Difference between S-Mode and VAUTO mode - Aircurve

[MrIvanDrago]

I know this has been covered somewhere, but looking for a quick answer.

What is the difference between S-Mode and VAUTO mode on the ResMed Aircurve. I know how they function, but take this for example:

S-Mode: 15.0/11.0 
VAUTO Mode: 15.0/11.0 PS4.0

Are they exactly the same thing, or is there something with S-Mode that is different? I know these settings would show flow limits in VAUTO mode, but wondering if there is something I am missing. Thx.

[Sleeprider]

S-mode is fixed pressure with set EPAP and IPAP pressure.
Vauto is auto adjusting pressure with EPAP min, Max IPAP pressure and PS
When EPAP plus PS equals IPAP in Vauto mode, the result is identical to S-mode. In your example above, you could set EPAP min 11.0, IPAP max 18.0 and PS 4.0, and the device would provide auto-pressure between 15/11 and 18/14.

[MrIvanDrago]

Ok great. I wanted to double check if it provides the exact same therapy. I know 'EasyBreathe' is an option in S-Mode and wasn't sure if that did something different.

[Sleeprider]

Easybreathe is the pressure transition you feel between IPAP and EPAP on Airsense 10, 11 and the Vauto, S and ASV. Easybreathe can be turned off on the Aircurve VPAP S, and is not available on the ST. Without Easybreathe, the pressure is delivered as a square wave and can be modified by "rise-time", while Easybreathe shapes the pressure to look like a cresting wave. You can see it in the Mask Pressure graph. I don't know of any reason not to use Easybreathe as it is more comfortable and quieter.

[MrsMontoya]

On Aircurve 11 VAUTO what the difference between these two settings? Wouldn’t they both be the same pressure, and act the same??

S-mode 15/11 
Or 
VAuto mode-15/11 PS-0

[Crimson Nape]

Hi MrsMontoya!   -  
That would be incorrect.  The VAuto mode has provisions for EPAP starting pressure, maximum IPAP pressure and Pressure Support (PS).  To achieve the same settings as you listed for the S-mode, you would set the following:
EPAP: 11
IPAP: 15
PS:  4
The PS value is added to the EPAP pressure to arrive at the IPAP pressure.  So, 11+4=15.  Or, so I've been told.

Your listing for the VAuto mode of 11 EPAP, 15 IPAP and a 0 PS, would make the EPAP and IPAP pressure the same through a pressure range of 11 to 15. Basically a standard AutoSet CPAP pressure range.
- Red

[THEVGE]

I actually just posted a thread on a Dutch forum as I seriously doubt that this is correct. My experience is that, for me e.g.,, S-mode P 10 PS 5, Easy Breathe ON, trigger VH, cycle MED, Ti-min 0.3, Ti-max 4.0 does NOT resemble VAuto with the exact same settings. Please note that statements below are very subjective and I should generate data to support this, still, due to this recent thread I want to chip in.

1 - My subjective feeling is that S-Mode is better for me than VAuto when using the same settings (but I probably need VAuto mode to adjust P during REM).
2 - In OSCAR I noted that especially the 1st hour of my sleep my breathing flow rate (both in and out) looks better in S-mode than in VAuto mode; after about an hour they become comparable. This could explain my subjective feeling.
3 - Why does OSCAR not plot these very important settings in S-mode? I do not see Easy Breathe ON/OFF, nor all the trigger/cycle/Ti-min/Ti-max settings. This makes me doubt if the set settings are actually used, or is this a limitation from OSCAR.

I will need some time to verify this, but this subjective feeling is already there for some time. Curious about your experiences.

To be clear, I have a Dutch Resmed 10 VAuto with SW SX567-0401 and it seems models vary significantly per country. The US clinical manual does state trigger/cycle/Ti-min/Ti-max can be set in S-mode. I am looking for a Dutch clinical manual to see if settings differ from the US.