Relation Spo2, apneas, and Leaks don't make sense

[insomeapnea]

Hello everyone,

I’m hoping someone can shed some light on a situation I’m facing. During a time of significant leaks, I’m observing a consistent Flow Rate with no apneas and stable high SpO2 levels. Any insights would be much appreciated! 

[G. Szabo]

As for the missing apneas, the instrument is not able to collect realistic information during this high leak rate; hence, the flow rate is tainted, and there are no reported apneas either.
Good oxygen saturation is a different issue. I guess it is like sleeping facing the wind. Even low breathing efforts can supply enough oxygen.

[insomeapnea]

Thank you for the plausible explanation but if you notice at time of zero or bellow 30 Leak Rate is when I had most of my apneas.

Attached is a date when the leaks where very high and I even I had Cheyne Stokes Respiration while the Leak Rate was almost zero and SpO2 over 94.

[G. Szabo]

Thank you for the plausible explanation but if you notice at time of zero or bellow 30 Leak Rate is when I had most of my apneas.

This is what I was discussing. Or I am misunderstanding you. 

You have events where the instrument operates within its specification limits. 

Here is an analogy: In the Second World War, airplanes returned from combat with bullet holes all over their bodies, including the wings, but no bullet was in the pilot's cabin. Some engineers suggested increasing the armour on the wings. Obviously, this was a misunderstanding of the message.  

As for your CSRs. Your repeated CAs might be misclassified. A magnification (some 3-minute window) would help the experts.

[insomeapnea]

This is what I was discussing. Or I am misunderstanding you. 

You have events where the instrument operates within its specification limits. 

Here is an analogy: In the Second World War, airplanes returned from combat with bullet holes all over their bodies, including the wings, but no bullet was in the pilot's cabin. Some engineers suggested increasing the armour on the wings. Obviously, this was a misunderstanding of the message.  

As for your CSRs. Your repeated CAs might be misclassified. A magnification (some 3-minute window) would help the experts.

Sample of 3 minutes with Cheyne Stokes. 

Please take note that the Leak Index is 0, oxygen levels are fine, but the Flow Limit is still flat.

As for your analogy, I would recommend reinforcing the armor on the entire plane and scaling up the engine accordingly.

[G. Szabo]

Sample of 3 minutes with Cheyne Stokes. 

These samples do not appear to be CS. I hope others can chip in to confirm it. 
You have a high FL, which should be addressed. There are two options: (I) increasing the minimum pressure to 16 cm, (ii) increasing the EPR to 3. Unfortunately, both will increase your CAs;  option (ii) is more seriously. I suggest starting with (I) and seeing the outcome first.
You would probably benefit from a bilevel machine because it can decrease the CAs while maintaining the pressure support.

[Jay51]

I agree with G. Szabo.  They don't look like real CSR.  CSR are very uniform and have a crescendo-decrescendo pattern.  Looks like several round balls on a string and very symmetrical.  And lasts for the majority of the night; not just a single, short instance like yours.  

Here is some reading from our Wiki on Cheyne-Stokes Respirations:   Cheyne-Stokes respiration


The most common cause of real, true CSR is heart failure.  There a few other possible causes for CSR as well.