Are Occasional Episodes of Cheyne-Stokes Respiration Reason for Concern?

[Melman]

I have been following SleepyHead data for 21 nights. Thanks to help from this forum I have gotten my AHI down to 0.0-2 most nights. I have had a couple of major outliers, 15.3 and 11.8. The 15.3 was before going from CPAP to APAP. The 11.8 was from last night and was an unpleasant surprise.
 
On the two nights with the AHIs of 15.3 and 11.8 I experienced single episodes of CSR lasting 21 min. and 31 min. respectively. Both were associated with multiple OAs and occurred during periods of significant flow limitation, I suspect due to chin tucks. What I find interesting is that I have data from an additional 5 nights during which there were periods of significant flow limitation lasting 15 or more but with few or no OAs and no CSR.  
 
What triggers CSR and is the frequency of two events in 21 days a cause for concern?
 
I have attached the graphs from last night and also from a night with a similar period of flow limitation but no CSR.
 
Thanks

[Sleeprider]

My observation is that CSR is a very persistent pattern and has a very characteristic pattern that is a very gradual waxing and waning of respiration, punctuated with a central apnea. While the machines will sometimes record this as an obstructive apnea, it is not associated with snores or flow limitations as your examples are. It would take a good closeup of the waveform to comment further.

A more accurate and generalized term for breathing with periodic characteristics is "periodic breathing". Your machine does not diagnose CSR, and you should probably just change the default description and abbreviation in Sleepyhead to be Periodic Breathing (PB).

[Melman]

  It would take a good closeup of the waveform to comment further.

Is this the closeup you had in mind? 

[Sleeprider]

That is just a series of OA.  You can see the breathing rapidly diminishes with increasing flow limitation to the point an apnea occurs, and a couple big recovery breaths occur before the process goes again. Contrast the dynamics with this:

[Melman]

That is just a series of OA. 

Thanks. So I guess there's no need to run to the ER.
 
I now have data from 13 nights using APAP. AHIs are 0, 2.36, 1.23, 1.27, 0.98, 1.92, 0.3, 0.91, 1.55, 0.42, 0.47, and 11.8. Given my limited understanding, it seems I’m doing pretty well (with the exception of the 11.8). Pressure has gone to the max of 14 on 6 nights. On 4 of those 6 nights I experienced several OAs and Hs at the pressure of 14. Is this an indication that I should adjust pressure settings or should I wait for more data?

I really like the 8 setting for the low pressure. It’s much more comfortable than the constant 10 I had before. 

[Sleeprider]

Your results are pretty darn good, and if your're comfortable, I wouldn't change anything. Your apnea events are not fully correlated to pressure because there is a physiological issue that can create events regardless of pressure. You're dealing with that effectively, and as long as you do, high pressure should not be needed. Pressure rises because your airway closes due to head and neck position, and as long as you prevent that, your moderate PAP works.