Think I may need an asv machine.

Hi all,
Here's my story so far. I was originally setup for a Bipap at 16/6, before picking up the machine I made a call into the doc to see if I could get and auto bipap after a lot of reading on here, this was granted and I was then setup for an auto bipap setup at 16/4 with a ps of 4. My first week I couldn't seem to get my ahi much under 8 with most of that being centrals in the 6 to 8 range looking at sleepyhead. After a discussion with Pugsy, I tried upping the bottom end to 6 which seemed to help for a few nights then my ahi started to clime, looking at the data it was the centrals. I then put it back to the doc's setting for a week and still no luck, so I then decided to try something different. I set the machine up for just straight bipap with with the doc's first settings of 16/6. Under auto I was running about 12/8 at 90%. Well that test didn't go very well as my ahi shot up to 16 with it being mostly centrals 50 some events in 7 hours. Most of them only lasting 12 to 20 sec's. Anyway after reading on here I think I may be one of the few that have pressure induced centrals. I have an appointment with the doc next week and will take my computer with data and see what he has to say vs my sleep study data which I don't have yet. I'm only a month into this, any other thoughts on this?

Thanks
Dan

Hi Dan,
Just some thoughts and questions.

It certainly seems that things are moving a little too rapidly. It sometimes takes awhile to get comfortable with a treatment. But here you are, onto Bipap and now ASV. You said your ahi was 8 but mostly centrals. Well they could be mis-scored and even if not, the total is not that many.

Are the centrals causing significant desats? Bet your sleep Doc has a recording oximeter to check that out. Are you having any periodic breathing? Do you have any underlying lung disease or condition?

ASVs are (or can be) difficult to breath with, expensive and and are designed for very specific conditions. Even if your centrals are long and causing desats, w/o CS or periodic breathing you don't really need the servo ventilation component. A Bi-Pap ST probably is more appropriate and easier to titrate and to use.

I'd suggest oximetry to determine if the centrals pose difficulty or danger and more time on BiPap to give your body time to adjust to treatment.

Are you feeling better on BiPap or are you just reacting to the data?
Jamis

With pressure induced centrals (if that is what you have) auto mode range may not be the best choice as that IPAP will vary and is already higher and higher pressures can cause centrals. Also straight bilevel with 6/16 not good because half the time you are at inhale of 16. Again much higher pressure.

Wonder what would happen with a very tight auto range so the pressures won't go so high? Or straight BiLevel with a much lower IPAP? If you could get the obstructive component under control at a lower pressure there may not need to be such a higher pressure and if centrals (if they are pressure induced) might come down to a manageable level.

Were you titrated at this pressure on a BiLevel machine?

jamiswolf and Pugsy,

I do have mild asthma and talked to my Doc at the request of my wife about a sleep test because of snoring and pause in breathing. The doc ordered the sleep test and after that ordered the bipap at 16/6 so I assume that is what I was titrated at. I don't yet have the data in hand from my sleep test, but I will ask for it next week during my office visit.

As far a sleep goes, I don't feel any different and didn't think it was bad to begin with (wife says different). I have had no problem adjusting to the machine or mask (Thank God).

I'm probably just over reacting to the data, and reading to much info, but when I see 50 + central events in 7 hours its kind of nerve racking.

When machine is in auto my ipap runs around 10-14 and epap 6-8.

Hopefully when the doc looks at my data from the machine it won't be as bad as it appears to me.

Thanks for the replies and hopefully it isn't as bad as I think.
Dan

Darimont wrote: I'm probably just over reacting to the data, and reading to much info, but when I see 50 + central events in 7 hours its kind of nerve racking.

Still Dar, that's only 7 an hour and they could be very short. You really have no idea of the significance w/o further data.

I agree with Pugsy that the auto BiPap is complicating things. I don't like such a wide PS. If I were in your situation, I'd disable the auto mode (by setting EPAPmin same as EPAPmax...) Just see how you do with more conventional pressures like 8 and 12. Bumping up the lower pressure and lowering the IPAPmax. Bet breathing would be more natural and perhaps fewer centrals.

But in the meantime, relax, it's not that bad. Ask the Doc about Oximetry or if you have a spare $100 laying around...buy one (recording pulse ox).
Jamis

Please keep us posted on how it goes. I tend to agree with Jamis's idea about using straight bilevel but since your doctor's appoint is upcoming soon might as well let him earn his fees.

I will give straight bipap a try this weekend as you guys suggested with the pressures tightened up to 12/8. I'll post back Monday after some playing.

Had my doc visit yesterday.

Talked to him about my sleep study, got a copy of it and talked to him about the centrals. Sleep study only mentioned a few centrals under the titrated pressures of 16/9. I took my laptop with my data from the start and showed him, he didn't think the centrals were a problem being most of them seem to be in groups just before I wake up to go to the little boys room and just after falling back to sleep and also just before waking for the day. I told him that I have played around with the settings and he didn't have a problem with it at all and was impressed that I'm keeping close tabs on whats going on and having sleephead software, which he hasn't seen before, but was very impressed with it also. I showed him the nights I put it in straight bipap at my lab titrated pressures and the centrals were all over the place, he noted that only true central detection can be done in the lab with the belts and ox meter. The lab report didn't note any excessive desat's with the centrals. He said to leave it in auto for a while longer and I could try tightening up the numbers as you guys have said and give my self more time to adjust to it.

At this point I haven't played any more with it, but will in future and let ya know. I have since had some good nights with and AHI just below 5, but for the most part its still running around 6-7.

Thanks again guys for your input.
Dan

Hi Darimont,
Your MD sounds like a reasonable and decent guy. Many Docs discount machine data so he's not alone there. But the machines can certainly diagnose an apnea by lack of breathing and they use puffs of air to determine if it's a clear airway or an obstructed airway. Granted, a chest strap along with the other PSG parameters gives more and more accurate info...but I feel the machines do a pretty fair job on CA recognition.

So keep an eye on things which I already know you will.
Jamis

jamiswolf wrote: I'd disable the auto mode (by setting EPAPmin same as EPAPmax...)

darimont has a Philips Respironics System One BiPAP Auto machine. As far as I know, you cannot "disable the auto mode" by doing as you suggest, jamiswolf. There is no "EPAP max" setting for that brand machine -- in any mode.

In that machine's auto mode the settings offered are max IPAP and min EPAP. There is no "EPAPmax" setting. There's also a max PS (maximum pressure support) setting which governs how far apart (as much as 8 cm) IPAP and EPAP are allowed to move independently from each other. The closest they can ever get to each other in auto mode is 2 cms apart.

The way to set that brand/model machine to not use auto mode is -- simply choose bilevel as the operating mode and set EPAP/IPAP how you want them. As I'm sure darimont knows, since he's been using his machine both ways -- in bilevel mode and in auto bilevel mode.

Thanks for the correction rested Gal...and like you say, Dari knew what to do despite my erroneous advice. I'll keep that in mind.
J

My trial on the PRS1 ends in 2 weeks and was wondering if it my be worth trying an S9 to see if it responds better, any comments on this.

Sometimes one brand or another, even of the same "type" of machine (in your case a bilevel auto) might work differently, for better or worse, for some people. Sure wouldn't hurt to give the other major brand a try. The Philips Respironics System One BiPAP Auto and the ResMed S9 VPAP Auto handle the "PS" (Pressure support) setting very differently from each other. It's possible one brand's way of doing "PS" might suit you better than the other brand did. There's no way to tell without trying both. So, yeah, if you have a chance to trial a VPAP Auto, I'd give it a whirl, if I were you.

Be sure to check out jnk's excellent description of the two completely different ways the two major brands work while using "Pressure Support" during auto bilevel therapy:

Jeff's (jnk) great explanation about the difference in how the ResMed VPAP Auto (and "25") and the Respironics BiPAP Auto handle the "PS" (Pressure Support) setting:
topic: ResMed VPAP Auto 25 Clinician's manual
viewtopic.php?p=376749#p376749

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Jeff (jnk) answering IFLEW's questions:
topic: ResMed Pressure Support
viewtopic.php?p=428022#p428022

Remember:

The data is pretty much meaningless when you're awake, even if you're laying in bed half asleep.

Don't just count the apneas, centrals, or hyponeas. Look at the waveform data and see how long they lasted, and whether you completely stop breathing or just breathe a little less deeply.