OSA on exhale?

[Albacore]

Does anybody else have experience with OA ( obstructive apneas ) on the exhale? I know I had issues with that prior to PAP therapy. My AHI hovers around 10 to 11 after three weeks of using this machine. The first 7 days of use showed an average AHI of 5.4. The machine was delivered with an incorrect setting of IPAP 15, EPAP 15. No different than straight CPAP. My prescription from the sleep lab was for bi-level therapy at 20 IPAP, 16 EPAP. Within the first week, I changed the therapy mode to bilevel. The RT who delivered the Machine stated that she seriously questioned the recommended settings from the Sleep Lab. So after talking with her, I tried 15 IPAP, 10 EPAP. I am wondering if my EPAP level is too low, causing OA on the exhale while i sleep. Prior to BiPAP therapy, I noticed that I would have OA during exhalation while falling asleep on the couch, or laying on my back, etc. Is it possible my OA is different from most people, and that I require a higher EPAP pressure? ( ie, maybe that is why pressures of 15 / 15 yielded lower AHI?) Is it common to have OSA on the exhale as well as the inhale?

[Wulfman...]

What do you mean with the acronym "OS"?


Den

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[Albacore]

Sorry that should have been OA (obstructive apneas). I have been literally wrestling with my auto correct on my phone lately. I should have caught that. I will try to edit that.

[Albacore]

Post edited......gotta watch that auto-correct like a hawk.

[Pugsy]

EPAP is probably too low if you are seeing more OAs.
Can you post an image of the detailed report so we can see what you are seeing? It would help us a lot.
Don't know how? This thread explains how we do it and has some examples.
Screen shot thread viewtopic.php?f=1&t=81072&p=737779#p737779

Generally EPAP for OAs and IPAP for hyponeas but I have found that often with hyponeas...if EPAP does better with the OAs then the hyponeas also reduce as a by product. So I tend to look at EPAP minimum as a starting setting to try to optimize first.

[Albacore]

Sorry. I just got my smart card, so no info on anything prior to the last 4 days. I got the 5.4 AHI figure from the machine itself after about a week of use. I wanted to get a week or so on the card before I submitted it for interpretation. I know a single night or two is not enough data to effectively evaluate. For now, I will bump up the EPAP to 12, and see how that works. Thanks.

[Pugsy]

When you get 2 or 3 nights with EPAP of 12...then post the report if you can.
The LCD screen averages are harder to evaluate when a change in pressure is done because of the 7 night average thing your M series machine offers.

The report will show the breakdown into OAs and hyponeas and give us a better idea if we need to mess with EPAP or IPAP or both. We can't get the breakdown on the LCD screen.

[Wulfman...]

Does anybody else have experience with OA ( obstructive apneas ) on the exhale? I know I had issues with that prior to PAP therapy. My AHI hovers around 10 to 11 after three weeks of using this machine. The first 7 days of use showed an average AHI of 5.4. The machine was delivered with an incorrect setting of IPAP 15, EPAP 15. No different than straight CPAP. My prescription from the sleep lab was for bi-level therapy at 20 IPAP, 16 EPAP. Within the first week, I changed the therapy mode to bilevel. The RT who delivered the Machine stated that she seriously questioned the recommended settings from the Sleep Lab. So after talking with her, I tried 15 IPAP, 10 EPAP. I am wondering if my EPAP level is too low, causing OA on the exhale while i sleep. Prior to BiPAP therapy, I noticed that I would have OA during exhalation while falling asleep on the couch, or laying on my back, etc. Is it possible my OA is different from most people, and that I require a higher EPAP pressure? ( ie, maybe that is why pressures of 15 / 15 yielded lower AHI?) Is it common to have OSA on the exhale as well as the inhale?

If you don't already have it........I'd suggest getting a copy of the sleep study and the prescribed settings.

I don't know how "common" it is, but it's been noted and discussed on the forum from time to time. One of the things that CAN be critical in the settings is the pressure at the point of finishing exhale and beginning the inhale cycle. There CAN be apneas (or other limitations) at that point. We particularly point this out from time to time to people who use ResMed machines with EPR.......which actually drops the pressure on exhale. If the "effective" pressure is dropped below the minimum that is needed, there can be events taking place at that point. P/R machines with A-Flex, C-Flex and Bi-Flex don't do it the same way and are dependent on the user's exhale effort and offer a little back-pressure to try to prevent events from occurring at that point.


Den

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[Albacore]

Will do. At this point, I almost wonder if turning on the auto-function might not be a good idea. My detailed report for last night showed zero large leaks, and zero percent large leak time, with a leak index of 42. Not sure what that means, but it sounds as though leaks are not a major issue. Anyways I will get back with you after 3 day of sleep with the new adjustment.

[Pugsy]

Large leak territory for your machine is up around 90 L/min.
The 42 L/min you are seeing as an average is total leak which includes the mask's expected vent rate and probably is real close to vent rate only...leaks are minimal to none most likely.
Full face masks typically have higher vent rates anyway and as the pressures go up so do the vent rates.
If you look at the leak line graph and don't see time around 90 L/min or above..no large leaks to worry about.

You can change to auto mode if you wish....
Maybe EPAP minimum 11 cm...PS max of 4 and IPAP max of say 16 (won't go there unless it thinks it needs to) and if it goes up it will drag EPAP up with it. Or if it thinks EPAP needs to be increase then it will push IPAP up.
In Auto mode on the M series machine the minimum PS is by default 2 cm and would then range between 2 and 4 as it sensed the need.

[Albacore]

Wulfman- I am looking at my sleep study now. It shows a prescribed setting of 20 over 16. The RT stated that she seriously questioned those settings, and thought they were awful high. My decision to try 15 over 10 was based on the fact that my initial settings were 15 over15 (incorrect according to prescribed settings) which yielded a seven day avg. AHI of 5.4 which I figured was pretty effective. I don't know, maybe the prescribed settings are correct after all. I guess I will find out as time goes on. I am determined to make this work this time. I was prescribed a regular CPAP seven years ago, but never could make it work, and abandoned it in frustration. I am finally at the place where I consider this to be a necessary lifestyle change, and am coming to terms with it. So I will work with adjustments, auto function, etc. until I get it right. Thanks for the replies.

[Wulfman...]

Wulfman- I am looking at my sleep study now. It shows a prescribed setting of 20 over 16. The RT stated that she seriously questioned those settings, and thought they were awful high. My decision to try 15 over 10 was based on the fact that my initial settings were 15 over15 (incorrect according to prescribed settings) which yielded a seven day avg. AHI of 5.4 which I figured was pretty effective. I don't know, maybe the prescribed settings are correct after all. I guess I will find out as time goes on. I am determined to make this work this time. I was prescribed a regular CPAP seven years ago, but never could make it work, and abandoned it in frustration. I am finally at the place where I consider this to be a necessary lifestyle change, and am coming to terms with it. So I will work with adjustments, auto function, etc. until I get it right. Thanks for the replies.

Well, about this time in 2005, I was prescribed a pressure of 18 cm. The sleep study stopped at 16, but the "doctor" thought that that wouldn't be painful enough and added two more cm. for good measure......AND, hinted that a UPPP might be necessary to force even more air into my body. I then asked about a Bi-PAP if he's talking about more pressure.

Anyway, I "tried" 18 cm. for about an hour or less and decided to try a pressure I could possibly sleep with. After all, I had the Encore Pro software to check my nightly data. So, I reset my CPAP to 10 cm. Lo and behold, that pressure produced AHIs of around 1.0 or less.......so, I left it there for about a year. Then in early-mid 2006, I decided to try a little more pressure, experimented with an APAP and by the end of 2006 I settled on 12 cm. And, that's where I've been ever since.


Den

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[bouncer]

Hi Albacore,
I too have OSA on exhalation - I also first noticed it when just relaxing and dropping off to sleep, especially on my back .... continually jerked awake by sudden high pressure exhalations. Although I've been told that apnoea is obstruction on inhalation or exhalation, I've never understood it and it seems different from most people with apnoea ....but I don't notice it at all when dropping off to sleep when using APAP and my AHI us usually around 1-2.
Sorry I don't know enough to help with your settings.
NB - my settings on inhale and exhale are the same .... no EPR

[djhall]

Is it common to have OSA on the exhale as well as the inhale?

On BiPAP you would expect OA to happen on the exhale if EPAP is too low. If EPAP isn't high enough the airway can fully collapse at the end of the exhale. That blocks the inhalation attempt from reaching the BiPAP and prevents the machine from switching to the higher IPAP pressure. H, RERA, and FL are partial obstructions so the machine can still detect the inhalation attempt, switch to the higher IPAP pressure, and blow them back open on the inhale if IPAP is high enough. So you first set EPAP high enough to prevent OAs, then increase IPAP (EPAP + PS) by increasing PS or by further increasing EPAP to reduce H, RERA, &/or FL.

[planted]

Blockage of exhale is exactly what I have. My tongue falls back and somehow creates a pocket with my soft pallet. I can breathe in with some difficultly but when I try to exhale the "pocket" fills up with air and creates a very strong resistance against my exhalation which requires either a change in neck position or tongue position to overcome. Strange stuff that took me a great deal of time and observation to figure out what the heck was going on back there. Just started cpap on my own to see what I can do about it.