[Pressure] Understanding Pressure Settings on ASV

[Suzee]

                [attachment=56352][attachment=56352]Understanding Pressure Settings on ASV
Please help me understand why my therapy has not been successful.

Hx: 75 y/o F, no hx of sleep apnea until soon after surgery in 2017.  S/S: exhausted and could not recover from surgery.  Had to quit working.  Finally in 2019, heart specialist thought about apnea and referred me to Sleep Specialist.

May 2019, in-lab PSG showed 60 events/hr in supine position (sleep position I must use r/t shoulder pain).  Started with Dream Machine CPAP.  Frequently had high number of CSAs.  Dr had ordered pressure of 5-20.  I could not tolerate these high pressures; (chest hurt and left me breathless throughout day.)  
 
New Dr advanced to Dream Machine BIPAP.  Again settings with high pressures which were intolerable so Dr. lowered to 5-10; but was too low to treat my apnea.  I was always tired, never felt rested and did not sleep well and the apnea continued.  I continued BiPAP for 1 yr. then Dr suggested I stop using BiPAP.  He said CPAP is not for everyone.   In the meantime I was able to function but always at a very low energy level.
  
Dec 2022 I had car accident.  My apnea became very severe.  Found new Dr. in Sleep Medicine.  Had three in-lab PSGs in 2023: (Ap '23), recommended Airsense 11 CPAP.  I used Airsense for 6 wks but that was triggering high CSAs and Cheyne-Stokes respirations.  I was sent for in-lab PSG #2 and #3 (May and June '23) before receiving Resmed Aircurve ASVAuto in July ’23.

Initially ASV pressure recommendations from Sleep Study: EPAP 5-11 cmH2O, pressure support 0-15 cm H2O per Dr orders.  I continued with restless sleep and ~ 10 AHI/hr.   Pressure was strong enough to push face mask (amara view) loose and cause a significant air leak.  Dr. lowered pressures to:  EPAP 5-11 with PS 0-10 cm H2O.  Then lowered to current pressures at EPAP 5-10 and PS 0-8.

Now, almost 5 months of using ASV, I am still miserable and severely sleep-deprived.  I fall asleep then am awakened usually 2-3 hrs later. I think the pressure is too high.  I try to go back to sleep but cannot because when I turn on the ASV the pressure escalates quickly and it feels like the machine is attacking me.
 
The AHI is usually under 5 but sometimes as high as 29. The Resmed sleep reports are not showing any CSA or Cheyne-Stokes any longer.  So some things are better.


I do have some air leaking but usually it is under 20.  I know that is not ideal.  I have tried different mask set-ups and liners to no avail.  Currently I’m using the F&P Evora full face mask.
 
I wake up in the morning with my belly bloated and in pain.  I must be opening my mouth.  I have tried 4 different chin straps unsuccessfully.  The tape over my mouth works, but I cough and choke a lot at night on the ASV so I need to be able to clear my airway.  The soft cervical collar has helped to keep me from dropping my chin down.

I am really struggling to try to resolve these problems.  I am so sleep-deprived for almost 12 months now that I am having great difficulty thinking.  I feel drained with no physical or mental energy.  Often I can barely perform my ADLs. 

My Dr does not seem to know what to do.  I don't understand the pressures settings on an ASV but I'm wondering if my EPAP pressure is too high or the pressure support begins too low at 0-8.  I've studied my Resmed Sleep Reports.  It looks like the SA event happens and then the air leaks, not the reverse.  I’m trying so hard but can't understand the graphs on OSCAR very well.
 
I read that if the Pressure Support is raised to a level for the machine to compensate for Central Apnea, the person will become 100% reliant on the machine, because PS suppresses respiratory drive in people with CA.

Any ideas would be appreciated.  And please share any information on how or where I can learn to understand how these pressure settings are affecting the machine and my sleep and what is most appropriate.  Thank you so much.

[SarcasticDave94]

Welcome to Apnea Board,

I've used the ASV for about 2 years, but nothing recently due to other breathing issues. However I never had an issue where I was reliant on it or that therapy was detrimental to my health.

Those 2 years with ASV were pretty good, best sleep I've had in years. I also have COPD so they clash a bit. And those 2 years on ASV, the only person that set my machine was me. Doctor and RT had less than a clue how to run it. The DME supplier RT had to guess at settings, so I was off to a bad start. Enter Apnea Board, where I learned how to make edits in an informed way.

OK on to helping your ASV do better. I'll just go through a few things, and if applicable then I'll suggest taking action accordingly. I can't tell the settings involving ramp. My experience was ramp and ASV didn't get along at all. So if ramp is on, you'll need to work on minimizing it, less time possibly.

Otherwise, there's some leaks that are hurting therapy and comfort. I began with the Amara View and it was not working for me. I had to move on to the Fisher and Paykel Simplus then the Vitera. Those or some of the newer models may be decent ones to look at.

Is there lots of natural mouth breathing for you typically? If not, maybe getting a mask that isn't full face helps. Smaller seal area that's within a nasal pillows mask will mean less mask surface to deal with, meaning less areas that can leak. So maybe a F&P nasal pillows or ResMed P10. If that's not suitable, a nasal mask or nasal cradle type. Again less surface to seal the better you'll be regarding leaks and lower disruptive sleep.

Pressure settings look less than ideal. I don't think the issue lies with EPAP so much as you have very little obstructive apnea. I think PS range isn't working well. I'm going to suggest you try adding a bit to PS min or PS Max, eventually both PS numbers need to go up, from what I'm seeing. Maybe you'll need to get to default PS 3-15 at some point but it's difficult to tell where this ends up. The PS portion of ASV is where those UA will be addressed, and given you're on ASV, these are likely Central in nature. Right now, the ASV lacks the power needed to combat those events because of lower PS. So maybe consider adding a bit to both. ResMed pressure settings allow 0.2 cmH2O adjustment increments so you've got a lot of little adjustment if you need to do it gradually, which is fine. But I think you're going to need more PS Min to have a greater pressure differential over EPAP for one, and higher PS Max to give the ASV some power to combat events. One indicator of lower PS Max is your pressure chart, see the tops there where it's flat and looks cut off. The ASV is trying to go higher but settings prevent this.

In case you've not yet learned about ASV settings, how it works is EPAP is your exhale pressure and mainly deals with obstructive events. Then PS which is pressure support, adds to EPAP to combat Central Apnea events. Both added gives the number you can't set on the ASV, IPAP which is inspiration pressure.

Just a few things to think about.

Others will add info, insight, other suggestions. Hope the info helps, keep us informed, and don't quit. We're here to help make the ASV do its job and make you sleep in the best comfort possible.

PS your path to ASV is typical. Insurance dictates the failure path through those other machines.

[Sleeprider]

First of all, you have positional apnea and need to correct that first. All of those UA events are obstructive apnea caused by chin-tucking or some kind of head/neck misalignment that obstructs your airway. This is so common we have some wiki articles to help.
Positional Apnea https://www.apneaboard.com/wiki/index.ph...onal_Apnea
Soft Cervical Collar https://www.apneaboard.com/wiki/index.ph...cal_Collar

Once you deal with that, we can certainly adjust your pressure and get this working correctly. Some people resolve the problem by changing to only one pillow or a flatter, less firm pillow others need a soft cervical collar. I assume you are not treating central or complex apnea, other than therapy onset, correct? We can get your pressure down and treat any therapy onset centrals if you take care of the positional issue. In spite of the fact positional apnea is very common Doctors are not trained to recognize this problem and do not understand nor treat this phenomenon. Once it's resolved your world will change a lot. One misconception needs corrected. ASV is designed to allow for spontaneous respiration and only applies pressure support as needed, when needed to maintain air volume. It can take several missing or short breaths for the ASV to reach peak pressure support, and where CA are involved, the device backs off to spontaneous very quickly. Patients do not become dependent on the ASV. They all have normal spontaneous respiration during the day. You will not become dependent on a soft cervical collar either, but you will need it at night unless and until this positional issue is corrected.

[SarcasticDave94]

I stand corrected. I missed the positional aspect of the clusters. It makes sense though.

[Suzee]

Reply to Sleeprider and SarcasticDave94:

Thank you so much for your response!  I appreciate it.
I apologize.  I realize now I did not send the screenshots through in advanced view so I am attaching so all advanced graphs are included.

Yes, I have positional apnea, which was diagnosed in my first PSG in 2019.  But since shoulder replacement surgery X 3, I have severe shoulder pain and am unable to sleep on either side.  I try to modify my position as best I can, leaning toward my side, but there is only so much I can do positionally because of the pain.

Yes, I bring my chin down to my chest, so finding the Apnea Board info about wearing a soft cervical collar has been very helpful and I've been wearing it now for about a month.

I also find my head-neck alignment is really bad.  I find I am trying to accomodate the mask and tilt my head awkwardly so as not to break the suction of the mask.   I have tried soft and firm pillows and changing the direction and position of the pillow.  I"m not sure if a CPAP pillow is the answer.

Yes, we are treating CSA along with OSA.   Etiology of CSA being the airsense 11, although my HCP feels my auto accident and whip lash may have also contributed to the CSA.  I don't think I am having CSAs currently but am unable to tell from the graphs.  When I have CSAs it seems to affect me neurologically and causes me to have some imbalance and difficulty when walking.

And yes, I'm a mouth breather.  I seem to be unable to control it.  I have tried 4 different chin straps and tape over my lips.  I am full of gas and very uncomfortable in the morning.  

As far as pressure settings, I have never been able to tolerate high pressures with any of the 4 different types of PAP machines I have used.  My HCP has lowered the pressure settings for EPAP and PS twice since my third PSG in June.  The high pressure seems to cause me to swallow air.  It seems to cause the mask to leak.  

And the high flow of air wakes me up.  It is like a night terror.  I get shaky and can't go back to sleep.  I am averaging 3 hours of sleep now for almost 12 months.   My HCP does not want to change the pressure settings.   But I am so sleep-deprived and this has been going on for so long that I am having real difficulty with thinking and remembering things.  I'm worried this is an early dementia brought on by lack of sleep.  And I have absolutely no energy for anything, including ADLs.

The high pressure hurts my chest.  My lungs and ribs ache.   It causes mucous to develop in my lungs at night so I get congested and cough and choke quite a bit through the night.  I wake up short of breath, breathing rapidly.  And it takes me a couple of hours in the morning to be able to breathe normally, as I continue coughing for several hours.  Then it clears and I am not otherwise congested until I begin using the ASV again at night.

I was told ramping was not compatible with ASV.  But last night I just started testing the ramp for 45 minutes, because I am trying to determine if a lower pressure setting is really what I need.  I am so exhausted.

Any more suggestions?  Your thoughts?
Thank you so much.

[SarcasticDave94]

Just to clarify, the positional Apnea Sleeprider has mentioned is due to the head and neck alignment and chin tucking aspect. This is known to severely restrict the airway, much like an Obstructive Apnea would be. This however can be reduced by thinner pillows or other means to keep the neck from kinking like a garden hose.

I'm not sure if you're aware, you can edit your settings on the ASV. Clicking home and the dial in at the same time and holding 5 seconds takes you into the clinical menu where settings can be edited. If you're wanting settings changed, don't wait on doc to do this. You'll likely be billed, and it's really unnecessary. When I had my ASV, I'm the only one that changed my settings. I don't need a script change either as it was my therapy.

[Sleeprider]

Let's make some changes to your ASV settings and clarify our objectives for a soft cervical collar. As Dave said, the soft cervical collar needs to encourage you to keep your chin in an elevated position to avoid obstruction. If you are using multiple or tall pillows, that is working against you, so stick to a single medium fill down or soft pillow, not foam or firm material. The problem does not come from sleeping on your back, it comes because your head tilts forward and obstructs the airway. You may need to try other models or sizes of soft cervical collar to get the fit you need. The ideal collar supports the back of the jaw and provides chin support without impinging on the soft tissues of the throat behind the chin. You should always be able to fit several finger behind the collar in front of your throat. If that's not the fit you have, keep trying alternatives.

You are going to do better with higher minimum pressure support (PS min). this will provide support to your inspiratory effort on every breath, so the only change I want you to make to your current settings is to increase PS min to 3.0. This should greatly improve comfort. This setting shows how to access the clinical settings. Just scroll down to PS min and rotate the dial until you see 3.0 and then press the dial in to set that pressure, and exit the clinical menu.

[Suzee]

To: SarcasticDave94

Thank you for sharing the information about the neck, chin, pillows, etc.  It is very helpful and I will try it.

As far as changing the pressures on the ASV, I was able to work with the CPAP and the bilevel several years ago but the ASV is out of my league.
I think I could adjust the EPAP and IPAP but am totally lost when it comes to understanding the Pressure Support.

Thank you, Dave.


To:  Sleeprider

Thank you for sharing, clarifying and guiding me with some very valuable info.    I am anxious to go take a nap with those changes.
I have been getting depressed because this has been going on so long, the HCP is not helping and I am not getting any better.   Oh, my gosh!  I am so excited to see if this helps.

Thank you so much.  I am grateful to you.

[SarcasticDave94]

OK, on the ASV settings, it's exactly the same principle that works in adjusting CPAP, with different setting areas to edit.

Besides humidity, heated hose setting, and ramp (which I don't suggest with ASV as it can enhance CA), maybe smart start and stop. Onto mode and pressure: there's Mode of CPAP, ASV, ASV Auto the last which is what I'd suggest.

• CPAP: single static pressure, Example if setting it to 10 that's all, no variables.

• ASV: gives some variable, single EPAP basically the same as any other CPAP. Then there's PS or pressure support. It'll be PS Min then PS Max, like other bilevels.

Note PS differential between Min and Max must be at least 5.

• ASV Auto: makes EPAP a range of EPAP Min and EPAP Max. PS will be identical to ASV mode PS. That's it, no more settings.

IPAP is not user set. However it is indirectly set by edits to EPAP and PS. IPAP equals EPAP plus PS. There are a few hard limits, 4 is minimum and 25 is Max.

Example only not saying use this
Default ASV Auto
EPAP 4-15
PS 3-15
IPAP will be 7-30, but again machine physically limits this to Max 25.

ASV Auto gives 3 pressure ranges for EPAP PS and IPAP.

Trust me, you can set this. If you've set CPAP or bilevel, you can set an ASV.

[Suzee]

Thank you for sharing the details and clarifying the settings, Dave.   I appreciate it.