Hypopneas vs Centrals – How to Optimize?

[jeffwpb]

Been using CPAP for probably 20 years, the last 2 using Resmed Autoset.   Had pressures set between 9 and 20, EPR of 2, and AHI was between 2 and 4 reliably, with max pressure between 12 and 13.  My last sleep lab titration, which recommended straight CPAP at 8 was five years ago. I found that I had better results using the Soft Response instead of Standard.  On Standard, the pressure would go up to the max quickly, maybe because of the flow limitations (95% numbers range from about 0.2 to 0.3) and then I was fighting leaks, so Soft worked better because max pressure was lower. I mostly get hypopneas and centrals, very few obstructives.   In the past few months my AHI increased sometimes above 9 or 10, don’t know why, and I am now sleepy for about an hour in the afternoon.  So I started looking for improvements, and it was difficult to see what was happening on Autoset with OSCAR.  I then did some tests in CPAP mode using several different pressures and also varied EPR.  I found the same thing that I have read here from others (thanks bonjour) where Centrals are best reduced using no EPR and Hypopneas are best reduced using higher EPR.  That’s my situation exactly.  The attached table shows what I did for the CPAP mode trial.  It seems like I can balance centrals and hypopneas to be about the same at EPR of 1, but not always, and the AHI is higher than I would like.  For example, while the table shows that a pressure of 8, EPR 1 might be the best from this data, I recently tried that again a couple days ago and got AHI over 7 from roughly 5 CAI and 2 HI.
 
So, are there any suggestions for me?  Am I fighting a losing proposition with the Autoset, and need a different bilevel-type machine, or just accept that results with EPR 1 are about the best I can hope for and make the pressure range settings accordingly.  If any OSCAR data are needed, I can do that.

   

[SarcasticDave94]

OK, here's a few questions to help you answer your questions. Just trying to prod thinking.

1. Do the existing CA and Hypopnea bother you?
   
2. Can you/do you want to just live with them or not?
   
3. What does a current OSCAR graph look like?
   
4. Is the AHI at or under 5? How often is it below 5 AHI?
   

Now, I'll make a guess on your answers to these questions. 1 is yes. 2 is probably no. 3 is yours to answer. 4 is sometimes it's at/below 5, other times it's higher.

1. If these in fact bother you, indicated by the post, you do have to act in some way.
2. doesn't sound like a good plan, to just continuing to be disrupted in sleep.

You should likely document your disturbances in some sort of sleep diary or similar method of noting complaints on the current status. These complaints will need to eventually get to your doctor to begin proving medical necessity for a machine change in some as yet undetermined direction. You're currently on a CPAP/APAP as I recall. You should try for a VAuto unless we can document CA are high enough from the PSG sleep study and OSCAR to justify an ASV.

And note the hypopnea can be obstructive or central based. OSCAR may show this data.

PS I would suggest if you're getting a script for another machine, suggest to stay with ResMed. Have it named, and include Dispense As Written in the script.

[Sleeprider]

Looking at your results, it is pretty clear that your CAI increases significantly with higher pressure or greater EPR (pressure support). So far the best results appear to be at a pressure of 8.0 with EPR 1, however these results are inconsistent resulting in variable AHI or RDI. You seem to have a low apneic threshold and it is likely your sensitivity to EPR is related to the loss of CO2 (hypocapnea) from higher ventilation.

The problem might qualify for ASV therapy which would allow you to maintain sufficient EPAP to resolve obstructive events, and PS to avoid the flow limitations, hypopnea and RERA, and would kick in more pressure support as needed,, when needed to treat centrals. ASV is the conventional therapy, but is often difficult to get unless your AHI is higher and CPAP is demonstrated ineffective. Particularly with COPD, this is a better therapy that could protect your tidal volume we can't see in this data. You're close, but it's going to be challenging to persuade your doctor to prescribe ASV, but I have seen it done very successfully.

Another alternative used by a few members is Enhanced Expiratory Rebreathing Space (EERS) http://www.apneaboard.com/wiki/index.php...ace_(EERS) This is simply moving the mask vent away from the mask and using some short sections of tube to hold a small volume of your expired air. This increases inspired CO2 and often improves both tidal volume and minute vent, as well as decreasing CAI and improving tolerance to pressure support or EPR. I think ASV would be the preferred solution, but this is worth putting out there because it's cheap and easy to do.

[Gideon]

Welcome to the forum.
First, you should be tracking to RDI, not AHI.  Your RDI is consistently over 5.
RDI = AHI + RERAs, RERAs are, in simple terms a series of flow limits that end in Arousal, Keyword arousal.
Let's see how all the events layout through the day, so post a standard set of charts including flow limits (they are a major factor in pressure increases.
Also, I'd like to see a 2 minute zoomed view of your Flow Rate around some typical Central Apneas.

Edit:  I hate it when we do that SR.  I was heading down the same path, including the possibility of EERS.  EERS will enable you to use a higher EPR while avoiding the Central Apneas.  I just wanted to see the charts before I went that deep.

[jeffwpb]

Thanks to all 3 of you for your comments.  I have posted here 3 charts.  One an overall from a recent night with EPR 3, a close-up of a central just before the CSR zone, and a close-up of a hypopnea because I'm unsure how to tell if it is obstructive or central.  As far as machines go, I have had such a time in the past with DMEs. Without elaborating, I decided several years ago that this is important enough to me that I consider myself self-insured for all my apnea stuff.

Be happy to add anything else you need, of course.  I really appreciate the time you have given already.  Jeff

   
   
   

[jeffwpb]

Next, here is one from a month ago with EPR 0 to show the Flow Limitations and change in CAI and HI.  This was when I was trying different things without much improvement.  Jeff

   

[optimalsleep]

Details Events Notes Bookmarks

(Orange bar) AHI 3.82

Left click Events
Double left click on clear airway events
left click on each event to expand to 2 minute segments

This will show what central are centrals.. A central will be at least 10 seconds.


post screenshots of a few central.....

Dave is right..... questions you need to come to terms about. I ask people I know personally on CPAP... how do you feel? I feel oook, shrugging thier shoulders. I want to feel better than ok. I felt like crap tooooo long. Now that I know what to do. I'M DOIN' IT !!

[jeffwpb]

optimalsleep, Thanks for the tip about the 2 minute slice for a central.  Yes, I am trying to fix my recently high AHI/RDIs.  Have been doing this a long time and for some reason something changed.  Am trying to get that fixed in some way if at all possible.  Here are 3 random centrals...

   
   
   

[optimalsleep]

others will chime in shortly.... I'd like to get thier take as well.

saw a sleep therapist compare OSCAR Centrals with polysomnograpic oscillations and during normal breathing a central would show up for a 10 second duration. I see abnormal breathing patterns within your Central events.

[Gideon]

OK Jeff, you have several choices on how to proceed.

1. Status Quo. Accept that this is about as good as it gets and take what your APAP gives you, EPAP=8 and EPR=0
2. Get a VAuto and try. Do understand that this let's use higher levels of PS which give higher levels of Central Apneas and very good obstructive events. It does have one other trick to try and that is to run with a high sensitivity setting that does, for a reason we haven't figured out yet, reduce centrals.
3. Try EERS. This increases the CO2 content of the blood a little to (hopefully) above your apneic threshold by forcing you to rebreathe a small amount of your exhaled air. The fact that altering your EPR show a good change in your central apneas shows some promise for this working. Your 2-minute zoom of your centrals shows some, but not a strong indication that this will work. It is fairly cheap and will work with any CPAP or BiLevel.
4. ASV, the machine that can address both obstructive and central apneas. Hard to get and the most expensive option.

Which way would you like to go?