Re controversy over changing pressure

[kteague]

My guess is the accusation of machines not being accurate had more to do with data reporting rather than pressure. These machines seem to have built in lots of allowances for variables and I'm satisfied that the the data is reasonably valuable even if not perfect.

Over a year ago, my pressure determined by a Resmed Autoset Spirit that consistently gave me an average AHI of between 1 and 2 was verified as therapeutic thru a sleep study. After several months now on a Respironics M Series Pro CPAP, I'm seeing an average AI of .4 and HI of .6 on my SmartCard readouts, and a recent sleep study confirmed that my treatment is effectively controlling my OSA. My results have been cross checked on two different machines, so I have no reason to be suspect of a machine's data.

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CPAPopedia Keywords Contained In This Post (Click For Definition): respironics, resmed, CPAP, AHI

[Snoredog]

I think there is a possibility that your doctor misspoke and/or you misunderstood or mis-remembered what she said.

My sleep doctor told me to keep an eye on my numbers if I wanted to, but it was more important to find the setting that made me feel the best than the one that gave me the "best" numbers. I think that makes far more sense (assuming one isn't having really bad desats, which I'm not).

And I think it's well-established that the software isn't a 100% accurate picture of how you sleep. For one thing, it doesn't record all your sleep time, it doesn't know when you're awake or asleep, it misinterprets ambient noise as snoring...

you mean like misunderestimate the accuracy of the software?

[geoDoug]

"Obsession" is such an ugly word. I prefer "addiction."

Doug.

[tillymarigold]

I think there is a possibility that your doctor misspoke and/or you misunderstood or mis-remembered what she said.

My sleep doctor told me to keep an eye on my numbers if I wanted to, but it was more important to find the setting that made me feel the best than the one that gave me the "best" numbers. I think that makes far more sense (assuming one isn't having really bad desats, which I'm not).

And I think it's well-established that the software isn't a 100% accurate picture of how you sleep. For one thing, it doesn't record all your sleep time, it doesn't know when you're awake or asleep, it misinterprets ambient noise as snoring...

you mean like misunderestimate the accuracy of the software?

What I don't understand is that people are posting here ALL THE TIME about discrepancies with their software, yet now that one person came in and posted saying that the software isn't accurate, all of a sudden everyone is jumping in going THE SOFTWARE IS SACRED, HOW DARE YOU MALIGN THE SOFTWARE?!?!

There are *tons* of known issues with software ... Silverlining often shows normal breathing as FLs, ResScan doesn't record any data during the ramp period, Encore Pro is infamous for recording "snores" that aren't ...

Look, I like having the software, because if I feel like $*** one day I can look at it for a good guess as to what the problem was, which might help me solve it, but then again it might not. But I'm getting sick of people pretending that the results from the software are 100% as accurate as a full sleep study with electrodes, snore mike, inhale and exhale pressure transducers, pulse oximeter, and audio and video recording. They're not. They're valuable, and if your sleep doctor really sucks or you don't have one or your insurance is making it impossible to get a sleep study, then having a machine with software is even more valuable.

Of course the ideal way to get a picture of the way someone sleeps would be to do a full-out PSG with all the equipment in their own house using their own bed/pillow/etc., several times over a relatively short period (say, 10 times in a month). That's not possible, and obviously a home machine is better at compensating for some of those things than an in-lab PSG would be. But the reading done by ONE sensor off a relatively cheap piece of home medical equipment is never going to be as completely accurate as a complete, in-lab PSG. There's a reason that a fully data-capable APAP is less than $1000 and one night in a lab is two or three times that.

And I'd rather feel great and have okay numbers than feel okay but have great numbers. That's all I'm saying.

[Wulfman]

tillymarigold,

I think more of us get bent outta shape by those that tell us NOT to use it (at all) because it's not accurate as opposed to knowing some of the discrepancies and still want to use it as a yardstick for our progress.

Den

[Goofproof]

As if the Sacred Sleep Study is accurate, right Den. I'll take my chances with mySleep Study , nightly. It may not be totally accurate, but I know the person making the decisions about my health weren't frying hamburgers and fry's last week.

Not that it's all bad, I did that 45 years ago too. Now I do other things, just not very fast. Jim

[Panhandler]

I think if we're looking at trends, rather than individual data points, the software is very helpful. If I was tuning to "feel good" I'd be fooling with it all the time, 'cuz some days are better than others. As long as my leak rate seems consistent and my AHIs aren't climbing, it's not worth fooling with changing pressures.

For me, any therapy that keeps my AHIs in the <2 range is good with me, and that's happening all the time.

I can see why some docs think the accuracy is a problem and why some are worried about patients obsessing over the data. It's just a specialized kind of hypochondria.

Even if I know my speedometer isn't accurate, it will tell me if I'm speeding up or slowing down.

[ozij]

There are *tons* of known issues with software ... Silverlining often shows normal breathing as FLs, ResScan doesn't record any data during the ramp period, Encore Pro is infamous for recording "snores" that aren't ...

Some people's breathing is flow limited (the wave looks different), for various reasons having to do with their anatomy. In those case, Silverlining has an option of telling the software not to respond to flow limitations.

Resmed made very rational decision not to record events that happen during settling time, or ramp time. So did Puritan Bennett. The don't record during thost times bacause those time are not represntative of your breathing when you sleep. True the machines don't know whether or not you are asleep -

I wouldn't call those "issues".

Resmed machines respond extremely fast to flow limitations - of any kind.

The Puritan Bennett 420E has a bug when reporting mixed apneas - and a person who has many of them should beware

Encore Pro seems to skip days, and sometimes the lcd and the software don't agree.

But its like Den said: when people suggest we use nothing, or just wait in misery for a new PSG - that's when we start hollering how good and helpful the software is for us despite its discrpancies.

Here's a problem caused by going only by what you feel, without software support: How do you know if you're miserable because your pressure is incorrect, or because your pressure is perfect, by your mask is leeking like a sieve? Or maybe you're mouthbreathing?

An autopap is not the right machine for diagnosing all sleep problems. But research shows that it's actually pretty good at arriving at the right pressure, when used for 2 weeks or so.

You may have noticed that the "professionals" who tell us the machines are "not accurate" never have data to back up their announcement. I expect professionals to be up to date on there professions literature, and to be ready to support there claims. Where is the data to show the the failure of the software? Where is study that had to stop using APAP because APAP was so unequal to CPAP?

Resmed makes Autopaps. Go to their site and browse Peter Farrell's favorites - he has a whole bund of links to studies. You can say he was selective. So, when you read those articles, see if you can find the articles citing those articles, that show autopaps are stuff and nonsense.


O.

[TXKajun]

Hmmmm, could this be deja vu....all over again??

viewtopic.php?t=3366

Kajun

[Wulfman]

Hmmmm, could this be deja vu....all over again??

viewtopic.php?t=3366

Kajun

Kajun,

You've been here long enough to know that there are rarely any "new" subjects on this forum.......just new people who haven't seen them before.....or new confrontationalists who want to stir the pot again.

It's ALL "deja vu" anymore.

Den

[WearyOne]

Here's a problem caused by going only by what you feel, without software support: How do you know if you're miserable because your pressure is incorrect, or because your pressure is perfect, by your mask is leeking like a sieve? Or maybe you're mouthbreathing?

Amen!

Not to mention, as I've have stated several times over the past week, there are people who have other health issues that can make one feel bad with fatigue, sleepiness, etc.. This data, even when it's not 100% accurate, can help you rule OSA problems in or out.

Pam

[tillymarigold]

Here's a problem caused by going only by what you feel, without software support: How do you know if you're miserable because your pressure is incorrect, or because your pressure is perfect, by your mask is leeking like a sieve? Or maybe you're mouthbreathing?

I specifically said that I like having the software for those reasons, actually. But the software can't address every issue that might be causing me to feel like ****. It doesn't know if I woke up during the night. It doesn't know if my breathing got screwed up when I went into REM sleep (a separate issue I have in addition to the UARS--a different type of breathing-related arousal that occurs only in REM). It doesn't know if my oxygen desaturated. In my case, it also doesn't know how long I spent in apnea, although I know other software types do. (And my husband is a much more reliable indicator of when I'm mouth-breathing or my mask is leaking than the software is.)

All I'm saying is that NEITHER the software NOR an in-lab sleep study is perfect, but scientifically speaking, the results from the complex medical equipment in the lab are simply more accurate than the results from the machine. And I don't know why all of a sudden people are denying the possibility that the machine's results could be less accurate.

Look, do you weigh yourself at home? I do. My scale measures my weight in fifths of a pound. It's probably accurate to the nearest 1/5 pound. But do you deny that a scale that was sensitive enough to measure my weight in ounces would be more accurate? It's the same sort of thing. If I wanted to know *exactly* how much I weighed, I'd be better off using a more precise scale. A home scale is good enough, but that doesn't mean it's not less accurate than a better one.

And if you'd rather have better numbers and feel less good than vice versa, that's your right, but I don't think telling a patient to go by how they feel and not by their numbers is an unreasonable thing, which I think is the point that the OP's doctor was making. If a patient isn't suffering other medical issues, it may well be better to use a pressure that's slightly less than ideal. Heck, I don't know, maybe that patient gets an AHI of 7 at a pressure of 10 cm and feels pretty good, but with a pressure of 11 the AHI drops to 3, but the patient is having trouble sleeping at the higher pressure and so the patient's sleep is more interrupted than it was at 10 cm, so they feel better with a pressure of 10 cm and an AHI of 7 than they do with a pressure of 11 cm and an AHI of 3. I'm sure there are other reasons that a higher AHI might be worth it in exchange for feeling better.

BTW There has been a study posted on this site or else on apneasupport.org, perhaps more than one, showing patients getting better benefits from straight CPAP than AutoPAP. I know there was one showing that is the case for patients with a specific medical issue (I think congestive heart failure) and I believe there was a more general one as well. I'm not going to go back and look for it though. But such studies do in fact exist, even if you haven't seen them.

[DreamStalker]

Dang girl! ... get your AHI under control there and chill a bit (it's all relative).

I guess I shouldn't define the term "precision" (not the same as accuracy) as it might blow this thread right off the froum.

[Flying_Norseman]

How about using how we feel AND what the software says in order to get optimal treatment? Since when does everything have to be either/or in this country? I don't think anyone here has argued that the software is more accurate than a sleep study. It would be interesting to see the results of a study where patients are Titrated at a lab and then given an APAP with software for a week and then compare what pressure they end up using.

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CPAPopedia Keywords Contained In This Post (Click For Definition): APAP

[Wulfman]

How about using how we feel AND what the software says in order to get optimal treatment? Since when does everything have to be either/or in this country? I don't think anyone here has argued that the software is more accurate than a sleep study. It would be interesting to see the results of a study where patients are Titrated at a lab and then given an APAP with softare for a week and then compare what pressure they end up using.

That's been MY philosophy all along. I also think there's a little psychological benefit to SEEING the therapy work.

Den