Newbie - need info on central apneas and other questions...

[arminio]

Hi! Iam new in all this so I have a lot of questions and I hope you'll help me to get some answers... I must appologize because my English is rather bad (it is not my native language) but I hope you will understand this post (at least a bit )

My diagnose is OSA and my diagnosed AHI is 45.2. Sleep study I did shows these numbers that are most interresting to me:

Duration of sleep during sleep study: 5 hours, 33 minutes
Obstructive sleep apnea (OSA): 49 events
Hypopnea: 157 events
Central apnea (CA): 20 events
Mixed apnea (MA): 25 events

AHI = 45.2

After sleep study, I was in hospital on CPAP device for 11 days to check how it works and to fix pressure that best suits me - for my case, they used old REMStar model M in APAP mode and S9 Resmed autoset and they set my therapy to min 4 max 14 pressure. During 11 days my AHI was between 3 and 7 which doctors condidered fine.

Now at my home, and for the past week, I am on Resmed S9 autoset in APAP mode with the same pressure setup and my AHI was between 2 and 3 which is good and much better than in hospital conditions. I also generally feel better - less sleepy and more energetic but nothing spectacular - and that's OK as doctor said (my apnea was untreated for several years so it will need more time for my body to adapt and to get full effect of therapy).

Now, what bothers me most are values I get now while on S9 - as you see from sleep study, hypopnea was main problem in my case. Then MA, and OSA, but there are also central apneas too.
Current values from sleepyhead after first week on S9 are much better - hypopneas are almost gone - there are approx only 2-5 hypopneas per night, 2-5 obstructive apneas, but there are still central apneas - but not 20 per night as without CPAP - on S9 I have only 2-6 (only one night it was 0!) - but these CA values still bothers me because, in my case, the biggest value I got in most days of first week on S9 is CA - other apneas occurs in much smaller amount.

So, how much central apneas are too much? Should I be worried and use BiPAP machine? My sleep doctor newer told me anything about 20 CA events from sleep study, and I didn't bother to ask about it because I thought all values are taken in consideration and therapy is prescribed according to that - but now I am a bit worried because while I am on machine, number of CA are the biggest of all apnea types (although much less amount than without S9). Also, I see that these CA events are not "clustered" together (which is good as I assume) - time space between them are mainly hour or more, athough last two nights I had two of them in sequence. And they usually lasts from 10 to 15 seconds. And they are not product of CPAP - I read that pressure above 10 can cause false CA - but in my case they occurs during various pressure - from 8 to 11.

Also, by definition I found online, apnea is 10 seconds without air flow - and in my daily data in sleepyhead (flow rate graph) I see some stops of breathing of 6-7 seconds that are not treated and not marked as apnea (I assume because CPAP machines recognizes only 10 seconds events) - that is OK? Do I need to worry about that?

Third thing that is interresting is Mixed Apnea - what is actually that? Is this "unclassified apnea" from sleepyhead? If it is, I don't have that values any more (unclassified apnea is 0 for all my first 7 days on S9)

Thanks in advance for reply to all who will reply

[DariaVader]

Congrats on getting your apnea under control. Sounds like you are adapting well, and you are correct that it may take a while to feel the full force of the benefits to your health

CA where the AHI is under 5 is not generally something that the Docs worry about. I presume that during the *ELEVEN DAYS* (wow) that you spent titrating at the hospital that they were making sure your O2 saturations also looked good - but if you are worried, that is what you might check. Also - the length of the events that you have.... If they tend to be 10 sec events, probably no issue. When the CA events have a duration that causes desaturation or the number of them raises your AHI higher then they become more worrisome.

[justMongo]

You did very well expressing yourself. Yes, a CA must be at least 10 seconds for the machine to score it.
I would not be worried at this point. Sounds like you are off to a good start.

Sometimes, when starting PAP therapy, pressure induces CAs; even at pressures of 8 to 11. They may decrease over the coming weeks.

If the CAs are of significant impact, the ultimate machine is the Adaptive Servo Ventilator (ASV) machine.

Follow your progress with the software; and keep your doctor informed of your concerns and progress.

Kindest Regards,

Mongo

[trish6hundred]

Hi arminio,
WELCOME! to the forum.!
It sounds like you are doing fairly well, keep up the good work.
You might talk to your doc about your concerns if they're worrysome to you.
Hang in there for more responses to your post and much success to you as you continue your CPAP therapy.

[arminio]

Many thanks to all for fast and helpfull replies!

Last night after 4 hours of sleep (gone to bed too late because I watched TV - something I finally can do without falling asleep a minute after I sit in front of TV set , and have been awaken by my kid too early ) on S9, I've got only 3 CA (clear airway/"possible central" apneas - not clustered together but dispersed widely - 2 in first hour within time span of 20 minutes and third in last hour of sleep) and 0 (NONE) other apneas! I assume that is great result especially when you consider that I had 20 CA in 5 and a half hours during my sleep study.

But, questions still remains - what are these 20 CA deteced during sleep study - because, if they are real central apneas, they should not vanish with APAP machine (as I assume)... But S9 somehow reduced that to 3 during approx. the same sleep duration. Or maybe S9 does not track all CA that sleep study machine track or S9 do this differently so values differed because of detecting algorithms? Who knows...
And I assume 3 CA per 4 hour's sleep are nothing to worry about (because I read that everybody has some number of them - even people who does not suffer from apnea).

Anyway, last night I had only 3 CA and nothing else. I am happy for now and I feel much better after 4 hours on APAP than after 8 hours of sleep without APAP!

I'll continue to track all values and see how things goes and check results with my doctor after few weeks (I'll give my body enough time to adapt to all this).

[DeepBreathing]

Hi arminio, welcome to Apnea Board.

That certainly is a great result, but every night is different, so we try not to pay too much attention to a single night's results. Once you've used the S9 consistently for a week or more, then review the overall trend. After that time if the centrals are not recurring then consider them cured! The S9 Autoset uses little pressure pulses when it detects an apnea - depending on the feedback from those pulses it will determine if the airway is open or closed. If the airway is open, it assumes it's a central apnea and records it but takes no other action. I think it's reasonably good at this diagnosis, but a proper polysomnograph would obviously be better. It's possible you are getting apneas which are a bit less than 10 seconds - these won't be recorded by the S9. However in SleepyHead you can set "Custom CPAP user event flagging" where you can set a lower threshold of (say) seven or eight seconds and that will be shown in the Sleepyhead graphs. This might give you some additional information.

By the way, can you tell us about your titration process? Did you actually spend 11 nights in hospital?

[Mosquitobait]

My CAs did not decrease for several months, but they did become shorter. Sometimes you generate CAs simply from turning over in bed. I still have, on average 5 CAs a night, but my events are much shorter than during my original sleep study. As to why you don't feel like you can spring out of bed in the morning, keep in mind that you may have complicating factors. In my case, the best they can get my oxygen saturation is 91% which is rather low, due to a slow heart beat. Sometimes you just have to focus on the improvements.

[arminio]

Hi arminio, welcome to Apnea Board.

That certainly is a great result, but every night is different, so we try not to pay too much attention to a single night's results. Once you've used the S9 consistently for a week or more, then review the overall trend. After that time if the centrals are not recurring then consider them cured! The S9 Autoset uses little pressure pulses when it detects an apnea - depending on the feedback from those pulses it will determine if the airway is open or closed. If the airway is open, it assumes it's a central apnea and records it but takes no other action. I think it's reasonably good at this diagnosis, but a proper polysomnograph would obviously be better. It's possible you are getting apneas which are a bit less than 10 seconds - these won't be recorded by the S9. However in SleepyHead you can set "Custom CPAP user event flagging" where you can set a lower threshold of (say) seven or eight seconds and that will be shown in the Sleepyhead graphs. This might give you some additional information.

By the way, can you tell us about your titration process? Did you actually spend 11 nights in hospital?

Last night I had 5 central apneas in 5 hours - mainly 1 per hour (and 3 obstrucive, and 0 hypopneas) - so, values varries from night to night with only one night with 0 central apneas... I'll review trend after few more days but obviously they are there... I didn't know about that option in SleepyHead - I will definitelly check that because in graph I can visually spot some 7-8 second apneas... If there are too much of them (and how much is too much?), is there a way I can treat these shorter events with S9 AutoSet? Can maybe VPAP version of S9 machine do that?
Also, I read somewhere that only if 25% (or more) of all apneas are central apneas, that is Mixed Sleep Apnea Syndrome diagnose where VPAP/BiLevel machine is prescribed (otherwise patient has OSA diagnose and uses CPAP or APAP). And in my case, during sleep study, I had 20 CA of 251 apneas which was about 8% and sounds like OK value... And even if I sum CA and mixed apnea (MA) from my study (although I don't know what polysomnograph considers as mixed apnea), it will be 20+25=45 of 251 which is about 18% and still below 25% and OK (I assume).

And yes - I was 11 days in hospital, but only 5 of them were for titration - usually, titrating test in hospital where I was, lasts for 4-5 days, but me and other patients get some cold with coughing etc. (when I come to hospital, doctors and technicians were already sneezing a lot so we all get sick from each others ) so after 3 days I also get cold and CPAP testing with sneezing and coughing was not very efficient so I need to spend more days after cold was gone (in total, I've been on titration process for 5 days, while other 6 days I was on CPAP but without much effect due to stuffy nose - not even full face mask helped a lot - so they needed more values for analysis and I was there longer than usuall).

My CAs did not decrease for several months, but they did become shorter. Sometimes you generate CAs simply from turning over in bed. I still have, on average 5 CAs a night, but my events are much shorter than during my original sleep study. As to why you don't feel like you can spring out of bed in the morning, keep in mind that you may have complicating factors. In my case, the best they can get my oxygen saturation is 91% which is rather low, due to a slow heart beat. Sometimes you just have to focus on the improvements.

This means that central apneas will be reduced in duration or maybe they will completelly vanish after some time on CPAP?

And, after a first week on S9, I do feel better, but still sleepy in the morning - actually, every day is different, let's say 50/50 - half mornings of this first week I felt more relaxed in the morning, and half not very much. But during the each day, I feel considerably less sleepy.

My oxygen saturation on CPAP in hospital was between 95%-99%, while during sleep study (sleeping without CPAP) shows values even below 90%! Unfortunatelly, I can't measure oxygen saturation at home.

[DariaVader]

This means that central apneas will be reduced in duration or maybe they will completelly vanish after some time on CPAP?

First let me say the amount of CA you have indicated is something that is normally not treated no matter the cause.

After that, it depends on what is causing the CAs.

- If you have true Central Apnea, it means you brain is neglecting to tell you to breathe due to a defect in or damage to the Central Nervous System (CNS). This will not be helped by pressure (could actually be made worse with pressure)

- if the "CAs" are an artifact of your reaction to CPAP pressure as I suspect given your o2 sats during titration, they will likely go down or completely disappear in time.

They bear watching. If the few you have are the first case, they may increase over time - but for now, you are probably fine with them as they are

[arminio]

Well, today is my 14th day on APAP and I am a bit worried... Because in last two days, my AHI went higher! For 12 days, I had it from 0.8 to 2.5 - but for two last nights my AHI went higher: the night before it was 3.4, and last night 4.1! And last night I had almost no leaks so it is not that...

And what bothers me most is again CA - last night I had 9 of them! And that is almost half of value I had during sleep study (20)! And 9 of them disperse during approx. 4 hour of sleep while on my slep study i had 20 during approx 6 hour of sleep. The night before when I had AHI 3.4, I had more OAs an hypopneas appeared again - these apnea types increased AHI because CAs then were only 4. Actually, during 12 first days, number of CA matched number of hours of sleep, and one night it was even 0, while OAs was reduced to 3-4 per night and hypopneas completelly dissapeared - all that until the 2 nights before when everything goes bad

Can worser AHI and reappearance of hypopneas and more CA can be caused by stress at work and other simmilar things that maybe reflects as some "aftershock" during sleep? Because I had some hard work last two days that will continue during next week also (short deadlines, lot of work and pretty stressfull two days and days to follow)... Also, strangely, these two days with higher AHI and more CAs/OAs and hypopneas, in the morning I felt more relaxed than when I had AHI 0.8! Strange...