I am a doctor. I realised that what was written about dry mouth was wrong. It is not due to air coming directly into the mouth from mouth breathing. The key to preventing air entering the mouth with nasal CPAP is to do with holding the tongue against the roof of the mouth when the CPAP is on. Putting tape over your mouth helps because the air cannot escape from the mouth but does not solve the actual problem. The secret is that your tongue holds itself against the roof of your mouth when you breathe in through the nose so that the air goes to your lungs. The tongue in the correct position blocks the mouth off from the posterior, nasal airway and prevents the air coming into the mouth from the nose and out through the lips which causes the mouth to dry, just as people who snore have a dry mouth. Humidifcation helps but does not solve the problem - the air coming from the nasal mask and out through the mouth is still drying.
The cause of this problem with CPAP is the pressure you are using is too high and your tongue, when you are asleep, cannot hold its position against the roof of the mouth allowing air to be forced into the mouth from the nose. The solution is to reduce the pressure of the incoming air. My pressures were set years ago at 14 but using the AirMini I have reduced them to 4.4 low and 9.0 high. I have an AHI score of less than 1.0 (total score 96/100) and no dry mouth, without using a humidifier. If you have a dry mouth problem then I strongly recommend that you have your pressure lowered until you have no dry mouth but keep your AHI score at less than 5.0 or preferably less than 1.0.
I have been using CPAP for 15 years and dry mouth has driven me nuts but become much worse since losing weight. It is not surprising that my pressure requirements were also lower with lower weight. What I am saying makes both medical and anatomical sense and worked immediately in my case. Thanks must be given to my friend BM who was the one to suggest this solution as he had tried it and found that it worked for him. I cannot comment on whether this would also work for full face masks as I have never used one, but I suspect on logical grounds that it would. It should also work for nasal pillow type mask.
If you want to test out the logic of this suggestion open your mouth and put your tongue up against the roof of your mouth and then breathe in. Despite your lips/mouth being open the air goes in through the nose. Now do the same thing again but drop your tongue as you breathe in and the air comes in through your mouth. Now try the same thing breathing out. It is the tongue against the roof of the mouth that keeps the air in the nasal air passages and out of the mouth when breathing in and out. Chin straps are still good but the real secret is the pressure you are using is probably unnecessarily high.
Sleep well all you CPAP users by setting the correct pressure to stop the apnea without being too high and causing dry mouth.
This sounds all well and true however what if the doctor increases your pressures when you tell him your pressures are already too high. I've been on cpap since 2003. Since then I've lost 80 plus pounds and started having dry mouth issues with my nasel mask. I had another sleep study done and my doctor put me on a bipap with my pressures now at 15 and 20. They were at 15. I'm still fighting dry mouth and I've switched to a full face mask. So, what do you do when you think your pressures are too high and the doctor puts you on higher pressures?
Good question. Get a second opinion is the obvious answer but the reason I put the post up is that I could not find anywhere on sites stating that dry mouth was from too high pressure. Your physician may not be aware of it - mine was not. If you machine gives you an AHI score then I suggest you try lower settings yourself and see what happens to your AHI score. Below 5 is normal but I prefer below 1. Whatever level does not give dry mouth and keeps your AHI score below 5 or 1 is the correct setting. My current settings are low of 4 and high of 8. I brought out and old ResMed S9 machine last night which gave me horrendous dry mouth. It was on 12 and 20 so I reduced it to low of 4 and high of 8 and tried it. No dry mouth! Did not need to buy an AirMini at all. -:(
Curious about what type doctor DoctorDoug71 is. Doctors who specialize in sleep disorders are board certified in sleep medicine. These are the doctors who write prescriptions for setting up a positive airway pressure machines. To disregard their expertise and fiddle with the settings on a machine they prescribed may be counter to the effectiveness of therapy or downright dangerous.
DoctorDoug71, if you are able to write prescriptions and a patient decides to experiment with dosage or frequency or the like, would you feel that the patient who acts as his own doctor when he/she has professional guidance is wise?
Hughes1963, ANY PAP machine can have all its settings changed by a patient if the patient looks for the know-how to do so hard enough.
DoctorDoug71 gave the best advice when he mentioned getting a second opinion if the first prescription isn't working or there are negatives. It has been my personal and subjective experience that the sleep doctors I have dealt with often work on a production basis and seldom have time to personalize their treatment and this situation may lead to poor initial set up of a machine relative to the patient's needs. I think rather than debate with this type doctor, better to find another who is willing to take the time to consider what the patient is saying or experiencing.
I had tremendous dry mouth. Since I played football in college and didn't study much biology or anatomy, all I can say is that I KNOW my jaw goes slack at night leading to snoring and obstruction of my airway. I stopped breathing for long periods as a result with very low oxygenation of my blood during those periods. The PAP therapy helped keep my airway open but it was a fight to keep my jaw from slackening and my mouth from opening with the main issue being very dry mouth. I began wearing what is called a boil and bite mouth guard, much as I wore when I was a tackling dummy. The mouth guard keeps my jaw from going slack by maintaining my bite in a closed-mouth position. Not sure what my tongue is doing while sleeping but guess it is on the roof of my mouth as suggested by the doctor. Different folks use different methods of dealing with their mouth opening. I am on a Bipap with 21/25 pressure settings and this combo works great for me. I tolerate the 25 pressure fine and the mouth guard causes no issues as I have been wearing these for years. I get little dry mouth with the moisture turned off but keep it on just a tad as I do tend to get chapped lips with it off all the way.
In any case, as a non-professional, these are only my personal thoughts but I do feel that if I pay someone for expertise, like a sleep doctor, I should try and heed that doctor's advice and maintain the prescription parameters unless they are not working then discuss the matter rather than fiddle with the machine's settings. I don't feel an AHI of any number is acceptable even if some standard says 5 an hour is OK. Cheers.
