[CPAP] Clear airway events and EPR

[Jwicks1995]

ive been having problems with waking up wide awake just as a feel like i just fallen asleep. Upon further investigation in sleepyhead the times these happen i am having a clear airway event. Lastnight it was 16 seconds. And from this moment i feel too switched on to get back to sleep. I somehow managed to fall asleep at like 5am. And at this time it registered a hypnopnea (17). With some research i found that reducing the epr may causes a difference so im going to see if that makes a different tonight. A problem with this is that simply reducing the epr from 2 to 1 causes the vent holes that connect the tube to the mask to leak air at a higher rate than before which creates a feint but noticeable hissing sound. Is this normal? I want to try reducing epr but find this sound irritating. 

Apologies for low quality photo.

[robysue]

It sounds to me like what you are noticing is normal sleep transition centrals that would not ordinarily be scored on a sleep test.  You probably never noticed them before you started CPAP simply because you were not paying much attention to your breathing before your adventures in CPAP land started.

The thing is: You now know that you have trouble breathing at night, and even if you don't think you are focusing more on your breathing as you are trying to get to sleep, you most likely are focusing on it much more than you used to.  With time, you won't wake up so much because you just noticed a normal sleep transition central apnea; with time you'll finish the transition to sleep and while the machine may very well score a CA (or two) during your transition, as long as the number of CAs remains low, they are nothing to worry about or lose sleep over.

You also write:

With some research i found that reducing the epr may causes a difference so im going to see if that makes a different tonight. A problem with this is that simply reducing the epr from 2 to 1 causes the vent holes that connect the tube to the mask to leak air at a higher rate than before which creates a feint but noticeable hissing sound. Is this normal? I want to try reducing epr but find this sound irritating.

Reducing EPR means that more air is being blown through the mask (to keep the pressure at a higher rate). And more air blowing through the mask means more air blowing out of the ventilation holes (higher pressures have higher intentional leak rates). And more air blowing out of the ventilation holes means there's a higher probability of sound being created by the exhaust flow, and that exhaust flow may very well sound like "hissing", particularly if it's hitting your mattress, your bed covers, your arms, or your pillow.

Since you describe the noise from the lower EPR as "irritating" I'd strongly recommend NOT reducing EPR from 2 to 1.  If the CAs you are noticing are just sleep transition ones, they may continue even with EPR turned OFF because they are a normal breathing pattern for many people, even people who have no sleep apnea problems.

[Jwicks1995]

Thanks for detailed reply. It seems i am becoming alot more anxìous due to all this and now it feels like during every sleep transition my alertness kicks in and my heart rate increases. I do also think this may of been happening prior to cpap. Would you suggest any particular plan of action? Or would the proper trajectory be to simply push through this somehow. 

My health is top notch. I also drink a calming tea before sleeo.Exercise and eat well. 22 years old. Previously had tonsils and nasal polyps removed. I have allergies and astha and use asthna medication for this. I do find it harder to fall asleep if i need to use my puffer more often. 

Just seems odd that i become aware during my sleep transitions. This in itself causes a strong lift in awakeness ruining my chances of resful sleep. And lastnight it just kept continuing.

[robysue]

Thanks for detailed reply. It seems i am becoming alot more anxìous due to all this and now it feels like during every sleep transition my alertness kicks in and my heart rate increases. I do also think this may of been happening prior to cpap. Would you suggest any particular plan of action? Or would the proper trajectory be to simply push through this somehow.

My own recommendation is to do something to take your mind off the breathing and reduce the anxiousness when you are trying to get to sleep with the CPAP on your nose.

In my case I found that I needed to have some music to listen too as I was going to sleep. I used Gregorian chant music becuase I didn't know the words and I didn't find myself "staying awake to hear that favorite song that will be coming up 3 songs from now" that happened when I tried to listen to favorite albums of folk music.

Going to bed only when I had started yawning really badly also helped.

And finally: If the CPAP or noticing the sleep transition stuff really woke me up and I found myself feeling anxious, I found that getting out of bed, going into another room and doing something soothing and sleep inducing helped.

Think of it this way: Going to sleep with a six foot hose attached to your nose is NOT natural.  And yet, that is what your body and your mind need to learn to do.  It takes time to get the body and mind to accept that this six foot hose and mask is a friendly thing rather than an unfriendly, uncomfortable thing.  So do anything you can do to help encourage your body and mind to learn that it does NOT need to worry about every new sensation (including those normal sleep transition apneas that you are noticing because you're unconsciously focusing more attention on your breathing).  Good sleep hygiene helps: Get up at the same time every day, regardless of how long it took you to get to sleep.  Try to not lie in bed more than 20 minutes while trying to get to sleep---if you're more awake after 20 minutes of trying to get to sleep, it's time to get up, go into a different room, and get your mind off the CPAP stuff for a while.

My health is top notch. I also drink a calming tea before sleeo.Exercise and eat well. 22 years old. Previously had tonsils and nasal polyps removed. I have allergies and astha and use asthna medication for this. I do find it harder to fall asleep if i need to use my puffer more often. 

It's not a surprise that if the asthma is acting up and you need more asthma medication that you have more trouble falling asleep.

Just seems odd that i become aware during my sleep transitions. This in itself causes a strong lift in awakeness ruining my chances of resful sleep. And lastnight it just kept continuing.

It is a temporary thing caused by the fact that nothing about CPAP seems "normal" to your mind or body yet.

The thing that you've got to watch out for though is getting into a nasty cycle of noticing the sleep transition stuff, starting to worry about it, and then just as you start to drift off, it happens again and you get even more alert and less sleepy. Standard self-help for sleep onset insomnia measures can make a big difference.  Google "sleep hygiene for insomnia" and you'll find lots of information about what kinds of behaviors encourage your body and mind to learn how to get to sleep in a timely fashion.  But if you are having a whole lot of trouble just getting to sleep every single night because you keep waking yourself up, you may want to report the problem to the sleep doctor. He may recommend a very short course of Ambien if you're willing to take it for a week or so since that can sometimes get someone over the kind of hump you're dealing with.

[ajack]

Did you have CA in your sleep test? If not they are probably pressure induced, you may have excess o2 and the body is waiting for the Co2 level to build up again to trigger a breath. By the sound of it you are only having a few. I wouldn't think about it if it's a few an hour. They should settle down.

They will get you back in for a sleep study if they aren't Happy. You are seeing a respiratory specialist?

Are you on a months trial???
Although you can buy what you want to, ask your doctor seeing you need a machine anyway. Have a google, asthmatics do better on a bipap/bilevel NIV, you can use it to treat a normal asthma attack. Any bad ones would still need A&E

[Jwicks1995]

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Thanks for the replies everyone. From what it's worth i thought id show you some data just incase this helps with anything.

[ajack]

That all looks good to me.
If you look at the instructions for displaying sleepyhead, it will really help with the advice you will get. Luckily, there is nothing wrong with your event flag graph.

I know what you are going through, it's scarey looking at all the rubbish during the night. Before you go to sleep tonight, for a half hour breathe funny, fast and slow deep and shallow, hold your breath till you feel uncomfortable, with your throat open and closed. Then look at sleepyhead the next day. Honestly, you will never worry again.

Your AHI is about 1, most would love that. If you want to, you could turn your flex/epr off and it may reduce the CA a bit, personally if you like the flex/epr I'd leave it. The probability is the CA won't be there in a couple of weeks/months anyway.
You could raise the pressure 1cm for the OA and H, but there is nothing wrong with leaving it exactly like it is. The cpap is working for you. Are tolerating it well and sleeping through. Getting a full nights sleep, with only a couple of 5 min wakeups? If so, I'd say you were fixed

[Jwicks1995]

Thanks for that! I would experiment by reducing/turning off epr although it creates more leak through the mask connector vent which is quite annoying. I do agree with u though and will take what you have said on board.  :

I am hoping these clear airway events become less frequent. And that my respiratory system will adapt even more as it has been 5 weeks. What initially sparked concern was a few night ago i couldnt fall asleep till 6am because as soon as i thought i was drifting off id get what felt like an adrenaline shot which would continuously keep me awake and thought maybe my body is learning to fight against the stopping of breathing which seems to be happening during transition into sleep.

[ajack]

If these CA are worrying you, I would turn the epr off and put up with the venting, it normally reduces induced CA. You aren't on high pressure, so you shouldn't miss it much.

Anything that you get while falling asleep is junk and not counted. You can get a CA while fully awake and out of bed. It isn't that unusual, mine end in rapid breathing, not like sleep CA.

I really think it's your body adjusting to cpap, trying to balance the o2 and co2. The rate per hour is less than 1 ca. That is well within the range of normal, If there were 20 an hour, it would be a different story.

[robysue]

Thanks for the replies everyone. From what it's worth i thought id show you some data just incase this helps with anything.

First screen shot:

See the large inhalations that occur before the central apnea is scored? That probably indicates this CA immediately followed a (spontaneous) arousal or a mini-wake. In that case, this could be a normal transitional CA as you go back to sleep, and it might not even have been officially scored on a PSG because of that.

As to what caused the arousal: Even people with totally normal sleep will have a few spontaneous arousals now and then. It's not uncommon to see this king of pattern (an arousal, followed by a CA) when you turn over in bed. And since you are not seeing a huge number of these things, it may not be worthwhile to try to eliminate every last one of them.


Second image:

This CA occurs during a stretch of flow limited breathing. (Look at the distorted inhalations both before and after the CA). And there's an H that occurs shortly after the CA---look at the event table. That H is not shown in the zoomed in picture of the flow rate, however. It could be this is a mis-scored event: It may be this is really an OA or a mixed apnea mis-scored as an CA.

My point is: The breathing is already unstable in a way that looks like flow limited breathing before (and after) the CA occurs. And it seems that EPR is unlikely to have caused this CA.


Third image:

This is another shot of the same CA as shown in the second image. Here we see both the CA and the H.  At this scale, we can see the breaths are flow limited for most of this whole period. The RR rate is a tiny bit erratic. And the H is a very subtle H rather than an in-your-face one. Given the time frame and the fact that the night started around 12:30, it's possible this might be what your REM sleep looks like. (The RR can become more erratic in REM and obstructive stuff, including flow limitations, can be worse in REM.) Or it could be back sleeping that's triggering the flow limitations.  We can't be sure from just the CPAP data.

It's worth noting that at this scale, we can again see there is a larger than normal inhalation that precedes the event. It could be you aroused briefly (perhaps because of the FL breathing) and then had a transitional CA as you were drifting back to sleep.  It's hard to say.