S9 Adapt AutoASV Pressure Support

Pressure support for the S9 ASV. I've been on the S9 ASV Auto for 13 days now and I'm sleeping good and feeling good. Except for 3 nights with one hypopnea each night the rest have been zero's. The machine is set on the default settings for Auto ASV which I'm using it in. Min EPAP 4, Max EPAP 15, MIN PS 3 and Max PS 15. I'd like to learn about PS in ASV and what it will do. Like if for example if I'd bump Min PS from 3 to 4 what do I add that to? Would I add that to Min EPAP 4 and that would now be 8? If I changed the Max PS of 15 what would that change? I want to learn more about this PS in ASV. When I was using the VPAP Auto I knew what to do with the PS. My high pressure has gone to 22 at times and I never felt it, had high pressure in BiPap so was use to it. I've not had a titration for ASV just had one for BiPap which was way off from the numbers I finally tweaked it to. All I can say is I love this machine and I'm sleeping and feeling so much better than when I was using my BiPap, it's so easy to breath with, you don't have that high pressure blowing in your face all night long. I'd appreciate any advice you'd give.

The best I can do is bump you up. Merry Christmas!

squid13 wrote:Pressure support for the S9 ASV. I've been on the S9 ASV Auto for 13 days now and I'm sleeping good and feeling good. Except for 3 nights with one hypopnea each night the rest have been zero's. The machine is set on the default settings for Auto ASV which I'm using it in. Min EPAP 4, Max EPAP 15, MIN PS 3 and Max PS 15. I'd like to learn about PS in ASV and what it will do. Like if for example if I'd bump Min PS from 3 to 4 what do I add that to? Would I add that to Min EPAP 4 and that would now be 8?

If Min EPAP = 4 and Min PS = 3, then your minimum IPAP = 4 + 3 = 7 cm.

If MIn EPAP = 4 and Min PS = 4, then your minimum IPAP = 4 + 4 = 8 cm.

In other words, bumping up the Min PS and leaving the Min EPAP alone increases the minimum IPAP. The minimum IPAP is always equal to Min EPAP + Min PS and the beginning IPAP for the night is equal to the minimum IPAP.

If I changed the Max PS of 15 what would that change?

Changing the Max PS changes how far apart EPAP and IPAP can be. On an ASV machine that will affect how much extra pressure the machine delivers when it's triggering breaths by using a very high IPAP and a low EPAP.

As an example:

Let's suppose that the current EPAP pressure is 5 cm and the machine decides that it has to trigger some inhalations---i.e. the ASV algorithm kicks in.

If max PS = 15, then the machine can use up to current EPAP + max PS = 5+15 = 20cm of pressure on the inhalations. In other words, during the time frame where the machine is triggering the breaths, it may deliver an IPAP = 20 and and EPAP = 5.

But if max PS = 16, then the machine can use up to current EPAP + max PS=5+16 = 21cm of pressure on the inhalations. In other words, during the time frame where the machine is triggering the breaths, it may deliver an IPAP = 21 and and EPAP = 5.

In general, on each machine triggered breath, the IPAP used in the "triggered breath" algorithm may rise to current EPAP + max PS. And the maximum IPAP that is possible over the course of the night is equal to max EPAP + max PS. So currently your max IPAP = 15 + 15 = 30cm (if your machine can deliver that much pressure).

So changing the Max PS setting will change the maximum IPAP pressure allowed.

Does that help?

Robysue Thank You for that great explanation of PS use in ASV, it cleared it all up for me. Have a Merry Christmas and a Happy New Year.

squid13 wrote:Robysue Thank You for that great explanation of PS use in ASV, it cleared it all up for me. Have a Merry Christmas and a Happy New Year.

Good job Robysue. I would just add that I like my PSmin to be not quite at the bottom of the its range, which on my machine is 3.0cmH20. I set it at 4.6cmH20 because at 3.0 there's a certain annoying wobble/oscillation at the initiation of my inhale breathing that I get when my inhale cycle is triggered (T2). This can sometimes wake me up. Thru a week's experimentation I found that if I raised my PSmin to 4.6cmH20 then it goes away... I can offer no profound explanation why this happens, however several members have commented that they have had the same experience. I call this raise in PSmin my 'pre-load' pressure, for lack of a better term. As a odd coincidence, on my mt bike fork I like some pre-compression dialed into the main spring... maybe that's what go me going down that track of reasoning. As a side note: I'm not suggesting everybody should do this, but if you experience that initial inhale wobble/ringing or see it in your pressure flow line via your software, give it a try.