Query on higher pressure

[retired_guy]

I think of misinformation as simply 'incorrect information'. perhaps I'm wrong about that.

To me misinformation is something that's created in attempt to lead or mislead people into thinking or doing something.

On the other hand incorrect information could have been created with no such attempt in mind, it could be simply the result of an error.

I see no one on this forum intentionally spreading misinformation, but I do see some incorrect information being posted. For example I am not guilty of the former, but I am guilty of the latter. I know no one who is perfect and never makes mistakes. We're all human, myself included. No one makes mistakes on purpose.

thank you for your information, however, I find that dictionaries do say that it is a a noun that's based on the transitive verb, 'misinform: to give incorrect information to'. eg: http://www.thefreedictionary.com/misinformation

though some do add "especially that which is deliberately intended to deceive." which indicates that it is not *only* deceptive information that is misinformation.

Merriam-Webster helpfully only defines 'mis-' as:
1 a : badly : wrongly <misjudge>
b : unfavorably <misesteem>
c : in a suspicious manner <misdoubt>
2: bad : wrong <misdeed>
3: opposite or lack of <mistrust>
4: not <misknow>

then lists a plethora of words that have that prefix.

Huh? So.. Does this mean Visitor's pressure is too high? Or maybe too low? Or maybe it means Visitor should shop around for an English teacher? I'm so confused.

[Sleepster]

if his machine ramped up to 12.6 immediately upon his first event and stayed there all night, he'd still have 12.6 95% and 12.6 max.

it doesn't matter if there's 20 data points, or 57,600.

I see your point and stand corrected. However, I would wager that if you looked at the data approximately 95% of it would be below 12.6.

Think about how CPAP machines adjust pressures and what would have to happen for your scenario to be realized.

[diamaunt]

if his machine ramped up to 12.6 immediately upon his first event and stayed there all night, he'd still have 12.6 95% and 12.6 max.

it doesn't matter if there's 20 data points, or 57,600.

I see your point and stand corrected. However, I would wager that if you looked at the data approximately 95% of it would be below 12.6.

Think about how CPAP machines adjust pressures and what would have to happen for your scenario to be realized.

thinking about it, I've seen apaps spend very little time at the max, and I've seen 'em spend a lot of time at the max. all depends on what's going on. I've seen graphs of people, here, that shot up to, and stayed right around the max all night long thanks to the max being too low and them still having flow limitations.

basically, we need more information (even a min and median would help, but a graph would be best) before we're simply guessing at random about how much time was spent at what pressure.

[diamaunt]

Huh? So.. Does this mean Visitor's pressure is too high? Or maybe too low? Or maybe it means Visitor should shop around for an English teacher? I'm so confused.

it means that visitors thread got hijacked by someone else asking about their 95% number, without providing any more info, and then ... things wandered.

[Sleepster]

basically, we need more information (even a min and median would help, but a graph would be best) before we're simply guessing at random about how much time was spent at what pressure.

Right. Looking back I see that he has a range of 12.4 to 12.8 in his profile and he didn't give us a median. Likely the min is 12.4.

I'd still be willing to wager that approximately 95% of the data is below 12.6.

[diamaunt]

basically, we need more information (even a min and median would help, but a graph would be best) before we're simply guessing at random about how much time was spent at what pressure.

Right. Looking back I see that he has a range of 12.4 to 12.8 in his profile and he didn't give us a median. Likely the min is 12.4.

I'd still be willing to wager that approximately 95% of the data is below 12.6.

well, if he ever comes back and posts a chart, I'll take you up on that

[robysue]

if his machine ramped up to 12.6 immediately upon his first event and stayed there all night, he'd still have 12.6 95% and 12.6 max.

it doesn't matter if there's 20 data points, or 57,600.

I see your point and stand corrected. However, I would wager that if you looked at the data approximately 95% of it would be below 12.6.

Think about how CPAP machines adjust pressures and what would have to happen for your scenario to be realized.

My 95% IPAP is consistently equal to 8.0 night after night after night. On some nights, my IPAP pressure is at 8.0 for 50% or more of the night. On many nights, it looks like I'm at IPAP = 8.0 for maybe 15-30% of the night. On a few rare nights, I'm at IPAP = 8.0 for only 10-15% of the night. So if you bet $$ that looking at my IPAP and data would reveal that the IPAP is BELOW the 8cm for approximately 95% of the time, you'd loose that bet.

Here's a typical good night where SH reports both my median and 95% IPAP are equal to my max IPAP setting of 8cm:



You'll notice that what keeps my IPAP pressure at 8cm for long periods of time are the PR search algorithm and repeated flow limitations. (It does appear that SH overestimates the median IPAP pressure here since I can only find about 2 hours of time with IPAP = 8.)

It's also possible to have the 95% pressure number equal the MINIMUM pressure setting, and this can strike people as an "oddball" case that's unlikely to happen, but it can and does happen. On the night shown above, my 95% EPAP is listed as 4 (my min EPAP) even though the max EPAP for the night is 5. (This is not uncommon in my data.) On this night, my EPAP = 4 at least 95% of the time. On this night, my EPAP = 5 for 13 minutes out of 328 minutes of run time; in other words, my EPAP = 5 for about 2.5% of the night and my EPAP = 4 for about 97.5% of the night.

[Sleepster]

On a few rare nights, I'm at IPAP = 8.0 for only 10-15% of the night. So if you bet $$ that looking at my IPAP and data would reveal that the IPAP is BELOW the 8cm for approximately 95% of the time, you'd loose that bet.

Yes, I see where my thinking was in error. Nevertheless, I'd still make the bet in the other case because his cap was set at 12.8 and his 95th percentile was 12.6, and I believe his minimum was set at 12.4.

In your case I'd not take the bet because your cap is set at 8 and your 95th percentile is also 8.

The scenario where your pressure rises to the cap of 8 and stays there for most of the night is believable. A scenario where his rises to 12.6, which is less than the cap, and stays there for most of the night I find hard to believe. You're experiencing events, flow limitations, or snores that keep you at your max pressure. What could be happening that would keep him at 12.6, just under his cap of 12.8?

Now if he had a min of 12.6 then I'd find it believable that he's spending 95% of the night at 12.6 because his AHI is so small; it's possible that his pressure rarely rises above the minimum.

All of this is so pedantic because his range is so small (12.4 to 12.8) that the differences are insignificant. Nevertheless I'm learning something that is or might be useful. So I keep participating in the discussion.

[Sleepster]

thank you for your information, however, I find that dictionaries do say that it is a a noun that's based on the transitive verb, 'misinform: to give incorrect information to'. eg: http://www.thefreedictionary.com/misinformation

though some do add "especially that which is deliberately intended to deceive."

Right. That's the sense in which I use it or think of it when I see it used.

A subtlety arises when misinformation is repeated, and it's often the nature of misinformation that it's designed to make people want to repeat it.

The person repeating the misinformation may not be aware that it's erroneous, in which case their intent is different from a person who is aware and repeats it anyway.

I witnessed someone repeat misinformation in this malicious way one time and it forever altered my opinion of this person. Let's call him Bob. Bob is a pro-union defender of employees with disciplinary issues. I have always disagreed with Bob on some fundamental political attitudes, but what changed is the fact that I used to respect him even though I disagreed with him.

What happened was a new college president was conducting a public town hall meeting and when asked by a local union officer about his intentions to fire employees he responded that he had no such intentions. He stated that he had in fact gotten emails from employees urging him to fire other employees, and that one of those emails provided a list of the names of eight employees.

The next afternoon I was in a meeting with Bob and he made a vague statement about having heard that the president had announced at last night's town hall meeting that he had a list of eight employees he intended to fire. I was not at the town hall meeting and at this point knew nothing about what had been said. Bob was so vague I pressed him and he told me the details, mentioning the name of the person he had heard it from and who the attendee was who he'd heard it from. (Hard to follow, huhh? That's another feature of well-designed misinformation, you need a flow chart!)

I found out later that Bob had already learned of the nature of the "misunderstanding". I talked to the person who had set Bob straight earlier that morning. Yet Bob went on to repeat it anyway!

So this is why I make the distinction between misinformation and mistaken information. To me this person was spreading misinformation in the most malicious manner. He wanted to discredit the new president and he didn't care if the truth got in his way.

He was much more than simply mistaken.

[diamaunt]

Yes, I see where my thinking was in error. Nevertheless, I'd still make the bet in the other case because his cap was set at 12.8 and his 95th percentile was 12.6, and I believe his minimum was set at 12.4.

respectfully, I don't think you're paying attention, all he *said* was:

My apnea is totally controlled with a maximum pressure of around 12.6 (typical nights AHI .2 to .6). However, my machine seems to think the maximum pressure should be higher because my 95% number always equals my maximum pressure number ,so I've been experimenting by raising the upper limit until my 95% value is always below it. For me, that's a setting of 14.

(post 8)

so, the data points are his 95th and his max from the night are always the same

he has 12.4 - 12.8 listed as his pressure, but who knows if that's actually what the machine is set to, or what he's seeing.

he also goes on to say that it wasn't until he raised max pressure to 14 that his 95th and max quit being the same. thus, once again, strongly suggesting the autoset spent much of the night trying to get to a higher pressure.