Anybody ever tested Auto-vs-NonAuto?

[rwalther]

Here's my discussion question ... Is it possible that the Auto feature of the machines that automatically build pressure to respond to breathing events, might actually take you to a pressure that is so high, that it also wakes you up ... doing more harm than good?

Stated a different way ... Is a breathing event partially controlled by a lower pressure, actually better than intervention at a higher pressure that actually ends up waking you from the ancillary effects of high pressure (mask leaks, discomfort, etc.)?

I've been watching my data, and it seems that when I have breathing events and the pressure strarts ramping up on my system (M-Series w/ A-Flex), I frequently get to a steadily pegged pressure point, and I frequently wake up.

I don't believe (although who knows) whether the wake-up comes from the breathing event not being controlled, but when it happens, I am instantly uncomfortable with the high pressure and it typically comes with some mask leakage.

My averages for the last 30 days are:

Average pressure: 10.1
Average 90% pressure: 12.5
AHI: 4.5

My MinPressure is 6.0 / my MaxPressure is 14.0. I've steadily adjusted my MaxPressure downward from 20, as my numbers improved, keeping the MaxPressure just above the 90% Pressure measurement.

All of my metrics (FL, VSI, OAI, AHI, etc.) have been trending in a positive direction since I started my therapy about three months ago.

I feel great, and consider this to be a huge success. That being said, I feel like I wake up a couple of times a night at a point where the pressure is always peaked, and pushing the 'RAMP' button to decrease the pressure always lets me drop quickly back to sleep.

I'm thinking about doing something dramatic ... like (a) dropping my MaxPressure to 8, or (b) turning off the Auto feature and setting my pressure at 8 ... or something like that to test my theory that the high-side of the auto-ramp ends up being a dramatic enough change to actually wake me up, instead of keep me asleep.

Has anybody done this? Anybody have any ideas about it.

This fits squarely in the 'interesting idea' or 'minor adjustment' category, as I'm waking up feeling well-rested and better than I have in years, irrespective of the (possibly) pressure-induced wake-up calls.

Thoughts? Advice? Hate-Mail?

Rusty

[LyleHaze]

As you mentioned, all Auto machines are capable of straight CPAP as well, so the ability to test your ideas is there.

If you do, I encourage you to work slowly, perhaps a week or two between each change, to allow yourself to adjust to the difference, and to prevent one bad night from skewing your data.

Personally, I prefer auto, as it will adjust to the lowest pressure that I need at the moment, which is different if I happen to be stomach or back sleeping at the time.

Sleep Well,
Lyle

[mindy]

I think there have been a number of threads on this topic and it always seems to come down to personal preference. I've used both APAP and CPAP and generally tend to prefer CPAP. As far as waking up, I was doing that with both and that seems to have improved with time. I started early last August and it's been just in the past month that I'm usually sleeping through the night --- with either CPAP or APAP. So I wonder if some of those arousals are just part of adjusting to xPAP therapy.

Rusty - have you thought of raising your lower pressure of 6 to something closer to your average pressure?

Mindy

[bap40]

I am on my first week with the A/flex and love it, but I have read quite a bit concerning people waking up wth the increased pressure the machine has hit. I don't have this problem myself but quite a few people do have that problem with this type of machine. This event was mentioned in some of the reviews I have read as a con. My steady cpap pressure is set to 10. My a/flex is set at 9-13 and on my second night with this machine the average of 90% was at 13 and I did not wake up. So, I don't know if this will be something you can get used to or not.

Good Luck

[ozij]

[quote="mindy"]I think there have been a number of threads on this topic and it always seems to come down to personal preference. I've used both APAP and CPAP and generally tend to prefer CPAP. As far as waking up, I was doing that with both and that seems to have improved with time. I started early last August and it's been just in the past month that I'm usually sleeping through the night --- with either CPAP or APAP. So I wonder if some of those arousals are just part of adjusting to xPAP therapy.

Rusty - have you thought of raising your lower pressure of 6 to something closer to your average pressure?Mindy

[roster]

......

Some of us do better and sleep better when on fixed pressure, or on a very narrow range.

True, but darn it, the charts the next morning are not nearly so interesting to analyze and obsess over.

[mindy]

Yea, Rooster - we wouldn't want to have boring charts, now would we!

Mindy

[ozij]

......

Some of us do better and sleep better when on fixed pressure, or on a very narrow range.

True, but darn it, the charts the next morning are not nearly so interesting to analyze and obsess over.

Absolutely....

By the way, I was told the when a Chinese person wants to wish you real bad things he says "may you live in interesting times"

I guess our version should be: My we all have a boring sleep....

O.

[Wulfman]

Rusty,

When you scrutinize your Encore "Daily" reports, are you looking to see what pressure seems to eliminate the events?

If your AHI average is still 4.5, you're obviously having events.......at what pressures are they occurring? If they're happening BELOW a certain pressure, then you need to bring your bottom pressure up. If you're getting runaway pressure increases because of snores, leaks or even apneas/hypopneas, then you probably need to limit the top pressure to something before that starts happening.

"Average pressure" is going to be a larger percentage than the "best effective pressure" because it may be too low (you're obviously spending more time there).......and, the 90% pressure MAY be a little too high (especially for determining a single-pressure setting).....depending on what's driving the pressure increases (which is part of what needs to be analyzed).

One of the ironies about the advice for determining pressure(s) is that we (yes, I said WE) tell people on single pressure to work up slowly, at about 1 cm at a time and for about a week at a time.......YET, users are told to set their Auto machines for a range of pressures.....which is obviously going to change more than 1 cm per night and many times per night.

For many of us, the pressure changes disturb our sleep. (like ME) Consequently, it's easier to become comfortable with one single pressure that will preempt the vast majority of events, and to be able to sleep better.
The challenge for each user with access to an Auto is to determine WHICH method and pressure(s) works best for them......APAP or CPAP.

Good luck.

Den

[LavenderMist]

The main thing when running the machine in auto is to make sure leaks are well controlled or you'll end up with the machine increasing pressure and chasing leaks all night. That being said, I seem to do better when leaks are in check and my auto is set to cpap mode at a straight pressure.

edited for grammar
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CPAPopedia Keywords Contained In This Post (Click For Definition): CPAP, auto

[Lineman]

I think it would be helpful to know why you wake up at the higher pressures. I mean if you can determine why you wake up, perhaps you can fix it. I'm thinking it may be just that you are not used to the higher pressures (something strange=something wrong= wakeup). Try sleeping in CPAP mode at the highest A-setting to see if you can adjust to that????

On the other hand, if it is because of mask leaks, those can be fixed. The mask has to be adjusted to seal at the highest pressure setting (14 not 6). Then again, If it is some physical problem I would want to know that too.

My sleep numbers have all improved since I went to APAP (10-15) but everybody is different. Though I can say that my FFM does not leak at 15 (max) and I don't wake up at the high points.

[rested gal]

Rusty - have you thought of raising your lower pressure of 6 to something closer to your average pressure?Mindy

My thoughts too. Your event may be starting out at too low a pressure, and creating a vicious cycle driving the pressure up.

Ditto those thoughts about the minimum pressure setting.

Instead of bringing the maximum pressure setting down, I'd have been raising the minimum pressure.

I'd set it at 8 - 20 or even 10 - 20. See how that goes for a few nights.

Another good point:

The main thing when running the machine in auto is to make sure leaks are well controlled or you'll end up with the machine increasing pressure and chasing leaks all night.

Some people do better with a straight pressure. No question about it.

But I do think a lot of the people who have problems with treatment when using an autopap are not setting the minimum pressure high enough to prevent most events...particularly the heavily obstructive events (full apneas)... right from the get-go.

[rwalther]

Well OK ... that's some great advice.

I'm going to do some analysis on exactly what the pressure is when the events that drive it up take place ... and then reset my minimum to attempt to avoid that.

It's a bit counter-intuitive, as you'd think that the high pressure is what would be causing this ... but after reading some of these posts, it makes perfect sense.

BTW ... leakage is a non-issue for me. I'm spot-on the manufacturer's expected venting numbers, and very rarely get a lot of variance, or large-leak readings in my software.

Thanks for all the advice.

Rusty

[billbolton]

Here's my discussion question ... Is it possible that the Auto feature of the machines that automatically build pressure to respond to breathing events, might actually take you to a pressure that is so high, that it also wakes you up ... doing more harm than good?

Yes, that is possible, but it doesn't even take high flow rates, even relatively small changes in the flow rate arising from APAP function are enough to disturb the sleep of a non-trivial numbers of OSA sufferers.....

I discovered I was better off with CPAP rather than APAP.

turning off the Auto feature

That's what I ended up doing.

Cheers,

Bill

[Catnapper]

Yeah, I tried lots of things.
Started with straight CPAP 15 cms. Just hated it. Dropped to 13 for a total of 6 weeks. Then went to a Resmed auto to see where my pressure should be. It turned out to be lower. Changed to the other R, an M series auto. Struggled with that for 3 months - it was an improvement over the other auto, but still not ideal. Changed to M series BiPap auto, and liked that a lot better. The doc had me do another titration and found that the BiPap auto had my pressure exactly right, so he wanted me to try BiPap without the auto. Did that for a bit and now am back to BiPap auto.

Currently I usually have 5 out of 7 nights with 0.0 AHI, no unusual leaks and I stay within a fairly narrow range of pressures. Things are looking good.

My friends here helped me so much. I guess you could say that is my success story.

You have to find what is right for you. Titration for me was a place to start, not stay. I never get to 15 and only rarely have a few minutes at 14. The real secret is the mask. Now there is another long story for me. Actually, mask and machine have to be the right combination.

Catnapper