Love the stability that ASV mode (not AS Auto) provides

[S. Manz]

".. ..Zoom in on the flow rate graph, are your breaths perfectly sinusoidal with rounded tops, or not?..."

Prefect Sinusoidal breath by breath graph

[sheepless]

I've been using my asv with fixed epap lately and I too prefer it.

how do you know you don't have oa? none in your sleep study? none on non-asv machines? I'm sure you must know the asv doesn't report oa or ca, just ua. you're ua and h may well be obstructive.

most if not all the previous commenters are not new to asv so you are missing some good feedback by assuming they don't know that asv is different than cpap/apap.

all that matters is if you're happy with your treatment. if you're not, I'm not sure your chart looks as good as you seem to think. the hairbrushy flow rate, the huge difference between med inhale and exhale time, the fact that your ps is maxing out most of the night and the 1.4 ahi are hints to that effect. some changes have been suggested, which I tend to agree with. first, your min ps of 5 is pretty high for most people and your max ps of 10 is pretty low for people with ca. second, it's pretty easy to get 0.00 ahi with asv yet you still had apnea and hypopnea in the latest chart. chances are, they're obstructive, which would benefit from higher epap. you have to experiment to figure out if they're oa or ca and what epap setting treats them out.

I think you're right on the money regarding fixed vs ranging epap for you but variable epap isn't usually more disturbing than variable ps. I think you can achieve better results listening to the folks that commented before me regarding increasing epap, decreasing min ps and increasing max ps.

it's up to you.

[Geer1]

My Ps min is not high at only 5

It is if all you have is central apnea or even obstructive apnea. The majority of CPAP machines produced and used all limit PS below 3 cm (all resmed autosets and dreamstation CPAP/APAP versions)... These machines are meant to support spontaneous breathing not act as a ventilator... 

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.

I know exactly how these ASV machines work, do you? The algorithm doesn't look at individual breaths, your Resmed looks at minute ventilation and targets 90% of your previous ventilation. If you look at minute ventilation graph will see a red line that shows this target level. If you take a small breath your minute ventilation is lower so the machine provides more pressure support on the next breath. Your machine calculates minute vent on a rolling average so if you take multiple small breaths it will provide more and more pressure support to try and get caught back up whereas if you only take one small breath and return to normal breathing things will stabilize and pressure support returns back to minimum and you continue spontaneous breathing. If you set minimum ventilation support too high you induce more central apnea and force the machine to work harder to maintain your breathing. 

Your data shows continuous support and pressure fluctuations throughout the night. You are never having periods of spontaneous breathing effort and this is likely due to the high PS min inducing central apnea/respiratory depression. Instead of trying to find settings that minimize this you have instead decided to handcuff the machine to make it more comfortable to you (by turning off auto epap and limiting PS max). Instead of trying to find settings that make this more comfortable perhaps you should try to find settings that minimize the amount of work the machine has to do? 

Resmed titration protocol says to use PSmin = 3 and gives no reasoning to change it. This is because these machines literally are programmed to increase PS as needed to deal with both central and obstructive/restrictive breathing, there is rarely any need to use PSmin higher than 3.

So the big question is why do you think you need PSmin of 5? Why do you need near ventilatory level pressure support?

[Geer1]

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.

ASV do not register central events because they have backup rate which interferes with the forced oscillation technique Resmed uses to determine if an apnea is central or obstructive in nature. ASV as well as all other Resmed machines with backup rate (ST and ST-A) do not use FOT and record all apnea as unknown apnea for this reason. You cannot assume that either your apnea or hypopnia are central or obstructive in nature, they could be either and usually hypopnias are central in nature in patients that primarily have central apnea.

My guess is your hypopnias are either residual untreated central apnea or are obstructive in nature. 

Although under 5 ahi is considered "normal" most central only ASV users seem to have 0 or close to 0 ahi due to capability of these machines.

[SarcasticDave94]

For me, Auto ASV with EPAP range was better. I tried ASV a part of 1 night without the EPAP range and found it to be "off". I never used it in that ASV mode again.

[S. Manz]

"...........What were the results with lower PS min or higher PS max?........."

Lower than Ps min 5 leaves me struggling (at times) with inhales and my Ps max at over 5  will wake me up with over-pressure.
This setting is the most comfortable yet since I started on ASV about 6 months ago with the lowest AHI and most uninterrupted sleep cycles.
I wake up relatively refreshed and regularly dream.

[S. Manz]

".....how do you know you don't have oa?..."

I know because none of my sleep studies (or my wife) report OSA.
OSA is more of a physiological issue whereas CSA is neurological . I have had CSA for pretty much all my life.
The low AHI reported as Hypopnea is well within the normal range and when I zoom in the graph it clearly shows 2-4 breaths on average that become progressively shallow before the ASV kicks in and breaks it up.
I can live with a AHI of below 5.  

[S. Manz]

".......You cannot assume that either your apnea or hypopnia are central or obstructive in nature, ......"

First of all, yes I can:-)
Hypopnea is hypopnea and resmed ASV algo registers it pretty correctly.
It starts with a shallow breath that gets progressively shallower and by the 3rd or 4th breath the ASV kicks in the IPAP max and ends it.
Without exception all my hypopnea events have identical characteristics.
At below AHI of 5 I would not even worry about these occurrences. My AHI hovers between 0.1 to about 3 and I am good with that.
Ps.
I know I don't have any OSA events because there's not a single occurance reported in my sleep studies over the years....and I don't snore either:-)
My issue is primarily central and I am by nature a very slow breather.
My insp. rate averages only 12 p/min.

[Geer1]

What makes you think you struggle with inhaling when PSmin is less than 5?

That would not be a central related issue and is indicative of either an obstructive/restrictive breathing issue or poor lung function.

[SarcasticDave94]

As I understand it, snoring can be an indicator, but it's not a requirement. Much like you don't need to be overweight to have Apnea.

I've definitely got high centrals without therapy, but I had my min PS at 3 or 4 with known respiratory disease, and my breath rate is about 10.

Maybe you have something going on regarding a respiratory issues that needs looking into.

I do have to wonder, is relatively refreshed good enough? I know what it was like for the ASV to give excellent therapy before COPD chimed in. I had better than relatively refreshed.