Why shouldn't you always use the maximum CPAP pressure?

We all have monkeys on our backs, humming boxes by our beds,
aliens on the roof, and wacky masks on our faces.
It could be worse . . .

Pugsy I really didn't mean that we would get ventilator dependent but I was wondering what if anything positive air does to our bodies; screwing with our baroreceptors, weakening the diaphragm? And if that is possible then you would want to use the least amount of pressure. But like you said about 24/7, maybe awake time is nulling out anything negative that positive pressure would cause to us.

WRX03 wrote: ↑

Wed Mar 21, 2018 5:59 am

Pugsy I really didn't mean that we would get ventilator dependent but I was wondering what if anything positive air does to our bodies; screwing with our baroreceptors, weakening the diaphragm? And if that is possible then you would want to use the least amount of pressure. But like you said about 24/7, maybe awake time is nulling out anything negative that positive pressure would cause to us.

I just don't see that happening unless maybe someone has some really serious other health issues where cpap pressures are contraindicated and if that were the case the common apap machine, which is what we are really talking about here, wouldn't likely to be prescribed treatment and the person would/should already be under a doctor's care for that problem.

I used an ASV for years...I forget exactly how many but 2 different ASV machines along with the higher pressures (over 20 cm at times during the night) it sometimes dishes out and I never had any issues at all with any of it. I never even had the common chest wall soreness that sometimes people get with the little bit of extra "work" involved with exhaling against the pressure...any pressure. And the few people who have had that chest wall soreness...heck I have seen people complain about it and they are only using 6 cm pressure. Certainly not high by any scale that I can think of.

For normal people who are using cpap/apap pressures to hold the airway open and prevent the OSA events...they need what they need and limiting the maximum because of a remote what if thing that might only apply to someone with some serious other health issues...is over kill IMHO. The machine won't go where it doesn't think it has a good reason to go. Now sometimes the reason it might have to somewhere really isn't that bad of a reason and the going there causes some problems worse than whatever the machine is trying to kill and in those instances limiting the max is a viable option but more most people there is no need.

If the machine could go to 100 cm on the apap mode (we know it can't but if it could) and we set the max at 100 but the machine only ever went to 10 cm..it really doesn't matter what the maximum is set at. It's only going to go where it thinks it needs to go for whatever reason it wants to go there and usually that reason is some sort of airway collapse. If we limit the max to 8 and it wants to go to 10...most likely the airway will collapse and that's a for sure thing that we don't want.

Now sometimes we do limit the max because going higher causes problems but those problems are usually only what was previously discussed in this thread....most common problems...aerophagia, central triggering (which is actually rare for it to be associated with apap higher pressures), or simply the sleep being disturbed by changing pressures because the person is just super sensitive.
IMHO aerophagia is probably the number one reason for limiting the max and making a compromise in effectiveness of cpap therapy and allowing a few apnea events to slip past the defenses because to use more optimal pressure creates a worse problem than 2 or 3 apnea events will cause.

You've gone out on a really long a really skinny limb here with the maybe affecting the diaphragm thing and I just don't see it being anywhere near a remote possibility for 99.9999999% of the people put on cpap/apap for just plain OSA.
Heck....even a constant pressure of 20 cm won't blow up a balloon...it isn't nearly as much pressure as people think it is.
Our bodies can handle a lot more without causing a problem...UNLESS there is maybe something else that is seriously wrong. Chances of that....very slim. If they are that sick...OSA is probably the least of their worries.

If someone has a well-documented contraindication to CPAP, it may be bad for them. Otherwise, slightly pressurized air is safe and beneficial.

Coughing? Sneezing? Now, those are dangerous. CPAP, not so much.

Otherwise, the idea with any treatment that is titrated is to balance effectiveness and comfort. A CPAP Rx is no exception to that.

I was unclear as to whether you meant to turn the constant pressure to 20, or you meant setting the high end to 20 on an automatic.

If you meant the latter, I stick by my previous answer.

If you meant the former, you should regard CPAP the way you would any clinical intervention. You would take the minimum dosage that successfully treats the condition, or slightly more. For instance it 8mg of a given medicine will control your blood pressure, you would be prescribed 10mg, not 20! The pill probably comes in 10mg, and many doctor believe in slightly over-treating (not grossly over-treating).