A Down Side to CFLEX??

[IWannaSleep]

I have been using my REMstar Auto w/heated humidifier for over 2 months now. It seems with every passing week I learn more about how my body responds to this therapy.

I have been continuously trying to tweak the settings, and everything else I do to bring my AHI down. My initial sleep study results showed my AHI was 45. Over time on therapy I've slowly made adjustments to bring my AHI down and I'm now sitting at an average of 7.5. Oxygenation tests show even with it this high my blood oxygen is remaining normal through the night. However I believe my still high AHI is limiting the overall improvement I am seeing in feeling rested and energetic.

One adjustment I made early on was to the cflex setting. I initially started out at level 3. But I noticed when I lowered the setting I consistently achieved lower AHI numbers. Ultimately I lowered it to a setting of 1 and saw even more improvement. I left cflex on because even at my moderate pressure setting of 9, I found the pressure relief on exhalation to be comfortable and help me adjust to therapy. It is a good feature for people new to therapy and adjusting to breathing against pressure.

However, last night I woke enough to notice on exhaling, I could feel my soft pallet collapse and a snore begin. This was only on exhaling. When the pressure returned on inhaling everything opened and air flowed smoothly. But as soon as I would exhale, bingo, a snore would start.

Now that I've adapted to using the machine, I don't think I will have trouble exhaling against 9cm. For tonight, and the next few nights, I have turned cflex completely off and am running straight on APAP. If I see a reduction in my measured snoring, and even a slightly lower AHI for these next few days, this will have answered a lot of questions.

I'm leaning toward the conclusion, for at least some of us, that cflex is useful as a tool to help us adapt to using xpap, but may also limit our ability to achieve optimum benefit from the therapy and we should wean ourselves off of it after we adjust. The jury is still out on this of course, but I'll keep you posted on my self-test results. And it will only be one data point, but one more than we have had to date.


Ron

[JL]

My results confirm the same thing yours do. AHI results with CFlex worst at 3, better at 2, better still at 1 and best if turned off. I've even tried changing the lowest APAP setting to "offset" the CFlex pressure drop...i.e. Normally set at 9 to 12 w/o CFlex so I bumped it to 10 to 12 with CFlex 1 setting. Results better without CFlex. Tried 11 to 12 with CFlex 2 setting. Results better without CFlex. Apparently as you either my airway starts to collapse sometimes at exhale or I have something of an irregular breathing pattern at times which "confuses" the CFlex and alogrithems of the Remstar Auto??

Really like CFlex but have adjusted to pressures without it. Nice feature though for those who need it to adjust to CPAP or those who it works fine for.

Jim

[Hardly Breathing]

I have noticed the same thing with my BiPAP and Bi-flex. If I have the exhalation pressure too low, I get more snores. The pneumatic splint is collapsing and not keeping the airway open on exhalation.

You may try to kick you pressure up a cm and still run the c-flex. You may get slightly more pressure than you need, but it will still feel comfortable.

You will know if the increased pressure is too high because the number of central apneas increases. I found this out in my home titration study.

Good Luck!

[TurboSleeper]

Hi, I am glad to see this. I think I am having the same problem. I have been on my Remstar Auto for about 4 weeks and I have been trying to make sense of the data. I was titrated at 9 cm h20 in my sleep study and I have set my unit at 7.5-11 with cflex on 2. I still do not think my index is low enough. I will try setting the cflex lower or off and look at the data over the next week.

Will the remstar auto collect data if I set it to cpap mode? I also tried setting the high pressure to 14 but it would wake me up in a run away at 14 two or three times a night so I reset it back to 11. The data on MyEncore seems to point to 9-10 cm h2o so I was considering setting it to 9.5 cpap mode but I do not want to lose the data if it does not collect data in cpap mode. Thanks I will post my results when I can determine a trend

Don

[ozij]

Will the remstar auto collect data if I set it to cpap mode?

Yet it definitely will.
O.

[Guest]

I've been able to substantially reduce my AHI by fine tuning the pressure range on my Remstar APAP. I did this by using the AHI to Pressure Chart on the free My Encore software program written by poster Derek from this board. Derek's My Encore program organizes and presents in some very handy charts the data colected by the card reader and Encore Pro program that you can purchase from Remstar for the Remstar APAP. The original pressure range on my APAP was 4-12. However, based on a few months of nightly data the AHI to Pressure Chart I got from the My Encore program showed that I was getting my lowest AHI at a pressure range of between 8 and 10. It also showed that I had a significantly higher AHI at a pressure setting of 7 or below, and that I occasionally needed a higher pressure of up to 11 or 12. Based on this, I narrowed the pressure range on my APAP (with my doctor's approval) from the original range of 4-12, at which I was getting an average AHI of 5 to 7, to a new pressure range of 8-12, at which I am now getting an average AHI of less than 2 (and occasionally less than 1). It's worked out great for me (thanks Derek), but please note that I had my doctor's approval for these changes. Whether this is just my personal situation or something that would work for others, I don't know. Ask your doctor. Incidentally, the C-Flex doesn't work for me so I don't use it.

[IWannaSleep]

I also used the MyEncore software to collect tons of data on how I respond to differnt pressures. With it I was able to fine tune my setup and get my AHI down to where it is. Prior to MyEncore I was only getting down to the 18 to 20 AHI range. Now I'm down to 4 to 8 range. So I'm still looking for ways to bring it down further. As in my earlier post I'm thinking turning off cflex will help.

After all the analysis I also determined I do best at a very narrow pressure range and am running between 8.5 to 9.5 cm. This correlated nicely to my sleep study results as well. My prescription was written for 9cm cpap.

I do not believe the CFLEX exhale pressure is related to the low setting of your pressure range. Even with my narrow pressure range setting I get a significant pressure release on exhale, and I only have it set at 1.


Ron

[Guest]

IWS - I'm the poster right above your last message. The recommended pressure from my sleep study was also 9 cm. Like you, the range I got after the fine tuning corresponded well to this (i.e., the Pressure vs. AHI Chart showed my lowest average AHI in the 8-10 cm range). I think we are on to something here: using an APAP set in a narrow range of pressures that corresponds to your sleep study titration. If I've learned anything from the APAP data it's that your ideal pressure numbers change slightly from night to night. An APAP set to a reasonably narrow pressure range seems much better for this than a fixed pressure CPAP. Ask your doctor.

[loonlvr]

This is very revealing. I will turn down my c-flex tonite and see what happens.

[zart]

my CFLEX is set at 3 and my CPAP is set at 10. I think (but don't know for sure) that I am doing better with these settings. When I first tried a straight CPAP without CFLEX there was no way that I could exhale against a setting of 5 let alone the setting of 10 that I ended up with, this was before my titration study.

I guess I don't really understand what CFLEX does, I thought it was dropping from 10 to 3 then back to 10 is that correct? If not I would like to know what is really happening. I do not think that I could do this without the CFLEX feature.

As soon as I can get a Remstar Pro 2 or Auto and can figure out how I am doing this will be less confusing...

I hope...

[rested gal]

I thought it was dropping from 10 to 3 then back to 10 is that correct?

C-flex gives "a drop" when you exhale, but there is no precise drop to it...no "exact" pressure number drop the way there is with a bi-level machine that can have a specific setting (the EPAP pressure) for a reduction when you exhale.

The "1, 2, and 3" in a C-Flex setting are simply for:

1. a little pressure reduction when you exhale
2. more reduction
3. most reduction

But there are no corresponding "cm H20" of pressure reduction associated with any of C-Flex's 3 settings. A C-flex setting of 3 doesn't make it drop down to 3 cm pressure or even make it drop 3 cm's. It's just a vague but definite reduction in pressure.

Many do find that C-Flex gives them a good deal of comfort breathing out, even if it's not the exact measured drop that one can get from a bi-level machine like a BiPap Pro 2 or a VPAP III. I like the C-Flex comfort factor (even though I don't absolutely need it) and I keep my autopap's C-Flex set on "3" for the most drop it can give.

My auto's pressure range is set for 8-15, but it rarely goes above 12. Stays on 8 over half the night. Experimentally I've set my auto on straight cpap with C-Flex, at various cpap pressures on up to 20, just to see what C-Flex feels like at higher pressures.

From 15 on up, I can't really tell much drop at all, and the inhale kicks back in way too fast. It got harder and harder, the higher I tried the pressure. I suppose the force of my exhalation is too weak to make C-Flex give much of a drop or even let me keep exhaling very long up in the stratosphere.

If I actually had to be on high pressures, I'd use a bi-level machine so that the exhale pressure could be set for an exact lower pressure. C-Flex seems to depend on the force of your exhalation and lets the higher pressure start back in when it senses your exhalation is starting to diminish. C-Flex doesn't wait until you've completely finished the exhalation.

A bi-level machine, on the other hand, will wait, and wait, and wait, at the lower pressure setting...even after your exhalation is completely finished. A bi-level machine won't start using the higher Inhale pressure until you actually start to draw your next breath. (There are bi-level ST's that will kick in if you don't start breathing, but that's a different feature altogether.)

Much about all these types of machines is a trade-off. Ideally, the autopap with C-flex lets a person enjoy pressure varying according to what's really needed throughout the night, plus giving a vague, but comfortable, drop when exhaling which can be a more pleasant pressure (vague though it is) to breathe out against.

Bi-level machines are going to blow one single higher pressure at you all night long when you inhale, but can back off the exhale pressure to give an exact drop that will work no matter how weakly you exhale or how high your Inhale pressure is set. That can be a lot more comfortable than C-Flex if a person truly needs a high pressure most of the night to keep the throat open.

It's also very possible that the way C-Flex kicks the higher pressure back in BEFORE a person has completely finished exhaling (it's designed to come back in that way...a tad prematurely) is what causes some to have trouble with it. However many who try C-Flex do like it and enjoy good treatment with it.

My personal opinion (not a doctor!) is that everyone ought to be given a two week trial on autopap with C-Flex immediately after a doctor diagnoses OSA from a sleep study.

Look at the data after 4 days using it with C-Flex. Turn C-Flex off and look at 4 more days of data. Do the final 4 days of the trial at the straight pressure the machine has found worked best... at that point use C-Flex or not, depending on what the doctor and the user prefer.

After the two week autopap trial was over, the doctor would have a much better picture of how the patient was doing at home and what pressure it took "most of the time" for him/her. The sleep study titration might have found the person needed "16" to take care of "worst case scenario." But the person might be able to sleep better at a pressure of 10 or 11 if that was found effective by the autopap during most of the night.

That's more work for the doctor -- to look at data several more times after the sleep study results. So...it will probably never happen as a matter of routine. But a trial with autopap could make a tremendous difference in what kind of machine was finally prescribed and what settings were used. Could sure make a difference in whether a lot of people would actually able to do this kind of treatment or not....instead of just throwing a cpap at them and saying "See me in 6 months."

[tbone106]

I actually have the Bi-Flex, relief on both inhale and exhale. However, if you ever look at the display, having the FLEX set, the pressure could drop as much as 1-2CMs.

For me, the unit is set to cpap 13 -- I'm not sure why, but I have seen it go as low as 10. Now people who say, no way, but I know what I've seen.

I also think straight CPAP might be better for as least me, as I seen to have apneas on the exhale. So keeping the airway constantly pressurized at the same pressure, I think I getting better relief. I think the bi-level setting might even even cause some apneas as the throat expands and contracts with changes in pressure.

I could barely take 13cm when I first started, now a few weeks later I have to check the exhaust port of the mask to ensure its still working.

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[derek]

Unfortunately, at least as far as I can tell, the Encore Pro database does not record C-Flex level. When I started the MyEncore project I was hopeful that I would be able to address the very issue raised in this thread, namely the effect of C-Flex level on AHI. Can't do it...

So, I'm about to start another "experiment": recording daily AHI and C-Flex setting on a spread-sheet and looking for differences. I will use CPAP at 10 cm. It'll take a few weeks to accumulate enough data to make any meaningful conclusions. Maybe some of you would like to do the same thing?

By the way - it's really heartening to see that some folk have been able to use MyEncore to improve their therapy...

derek

[JL]

Derek...Really would be interested in the data you accumulate. There definitely seems to be a correlation in AHI with/without CFlex in some of us...whether it's short/weak exhalation, irregular breathing patterns, apnea events happening during the exhale, etc.

As Rested Gal stated and Respironics literature states the amount of pressure relief delivered with CFlex is based on the patient's expiratory flow and the CFlex settings. Their chart implies at CPAP 11 cm with CFlex 1 setting results in a .3 - .5 pressure drop, a CFlex 2 setting results in a 1 - 2 cm drop and a CFlex 3 setting results in a 2.3 - 3 cm drop. This variable relief is pretty hard to equate to our own situations as we are each so "unique." It sure is a nice option for those who can use it though.

Jim

[tbone106]

By the way - it's really heartening to see that some folk have been able to use MyEncore to improve their therapy...

derek

Derek, the only way to look at ALL THE DATA is via your application. With the encore software you can only look at period between downloads. Since I don't have an APAP, I've been experimenting with various pressures. With Encore, I limited to the range between downloads of information,in my case 4 to 7 days, whereas your software allows to me see from day one.

In my situation, your software has replaced the encore software which I only use to download information off the card.

I now have three months of great data at the various pressures, my next hurdle is to determining the best pressure settings based on ALL the information I've gathered -- I know your software provide lots of graphs, however, I need a big picture, take in all the information and spit out a recommended setting..Ok, if it could balance my check book also that would be great. And while your at it



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