Thinking things through

[AMP2011]

I have been on a CPAP for over a year. The initial 3 months were tough and my initial titration was an approximate 7 based on a bad first sleep study. I could not return for further studies for a year, but did a home study using a small home study system (type used for screening). This home study suggested 'problems' related to unstable sleep, but my snoring was under control. AHI was 19 in my first study (with severe snoring). I remained on a pressure of about 11 or 12 for most of the last year, as low pressures kept me awake and resulted in unstable sleep. However, at this higher pressure it seems I have more centrals. RERAs are constant at about 0.8. Data for the first months suggest AHI of 1.2, with 1.7 in the most recent six months. Centrals make up 0.3 of this, but RERAs make up 0.8. A recent sleep study (study '3') suggested a lower pressure (7.5) to reduce centrals. I tried this for 2-3 weeks (AHI went to 5.5, mostly OS and H), but found I had to increase the pressure back to 10.5 (AHI down to 1.25). I sleep poorly with the lower pressure. At 10.5 I sleep better, but have higher centrals (about 7 a night). Overall my sleep is not great, but it better on 10.5. Not feeling greatly refreshed under any condition, but better at 10.5. While these numbers are not severe, I'm not feeling great or seeing massive benefit from CPAP yet. I can see the centrals and hyponeas are long (according to CPAP data), but I do not know how bad I desat (intial study suggested 82%). I tend to have more OS events early in the night (wonder if the sleeping tabs are contributing) and more Hyponeas in the last 5 hours of sleep (after sleeping tabs are worn off). I have a severe sleep onset problem (hence sleep tabs).

I am wondering what others think about balancing Hyponeas/OS events and risk of centrals. If I feel worse with higher H/OS, then how much do the centrals matter? With the varying pattern of needs during the night, would this suggest the need for a BiPap/APAP. I find at lower pressures that I tend to wake in the first 4-5 hours feeling I can't get enough air (like sucking through a straw). High pressure (10-12 makes for easier breathing and syncing of breathing in the early morning hours). I find CFlex 3 is best.

Any advice welcome. I want to master this sleep thing. PS have lost 10 pounds through diet, which has not made a difference to sleep.

[Pugsy]

At 10.5 I sleep better, but have higher centrals (about 7 a night)

f I feel worse with higher H/OS, then how much do the centrals matter?

I wouldn't even give more than a passing glance at 7 clear airway events (or centrals) over the night unless the night was only an hour or two long. CA index less than one over the whole night? I wouldn't be concerned with it at all.
Some of those flagged events could be sleep onset central, turn over in bed hold your breath central, or an occasional true central or any combination of those.

I would be using the settings that gave me the best quality of sleep and well being and if that happened to correlate with lower AHI then all the better.

Seven centrals in an hour, every hour, all night long, every night... then I would worry about centrals and possibly investigate other pressures and/or other machines.

[archangle]

What software are you using?

Don't just look at counts of events. Look at duration. Look at the waveforms at the severity.

One 11 second apnea does not equate to one 120 second apnea.

An apnea where you're still breathing at a reduced flow rate does not equate to one where you completely stop breathing.

[AMP2011]

Dear Archangle and Pugsy

Those are both useful replys.

I use SleepyHead and Encore Pro 2.

When I look at the data I can see that a useful perspective is to see where the pressure pulses are (SleepyHead software). I generally seem to respond to them. Most events are short (5-15 secs) with a few lasting 30-60 secs (exceptional events on one or two nights in a week, but not usually). I'd imagine that the desats are not that bad on most nights. I can see some events where there is no indication of a leak (leak graph), but the flowrate goes up to the top of the graph and then is followed by no breathing for 60 seconds (5-6 pressure pulses) and then a return to normal breathing thereafter (with a '20' leak showing). I imagine those are the worst events.

I am trying to figure out how come I am not getting the 'refreshed' bit that some cpap users get. My breathing can be eratic in periods at night, but I am still breathing. Previous studies said I spend very little time in REM and have frequent arousals (preventing sleep quality or sleep efficiency). So I am wondering if this is a breathing/apnea issue or something else.

AMP2011

[Julie]

You're using a nasal mask now, but are you sure your mouth is always closed when you're asleep and that you're not losing cpap air that way? If it's a possibility (as it would be for anyone not being watched all night), consider trying out a full face mask, or at least taping for a few days to test it out.

[Pugsy]

I am trying to figure out how come I am not getting the 'refreshed' bit that some cpap users get. My breathing can be eratic in periods at night, but I am still breathing. Previous studies said I spend very little time in REM and have frequent arousals (preventing sleep quality or sleep efficiency). So I am wondering if this is a breathing/apnea issue or something else.

If you figure out the secret to that "refreshed" feeling I see others (and I turn pea green with envy) mention please let me know.

I do know fragmented sleep will mess with how we feel. It simply messes with the normal sleep architecture needed for good restorative sleep. I deal with that every night. Some nights I win, some nights I don't. Pain is my culprit.
So I follow my own advice...when we don't feel the good numbers start looking at other possible culprits that might impact how we sleep in general or even how we feel in general.
Meds? Pain? General health? Insomnia (frequent wake ups can be a form of insomnia..doesn't have to be the classic can't get to sleep insomnia)? Hours of sleep? Bed comfort? You get the idea...anything that can mess with how we feel and doesn't have to be directly related to sleep itself.

[archangle]

I can see some events where there is no indication of a leak (leak graph), but the flowrate goes up to the top of the graph and then is followed by no breathing for 60 seconds

Is the "no breathing" a complete flat line, like your throat has snapped shut trying to exhale? I think of those as classical obstructive apneas. Do you get a big pulse of exhaled air at the end?