Wave shapes - Central vs Obstructive Aepneas

[gpk111]

I've been analyzing the wave patterns recorded by my new ResMed S9 with ResScan. The available breath-by-breath details are fascinating. As part of my experimentation, I've been holding my breath (obvioulsy when still awake ! to analyze the resulting wave patterns. I take 5 shallow breaths just prior to holding my breath to conclusively "mark" the event.

Results: Everything is recorded as expected, except some of the events are recorded as "Central" and some as "Obstructive" aepneas. Since I held my breath for at least 10 seconds each time, no partial aepneas are recorded nor expected.

Any thoughts on how central and obstructive events are differentiated?

[dave21]

An Obstructive Apnea will show when there is a blockage in the upper airway, I'm not sure that holding your breath (although I haven't tried it) would net the same result, but effectively if the CPAP/APAP notices a blockage in the amount of air that is coming back into the machine because it can't get through then I'm guessing that would similarly replicate an obstructive apnea because the CPAP/APAP will be monitoring that there's not enough flow (e.g. restriction).

For a Central Apnea, there is no blockage, so the flow and minute graphs should not show any abnormality as far as I understand it.

Thanks
Dave

[Ruffinit]

I have no ideas how it comes about recording the difference between the two, but the ResScan 3.7 shows a CSA as just a small box or event. Because I have CSA, I record from 0 to 8 per night and apneas show up as little red mushrooms on the chart which I have maybe 1 or 2 a week, they have a number associated within that mushroom which I expect would be the number of seconds that apnea was in effect.

[gpk111]

An Obstructive Apnea will show when there is a blockage in the upper airway, I'm not sure that holding your breath (although I haven't tried it) would net the same result, but effectively if the CPAP/APAP notices a blockage in the amount of air that is coming back into the machine because it can't get through then I'm guessing that would similarly replicate an obstructive apnea because the CPAP/APAP will be monitoring that there's not enough flow (e.g. restriction).

For a Central Apnea, there is no blockage, so the flow and minute graphs should not show any abnormality as far as I understand it.

Thanks
Dave

Dave,

Great tutorial on the link (s). Thanks for creating it.

[dave21]

Thanks, I'm keeping it up to date every few days by adding more content. Hopefully it'll be a complete FAQ on most things CPAP both for the beginner and people wanting to advance to the next stage of checking their stats vs reducing their AHI's.