ASV Settings -- looking for suggestions

[croc297]

My AHI was 65.5 before treatment.  I have progressed thru CPAP to BiPAP and now on an ASV . CPAP wasn't tolerable and AHI's where still high.  Under BiPAP my AHI came down to low to mid 20's.  Under ASV I'm averaging now around an AHI of 16.3  .  Seems resistant yet to come down much more.

I attached a couple screenshots -- my current settings are shown below -- thoughts -- what to do different ?

AirCurve 10 ASV
PAP Mode: ASVAuto
Min EPAP 9.0 Max IPAP 30.0 PS 6.0-15.0 (cmH2O)

Thanks !

[SarcasticDave94]

You probably can reduce PS Min to 3 or 4 for better comfort.

Ramp... You either need to increase to about 7 and maybe a few minutes, or make timing Auto for now, but eventually you'll want to remove it entirely. It's counter-productive to therapy, there'll be no therapy while it's active, and the variability from Ramp to therapy pressures may induce CA.

Third, you likely are chin tucking or having Positional Apnea. Your head and neck are likely getting into a position where your airway is being kinked closed like the garden hose. Unless you have a stack of pillows or some odd sleep position causing this, you'll probably need to consider a soft cervical collar to physically hinder kinking the airway. The indicator for me about this? Look at OSCAR charts and notice that constant flags under hypopnea that are sometimes clustered, and the fact your ASV parks at Max IPAP nearly 25 frequently with no effect on those events. This is your big enemy right now.

Take a look HERE on the wiki regarding Positional Apnea.

[Sleeprider]

A couple possibilities here. Your minimum PS of 6.0 is working against you forcing hyperventilation, which is stimulating CA that have become hypopnea. Let's use PS min 3.0, and if necessary for comfort you can take that to 4.0. I suspect you have some positional apnea. and may need to protect your airway from poor cervical alignment. Describe your sleeping positions and any pillows, wedges, incline etc. https://www.apneaboard.com/wiki/index.ph...onal_Apnea So once again, Dave nailed the same issues I see.

[croc297]

Thank you @Sleeprider and @SarcasticDave94 for your thoughts -- very appreciated.

Some responses :

• I generally sleep on my back following several rounds of spine surgery including de-comprehension and fusion.  I have not been comfortable on my side for a good while.  I sleep in a recliner -- whole chair at a slight angle. 
  
• Following your notes I went out today and bought a cervical collar so will give that a try.  
  
• I agree with ramp reduction -- it used to be 45 mins from the awful CPAP days -- but since BiPAP and ASV have it down to 15 now -- and will continue to reduce or go auto as the ASV is tolerable which the CPAP wasn't.
  
• Note sure what to make of the centrals (which the BiPAP used to describe them as) vs now the "unclassified" (which the ASV calls them).  From the patterns I think they are the similar things.  Overall they haven't seem ramp related but most commonly from mid-night /early am onwards -- when my neuropathy also flares.  I've often wondered might there may be a a correlation between my spine condition/aggravation/neuropathy and the centrals .  My spine issues are mainly lumbar not cervical  -- so may be co-symptoms with centrals but not causal.
  
• I'll start there -- and look at PS possibly next
  
• My mins O2<90 and <88 is still high -- I realize our journey's /conditions are very different but the physicians seem very focused on AHI -- I don't understand why O2 sensors aren't routine or at least initially. I have nights with good AHI's -- but not good <88 O2 scores.  In terms of how I feel O2 is more predictive then my AHI -- but that's another topic.
  

Again I really appreciate the suggestions !

[Sleeprider]

The UA events are assumed to be obstructive as are the hypopnea. You have plenty of PS to overcome open airway or central events, so we're pretty certain it is your upright sleeping position without cervical protection that is to blame. You will be surprised at the difference that a cervical collar can make, but don't be surprised if it takes more than one attempt to get it right. Your inclined sleep position will be a challenge for the collar, and we need a fit that protects alignment without impinging on the soft tissues of the throat behind your chin.