Question for the ASV people here…

After more than 12 years on CPAP/APAP I was recently diagnosed with Complex Apnea, and I got a Resmed S9 "VPAP Adapt" two weeks ago. (The main problem seems to be UARS - the ASV machine is being used to normalize the airflow signal in an attempt to avoid EEG arousals.)

It took me a couple of nights to get used to the ASV machine, but I'm fully acclimated to it now. The only “problem” is that it feels as though the machine causes me to breathe at a slightly faster rate than I think I normally would. It could just be a matter of perception however, as the machine “wants” me to start inhaling immediately after I finish exhaling; whereas my natural breathing pattern may have a brief pause between exhalation and inhalation.

I would like to know if anyone else has experienced a similar “situation” such as this. I don’t think it’s a huge problem, but I am curious to know what other people’s experiences have been, and find out if anything can/should be done about it? - Or... is it really just a matter of perception (as I said above) and it's a "non-issue"?

Thanks in advance for your help!

I have the other brand of ASV, so maybe can't compare. I have noticed that my breath rate goes from about 12 breaths a minute to 20 when I am asleep. My volume goes way down, too, so it seems as though the machine is causing short, shallow breaths. Maybe that's why I always feel so bad when I wake up, I don't know.

As far as switching from inhale to exhale, I had to turn off the BiPap part and just run in in CPAP, because I couldn't get to sleep with all of that switching going on.

Oops! double post

Yeah, my daytime breathing rate is 8-12 BPM but my ASV likes me to breath at 17-19 BPM. SWS has made me aware that "complex apnea is a hypocapnic disorder", meaning that we have too little CO2 in our blood and lungs for proper regulation of breathing. The link he shared with me is pretty convincing. I googled for this: https://login.medscape.com/login/sso/ge ... jAy&ac=401
paper that SWS put me on to and found the link below which has the text but does not require registering.
http://www.talkaboutsleep.com/message-b ... hp?t=13557[/url]
If you divide minute volume (L/min) by BPM you get liters per breath. I find that mine is about 1/4 of a full breath. I figure/speculate that this means a shallower breath leaves more CO2 in the lungs and contributes to triggering normal breathing. So, in summary I think the ASV algorithm effectively settles on a minute volume that maintains proper CO2 concentrations in our lungs, such that we mostly breath on our own. My RT has suggested after experiencing months of central apnea restricting blood oxygen, that it may be 6 months to a year before the cells involved in such regulation become reset to more normal levels. Perhaps then I will breath slower and deeper? I do not know.

Edit: This does not mean we should fiddle around with CO2 on our own!

You mentioned you prefer to breath out more slowly than the ASV will let you. Mine does that also. This will become comfortable with practice. My machine is super touchy about breaths. Its either in or out, no sitting on the fence. So, if I start to breath out and then wobble and take the tiniest breath in, then its too late! That is the next breath and the ASV switches to breathing in. And vis versa when breathing in, a hesitation can suddenly become the trigger to full exhale. So the trick if you get out of step is to give up and breath out and then take that next breath right away. Pretty soon you won't even notice that you are trained to breath either "in" or "out" but not ambiguously any more. Your unit may have a 'rise time' adjustment that can make this seem less severe. I've ended up with mine set at 0. I saw no benefit in higher rise times.

I sometimes encounter that issue. This often happens after I struggle with getting my mask properly sealed. I then find the respiration rate it thinks I have is too high to be relaxing. That normally slows as I fall asleep. However, sometimes I have to turn off the machine and turn it back on. This resets what the machine thinks is my average breathing rate.

In another two or three months you will probably find you will not notice this as much as you do just a few days after starting ASV therapy. It's amazing how flexible our bodies can be.

Mr. Bill: Interesting information. Indeed, most primary central apneas are a hypocapnic issue, but in my case the centrals are iatrogenic, i.e., induced due to pressure intolerance on xPAP. The new Resmed S9 based ASV unit does not have a rise-time adjustment in any of the clinical menus. I’ve looked at everything to see if it’s buried in there, but to no avail.

JohnB: Being a longtime hosehead, I’ve already adapted very well to the ASV rhythm; and indeed the machine will adapt to provide a slower respiration rate while asleep. During the first two nights, there were times where I experimented with trying to manually control my breathing at a lower pace, but fighting against the machine was fruitless. I learned to just trust the machine and not try to regulate it. It really is just a matter of the machine wanting an immediate inhalation at the end of exhalation, with no pause in between. (as noted by Mr. Bill above.) You are correct in noting how flexible & adaptive our bodies can be, but I also think that it would hypothetically be best if the machine would emulate each persons natural rhythm more effectively. Maybe the next generation of software will do that? Who knows…

[quote="ignorant1"]Mr. Bill: Interesting information. Indeed, most primary central apneas are a hypocapnic issue, but in my case the centrals are iatrogenic, i.e., induced due to pressure intolerance on xPAP. The new Resmed S9 based ASV unit does not have a rise-time adjustment in any of the clinical menus. I’ve looked at everything to see if it’s buried in there, but to no avail.

I keep reading that many of the CPAP treatment emergent central apneas are generally innocuous and self-limited. Have you considered it when you decided to switch to an ASV?

I have been using a Resmed VPAP Adapt SV for 5 weeks now and I have noticed the same thing. I dont really want to breath as fast as the machine wants me to. I mentioned this to my treatment consultant at Res sleep and he just shrugged it off. It was my understanding that the machine would work out how I breathe and then it would work in that manner. It seems to me the machine just does what it wants to.

I am going to pick up my new S9 VPAP Adapt SV tomorrow,let see how it goes.

Avi123: Point well taken, and definitely considered prior to the decision to go with ASV. However…

Although many xPAP emergent centrals may not be an issue for many (most?) people, and those pressure induced centrals may be self-limited to an extent, they do affect different people in different ways.

I would never construe myself as an expert, but ANY breathing event that causes an EEG arousal fractures the continuity of one’s sleep. Period. In a UARS patient, a “non-scorable” event (in the classic model of apnea / hypopnea scoring) such as a flow restriction may still cause EEG arousals. This is due to a hypersensitivity to airflow restrictions, (a.k.a flow limitations). In a UARS patient, a drop in 02 saturation does NOT need to occur in order to cause an EEG arousal. In these instances, an ASV machine is used to eliminate pressure intolerance & normalize the flow curve, preferably for both inhalation & exhalation.

Ozze_dollar: I'm not sure if the actual breathing algorithms have changed (much?) from the older S7 based Adapt SV versus the S9 based VPAP Adapt, but there are some improvements such as no need for the machine to "learn" the nasal interface, plus the ability to use many other masks & nasal pillows that would not work with the older unit. I'd be curious to hear back from you to see if there is any noticeable difference between how the two machines function for you.

JohnBFisher wrote:In another two or three months you will probably find you will not notice this as much as you do just a few days after starting ASV therapy. It's amazing how flexible our bodies can be.

ditto..

Just a quick post to keep an eye on this topic. I just got new S9 VPAP adapt today - first night is tonight.

Bright Choice wrote:Just a quick post to keep an eye on this topic. I just got new S9 VPAP adapt today - first night is tonight.

So how was the first nite?


JeffH

JeffH wrote:

Bright Choice wrote:Just a quick post to keep an eye on this topic. I just got new S9 VPAP adapt today - first night is tonight.

So how was the first nite?


JeffH

It went "ok". I think that I can adapt to pressure changes and rate over the next few nights. What kept awakening me was small bursts of air that filled my cheeks. My lips were closed and I scored zero leaks in Rescan but the "bursts" kept awakening me. They were not all that frequent but I am trying to figure that out. Switched masks from Swift FX to Quattro FX and the bursts continued. Then I put a chin strap on in addition to Quattro FX and it got better. Slept ok but I have a headache and feel hungover today. I am assuming it is a process of adapting but if anyone has an answer to the "bursts" it would be helpful.

Thanks for asking!

A mask liner helps a LOT with the Quattro FX and an ASV machine. Most masks work fine as long as the pressure range remains fairly constant. That's something the ASV does NOT do. The wild swings in pressure cause the mask to leak, which wakes me up. The mask liner helps the mask work better (at least in my case).

Pad-A-Cheek and REMzzzs both make mask liners.

JohnBFisher wrote:A mask liner helps a LOT with the Quattro FX and an ASV machine. Most masks work fine as long as the pressure range remains fairly constant. That's something the ASV does NOT do. The wild swings in pressure cause the mask to leak, which wakes me up. The mask liner helps the mask work better (at least in my case).

Pad-A-Cheek and REMzzzs both make mask liners.

Thanks! I had forgotten that I have a padacheekfor the Q FX. I will use it tonight.

Any idea what causes the "bursts"? My mouth was closed, no leaks, I was very conscious about keeping my tongue in place to seal the back of my throat but these burps of air kept me from sleeping soundly.