what a timely thread. I am getting very similar conditions. I'm gonna call it period breathingic since it seems to meet that definition. Note that I also record audio so I can often infer if I'm waking up, moving or vocalizing (mumbling in my sleep or grunting). I sync the audio with the cpap recording and I can usually match the events with some movement or noise, which gives me a clue as to whether or not I'm in quiescent sleep, or just falling to sleep. Not as good as EKG, of course, but its what I have.
Here's what I've found so far:
1) The episodes of PB are strongly correlated with falling to sleep. I will usually get one of these episodes when I am falling back to sleep. The duration and amplitude will vary.
2) there have been some episodes that I can't correlate with any audio event. They just seem to start on their own, usually with a sharp intake of breath that comes out of no where though the breathing pattern up to that point has been steady and normal. I do notice that some of the sharp intakes are preceded by movement and/or vocalization, as evidenced by the audio recording, which might indicate that I'm waking up before the periodic breathing starts, or at least moving to a lighter stage of sleep.
3) When I look at the periods of uneventful sleep (i.e. when there are no obvious variations in breathing, pulse, O2, no events detected, and the audio has nothing of interest), I often have some oscillation in my breath. That is, the amplitude of the flow plot will vary by 10% or so with a period similar to the plot below.
4) pressure does not seem to affect it. I have had periods of perfect sleep of up to 4 hours with none of these events at pressures from 8-10, and I have had nights where the machine was set to CPAP mode at a pressure of 8.5 or 9, and I get them. I set the ramp start to 4cm, and I got them all during the ramp.
5) I have been using CFLEX (AFLEX drives me crazy as it feels like it's pushing air down my throat) and have tried settings of 1, 2 and 3 with no difference.
6) It varies from night to night. I don't have enough data yet to correlate it with anything, such as how tired I am, but some nights I see events only at the beginning of the evening and after I've gotten up to pee. Other nights I see events thru the night. I am aware that on the nights with fewer events I sleep more continuously than on nights with more events, but I'm not sure which is the cause and which is the effect.
I think this breathing pattern has nothing to do with my obstructive apnea or my CPAP. I have long experienced the following, since way before I was an adult:
I feel my self falling asleep, then suddenly I startle awake. Sometimes I just feel like an electric jolt has woken me. Sometimes I feel like I'm falling backwards. Sometimes I feel like I'm drowning and desperately need air. In the last few years it's mainly been the jolt.
Since my teen years I have had trouble falling to sleep. I have felt exhausted and start to sleep, but wake up as described above. I think I finally have an explanation. I don't know what causes it, but when I'm falling asleep I do the PB thing.
I've read some explanations of PB. one is that hyperventilation causes it. Another is that the brain "forgets" to breath. Another is that it is more likely to occur in REM sleep. And, no, I have had no stroke or heart trouble and I am a very healthy 67 year old.
As a sound tech, I see beat frequencies. If my wake breath circuit and my sleep breath circuit had slightly different frequencies, then this is exactly what I would see if they were both running while I fell asleep, i.e. a beat frequency equal to the difference between the two frequencies. (I have no idea if there even are two circuits).
Anyway, I gather that this is fairly common and was happy to see this thread. I hope my experience helps someone.
If anyone has suggestions of how to reduce it, I'm open to them. I am planning on trying more pressure settings and taking more data over time.
Also, I would love to have a home device that can record sleep states. I hate the idea of going to a sleep lab. Anybody know of one?