(07-05-2016 07:08 PM)green wings Wrote: Tongue Seal/Preventing large leaks from your mouth while using CPAP therapy.
Finding out if you are going to be able to use a nasal (or nasal pillows) mask without excessive large leaks is very important. If it does turn out that you leak air from your mouth frequently, you will need to either switch to a full-face mask or try a chin strap with your nasal mask to see if that will help your jaw to stay in a position to keep your tongue from moving forward and letting air escape from your mouth. People who like using a nasal mask or nasal pillows but who leak air from their mouths usually try the chin strap to see if it will stop the large leaks. If it doesn't, they end up switching to a full-face mask.
You will read comments about "tongue seal" where people are talking about preventing leaking air from the mouth during CPAP therapy. You can get an idea of what this is by inhaling (without CPAP) machine) and then opening your mouth while you exhale. Put your hand in front of your mouth. Normally, no air should escape from your mouth while you exhale through your nose. You can then consciously relax the base of your tongue and move it forward while exhaling, and you will begin to feel air coming from your mouth.
You want to keep your tongue in a position while using CPAP so that air can't escape from your mouth. The higher your treatment pressure, the more difficult it becomes to do this for most people. If you look at the user profiles for people who use pressures of 15-20 cm, most of them use full-face masks. With a full-face mask, your mouth is included in the CPAP/human pressure circuit, so it doesn't matter if air leaks from your mouth.
Some people are able to use nasal masks or nasal pillows at higher treatment pressures. I think this really depends on the anatomy of your jaw and tongue. You don't really know whether you will need a full-face mask until you see how you react to the pressure.
Some people say that they have been able to successfully train themselves to keep their tongue in place.
You will notice that people tend to be boosters for the type of mask that they like.
I have been talking about "large leaks". If a leak is less than a certain amount (I think it's 34 liters/min), it doesn't count as a large leak. Your machine gives values for "total leak" and "unintentional leak". The "total leak" number includes the air vented from your mask. "Unintentional leak" is the number that you want to keep an eye on to make sure it isn't having a negative effect on your therapy. If "unintentional leak" goes over 24 L/min, it will be flagged as "Large Leak".
The amount of "large leak" that you can have and still have effective therapy isn't a hard and fast number. The ResMed CPAP machines give a smiley face when Large Leak happens for less than 30% of your sleep time. 30% of the time seems like a huge number to me. I think you just have to ask the opinions of people on this forum about your graphs if they are showing very much large leak. And, as always, be guided by how you feel when you wake up in the morning (assuming you felt the effects of untreated sleep apnea before you were diagnosed. If you didn't, then how you feel may not be a helpful guideline.)
Hi green wings,
Thank you so much for your detailed reply! Thanks for your advice!
Some reply that I gather from your two posts:
- I am using C-Flex 3. I plan to try A-Flex for a few days for now.
Quote:How does the pressure from the machine feel to you when you are awake and it's at values of say, 6-8 cm? I ask because it sounds like you are fairly sensitive to the sensation of pressure coming from the machine right now. Have you had any problems with swallowing air? How long does it usually take you to fall asleep with the machine on?
- With 4cm it is fairly easy to fall asleep for me; with 8cm, it is really hard; and I also tried 6cm which is not too bad. And thanks for reminding me about ramp! It should make it easy to fall asleep.
- I will try 6-12 for a few nights and see how my AHI changes...
- For the "tongue seal", I do have similar problem about leaks; should I try the full-face mask? I just got one but found it much heavier / less comfortable to wear than nasal mask, but I think I should give it a try.
- For autonomy, I was diagnosed as 'mandibular retrusion', which means my jaw is located in a position that is closer to my neck and potentially shrink my open airway and makes me easy to snore and/or have sleep apnea.