Why do small leaks increase Apneas?

I am curous about why small leaks cause increase in AHI, specifically Apneas. Obviously large leaks cause an increase because the pressure is not able to keep up with the leak and you are not getting effective therapy. But isn't the CPAP supposed to attempt to keep pressure constant in smaller leaks? So shouldn't the AHI stay the same during lower leaks if it is succesful ? In my chart below, it is obvious almost every Apnea is during a leak period and can be assumed the leak caused it. (Unless somehow my Apneas are causing the leaks, LOL) . The leaks I know are being caused by 2 factors. One is positional as I move a lot in my sleep and sometimes knock the mask against the pillow. When I wear the mask tighter it helps but then it is too uncomfortable and leaves marks for too long. The other is I have oily skin. Even though I wash thoroughly before bed, within 4-5 hours I start getting leaks caused from my skin oils. I get small leaks like you get from moisture. I can feel the oil on the seal and I know that is the cause. I usually get up, wipe the mask and my face, and go back to sleep. It always eliminates the leaks. I tried Remzzz's but they don't work for me.

But my question is just about the machine not reacting to the smaller leaks. If I increase the pressure will it likely give me a higher pressure during leaks ? Or will it be the same? The machine is a Remstar Pro M series. I do not use any bells or whistles, no ramp, no Cflex, no humidity. I find it comfortable at straight pressure in a FFM.

I doubt if it is the leaks that lead to the increase in apneas.

I'd be willing to bet it's positional. You roll onto your back and snore and have apneas.

DoninOrlando wrote:I am curous about why small leaks cause increase in AHI, specifically Apneas. Obviously large leaks cause an increase because the pressure is not able to keep up with the leak and you are not getting effective therapy. But isn't the CPAP supposed to attempt to keep pressure constant in smaller leaks? So shouldn't the AHI stay the same during lower leaks if it is succesful ? In my chart below, it is obvious almost every Apnea is during a leak period and can be assumed the leak caused it. (Unless somehow my Apneas are causing the leaks, LOL) . The leaks I know are being caused by 2 factors. One is positional as I move a lot in my sleep and sometimes knock the mask against the pillow. When I wear the mask tighter it helps but then it is too uncomfortable and leaves marks for too long. The other is I have oily skin. Even though I wash thoroughly before bed, within 4-5 hours I start getting leaks caused from my skin oils. I get small leaks like you get from moisture. I can feel the oil on the seal and I know that is the cause. I usually get up, wipe the mask and my face, and go back to sleep. It always eliminates the leaks. I tried Remzzz's but they don't work for me.

But my question is just about the machine not reacting to the smaller leaks. If I increase the pressure will it likely give me a higher pressure during leaks ? Or will it be the same? The machine is a Remstar Pro M series. I do not use any bells or whistles, no ramp, no Cflex, no humidity. I find it comfortable at straight pressure in a FFM.

As I was about to respond.....I see "Guest" said essentially the same thing I was about to. It's a "positional problem".....not a "leak problem" (except that when you're on your back, you're leaking more, too).


Den

DoninOrlando wrote:... I am curous about why small leaks cause increase in AHI, specifically Apneas. ...

Actually, those leak rates are fairly high. The machines will compensate, but beyond a certain point they can not effectively compensate.

In general, the suggestion is to keep the leak rate to less than 35l/m (liters per minute) or there abouts. Your numbers were well above that ... in the 45 to 50 range at the start of the obstructive events.

The other question is which came first, the obstructive event or the leak? It's possible (since these are clustered together) you were in deep sleep and/or REM sleep. Our bodies (especially in REM sleep) tend to relax more than other stages of sleep, so obstructive events tend to occur more frequently then. If you relax more, you tend to leak more and you tend to have more obstructive events, but the sleep stage may have triggered both.

However, once the obstructive events occur, it's hard for your system to compensate when you have such a high leak rate. So, you definitely need to tackle that issue.

DoninOrlando wrote:... (Unless somehow my Apneas are causing the leaks, LOL) . ...

Exactly! Which comes first? In this case (because they are clustered together), I suspect it might be due to REM sleep or sleeping on your back or both. But that's just a guess on my part.

DoninOrlando wrote:... The leaks I know are being caused by 2 factors. One is positional as I move a lot in my sleep and sometimes knock the mask against the pillow. When I wear the mask tighter it helps but then it is too uncomfortable and leaves marks for too long. The other is I have oily skin. Even though I wash thoroughly before bed, within 4-5 hours I start getting leaks caused from my skin oils. I get small leaks like you get from moisture. I can feel the oil on the seal and I know that is the cause. I usually get up, wipe the mask and my face, and go back to sleep. It always eliminates the leaks. I tried Remzzz's but they don't work for me.
There's another recent post about cleaning masks. Some do it frequently. Some note that the slight oil on the mask actually helps it seal better. Go figure. You will need to find what works for you. Wish I could offer more sure advice, but it really seems to be a matter of choice and your body / face.

DoninOrlando wrote:... But my question is just about the machine not reacting to the smaller leaks. If I increase the pressure will it likely give me a higher pressure during leaks ? Or will it be the same? The machine is a Remstar Pro M series. I do not use any bells or whistles, no ramp, no Cflex, no humidity. I find it comfortable at straight pressure in a FFM.
A higher pressure might help. But often in that pressure range it can lead to central apneas instead of obstructive apneas. Getting the leak rate under control is the most important issue. For more informaion about the ResMed masks, see the following URL:

http://www.resmed.com/us/assets/documen ... sa_eng.pdf

At a pressure of 11.5 your Quattor FFM will have a flow rate of about 40l/m. You have a leak rate of an additional 40 to 45l/m at the same time as the mask flow rate. That's a LOT to try to maintain the pressure.

Hope that helps.

John,
I guess I was mostly looking at the leak numbers for the night. It shows no large leaks, and a leak rate of 43 against an expected leak of 40 is among my best yet. It can only go down to 40. Remember this machine does not program in the leak rate for the mask so 43 is my total including the expected 40.
I was joking about my Apneas causing the leaks but you bring up a very good point I had not considered. I know when I sleep on my back during REM my jaw drops so far my mask leaks very bad waking me up. And that is with the FFM. That is why I don't think I slept on my back at all. The leaks are far worse than these and usualy enough to wake me up. It also causes real snoring which wakes my wife and she in turn wakes me (intentionally).
But you may still be right in that REM sleep is still causing enough relaxing to cause the leaks, regardless of position. Not sure how to tackle that though. I suppose I could try to cut back on REM sleep Just kidding. I've been that route and it definitely didn't work
By the way, the snore rate is mostly false as I only snore when on my back and the wife is good about waking me. And the very high leak rates show it (much higher leak rate). This software always shows snores with leaks and I believe it is the vibrations of the leaks on the mask. The wife says my snoring stopped when I started Cpap and she could not even sleep in the same room when I did.
Don

DoninOrlando wrote:... Remember this machine does not program in the leak rate for the mask so 43 is my total including the expected 40. ...

I had forgotten that about EncoreViewer. Good point.

DoninOrlando wrote:... It also causes real snoring which wakes my wife and she in turn wakes me (intentionally). ...

You seem to have the same helpful approach from your wife. Before my ASV unit, I sometimes thought I had a vibrating bed, since she would shake the bed enough to wake me. And as you might imagine with a lot of central apneas, neither of us slept well.

DoninOrlando wrote:... But you may still be right in that REM sleep is still causing enough relaxing to cause the leaks, regardless of position. Not sure how to tackle that though. I suppose I could try to cut back on REM sleep Just kidding. I've been that route and it definitely didn't work ...

Oh, I know that feeling as well. I got so REM sleep deprived that I would dream just by closing my eyes. That's an odd feeling, to say the least!

DoninOrlando wrote:... the snore rate is mostly false as I only snore when on my back and the wife is good about waking me. ...

Frankly, I wish more sleep doctors would query bed partners. I struggled with central apneas for a long time. My wife complained about it. I've had doctors dismiss both me and her. I wish I had pushed harder to have it addressed a long time ago. I know my poor health now is a direct result of untreated sleep apnea. Oh, well. Live and learn!

DoninOrlando wrote:... The wife says my snoring stopped when I started Cpap and she could not even sleep in the same room when I did. ...

Glad it's getting things under control. And good it allows you and your wife to sleep together. My wife put up with me. Of course, the final straw that sent me to my doctor about my sleep problems (almost 20 years ago) was when I snored so loudly that my children woke up screaming. Needless to say, I got the mother of all dirty looks from my wife. She simply said "You get one of the kids and you WILL go to the doctor!". Sometimes, arguing is pointless - especially when you know she's right!

The reason I was assuming the leaks were causing the apneas is I can get a lower leak rate and lower AHI with a pillows mask. But I guess the REM sleep would not have caused mask leaks with pillows since relaxing the face muscles does not change the nose shape. I can also get somewhat better numbers with a nasal mask. Unfortunately, the only way either nasal or pillows works is if I Use Afrin, wash and shave for tape to stick, ad breathright strip, tape mouth, use chinstrap or other reinforcement for mouth like a wrap, add mask, and try to find a comfortable position I feel like a wrapped mummy with all that crap and bedtime is a 1 hour chore. It kind of takes the fun out of sleep I just can't sleep like that and sometimes laid awake for hours. Also could not breath through nose consistantly without Afrin and that's not good either, (although my sleep doc is not against Afrin if no other way works). I tried the neti pots, sprays, drugs, allergy medicines, all prescriptions including flonase, nasonex, veramyst, and more... I am not doing surgery. I will make a FFM work, and when nasal is clear occasionally use nasal mask.

DoninOrlando wrote:... Unfortunately, the only way either nasal or pillows works is if I Use Afrin, wash and shave for tape to stick, ad breathright strip, tape mouth, use chinstrap or other reinforcement for mouth like a wrap, add mask, and try to find a comfortable position I feel like a wrapped mummy with all that crap and bedtime is a 1 hour chore. It kind of takes the fun out of sleep ...

Yikes! I can certainly understand that discomfort!

DoninOrlando wrote:... Also could not breath through nose consistantly without Afrin and that's not good either, (although my sleep doc is not against Afrin if no other way works). I tried the neti pots, sprays, drugs, allergy medicines, all prescriptions including flonase, nasonex, veramyst, and more... I am not doing surgery. I will make a FFM work, and when nasal is clear occasionally use nasal mask. ...

It takes a good bit of tweaking to get it to work. You don't want the hose to interfere or pull the mask. You want it tight enough to keep a good seal, but too tight leads to headaches and mask impressions that last all day.

As I've noted, the Quattro FFM works well, but I'm looking for something that works better!

JohnBFisher wrote:
As I've noted, the Quattro FFM works well, but I'm looking for something that works better!

John,
I think I will always be looking for a better mask. Funny thing is my last improvement in a FFM was just a different size Quattro. Early on I had the Medium size and it was leaving red marks and felt too tight so I switched to Large. The large was more comfortable and left less soreness on the nosebridge. However I kept the Med as a backup. I recently tried the Med again and it had fewer leaks and gave better numbers than I usually get on the large. Of course it left a red mark on my nose that is still there. I guess it just fits tighter and leaks less, but is less comfortable. Why do you always seem to have to give up something to make progress somewhere else ?
Don

DoninOrlando wrote:... Why do you always seem to have to give up something to make progress somewhere else ? ...

Had you not heard? (And this is only half way joking!) It's the

Marhsmallow theory of life: Press one place to try to nail it into place and the rest just squeezes out some other side.

So what's one to do? Just sit back, pop a few in your mouth and enjoy the sensation - rather than trying to fully control the shape!