[Treatment] Clear airway / central apnea events -- causes and solutions?

[mitzvahtime]

Hi all, first off, big fan of this forum; it's helped me to dial in my CPAP usage after several months of struggling with adherence, mask fit problems, etc.

I've finally landed on a mask + paraphernalia that allows me to be broadly leak-free and address most of my Obstructive Apnea events. However, I'm still sitting at an AHI of around ~2-3 with primarily Clear Airway events, and I continue to subjectively feel tired in the mornings, have big bags under my eyes, etc. I understand that central apnea is harder to treat, but I was wondering if there were any techniques that are associated with better CA outcomes. Also, how likely are the CA outcomes to be misclassified OA or other events? Any advice given my chart would be much appreciated.

Context on me, in case it helps: I'm 5'10 140 pound 35 year old male, untreated AHI of ~15, using Resmed Airsense 11 set to [7-11] with no EPR, with the F30i mask, a semi-soft cervical collar, and a wedge pillow. I also have refractory dyspepsia + GERD despite medication, as well as a deviated septum, both of which influence my sleep quality. I've attached screenshots of my Oscar readout.

Thanks!

[Gideon]

welcome to the forum

Those in the zoomed view are IMHO misclassified as they are likely you holding your breath while tossing in response to the preceding arousal. The problem is not the CA but the arousal.

You start the zoomed view with normal breathing then take several deep breaths which indicate arousal (these look like they could be CO2 induced but without lowering your CO2 levels to below your apneic threshold which would have resulted in a central apnea)then a period of restricted shallower breathing followed by a recovery breath that is typical of an obstructive event and labeled as a hypopnea, this series would call a RERA. The recovery tapers off to extended arousal followed by what is likely a breath-holding while tossing during the recovery and is (mis)labeled as a CA event. The recovery from that appears to be a CO2-induced recovery that transforms into another arousal which is likely followed by some breath-holding again labeled as a CA. The breathing following both of these CA events does show the signs of being at least CO2-influenced breathing though much less so with the second event.

The bottom line is that you appear to be close to your apneic threshold. Other CA events that you have may well be purely complex or Treatment-Emergent Central Apnea, though I cannot tell without seeing the zoomed flow rate for them. You need to watch your central events (CA) and not be afraid of them. This type of CA event mostly will/may go away over time but I would want a low rate of them, about what you have here to promote your body to adapt to them. I'm not sure if they will for you since you say you have been using CPAP for several months.

The key on your device is to maintain a low EPR for now.

[mitzvahtime]

Thanks for reviewing my data, much appreciated. If I understand you correctly, the CO2 levels in my blood might be getting somewhat high (presumably because I'm not getting enough oxygen in sleep), and thus I am waking up, tossing and turning (pausing my breathing), and then gasping for air? 

I believe I have EPR turned off in my CPAP, so presumably my central events aren't being caused by EPR.

Some follow-up questions:
-What might be causing me to reach the point of arousal / be close to my apneic threshold?
-What makes you say that these events will likely diminish or go away over time? (Assuming EPR isn't playing a role)

In case it's helpful to have some more zoomed in context, I've attached screenshots for 3 other CAs.

Thanks!! Really appreciate you digging into this with me.

[Gideon]

The only legitimate central is in the center chart, it is ideopathic and not CO2 influenced.

The use of any CPAP, even with no EPR or pressure variation, pure simple CPAP can cause complex or treatment Emergent Central Apnea. That is evidenced by the waxing and waning, almost done wave appearance in the Flow Rate.
It is characterized by low CO2 levels in the blood with a central apnea occuring if you go below your apneic threshold. The use of a CPAP alone can improve your breathing to the point where this can occur. You are just (in)lucky to be one.

[mitzvahtime]

Okay, cool, thank you for the analysis. Look forward to talking through this topic in more depth with my doctor.

[HenryECole81]

Using ResMed  AirSense 11 Auto on CPAP  fixed 12, many of my recorded Events are flagged as Clear Airways.  The overnight AHIs vary from 2.5 - 6 with most of the AHI events per hour flagged as Clear Airways (very few Obstructive events) . However,  4%-12% percent of total events are flagged as Cheyne-Stokes. All flagged Cheyne- Stokes coincide with flagged Clear Airways, but not all Clear Airways are flagged as Cheyne-Stokes.   I wear an O2 Ring that shows 95-98% O2 all night with the CPAP (Ring O2 score of "9.9 or 10"). Without the CPAP, there is much higher O2 variability, with 10-30% of the O2 below 94, often in the 80s. 

I am a very fit 80 year old Master swimmer  at  All America and Top Ten National level, with no problems with heavy hour team workouts other than normal being pooped at the end.  I do have a 40 year long term, very low resting heart rate of 36 - 42 bpm rising to 110-120+ during swim sets but falling back to 60k+ between sets. I can fairly comfortably swim 50 yards or more underwater, though generally just 25 in practice sets.  I have long term totally asymptomatic A Flutter that is cardiologist monitored. 

Question: Cheyne-Stokes is described as likely caused by a very serious heart condition.  My pulmonologist has not been concerned with the number of Cheyne-Stokes, saying they are actually Central - Clear Aways related.  What are the Apnea Board and members  observations on this and the relation between Cheyne- Stokes and Clear Airways?

Thanks

[Jay51]

Thank you for posting that.  I have a resting heart rate usually in the 40's that gets down into the 30's sometimes with sleep.  Athlete here, too.  

If you could download OSCAR and post some of the CSR (maybe a few 3 minute zooms of close up flow rate when it says you are having CSR), it might possibly show if these are true CSR or not.  CSR has a distinct pattern of crescendo-decresceno and then flat line CA.  The vast majority of members who post with OSCAR charts that say CSR are false.  Only a very rare few are accurate.