.

[Walla Walla]

I'll try and explain pressure support (PS) in my simple minded way. PS is just the difference between inhale pressure and exhale pressure. So if your PS is 4cm than your inhaling at 14cm than your exhaling at 10cm. If your machine is set on auto then pressure will increase and decrease as needed between the minimum EPAP setting and maximum IPAP setting while maintaining a 4cm difference in PS. There's no need for a maximum EPAP since the EPAP always remains 4cm below the IPAP.
The Resmed VAUTO doesn't have variable PS settings.

[Gideon]

REPLY: But with my aircurve settings of Epap 8, Ipap 14 and PS 4, if your formula is correct, my numbers will never add up, for 14 does not equal 8 plus 4 (12)
Since I get sick at that high exhale pressure I must get it at least down to 7 - and lower if possible, so using your formula the only way I can get low epap and high ipap is to have I = E+P being 14= 7+7. But if PS can raise EPAP, I'm in trouble.
Ironically, with straight CPAP of pressures adjusting from 4-8 continusouly, if my cpap pressure hit 8, I was up clawing at my mask as I was about to vomit into it. I don't know how to make it any more clear how horrible is is to exhale against a pressure of 8. I do recall getting through nights with pressures 4,5,6,and 7. But not if it hit 8.

The settings are for Min EPAP, Max IPAP, and PS
Since you want to limit your EPAP to 8 set your Max IPAP to 8 + PS which is 8 + 4 = 12  so IPAP Max = 12.  Based on your experience with CPAP this is NOT what you want.
My suggestions and this is simply to avoid a pressure of 8 (though you may be able to handle higher pressures with the VAuto because of the Pressure Support)
are the following

IPAP Max = 7.6 (This will prevent the VAuto from generating pressures >= 8)
EPAP Min = 4 (The same start as your CPAP)
Pressure Support = 3 (Low for a biLevel but will let the VAuto algorithms kick in.
(Therapy from the above settings could be achieved with a ResMed Autoset)

This will closely match your CPAP which you said you tolerated.  THESE ARE SAFE SETTINGS.
START with this and post the charts when you can so we can see what is happening.
Don't be surprised if we recommend increasing IPAP Max to > 8 and also increasing PS to 4 and possibly beyond.

NOTE:But it does NOT allow me to restrict how large Epap will get. It only lets me set a bare MINIMUM. Is there no way around this?

EPAP Max (not actually a setting) = IPAP Max - PS Pressure Support.  EPAP will NEVER exceed this value.

REPLY: I do have it in VAUTO mode, but have no idea how it 'adjusts' if I ever do have an apnea... does IPAP yank up EPAP? or PS, or does EPAP yank up PS or due to PS. I have no idea. So yeah, I know this units is supposed to react, but I keep going back to the same problem - what numbers for I, E, and P do I set so that I never get ill at total expiration pressures 8 or more? Do i have to set a NEGATIVE value to PS? like PS -7?

On the VAuto EPAP is the ONLY pressure that is changed until the pressure reaches IPAP Max when upward adjustment stops.

Repeating
IPAP Max = 7.6 (This will prevent the VAuto from generating pressures >= 8)
EPAP Min = 4 (The same start as your CPAP)
Pressure Support = 3 (Low for a biLevel but will let the VAuto algorithms kick in.
(Therapy from the above settings could be achieved with a ResMed Autoset)

This will closely match your CPAP which you said you tolerated.  Again, THESE ARE SAFE SETTINGS based on the CPAP info you provided
START with this and post the charts when you can so we can see what is happening.
Don't be surprised if we recommend increasing IPAP Max to > 8 and also increasing PS to 4 and possibly beyond.

[Kahri]

Am I now in the right topic area? I was 'moved', but don't know how to be sure where. I just tried posting and it didn't like where I posted as I didn't have permission.