In anticipation of my BIPAP Re: New Thread

[Plmnb]

Oops, just noticed Target Va IS adjustable. Should I leave it where it is?? It can be changed up or down by increments of .1 at a time.

Thanks

[Geer1]

My idea behind setting a lower Va is the for the same reason that ASV targets 90% of spontaneous. You don't need the ventilation capability iVAPS offers, you just need a machine capable of providing high PS at times during your periods of bad flow limitation (ASV probably would have worked for this but ST-A should definitely work). Your spontaneous volume looks like it has been ~6.25(you can confirm in OSCAR), using 90% of this as ASV would the support target would be 5.6. Our different stages of sleep require different levels of ventilation which is why I would look at your OSCAR data and see what your minute ventilation usually fluctuates between under spontaneous breathing. If Va is set lower than this then it should be only support your breathing when it is necessary. The higher you set Va the more ventilation work it is going to do for you which I don't think you want, you don't have COPD or anything else that should requires that kind of support.

If you do the learning mode you need to be careful and verify that the settings are appropriate. Another user did his recently and it came up with a Va over 10 and he had horrible sleep because the machine was over ventilating him.

[Plmnb]

Hi Geer1. (Sleeprider was able to split this thread for me.)

I believe your speaking of the Va Target Va setting I didn’t realize I could change it.  I read in Sleeprider post a few posts ago, the the Target Va is based on height.  Supposedly this is automatic, or so I was told.  But it is confusing because it can be changed.

Plmnb

[Geer1]

Target Va is calculated using your height based on an average formula. Not everyone is average and some have higher or lower ventilation requirements which is why it is possible to adjust this value.

If you set Va above your spontaneous breathing level this machine will force you to breath more air as that is what this machine is meant to do (supplement poor spontaneous breathing).

Your overview tab in OSCAR can quickly show you what your median minute vent is for each day. For example mine fluctuates between 6 and 8 with most nights being around 7. When I look at my daily graphs on nights when my median minute vent was around 7 I can see periods where my breathing looks fine with minute vent of 6. If I was using iVAPS I would set my target Va at 6 because of this.

[Sleeprider]

The new thread for ST-A is here http://www.apneaboard.com/forums/Thread-...-with-ST-A