(10-03-2015, 03:13 AM)DeepBreathing Wrote: G'day Louver528, welcome to Apnea Board.

As you're no doubt aware, ASV machines are used to treat central apneas and periodic breathing (eg Cheyne-Stokes respiration). I have mixed apnea (both obstructive and central in about equal proportions) with an untreated AHI of 62. I use a Resmed S9 VPAP Adapt, which was the immediate predecessor of your Aircurve. (I assume you've got the Aircurve ASV?)

Before going on to the Resmed I had a month's trial on the equivalent Respironics machine, but we just didn't get on. It always felt like the machine was trying to force my breathing rate, which effectively prevented me from sleeping properly. I later found out (from this forum) that there are a whole bunch of adjustments that need to be made on the Respironics to fine tune it to your needs. By that time I had gone onto the Resmed and it was love at first breath! The Resmed algorithm is quite different, and (to me) it feels like the machine is following my lead, rather than the other way round. My AHI dropped from 62 untreated to ~25 on the Respironics to below 5 on the Resmed. It's now consistently below 1.5, usually below 1 and I get the occasional 0.0.

Setting the pressure is more complicated on these machines. You need to set the expiration pressure (EPAP) low enough to be comfortable but high enough to control obstructive apneas and hypopneas. The pressure support (PS) is the extra pressure the machine delivers when you inhale. It must be set low enough to be comfortable, but allowed to go high enough to treat central apnea. And your inhale pressure (IPAP) should be set at a maximum which is comfortable but still high enough to treat the centrals. The easy formula is EPAP + PS = IPAP

I note in your profile your pressure is 80 F - this is actually your humidifier temperature. Your pressure will be made up of the EPAP, PS and IPAP as described above.

The fact that the machine can respond extremely rapidly to a cessation in breathing is good, but it can sometimes be enough to wake you. This is annoying but it doesn't take too long to get accustomed. It can also kick in with a pressure burst before you've fallen properly asleep, which is likewise annoying - in this case just blow back hard and the machine will get the message.

I should also mention that Resmed have aborted a long-term clinical trial of their ASV machines due to an increased chance of death for patients with a particular type of congestive heart failure. You doctor should have discussed this with you (mine didn't) so if you have (or think you might have) congestive heart failure, it's time for a deep and meaningful chat with your doc.

If you have any specific questions I'd be please to answer them.