New ASV Dreamstation help

[chicken]

last thread link below.
http://www.apneaboard.com/forums/Thread-...n-new-post

I received a new dream station 900 ASV auto. as the APAP did not work.
there is no sleepyhead screenshots as the 900 does not work with sleepyhead/mac.
the first cpap/ APAP said i had lots of OA's but per sleep  study all i have is hypopnea  and centrals.
with the new ASV my AHI = around 7.
my first sleep study i had a AHI of 7.8 centrals and hypopnea.
with the APAP i was getting a AHI of 28 and lots of periodic breathing around 60%
i don't know if the ASV, AHI'S are from me before i fall asleep or what as the dream mapper software only shows total.
so i went from AHI of 7.8 with no pap to about the same with ASV. my low was 2.8 my high was 9.9.
i only have hypopnea now per the dream map software on the asv.
also my spo2 has not changed at all, that was the whole reason they put me on cpap.
i get around 100 to 300 spo2 drops of 4% or more for 10 sec. or more.
the APAP made me extremely tired but the ASV makes no difference in how i feel.
the ASV is set at 4/15 EPAP ONLY
so its just a respirator staying at 4 then pumping air up to 15 as needed then it goes back to 4.
i wish i knew the point of this?

[Sleeprider]

Your Dreamstation has several modes, and we want to get it into the Auto SV mode so your EPAP can adjust in a range. Also, it would help to set both minimum and maximum pressure support (PS) or comfort and to resolve the apnea. A fixed EPAP of 4.0 is certainly questionable. I think you can use EncorePro software from the forum with your new machine for at least some detailed data. It isn't much, but it may help.

If you don't mind, give us a rundown on your settings: Mode, EPAP Min, EPAP max, PS min, PS max, and anything else you see that might be relevant.

[chicken]

the settings are 4 min. to 15 on EPAP with max at 25
IPAP/ps is min. 0 max 20.
BPM=auto
my 90% pressure is 5
 it runs like a cpap at 4 pressure but it will ramp up the inhale pressure if i pause/stop breathing on that breath.
when i wake up its at 5/5 
dream map software says like 1 central 0 o's and 37 hypo apneas.
not sure if all the hypo apneas are marked before i fall asleep or after?
my SPo2 reading looks the same with lots of drops.

[DeepBreathing]

Just a quick explanation of how ASV machines are supposed to work (though it sounds like your setup is not typical):

EPAP (Expiratory positive airway pressure) is the pressure maintained while you're exhaling. This is the pressure which splints your airway open to prevent obstructive apneas.

PS (pressure support) is the additional pressure the machine applies when it detects you're inhaling. Can be set at zero or some higher value.

IPAP (Inspiratory positive airway pressure) is the pressure the machine applies while you're inhaling.

IPAP = EPAP + PS

On your machine you can set EPAP minimum, EPAP max, PS min and PS max. You can also set maximum pressure (anywhere from 4 to 30 cm H2O) and breaths per minute backup rate. The settings available at any given time will depend on the mode the machine is set to. I'm not familiar with the Dreamstation ASV, but I assume you'll have a CPAP mode, an ASV and an ASV Auto. It would be good to know which mode your machine is set in.

The ASV machine monitors your breathing on a breath-by-breath basis. If there is a reduction in airflow, the machine will increase PS to compensate. If airflow reduces completely (ie an apnea) it will give you a big pressure kick to get you breathing again.

the settings are 4 min. to 15 on EPAP with max at 25
IPAP/ps is min. 0 max 20.

This sounds like your settings are: EPAP min = 4, EPAP max = 15, PS min = 0, PS max = 20, and maximum pressure is set to 25. IPAP will range between 4 and 25. Can you confirm that is the case? I read above that you can't get #SleepyHead to work with this machine, but you may be able to use Encore Pro, available from the private links section of this site. From what I've read this is not a particularly friendly program, but if you can get it working it would help greatly if you could post some screenshots.

[Sleeprider]

Chicken, expanding on what Deepbreathing says above, the titration protocols all suggest using pressure support for hypopnea. We have observed that the Philips Auto SV Advanced machines do have a problem responding and stopping hypopnea. I have no personal experience in ASV, but have worked with many members and found some things that seem to work pretty well when this kind of event rate presents itself.

I suggest a slightly higher starting point in EPAP min. For now I would take it slow and suggest 5 cm EPAP min. Your EPAP max is almost not relevant since the machine only goes as high as indicated by obstructive events. I think you will benefit from a PS min of 2.0. This makes breathing easier and gives the machine a bit of a head start on hypopnea. I would not exceed a PS max of 15, and I would suggest it is rare to see someone that even needs more than 12 cm. I have to say, your setup sounds like it was done by someone that is clueless on how these machines work. I'm not claiming to be better, but I think if you're willing to try some changes, it might help.

[chicken]

settings are: EPAP min = 4, EPAP max = 15, PS min = 0, PS max = 20, and maximum pressure is set to 25. IPAP will range between 4 and 25.
look about right.
my AHI was 2.2 last night with 8.6 hours of sleep.
the sleep study spent most of the time trying BIPAP settings, getting up to 19/15 pressure then
the last hour they switched it to ASV.
my concern is my spo2 the whole reason for cpap, has not changed?
i need to get more oximeter data then go from there i guess.

[Sleeprider]

You were never given a titration study, right?