06-22-2016, 07:12 AM
(This post was last modified: 06-22-2016, 07:16 AM by Tiercel.)
What is "Clear Airway" it's not in the sleep disorder glossery
In trying to understand my stats and get the most out of this long resisted solution I downloaded SleepyHead.
There is far more that I don't understand than that I do understand. One of the most confusing is that it lists clear airway like it is an "event". Does it mean all is well, or is it some classification of an AHI?
Here are a few stats from last night. I am still having 8 - 10 events per hour which is better than 40 during the home sleep study
Thanks!
Large Leak 29.91%
Clear Airway 8.81
Obstructive 0.84
Unclassified Apnea 0.42
Hypopnea 0.21
RERA 0.42
RE: What is "Clear Airway" it's not in the sleep disorder glossery
Clear Airway is when your brain forgets to tell your body to breathe. Causes for a CA can range from recording data while you're still awake or while you're waking up, the body not being accustomed to the higher inhale pressure or using the EPR that can washout your CO2 levels. . . on up to more complex reasons.
I have included links that provide more information about apneas and the reporting of events.
Sleepyhead Beginner's Guide:
http://www.apneaboard.com/forums/Thread-...ns-Answers-
Discussion?pid=73182#pid73182
Wiki (link at the top of the page):
http://www.apneaboard.com/wiki/index.php...=Wiki_Home
I hope you will find these useful.
06-22-2016, 08:11 AM
(This post was last modified: 06-22-2016, 08:16 AM by Tiercel.)
RE: What is "Clear Airway" it's not in the sleep disorder glossery
I just did some digging to see if I can answer my own question and it "seems" that Clear Airway (CA) means I am not breathing but the AirSens 10 Auto is somehow able to sense that my airway is open. It also seems that since during my 5 nights the CA events were from about 45% to 80% of my events that I might have some Central apnea going on.
Hmmm,.... You know, it is strange. on several occasions even when getting sleepy watching TV with the CPAP on I noticed it was almost like I would forget to breathe WHEN I WAS STILL AWAKE ! I would breathe and wonder why I did that an how it was affecting my stats
Weird ????
RE: What is "Clear Airway" it's not in the sleep disorder glossery
CA events are about all I have...in moderation. Any 10-second cessation of breathing can be scored, so while some may indeed be central apnea, they can also be just changing position in bed, swallowing and other junk that is meaningless. For most of us being treated for obstructive sleep apnea they are benign and may not even be disruptive to sleep. Many times CA is scored at the beginning and end of the sleep session when we're not really sleeping, and we will often refer to this as "sleep-wake-junk" (SWJ).
To know the difference between benign incidental CA and the type that is disruptive, you need to look at duration, and zoom in on the respiratory flow chart. If you see a flat line of breathing followed by a good spike of recovery breathing, then it's more likely that was a real central that you needed to arouse from sleep to resolve. CA in low numbers is really not a problem, but when it becomes clustered in the middle of the night it might be complex apnea that is the real deal.
We see a lot more CA in new users, people adapting to higher pressure, and the use of EPR or pressure support that can wash-out CO2 and cause centrals. There is a lot to learn to try to decide if it's something to actually try to minimize, or ignore. For the most part CA under 3.0 per hour is probably fine. Over that, it might be worth looking into why it is happening and try to minimize it. For new users, it's important to realize, it often goes away in a few weeks without intervention.
RE: What is "Clear Airway" it's not in the sleep disorder glossery
(06-22-2016, 08:11 AM)Tiercel Wrote: I just did some digging to see if I can answer my own question and it "seems" that Clear Airway (CA) means I am not breathing but the AirSens 10 Auto is somehow able to sense that my airway is open. It also seems that since during my 5 nights the CA events were from about 45% to 80% of my events that I might have some Central apnea going on.
Hmmm,.... You know, it is strange. on several occasions even when getting sleepy watching TV with the CPAP on I noticed it was almost like I would forget to breathe WHEN I WAS STILL AWAKE ! I would breathe and wonder why I did that an how it was affecting my stats
Weird ????
Hi tiercel,
What you are experiencing is fairly typical of "sleep wake junk". Your body is in a transition stage between being awake and sleep. It is a time when your autonomic nervous system is taking over breathing for you. You can look at your stats and graphs using the Sleepyhead Software to get a better picture of when the CA events are happening and what you can do about them. If most of your events are during transition periods between sleep and wakefulness you can disregard that data as "sleep wake junk". If the CAs are spread out through the night it is more likely that you might need some minor adjustments in pressure support. Specifically you may need to narrow the gap between Inhale IPAP and Exhale EPAP pressures. This kind of adjustment reduces the washout of CO2 from your blood. It is this "washout" which fools your body into thinking you have done enough breathing and that you can take a little break. Your numbers are close to being satisfactory. Therefore, small adjustments may be all that you need. Feel free to post a screenshot of your Sleepyhead charts to get more feedback.
RE: What is "Clear Airway" it's not in the sleep disorder glossery
My sleep test had very few Centrals and since starting CPAP I have noticed getting these CA events. Excluding the SWJ, I still sometimes get a cluster of them in the middle of the night. So I suspect it is this washout effect. Would decreasing EPR to 1 be enough to show an improvement if that is it? EPR is currently 3 but as my CPAP is fixed at 6 and the machine will not go below 4, the EPR is effectively 2.
06-22-2016, 07:47 PM
(This post was last modified: 06-22-2016, 07:54 PM by Tiercel.)
RE: What is "Clear Airway" it's not in the sleep disorder glossery
I think this is a link to a screenshot of some of my CA events on DropBox
https://dl.dropboxusercontent.com/u/8041....42.42.png
Am I correct that the number in parenthesis after an event indicates the number of seconds of the duration?
Thanks for all the great input.
RE: What is "Clear Airway" it's not in the sleep disorder glossery
(06-22-2016, 07:47 PM)Tiercel Wrote: I think this is a link to a screenshot of some of my CA events on DropBox
https://dl.dropboxusercontent.com/u/8041....42.42.png
Am I correct that the number in parenthesis after an event indicates the number of seconds of the duration?
Thanks for all the great input.
Hi Tiercel.
Your leak rate is probably the first thing to correct. Your mask, as do all the others, normally vents a fixed amount of air so that you get a proper mixture of inhaled gasses. Large leaks get rid of some of the CO2 that you would normally re-breathe. Try adjusting your nasal pillows for a better fit and then consider a nasal mask if that doesn't work. Once your leak situation is under control we can re-evaluate.
Rich
RE: What is "Clear Airway" it's not in the sleep disorder glossery
(06-22-2016, 06:44 PM)Sn00zeAlarm Wrote: My sleep test had very few Centrals and since starting CPAP I have noticed getting these CA events. Excluding the SWJ, I still sometimes get a cluster of them in the middle of the night. So I suspect it is this washout effect. Would decreasing EPR to 1 be enough to show an improvement if that is it? EPR is currently 3 but as my CPAP is fixed at 6 and the machine will not go below 4, the EPR is effectively 2.
Hi Sn00ze Alarm,
Look at my reply to Tiercel. I was looking at data from Sleepyhead and saw that he had a considerable amount of time spent with large leaks. It would help if you posted some more data in a new thread. You will get a lot more people looking at your issues that way. You may also have other issues that could be addresses that way.
Rich
