“Why is My Mouth So Dry With CPAP Use?”

I must have struck a chord with yesterday’s post on dry mouth, given the responses I’ve received.  Dry mouth is a very common symptom associated with sleep.  So let’s continue this topic, but with a little twist.  Do you awaken with your mouth feeling dry during a night of CPAP use?

As mentioned briefly yesterday, obstructive sleep apnea (OSA) is a sleep disorder of breathing associated with episodic collapse of your upper airway while you are sleeping; sleep disruption, gasping sensations at night, witnessed breathing pauses during sleep, substantial snoring, and daytime sleepiness are common clinical features of this very prevalent but under-recognized medical illness.  CPAP (continuous positive airway pressure) is a primary form of treatment for OSA.  CPAP is an electronic device which pressurizes room air and gently sends it down the throat via a mask to keep the airway open all night.  If properly used, CPAP stops the snoring and breathing pauses, deepens your sleep dramatically, and therefore makes you feel much better and more awake and alert during the day.

 

Some still think of CPAP use as a primitive, invasive, or unavoidably uncomfortable medical therapy based on what they’ve seen or heard a decade or more ago; this is unfortunate, in part because many people end up foregoing medical evaluation and treatment for their sleep apnea for many years based on an erroneous perception of what their treatment may be like.  There are now dozens of mask interfaces available, each with different sizes; the CPAP devices themselves are much smaller and quieter than they used to be, with lots of bells and whistles to make them more comfortable and easier to use.  If used properly and if you are willing to use it, CPAP can be an absolute game-changer; untreated sleep apnea can wreck your life, and proper treatment can dramatically turn things around.

Having said that, though, there are lots of potential ways for CPAP use to go wrong, causing people to have difficulties using it or to stop using it altogether.  I will write about these problems more in later posts, but one problem some CPAP users may have is dry mouth.  The majority of CPAP users don’t have substantial problems with this, but if this is relevant to you or someone you know, read on.

Presuming that your dry mouth isn’t caused by one of the problems I wrote about in yesterday’s post, and if the dry mouth started or became much worse after having started CPAP, most likely this symptom is caused by oral leak or oral breathing.  Your jaw muscles naturally tend to relax when you fall asleep.  In some cases, the lower jaw (mandible) may then drop slightly due to gravitational forces.  If you are using a nasal mask (i.e., a mask that covers your nose but NOT your mouth) or nasal pillows (i.e., soft prongs which are placed gently at the entrance of your nostrils), and if the mouth opens a little, then air from the CPAP device may then divert and escape out of your mouth.  This is obviously a problem.  The air dries your saliva, first of all, causing you to awaken more from sleep with that uncomfortable, parched, “Sahara desert” feeling in your mouth.  Just as importantly, though, if air is leaking out of your mouth and escaping into the open space instead of going down your throat the way it should be, then you aren’t being adequately treated because your airway may again be predisposed to collapse due to insufficient air pressure.  So due to sleep disruption and inadequate treatment, oral leak can lead to a perception that CPAP doesn’t work because you may still feel sleepy during the day despite CPAP use.

Oral leak is a very fixable problem.  Don’t turn your CPAP device into a very expensive doorstop because of it.  Before reading how to repair oral leak below, though, make sure you’ve determined where the dryness is; this is particularly important because people often don’t actually feel the air coming out of their mouths, because the leak happens while they’re asleep (when you awaken your muscles abruptly regain their tone and the mouth usually closes).  If the sensation of uncomfortable dryness is in the nasal passages and/or the back of the throat, but NOT in the mouth, oral leak is probably NOT the problem; I would suggest increasing the heated humidity in your CPAP device if this is the case.  However, if the dryness is clearly localized to the mouth chamber–with a pasty sensation in the mouth, for example, a feeling of having to “peel” your tongue from the roof of your mouth, dryness of the lips and teeth–oral leak is then likely the cause.

1.  If you’re using a nasal mask or nasal pillows and you like your current setup, a chinstrap is usually effective.  When wrapped gently around the head, it mechanically keeps your mouth gently closed.  It does not need to placed tightly; it should be just secure enough to be effective, but not so tight it’s uncomfortable.  People usually become accustomed to chinstrap use pretty quickly.  Many straps are made of thin neoprene.  However, particularly for my patients who are more heavyset or who have larger neck circumferences, I prefer a “deluxe” or “heavy-duty” chinstrap, which is wider and made of less stretchy material and therefore more likely to be effective.  An added bonus:  in some cases chinstrap use can be temporary; over time you may find that tendency toward oral leak has stopped after having discontinued the use of the strap.

2.  Another way of addressing oral leak is with the use of a full face mask, which covers both the nose and the mouth.  There are now many different full face masks available on the market.  Potential issues with full face masks, however:  since they’re larger masks, they may be more prone to leak than smaller masks; also, they don’t keep the mouth from opening, so you can still have some dry mouth if air continues to go in and out of your mouth (though usually substantially better).  Try increasing the heated humidity (which usually comes standard) in your CPAP device should this be the case.  But if you’re already using a nasal mask or nasal pillows and you’re comfortable with your current setup, a chinstrap usually does the trick with relative ease.

3.  Finally, as mentioned in yesterday’s post, addressing problems causing decreased airflow through the nose (such as seasonal allergies, hay fever, sinusitis, or anatomic nasal disorders) may well reduce the tendency to open the mouth during sleep.  Consider a visit to your primary care physician or an ear, nose, and throat doctor should you have symptoms that suggest such problems.

Sleep well tonight, everyone, and stay warm!

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2 comments on ““Why is My Mouth So Dry With CPAP Use?”

  1. Great post! CPAP treatment can be quite a daunting measure to fathom if you’re sleep apnoea sufferer but you have to weigh up the benefits of using such a device. You may suffer a from a dry mouth but it will dramatically improve your sleeping habits. If you’re really not keen you could also try curing your symptoms altogether by losing weight or quitting smoking.

    • Thank you so much for the kind message! I recognize that this particular post is directed toward a more concentrated audience, but still, millions and millions of people ’round the world have obstructive sleep apnea, and the treatment for this problem can be great if potential problems associated with those treatments can be isolated and resolved. Losing weight can make sleep apnea better, and in some cases, depending on a number of factors (including baseline obesity, neck circumference, and how bad the sleep apnea was to begin with), can make it go away. I appreciate your checking in!

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