[CPAP] Rainout/dry mouth issues

[rowlf914]

Hi all,

I am a CPAP newbie...I just started last week.  I've been able to tolerate the pressure all night for each night, but am having issues getting the temperature and humidity correct.  I have a ResMed Airsense 11 with Climateline tubing and the AirTouch F20 full mask.  The first two nights I did not change settings other than to turn off the ramp.  From the start I've had very dry mouth in the morning.  The auto settings I believe are temp 81 and humidity 4.  I have fiddled with the tube heat and humidity settings.  Humidity of 6 gets rid of the dry mouth but causes rainout, which wakes me up.  I tried setting the temperature of the tubing to 78 one night, and 82 the next, which did not help the rainout issue.  This morning the rainout was bad enough that I stopped the machine about 4:30 this morning.  After reading what other users have said, I have reset the tubing for max temperature, leaving the humidity setting at 6.  The temperature in my bedroom ranges from almost 80 at bedtime to around 75 in the morning.  I am going to get a tubing cover to see if that helps, and am going to reach out to my rep at the DME, as I think my mask may be too small.  

Does anyone have any suggestions as to what else I can try?

Thank you!

Dave

[Rich66]

A big cause of dry mouth is 'open mouth'. It could be inhaling or exhaling. Look at your Oscar chart and check for Large Leaks. Dry mouth would always wake me up. Mine was from pressure pushing air into my lungs and that air coming right out of my mouth. For some people, it's a mask adjustment needed or a different mask -- for others, like me, I use tape to keep my mouth shut.

[rowlf914]

I'm going to see my DME rep tomorrow about my mask...I think it's too small.  And I think I fall asleep breathing through my nose, but obviously at some point I start breathing through my mouth.  Maybe a chin strap is in my future as well.  

[Geer1]

Mask leaks causing dry mouth is usually with a nasal mask. If you are having lots of leaks could be causing a bit of an issue though.

Rain out is caused by condensation in the tubing or moisture build up from high humidity. Condensation is caused by a temperature difference on inside of tube and outside of tube (outside being colder causing the humidity to condense).

There are a couple things you can try to improve this. Higher room temp although the 75 to 80 is already warm so unlikely to be the issue. Higher hose temp although you said you have tried max. Hose cover will insulate the hose and help against condensation. Situating the cpap machine lower than the bed and having hose run downhill to it will cause rain out to run back to machine rather than into your mask. Also confirm your heated hose is working.

[rowlf914]

Thanks, Geer.  I was already going to bring my machine to the DME to check the heated tubing, but I suspect it is working.  The settings I used last night did not create rainout, although I did see a small amount of condensation in the tube this morning....nothing like it has been though.  The tubing does no feel warm on the outside, even at max temp, although I've read that this is normal.  I reasonably sure my mask is too small and is leaking around the bridge of the nose at times.  Again, I'll be taking my gear into the DME to check both the tubing and the mask.  

All of this is new, and I know it can take some fiddling with everything to get it right.  I'm sticking with it...at some point it will all come together just fine!

[DaveL]

I've been trying a mask I purchased. It's a F&P Evora Full, a full face mask. I have leak problems and I figured a way to find where the leaks are.

I put the mask on; it's not connected to the machine. I adjust the straps where I think they should be.
Then I lie down on the bed.

The mask has a hose on it (not connected; it's open at the end) I take a deep breath then plug the end of the hose.
I blow through my nose into the mask. It's really obvious where it's leaking

I adjust the two top straps, loosening them.

Then I check for leaks the same way, and adjust the two bottom straps.

This allows the mask to balloon out and seal on my face.

I've done the same with my regular mask. That's a nasal mask, a ResMed N20.

Then of course I use the mask hooked up to my machine.



Maybe this method will help you find a good fit.

A caution...little changes make a big difference. And you should check strap lengths when you're done. The two top straps should be the same length.
The two bottom straps should be too.

DaveL
Toronto

[Ockrocket]

To assist with rainout reduction have your CPAP machine on the floor, or at least lower than your mattress, and loop the hose above your head so it hangs in an arc - this will catch most of the condensation that forms in the hose before it reaches the top of the arc and lets it run back down to the machine instead of into your mask.

[rowlf914]

I do already have my machine lower than the mattress, and I've considered running my tubing just as you have pictured...I'll have to rig something up.  The cover for my tubing should be here today...hopefully that will help.

Thanks to everyone for the suggestions.  I always say that if I've got a problem with something, a hundred other people have had that problem and at least one has a solution.  I'm glad I joined this forum!

[rowlf914]

So I got the cover for my Climateline tubing last week, and things are going much better.  I'm only waking up once at night, have only had on incident of rainout, and my AHI is down to less than 1 for the past three nights.  I'm still waking up feeling tired, but not as badly as before.  I think this may be working!   

[Yaatri]

As Rich66 pointed out, primary cause of dry mouth is breathing through the mouth.  I used have terribly dry mouth.  It would so dry that my tongue would be stuck to the palate (roof of the mouth) or like my mouth was stuffed with cotton.   The throat also hurt as it would be dry.  I swallowed a lot of air too.  I would expel that air after I woke up in loud long burps.

My pressure was 22.  It would draw so much moisture from the tank that the tank would be dry halfway through the night.

gradually I stopped breathing through the mouth and now I don't burp when I get up in morning and water in the humidifier lasts all night.

Rainout:  Rainout occurs when temperature of the moist air drops below the due point, or the temperature at which RH (relative humidity) is 100%.   The pressure in the hose and the mask is at the highest just before you begin inhaling it.  As you inhale, the pressure drops a little and the air under pressure expands. Expansion leads to cooling. If temp of the air inside the hose or the mask drops below the dewpoint, some of the water from the humid air would condense inside the hose or the mask.  You are adding moist air to the mask when you exhale too.  The air has high RH, it's more likely to lead to rainout.  I rarely humidity setting higher than 4.

From 2008-15 I did not have a heated hose. I would pull the hose inside the covers as much as I could during the winter to prevent rainout. 

Of course we are all different  I am used to dryer air as I have spent a lot of time in long haul flights lasting as long as 14-17 hours many times a year plus shorter flights lasting 8-12hours. I also grew up in a dry area.