02-14-2016, 02:31 PM
(This post was last modified: 02-14-2016, 02:34 PM by wolson.)
(02-14-2016, 02:21 PM)OMyMyOHellYes Wrote: Point is you DO get humidification, not as much, but you do get some, even without heating the water. And that "some" is a lot more than most folks get during sleep. Heating water increases vapor pressure. Hotter air has more moisture carrying potential (lower relative humidity). I get that. I really do.
But frankly, we don't "need" the humidification. Billions and billions and billions of people (forgive the Sagan moment) sleep every night without added humidity. The ambient air a non-PAP bed partner breathes is the roughly the same relative humidity as the air breathed by the non-humidificated PAPer. Some folks get spoiled by the artificially high humidity and "need" it.
Unfortunately some people do need additional humidity to sleep in dry climates. Where I live, in Central Wyoming, one of the most common advices given by physicians when examing a patient with sinusitis is get a humidifier.
Some people adjust but many don't particularly in the Winter when the air does not hold much water. For many people, without the additional moisture, they develop headaches and stuffy noses which prevent them from sleeping. In extreme cases, their nose will actually bleed! Mine still does occasionally.
Yes, some people don't need it. But don't discount the people that do need it.
The hygrometric chart shows the amount of water in the air. Here is a better chart for relative humidity:
Walter W. Olson, Ph.D., P.E.
They may need higher RH, but no more than they would need it without PAP therapy.
And the original question implied that passive was good enough for the inquirer.
I sometimes use it on my machine because it makes it easier to dig out boogers first thing in the morning.
[quote='OMyMyOHellYes' pid='150371' dateline='1455477705']
Point is you DO get humidification, not as much, but you do get some, even without heating the water. And that "some" is a lot more than most folks get during sleep. Heating water increases vapor pressure. Hotter air has more moisture carrying potential (lower relative humidity).
Folks, physics is phun, but it's really about the "target tissue" here - IE the nasal mucosal membrane. That's what's "relative" about all of this (pun intended...) - some folks make more mucus than others, some have bigger Schnozzes than others, etc. - but folks don't normally sleep with several liters per minute of wind blowing up their nose, so the evaporative effect of that WILL cause drying. No discomfort for some, really bad for others. Recall that in cold weather the nose runs trying to protect the posterior passages (and your lungs) from the dry cold air, but that's when you're up and going (and the lung irritation of the dry air is triggering alot of that mechanism) and not when your sleep hormones have everything turned down - so for some, the compensatory mechanisms just don't work well (or can be on meds with "anticholinergic" side effects that cause dry mouth, dry nose, constipation, etc.)
The humidifiers in CPAPs generally shoot for 70-95% humidity at their setting ranges, with the goal of making it as hard as possible for evaporation to occur even in that steady "breeze" to counter the drying effect - and heating the water helps with the humidification and also gets the air temp closer to body temp (hence those fancy heated hoses some devices have).
Here in the humid midwest where it's rare to get below 40% relative humidity I've been able to go either way (I get a dry nose but doesn't usually bother me without humidified air). Actually kind of clears my nose sometimes in the hot summer to have the filtered dry air instead of the pollen laden humid mess that is midwest summer air. However living in Colorado at 4500 feet (<30% rel. humidity common), it was a totally different story - would kill me if I forgot to fill the tank. And at our Mtn Cabin @ 8500 feet, of course even the high settings weren't always enough and it was still a little uncomfortable, had to get a hot shower going to soothe things most mornings.
So the point medically is to learn how to use the settings available on your device to get the sweet spot of a comfortable non-irritated nose in the AM -- and understand that you may have a changing need based on the air around you or other things affecting your nose - allergies, dust/pollen, colds, etc. There's no medically best answer or good or bad option here (other than to know in general it's pretty irritating to your nasal mucosa to get all dried out, can stir up / aggravate your sinuses / throat).
Most important of all of course is to use your device and correct that underlying apnea or sleep disordered breathing -- that is DEFINITELY not good for you as your lung neuro and cardiac and endocrine docs will all tell you - that's a contributor to alot of very serious chronic conditions. I've had dozens of patients whose apnea led to or at least contributed to metabolic strain, obesity, diabetes, overuse of uppers to try to function, and eventually an early death form a combination of all the problems that causes.
Joe Spurlock MD