What's the point of minimum pressure?

[cabanalane]

That's not the question, I know what minimum pressure does. The Tech set my pressure range 7 to 15. Resmed 11 BTW.

Looking at my report, my average is 13.6.

My max is at 15 so it won't go over 15.

I don't believe my machine is even in 7 range all night. Therefore do you think it's more effective to set my minimum closer to the average? Maybe 10, 11, or 12?

My settings have been min 7 and max 15 for years. The doctor visits have been....ok, you are doing great. It's still several months till my next appointment, and this question pop into my mind.

Just wondering what you guys think and your experiences.

TIA.

[Pugsy]

The purpose of the minimum pressure is to do a decent enough job preventing the airway from collapsing yet close enough to perhaps some special circumstances where the pressure needed is more so the machine can increase (within the set parameters) it can get to where it needs to be quickly enough to prevent additional airway collapses.

Sometimes some people might need more pressure when on their backs (and they can't stay off their back) or even when in REM stage sleep. They don't/won't need the higher pressure all the night though....just part of the night.
I happen to be one of the REM stage sleep higher pressure needs myself. I might need 6 cm more for REM related events but I don't want to be using 6 cm more ALL night long just to maybe deal with maybe needed more stubborn events during REM.

Would need to see some detailed reports to offer advice about increasing the minimum pressure a bit.
Can't tell much from just what you said.

[cabanalane]

Just for my knowledge, is "too much" pressure a bad thing? I don't mean having the machine crank up to 20, when one really need 10.

The machine does auto adjust. Just wondering. If too much pressure does not cause leaks, or affect comfort level, etc. Is more pressure a bad thing? To be specific, does the body get used to it in that negative way, where one would need more and more pressure?

[ChicagoGranny]

Therefore do you think it's more effective to set my minimum closer to the average? Maybe 10, 11, or 12?

Possibly. If you get a free account at SleepHQ.com, upload the data from your machine's SD card, and post the link here, some members will help you. I highly recommend it. We have some members who are very good at helping with machine settings.

To be specific, does the body get used to it in that negative way, where one would need more and more pressure?

No.

If too much pressure does not cause leaks, or affect comfort level, etc.

It can. But if you need more pressure, you need more pressure.

[ChicagoGranny]

does the body get used to it in that negative way, where one would need more and more pressure?

Some sleep doctors claim if you stop CPAP, there is still some benefit of holding the airway open for a few days. I'm skeptical but don't have enough evidence to argue with them.

[Pugsy]

If too much pressure does not cause leaks, or affect comfort level, etc. Is more pressure a bad thing? To be specific, does the body get used to it in that negative way, where one would need more and more pressure?

I don't buy into the "too much pressure from auto adjusting machines" mentality because the machine isn't going to just out of the blue go increasing the pressure. It has a very valid reason for doing anything and everything it does.

Besides who or what decides that the pressure is "too much".

Does the machine ever make mistakes??? Sure it does. I have seen pressures increase but only in respond to what it records is going on. I have seen the machine flag an OA and then increase the pressure but I wasn't asleep when the OA was flagged.
Doesn't really matter that I was awake..at least to the machine since it can't determine sleep status..because the machine is just doing what the auto adjusting algorithm is telling it to do.
In its mind the machine doesn't make "mistakes". Doesn't happen a lot anyway so I don't dwell on it.

A person needs what they need in terms of pressure and there's really no good way to designate what constitutes "too much pressure".

I prefer to not use the term "too much pressure" and instead prefer to just say what the machine is doing...it's increasing the pressure based on what it senses is going on and might be needed. Now do those increases sometimes cause a problem of some sort??? Sure they can. Might causes worse leaks, might cause wake ups, might cause aerophagia, might cause breathing comfort issues, might cause central apneas...and if/when that happens that is when we do some thinking about just how to proceed.

BUT in general.....if increasing the pressure doesn't cause a problem then I see no need to worry about it....I have seen pressures into the high teens. I just assume the machine has (what it thinks is) a good reason and trust it and it never caused me any of the problems I listed above so I just shrugged my shoulders and moved on.

[ozij]

That's not the question, I know what minimum pressure does. The Tech set my pressure range 7 to 15. Resmed 11 BTW.

Looking at my report, my average is 13.6

Which report is that?
On which machine?

The machines I know don't reprort or calculate average pressure. They do report the percentages of time of time spent at or above a specific pressure. So, does your machine report you spend 50% of your time at or above 13.6? or is it 95%? If you need that pressure for 5% of the night, and your machine goes there, that's fine.

I don't believe my machine is even in 7 range all night.

We have to see your data, and you have to learn how to read it. For all we know you could be spending 40% of the night at 7 - and if that's the case, why go higher for that part of the night?

The doctor visits have been....ok, you are doing great.

And how do you feel when you wake up?

[ozij]

There are two things we have to understand about APAP's:

1. They have specific rules of responding to what they see in the breathing patterns. That's their "algorithm" and different machines have different algorithms. You will even find some machines that have two algorithms for you to choose from. The machines are all reliable in applying their algorithms.
2. The machines apply the algorithm according to their interpretation of the breathing pattern. That's where mistakes can happen because the interpretation may be wrong, i.e. not valid:
   In other words:
   The machine interprets something as a snore when it's not.
   The machine interprets a central apnea as though it were an obstructive apnea
   The machine interprets a flow limitation caused by structural issues as though it were a flow limitation it could solve by raising the pressure.

Whether or not an APAP's algorithm works well a person's breathing pattern can only be discovered by seeing the person's breathing flow and the machine's responses through the night. Actually, through a number of nights.

Can an APAP raise pressures too high because it misinterprets breathing patterns? Yes, it can.
Can an APAP lower pressure again and again to levels at which events happen and disturb one's sleep? Yes it can.

You never know what it does when you're asleep unless you check the breath by breath data carefully.

[cabanalane]

Thanks Everyone. Great points. Currently, I'm using the report my machine gives me. Resmed 11. The average they give me are based on 12 months. Just signed up with Sleep HQ and got my SD card ready. It should provide me with more info.

Something else just popped into my mind, from reading above. My mask is F30i. The air tubes does run on both sides of my head. I'm both a back and side sleeper. On the side, just noticed, that I do crush the tube with my face on the pillow. I wonder if that gives an inaccurate reading too, and the machine compensate because it thinks there's some sort of obstruction.

How am I doing? According to the app, events are less than 5. How do I feel? Ok. Bad habit that I generally get 5-6 hours of sleep a day, so that's on me. I don't know what 8-10 hours of sleep is like since college days, 30 years ago.

[Pugsy]

My mask is F30i. The air tubes does run on both sides of my head. I'm both a back and side sleeper. On the side, just noticed, that I do crush the tube with my face on the pillow. I wonder if that gives an inaccurate reading too, and the machine compensate because it thinks there's some sort of obstruction.

Compressing the air tube on one side doesn't/won't affect the machine's ability to record or respond.
Side sleeping and compression of the air flow in the affected side of the tube was factored in to the design of the mask.

[ChicagoGranny]

On the side, just noticed, that I do crush the tube with my face on the pillow. I wonder if that gives an inaccurate reading too, and the machine compensate because it thinks there's some sort of obstruction.

Not a problem. ResMed tested their machines with either side completely blocked off.

I've been using the F30i for several years. Everything works fine when I sleep on my sides blocking one side of the tube.