Recovery Breaths

[PaytonA]

Often we use large recovery breaths at the end of an apnea to determine that it was actually an obstructive apnea. My feeling is that this is probably a good sign since one had been trying to breathe for 10 seconds or more and couldn’t and finally was able to due to removal of the obstruction. This seems like a normal reflex and a good indicator.

If your brain is not telling you to breathe because your CO2 is low and then it gives you the signal to breathe, it seems correct that there would be no gasp to get air and that would be a central apnea. Is there a condition, maybe do to a malfunction, that would cause one to gasp for breath at the end of a central? If your brain just plain forgot to tell your system to breathe for enough time, you might feel starved for air and when your brain finally woke up I would think that you might gasp for a breath making it look like a recovery breath which would normally make it considered to be an obstructive apnea except not by the machine.

What are your thoughts concerning using recovery breaths to distinguish obstructive apneas and a lack of recovery breaths to distinguish a central apnea.

My ponderings. What are your thoughts?

Best Regards,

PaytonA

[Sleeprider]

I think your idea is a good one, but anytime I'm trying to evaluate CPAP data, I do it with a healthy dose of uncertainty.

[Sleepster]

Is there a condition, maybe do to a malfunction, that would cause one to gasp for breath at the end of a central? If your brain just plain forgot to tell your system to breathe for enough time, you might feel starved for air and when your brain finally woke up I would think that you might gasp for a breath making it look like a recovery breath which would normally make it considered to be an obstructive apnea except not by the machine.

I would think that the human body is capable of responding to either a central apnea or an obstructive one with a gasp. In either case the brain got the low-oxygen signal, so it might respond the same in either case.

What are your thoughts concerning using recovery breaths to distinguish obstructive apneas and a lack of recovery breaths to distinguish a central apnea.

You could look at your data, searching for recovery breaths, and examine the preceding apneas. If the occurrence of obstructives there is different from elsewhere, you may have evidence to support your idea. For example, let's say 75% of your apneas are obstructive, but 90% of the apneas preceding recovery events are obstructive. If that's repeatable across multiple nights for multiple people you might be on the something!

[PaytonA]

It is not my idea. It is an idea that I have heard espoused by different people at different times. I am just trying to see if there is a consensus. If this is not the indicator in use, how do we determine if a OA is a real OA or if a CA is a real CA?

Best Regards,

PaytonA

[Sleeprider]

Payton, it is generally but not always true for me, but I really don't have any way to verify whether the exceptions are incorrectly flagged, or a real response to the flagged event. When I see sporatic CA events in peoples data immediately followed by a strong flow spite, I suspect that CA may be improperly flagged.

I have access to a data from a number of different people, including a CHF patient. I can show you a series of CSR where the apneas are alternately flagged CA and OA. I'm pretty sure the ones marked OA are an error and the steady waxing and waning of respiration is the same for both events. Let me know if you want a screen shot. I just find the event flagging to be unreliable, and use the respiration recovery breath or lack of it as a confirming clue. In the case of the CHF patient, an OA result from the pressure pulse may be fluid in the lungs giving the appearance of an obstructed airway. When I have an OA event, I usually see a strong recovery breath or even a double inhale, while most CA events the respiration simply restarts at the same volume it left off with.

It's interesting stuff, but as I said in my first post, a healthy understanding of the uncertainty needs to be taken into account.

[kwhenrykerr]

Good question. I will look at my data more. Thanks PaytonA

[PaytonA]

Payton, it is generally but not always true for me, but I really don't have any way to verify whether the exceptions are incorrectly flagged, or a real response to the flagged event.  When I see sporatic CA events in peoples data immediately followed by a strong flow spite, I suspect that CA may be improperly flagged.  

I have access to a data from a number of different people, including a CHF patient.  I can show you a series of CSR where the apneas are alternately flagged CA and OA.  I'm pretty sure the ones marked OA are an error and the steady waxing and waning of respiration is the same for both events.  Let me know if you want a screen shot.   I just find the event flagging to be unreliable, and use the respiration recovery breath or lack of it as a confirming clue.  In the case of the CHF patient, an OA result from the pressure pulse may be fluid in the lungs giving the appearance of an obstructed airway.  When I have an OA event, I usually see a strong recovery breath or even a double inhale, while most CA events the respiration simply restarts at the same volume it left off with.  

It's interesting stuff, but as I said in my first post, a healthy understanding of the uncertainty needs to be taken into account.

I would be interested in seeing the CSR. There is another case that may lead to the appearance of a scoring error. Where the event starts as a CA and ends up with the airway collapsing into an OA. I have not seen this but robysue claims that it does happen and I can see the possibility. I assume that the machine would score this as an OA even though it started as a CA and you might not get(?) a recovery breath.

Best Regards,

PaytonA

[Sleepster]

If this is not the indicator in use, how do we determine if a OA is a real OA or if a CA is a real CA?

A CPAP machine uses pressure pulses to see if the airway is clear. APAPs need to know that so they can raise the pressure in response to OA's and not raise the pressure in response to CA's.

The only thing better than that, as far as I know, is the chest belt used in a sleep study. It can show a lack of respiratory effort, verifying a CA.

[srlevine1]

I can show you a series of CSR where the apneas are alternately flagged CA and OA.  I'm pretty sure the ones marked OA are an error and the steady waxing and waning of respiration is the same for both events.  Let me know if you want a screen shot.   I just find the event flagging to be unreliable, and use the respiration recovery breath or lack of it as a confirming clue.  In the case of the CHF patient, an OA result from the pressure pulse may be fluid in the lungs giving the appearance of an obstructed airway.  When I have an OA event, I usually see a strong recovery breath or even a double inhale, while most CA events the respiration simply restarts at the same volume it left off with.  

I  would appreciate seeing a confirmed case of CSR in someone with CHF and someone without CHF so I can better evaluate some past occurrences of breathing flagged as CSR using a ResMed AirSense AutoSet 10. Also what would be a good time scale to measure against.

Thanks.

[kwhenrykerr]

   
What is your idea about this event ?