[Diagnosis] Round 2 Sleep Test

[Rubicon]

I would give 6/EPR3 another shot.  The 3/11 study was a 11/EPR3 night and breathing instability only started to rear it's ugly head, so let's try to differentiate between sleep and apnea.

[Rubicon]

Specifically, we'll be looking at 2 other parameters:  Minute Ventilation and Tidal Volume.  Your breathing seems to be most stable with MV at ~3.0 L. and VT at ~300 ml.:



If, in fact, an excess of those parameters is creating an issue, we should be able to tease that out.

[Rubicon]

That said, is EPR the culprit?  Here's a block at 9/EPR3 and you're happy as a clam:



So I don't think we have an Aha! moment yet.

[Geer1]

A 26 minute duration of good data indicates nothing other than that breathing was good during that short period. Why don't you post the 40+ minute example of periodic breathing starting ~ 4:10 from that same night? You seem knowledgeable enough to know you can't cherry pick data in cases with a central apnea aspect.

pearlpearl, central apnea is notoriously inconsistent, you can have 2 AHI one night and 15 AHI the next night with no change in settings. Just like how your sleep study showed reasonable breathing most of the night and an hour of horrible breathing. You need to look at trends and average your results over multiple days. The reason I disagree with using 6/3 (actually 6/2) and trying to compare it against 5/3 (actually 5/1) is what are you comparing? Are you comparing the higher pressure or the higher EPR? The fact is you have to compare both which and it is impossible to draw any conclusions when doing so because you don't know which variable is causing the change.

Rubicon does bring up a valid point in that EPR doesn't act as the trigger itself, EPR just worsens central apnea caused by a trigger. The trigger is usually any sort of sleep disturbance (obstructive apnea, spontaneous arousal etc) and they act as triggers by causing larger amplitude breaths (recovery or arousal breaths). Those larger breaths wash out your CO2 which causes the first central apnea to occur and then the central apnea or periodic breathing may repeat until breathing stabilizes again. From that recent data Rubicon posted there was a clear arousal just before 4:10 which caused large amplitude arousal breathing (flow rate is larger as is TV and MV). From the minute vent and tidal volume charts you can see how your breathing fluctuated largely after this and then slower over time it approached more normal breathing but it took a half hour to do so and it never actually hit a nice steady state like the breathing example earlier in the night that Rubicon posted (can see how smooth that TV/MV was in the red rectangle area.

Sleep transition central apnea in its truest form occurs just because of larger amplitude breathing while awake that washes out CO2 after the transition to sleep. You may have some of this but for the most part you have a regular CO2 driven central apnea issue that follows things like arousals etc. Sleep disturbances and spontaneous arousals are normal occurring 10+ times per hour in most individuals so you need to take that into account and try to find settings that don't anger central apneas after these normal arousals. 

EPR wreaks havoc in CO2 driven central apnea cases like this because if makes it easier to exhale and to wash out the CO2 which makes it easier for the first central to occur and harder for the breathing to stabilize after it does. ASV on the other hand treats central apnea like this by adjusting EPR (called PS on an ASV) for each individual breath such that it stabilizes your breathing quickly since your body struggles to do so on its own.

My understanding is that you have tried different settings in the past so lets see a screenshot from your statistics page scrolled down to the "Changes to Prescription Settings" section. This section shows us the pressure and epr settings you have used and average ahi at each setting. Depending on what settings you have tried in the past it may help confirm what has worked better or worse for you. I still think you should use a progressive, systematic approach to find ideal settings but I feel this data may help confirm that EPR of 3 makes things worse. If you have already extensively tried numerous settings it may confirm that nothing has consistently worked.

[Rubicon]

Why don't you post the 40+ minute example of periodic breathing starting ~ 4:10 from that same night? 

I can do that!

BRB...

[Rubicon]

Absolutely not periodic.  Doesn't even look like sleep.  SWJ.

[David Clark]

See...this is the kind of stuff I want someone to do with mine. Posting a screenshot or two is one thing but having you actually look at the data is entirely different. I need to figure out how to get mine so you can look at it if you want.
You guys are doing great work here.

[pearlpearl]

I would give 6/EPR3 another shot.  The 3/11 study was a 11/EPR3 night and breathing instability only started to rear it's ugly head, so let's try to differentiate between sleep and apnea.

My apology i think i missed out something.  The 3/11 ->11/EPR3 i think was an exception night.  After refer back to my notes, i was having a big hives flared up that night and following few days and i took Antihistamines.  Hence, there wasn't any data after 3/11 as i didn't hooked on to my CPAP.

[pearlpearl]

A 26 minute duration of good data indicates nothing other than that breathing was good during that short period. Why don't you post the 40+ minute example of periodic breathing starting ~ 4:10 from that same night? You seem knowledgeable enough to know you can't cherry pick data in cases with a central apnea aspect.

pearlpearl, central apnea is notoriously inconsistent, you can have 2 AHI one night and 15 AHI the next night with no change in settings. Just like how your sleep study showed reasonable breathing most of the night and an hour of horrible breathing. You need to look at trends and average your results over multiple days. The reason I disagree with using 6/3 (actually 6/2) and trying to compare it against 5/3 (actually 5/1) is what are you comparing? Are you comparing the higher pressure or the higher EPR? The fact is you have to compare both which and it is impossible to draw any conclusions when doing so because you don't know which variable is causing the change.

Rubicon does bring up a valid point in that EPR doesn't act as the trigger itself, EPR just worsens central apnea caused by a trigger. The trigger is usually any sort of sleep disturbance (obstructive apnea, spontaneous arousal etc) and they act as triggers by causing larger amplitude breaths (recovery or arousal breaths). Those larger breaths wash out your CO2 which causes the first central apnea to occur and then the central apnea or periodic breathing may repeat until breathing stabilizes again. From that recent data Rubicon posted there was a clear arousal just before 4:10 which caused large amplitude arousal breathing (flow rate is larger as is TV and MV). From the minute vent and tidal volume charts you can see how your breathing fluctuated largely after this and then slower over time it approached more normal breathing but it took a half hour to do so and it never actually hit a nice steady state like the breathing example earlier in the night that Rubicon posted (can see how smooth that TV/MV was in the red rectangle area.

Sleep transition central apnea in its truest form occurs just because of larger amplitude breathing while awake that washes out CO2 after the transition to sleep. You may have some of this but for the most part you have a regular CO2 driven central apnea issue that follows things like arousals etc. Sleep disturbances and spontaneous arousals are normal occurring 10+ times per hour in most individuals so you need to take that into account and try to find settings that don't anger central apneas after these normal arousals. 

EPR wreaks havoc in CO2 driven central apnea cases like this because if makes it easier to exhale and to wash out the CO2 which makes it easier for the first central to occur and harder for the breathing to stabilize after it does. ASV on the other hand treats central apnea like this by adjusting EPR (called PS on an ASV) for each individual breath such that it stabilizes your breathing quickly since your body struggles to do so on its own.

My understanding is that you have tried different settings in the past so lets see a screenshot from your statistics page scrolled down to the "Changes to Prescription Settings" section. This section shows us the pressure and epr settings you have used and average ahi at each setting. Depending on what settings you have tried in the past it may help confirm what has worked better or worse for you. I still think you should use a progressive, systematic approach to find ideal settings but I feel this data may help confirm that EPR of 3 makes things worse. If you have already extensively tried numerous settings it may confirm that nothing has consistently worked.

Geer1, you may be right.  In the past, when the EPR set at 3 between pressure from 8 ~ 12.  My CA shot up real high but tame the OA.  My technician here insisted that EPR setting at 3 and rebutted me from lower it.  I secretly when to lower the EPR to 1 & 2 for a few nights (1/16 to 25/1) the CA did came down but went up too is like roller coaster ride.  I couldn't continue with that setting as it was not ordered by the doctor.  I have little knowledge with how the machine works for me therefore i have no clue how exactly the CA came down and went up.  If i can achieve to strike a balance with low CA and OA with that machine.  i will be a happy women.  Between, just to share some personal profile.  I am in my early 50s, postmenopausal.  I am 5'2", Weight 51kg.  I don't think i am obese with thick neck but the doctor diagnosed me with a narrow jaw with thick tongue.  I do experience insomnia some nights but i am still feeling okay during the day.  I don't have a sleepy or lousy feeling.

[pearlpearl]

Oh my where am i now? Yesterday at 6/EPR3 was no good too. I am looking at the big AHI number was at upper 10 range.

I think i will stick to 6/EPR3 for tonight and i will have 3 nights (3/28, 3/29 & 3/30) to review. I will post the 3 nights reports, I don't think is nice to post the report everyday to annoy everyone. Thank you so much in helping me out!