Welcome to the forum CarlosSky,
First let's talk about Mr. Red Frowny and his companion Mr. Green Smiley. Mr. Red Frowny shows up only when the leaks are genuinely out of control and are both large enough
and long enough
to adversely affect the efficacy of your therapy and the accuracy of your data.
A Large Leak is defined by Resmed to be any (unintentional) leak that is AT or OVER 24 L/min. In other words, you're loosing at least 24 L/min of air above and beyond what the mask is supposed to vent at your particular pressure.
And Mr. Frowny shows up when your leak rate is in Large Leak territory for at least 30% of the night
For a more detailed examination of what Large Leaks are and how they affect things, see 8. Leaks
in my SleepyHead guide.
So far you've tried a variety of nasal masks without much success. This may mean you need to try an alternate style of mask. This may mean you need to try an alternate style of mask. The most common cause of long, Large Leaks is probably mouth breathing. But improperly adjusted headgear can also cause a lot of large leaks.
So: First of all, review the mask fitting guidelines for your mask. If the mask you prefer uses an air cushion to form the seal, it's critically important to make sure the headgear is not too tight. Overtightening the head gear prevents the cushion from fully inflating and that leads to leaks.
Next: Is there a high probability that you are a mouth breather? If you are, then it's really important to start looking at your leak lines in either SleepyHead or ResScan so that you can determine the full scale of the problem. You already know you are seeing Mr. Red Frowny several times a month. But it's important to figure out if Mr. Green Smiley is showing up on a lot of nights where the large leaks are pushing the 30% line, but staying just below it. If multiple, long, large mouth leaks are often seen in your data, you need to figure out a way of dealing with them----regardless of who shows up in the morning on the LCD.
There are two main ways of dealing with mouth leaks:
1) Switch to a full face mask that covers the mouth as well as the nose.
2) Use a chinstrap or taping and try to train yourself to not mouth breathe.
Which approach is "best" really depends on your preferences.
Now to address some of your other questions:
(07-05-2014, 09:03 AM)CarlosSky Wrote: When I awake after a short sleep I stay in bed with my mask on for an hour or more. I understand that the sleep result numbers can be distorted when using the mask when awake. How can I try to get back to sleep which sometimes works for me and not distort the sleep results numbers?
The easiest way I can think of requires using the SleepyHead software to analyze the data.
You can turn the machine OFF and then back ON when you wake up and decide to lie in bed for a while with the hope of getting back to sleep. This starts a new "session" in the machine's data. When you load the data into SleepyHead, you have the ability to turn individual sessions "off" and "on" by clicking on them. When a particular session is turned "off", SleepyHead ignores that data in the computation of all the statistical stuff (AHI, leak, usage, etc) and omits that session's data from all the daily graphs. One nice thing about this system is that it allows you to see how these long periods lying in bed while awake affect or distort your data.
Quote:What are the recommended maximums for the AHI, AI and Central AI?
Treatment is considered effective if the total AHI is consistently less than 5.0 night after night after night .... AND the leaks are under control.
Every one will have a bad night now and then: The aliens visit or you're sick with the flu and the AHI spikes (well above) 5 for a day (or two) and then returns to your typical AHI numbers. So it's the consistency that's looked for. If your AHI is almost always under 5.0, then the docs are happy. And they don't really care very much what the distribution of the events is as long as the total AHI is less than 5.0.
If the AHI is often above 5, then the distribution of events becomes very important. If the OA and H's are why the AHI > 5, then chances are more pressure may be needed. If the number of CAs is why the AHI > 5, the sleep doc may need to investigate the possibility of complex sleep apnea. (Complex sleep apnea seems to be a problem in about 10-15% of new PAPers.)
Quote:If my AHI, AI and Central AI are within normal ranges how can the leak be so high (I read many posts with examples of leaks around 10).
The thing about long, large leaks is that they can seriously affect the accuracy of the data: When the leaks are over 24 L/min for any length of time, the machine can have problems accurately detecting the breathing, and when the machine can't accurately detect the breathing, it becomes extremely difficult for the machine to score events.
And then there's also this to consider: Apneas don't cause large leaks. You can have a truly horrendous AHI because the pressure is too low and have a perfect leak line.
But large leaks can allow more events to happen because the machine can't maintain the needed pressure AND it may not be able to score those events because it can't follow the breathing. I talk about this in 8. Leaks