(06-12-2015, 03:52 AM)DeepBreathing Wrote: Hi pizza41466, welcome to Apnea Board.
There are a lot of questions and sub-texts there, so I'll try to work through them...
Central apneas occur when the autonomous nervous system doesn't get the "breathe now" message to the lungs and associated muscles. This can occur if the level of CO2 in the blood is too low, and that in turn can be caused by PAP therapy. A constant pressure or autoset machine won't eliminate central apneas - you need an ASV machine for that, and they are really expensive. It's not uncommon for new users to experience central apneas until they adjust to the therapy. In your case, you had about 50% centrals at your first sleep test, so the question now is whether the number of centrals per hour is now higher when you're using the machine?
The related question is what is your AHI now (using the machine)? You mentioned having a 2.4 and 4.5 - is this a typical range? If so, it is below the target threshold of 5, which is regarded as being well controlled. Of course lower is better, but 2.4 to 4.5 is OK if not exactly ideal.
I don't think there is a direct relationship between central apnea and having long pauses in breathing while awake. AFAIK the two situations are controlled by different parts of the brain (though I stand to be corrected on that). I certainly notice my breathing slows right down and stops for maybe 10 - 15 seconds if I'm concentrating intensely on something. That's not the same as stopping breathing when asleep. So I don't think central apneas are a habit.
As for tinnitus - I hate it! I get a persistent loud high pitched whistling in my right ear (and to a lesser extent in my left). It's always worse when I'm tired or feeling off-colour. So to that extent a high AHI may contribute, simply because it makes me more tired.
Hope this helps.
Hi DeepBreathing, thanks for the thoughts on Central Apnea. Since yesterday I use the Swift FX pillow mask, that I have purchased online, and noticed, that the DME-technician, when delivering the machine, days ago, has set the mask selection to nasal ultra alllthough he new, that I had a F&P pillow mask (one reason more to do the setting of the machine oneself). After correcting this, I saw much faster responses in the pressure curve than before in the SleepyHead report. The second half of the night was nearly perfect. In the meantime I have found a very nice description of day and night breathing patterns by Worn_Out_In_Lebanon
RE: Airsense 10 & Central Apnea Detections
Here's some info on how waking up, or arousals, followed by drifting back off to sleep, can contribute to CA's.
From the wikipedia entry for Sleep_and_breathing.
It describes (very briefly) that on waking you may breathe faster for a bit to drive down the CO2 which is now perceived to be too high, and on falling asleep you may breathe slower or even stop to let the CO2 level climb again to the different "set point" needed to trigger the next breath.
Set point of ventilation is different in wakefulness and sleep. pCO2 is higher and ventilation is lower in sleep. Sleep onset in normal subjects is not immediate, but oscillates between arousal, stage I and II sleep before steady NREM sleep is obtained. So falling asleep results in decreased ventilation and a higher pCO2, above the wakefulness set point. On wakefulness, this constitutes an error signal which provokes hyperventilation until the wakefulness set point is reached. When the subject falls asleep, ventilation decreases and pCO2 rises, resulting in hypoventilation or even apnea. These oscillations continue until steady state sleep is obtained. The medulla oblongata controls our respiration.
From a book titled Fundamentals of Sleep Technology by Teofilo Lee-Chiongy:
The sensitivity of the respiratory system to CO2 is affected by the sleep/wake state. CO2 sensitivity is highest during waking and lowest during quiet, non-REM sleep, with REM sleep having intermediate sensitivity. The abrupt decrease in CO2 sensitivity at sleep onset, while the waking CO2 level persists for a few seconds, may be a mechanism of sleep-onset central apneas.
Anyway, the net effect for me, is if I sleep soundly, I get less CA's. If I'm restless and waking up a lot, I get more CA's. I always see a small cluster in the beginning of my graph every night at the time I'm drifting off to sleep. I often see a couple after the gap in the graphs where I took the mask off for a bathroom break. I figure the random ones are probably pegged to a period where I was fidgeting with the mask, waking up while rolling over, etc.
If you are getting disturbed more, from getting the new machine dialed in, I would guess your CA's are from those disturbances more than anything else.