I have a mild case of OSA and have been on CPAP for a little under a year now.  I had some trouble acclimating to it, and I occasionally have some sinus trouble, but otherwise I've been pretty satisfied with it.  I've had an issue lately though.

I've been waking up at roughly the same time every night (around 4:00) in a sweat with the no-oxygen weariness feeling.  It's not an obstructive problem, because I know what that feels like.  It just seems like I'm not breathing.  When I exhale against the pressure, it's a looooonnnnnng breath and then I hit this odd, perfectly balanced spot- and the inhalation takes a while to show up.

The only other variable that I can think of that could possibly relevant is that I've been a heavy runner my whole life, but lately, because of some schedule changes and some unrelated health issues, my running regimen has been very irregular.

Does anyone have any insights into this?

I know with my centrals it is like a gasping feeling at times. But sense I have a machine that sense when i don't I don't really wake up as much from them. What type of machine do you have, are you able to look at your data at all on it? What is your pressure setting?


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Severe Central & Obstructive Sleep disordered breathing
AHI:116.4
Lowest Sat 85% High96.1%
Total Central,Obst,& mixed 190/hr
Out of that total 66 were Hypopneas
IpapMin7 max16 Epap6
Bipap Auto SV
Resmed Mirage Swift II

Tsanuge121 you need to talk to your sleep doctor, you just might need your pressure adjusted, or you might be right and you maybe having CA's. I went thru the same thing, a year an a half later and six sleep studies  later and I am on VPAP ASV. Hopefully you won't need that, but you definitely should be checking with your sleep doctor to find out what is going on! It might very well be time for you to have another sleep study!  I wish you well ! Good Luck to You!


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White Beard with a White Beard
Resmed VPAP Adapt SV Enhanced, HumidAire 2i, ResLink with Model 8000 Flex sensor Pulse Oximeter, and ResScan 3.5 software. Respironic EverFlo OPI Oxygen Concentrator 3 lpm
EEP 9.0, min PS 6.0, max PS 16.0

I have a no bells and whistles CPAP that keeps me pressurized but does nothing else.  My initial sleep study showed an AHI 13: about 3 hourse of sleep, 39 events, all but 3 were hypopneas; however, one of the full-stops was scored as "mixed."  My pressure is 8, but the titration showed that I was only corrected down to an AHI 2.5

I'm not sure if "gasping" is the right word; what I feel is more subtle.  It just seems like my body thinks it doesn't need to breathe, and I have to remind it.  I also can't shake the feeling that it's under the impression that the CPAP has relieved it of its responsibilities. My mask is overdue to be replaced and seems to be leaking more than usual, but I don't know if that would account for it.  

Maybe I'm just being paranoid; I mentioned that I'm a runner and I suppose that when I'm in a deep sleep, I have some long, slow breathing cycles.  I feel fine during the day- no fatigue or anything.  My sleep is very sensitive to this stuff, and if it was real serious, I'd be having a rougher time.  Last year when I was finally deciding to go get checked out, my AHI 13 was preventing me from getting virtually any sleep at all until I got on CPAP.

Oh well, I suppose I'll have to go get another study.  I'm just interested in hearing some descriptions of what CA feels like.  I had figured out that I had OSA long before I had a study just from the descriptions I read on this board, so I thought I'd ask around before deciding if I should call my doctor or wait for the next scheduled visit which isn't until after the year rolls over.

I also have times during the day when I seem to not be breathing and I have times at night that I break out in sweats.  I will break out in a sweat sometimes during the day.  It's possible that you have anxiety associated with OSA.  I hear that it is very common.  I actually make myself settle down more often now since I know this to be the case.  It is possible that you are dreaming and are reacting to your dreams.  I sometimes wake up during a dream if something scared me.  I think its got a lot to do with working with the CPAP to improve your sleep.  You would be surprised what can interfere with sleep, even if the CPAP is correcting your OSA.  I know the CPAP has made me less tired, but I also stuggle sometimes to sleep all night long with it.  It it possible that you are mouth breathing during the night.  Is your mouth dry at night or after you wake up.  If so, then I would ask your doctor about a chin strap to keep your mouth closed.  If you are mouth breathing, I understand this can cut down on the effectiveness of the CPAP and you could be have apnea events anyway.  I think I mouth breath sometimes and I have tried the strap, but its just one more thing to strap to my head at night.  :)

Tanuge121,

The only way to tell what is going on is to talk to your doctor and have a sleep study.  But I want to simply describe how a high pressure above what you need can induce central apneas as it relates to the way you describe you feel.  I have to reiterate however, that the only way to know is to talk to a doctor and have a sleep study.  It is just as probable that you are having anxiety or something else going on.

The major signal to breath is a rise in carbon dioxide levels.  CO2 and H+ concentration (which refers to pH and related to the level of CO2) levels in cerebral spinal fluid are detected by a chemoreceptor in the brain’s medulla called the Central Chemoreceptor.  Additionally, an increase in blood CO2 is detected by the Peripheral Chemoreceptors located in the aorta and carotid arteries (called the aorta and carotid bodies).  The peripheral chemoreceptors also detect O2 levels.

If a CPAP pressure is too high, then CO2 is literally “blown off” and the signal to the brain to breath is removed until either the oxygen level drops to a trigger level or the CO2 level rises again.  Here are the blood levels (called the Threshold) that trigger the response to breath:

The threshold pO2 for activation is 60 - 80 mmHg with normal arterial pO2 about 95 mmHg. Any elevation of pCO2 above a normal value of 40 mmHg, or a decrease in pH below 7.4 causes chemoreceptor firing.

Vicki


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That which does not kill you makes you stronger-Friedrich Nietzsche
Friedrich must of had apnea.

I agree with Vicki for sure.  I will add just one thing that is not proven, but may help.  Have you ever tried Yoga breathing?  Many people will breath with only a small capacity of their lungs and do so very shallow and much more often.  Yoga teaches you to be a more relaxing breather.  No as I say that, I have only tried in once or twice, but I am wondering as I type this if this is something that would also help me.  It would not hurt to try.  You can do Yoga breathing just about anywhere.  I have heard that it help to train your body to take deep more relaxing breaths.

Thanks for the info Vicki.  That does sound similar to what I've been experiencing.  I am definitely out of whack when I wake up: tense, elevated heart rate, ultra slow breathing pattern; it feels like my BP is way up, like my whole body is pressurized, not just my airway.  I've taken off the mask and spent the last hour or so dozing without it and felt like everything returned to normal.  

This is not the claustrophobic, anxious feeling that I used to have during the first few weeks when I started CPAP, but it could be some type of anxiety.  What you are describing sounds more likely than "real" CA, because I never experienced anything like this before CPAP and never do when I occasionally nap without it (the "snickle-snickle-<close>" of the OSA is a feeling I'm quite familiar with).  I suppose I'll have to get another study and maybe a smarter machine- my doctor probably felt like a simple CPAP machine was sufficient for a mild case.

Laynei, in answer to your question about yoga, I have been a long time practioner of yoga and meditation. I can not recommend it highly enough; it has proven very useful in helping manage my sleep problems.  Unfortuantely, just as with my running regimen, my yoga practice has lately been irregular.

I'm still wrestling with this issue.  I haven't gone to see the doctor yet because it comes and goes (at least I think it does.)  Last night I woke up, and my mask was leaking.  I have a beard and use a full face mask.  Usually I keep the beard very closely cropped and I've never noticed it causing a leak, but lately it's gotten a little thicker and I think it might have been causing a leak last night (I was also lying on my side- almost on my stomach).

Could a mask leak cause the experience I desribed in the original post?