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+--- Thread: Love the stability that ASV mode (not AS Auto) provides (/Thread-Love-the-stability-that-ASV-mode-not-AS-Auto-provides)
Love the stability that ASV mode (not AS Auto) provides - S. Manz - 09-12-2021
I am a CSA apneac with a very high event count (58 per minute) without my ASV.
I have tried titration in both ASV and ASV Auto modes and find that I can't get a good night sleep with ASV Auto variable EPAP titration throughout the night. So after some research I came to the conclusion that the ASV-Auto mode is best suited for "complex' situations where the user of the therapy has both CSA and OSA obstructive events. In such cases Auto ASV can deal with OSA events by auto-titration of EPAP setting and also deal with CSA events with auto-Titration of IPAP settings, however since I do not have any Obstructive events, ASV mode where the EPAP pressure is kept at a constant and my IPAP pressure max's out at a relatively low pressure, keeps me sleep the best with a fairly good AHI of below 2. (see the screenshot from last night, attached).
How does your ASV settings work out for you? My doctor had recommended that I keep my setting on "ASV Auto" at maximum settings but not only did these high pressures kept me up all night fighting with the machine, I also found that very high pressures also help increase Apnea episodes over time.
Let me know what you think and how your pressure settings are helping you get a good night asleep.
RE: Love the stability that ASV mode (not ASV Auto) provides.. - WearyLamini - 09-13-2021
You have a nonzero amount of hypopneas and wild pressure swings. Zoom in on the flow rate graph, are your breaths perfectly sinusoidal with rounded tops, or not?
If not, then you are experiencing inspiratory flow limitations, and the reason the pressure is so crazy is because your EPAP is too low and the machine is going crazy trying to apply enough pressure support to keep up. Also, 5 minimum PS is really high for someone with no/minimal airway obstruction, and could be causing centrals(that the machine then compensates with backup rate) on its own. Try switching to EPAP 6, PS 3-10 for starters.
Anyway, post some zoomed in pictures of your breathing.
Also, if I can ask, in My Options->About, what does your SW field say, e.g. SX567-0305?
RE: Love the stability that ASV mode (not ASV Auto) provides.. - Sleeprider - 09-14-2021
We have a number of ASV users that find the fixed EPAP mode to be better. You are using a PS range of 5.0 to 10.0 and it shows as a very flat line on the pressure graph, and the high minimum PS may be decreasing spontaneous breathing. What were the results with lower PS min or higher PS max?
RE: Love the stability that ASV mode (not ASV Auto) provides.. - S. Manz - 09-19-2021
ASV characteristics are breath by breath adjustment so the graph looks vastly different to non-ASV machines.
RE: Love the stability that ASV mode (not ASV Auto) provides.. - S. Manz - 09-19-2021
My sw is SX 567-0302
RE: Love the stability that ASV mode (not ASV Auto) provides.. - Geer1 - 09-19-2021
If you only have CSA than high PSmin is counterproductive. High PSmin lowers CO2 levels which increases central apnea. If all you have is CSA then the only function you need from ASV is backup rate and variable PS (which is part of ASV as long as you have a range between PSmin and PSmax). The backup rate forces you to take a breath when your brain decides it doesn't need to and the variable PS adjusts to supply enough air depending on your spontaneous efforts.
I didn't read all your old threads/posts but it seems clear you have tried some weird settings I assume in a guess and check manner.
Apnea and treating it really isn't that complicated. EPAP holds airway open to fight obstructive apnea/collapsing airways. Pressure support helps force more air through a restricted airway. Backup rate encourages you to take a breath when your body doesn't spontaneously take one. Variable PS targeting minute ventilation (as your Resmed does) increases and decreases machine ventilatory support as needed to maintain target ventilation.
With your ASV you only really have four settings. EPAPmin, if you don't have obstructive apnea than minimum of 4 makes sense. Auto option, treats obstructive in patients that have worsening obstruction in different sleep stages/positions, if you don't have obstruction makes sense to turn it off. PSmin, you set this to maintain minimum amount of ventilatory support but need to take note higher ventilatory support almost always worsens central apnea. PSmax is then used to give you a variable range of PS so the machine can adjust ventilatory levels as necessary. Reducing PSmax handcuffs the machine reducing high pressure effects such as waking you up, aerophagia etc but if you set the range too low the machine may not be able to treat central apneas effectively and you may see residual apnea/hypopnea.
That all said from your data in other threads it isn't clear that this is all central related, a lot of the examples posted appear like they could have an obstructive or positional aspect. I couldn't find any sleep study results but am curious to know if they noted obstructive events in which case trying a higher fixed EPAP or a cervical collar may be worthwhile.
If all central than PS range of 3-10 makes a lot more sense than current settings.
RE: Love the stability that ASV mode (not ASV Auto) provides.. - S. Manz - 09-19-2021
My Ps min is not high at only 5
RE: Love the stability that ASV mode (not ASV Auto) provides.. - S. Manz - 09-19-2021
You need to read up on ASV machines.
Their algorithm follows every breath so their graph characteristics are entirely different to regular auto cpap machines, which I think is where your confusion comes from.
RE: Love the stability that ASV mode (not ASV Auto) provides.. - S. Manz - 09-19-2021
".....If all central than PS range of 3-10 makes a lot more sense than current settings..."
My Ps is 5 to 10 which is very close to what you think it should be, except that I am more comfortable with Ps min at 5 instead of 3.
RE: Love the stability that ASV mode (not ASV Auto) provides.. - S. Manz - 09-19-2021
ASV machines don't register Central events because their breath by breath algo will breakup central apnea episodes before they occur.
The small AHI that you see in my graph is registered Hypopnia episodes which are well within the normal range of below 5 AHI.
And sorry about making several responses but I am responding to as many points in your post as I can, separately rather than posting a ling winded response.