Remstar Auto - Non-responsive events?

rested gal,

You are right in what you say and I too am a fan of autopaps (I have a REMstar with Cflex) However I've noticed from my data that the smaller the range the less events I have e.g. If I have it set 4-20 I get AHIs of 6-8. If I set it to 6-20 I get AHIs of 4-5. When I set it to 10-20 (10 being my 90%) the AHI dropped to 1.4. (By the way although I leave the top open at 20 my pressure never reaches more than 13). I'm beginning to wonder if setting the start pressure to your 90% is a good way to optimise the machine?

However this may all depend on the nature of events an individual has. I have a higher concentration of hypopneas that apneas and believe I have UARS rather than OAHS.

Have you any findings that would conflict with or corroborate this?

cpaper,
This is just conjecture: if you set the lower limit too low (beneath you treatment level) It will take longer for the machine to "pop up" to the critical pressure when events take place, thus letting more get through untreated.

Take a look at the daily detail reports and see just where your machine is spending the night, and try to correlate the occurence of events with pressure. If they are all occuring at a low pressure then that would tell you to increase the minmum setting.

Just a thought...

I have seen similar results also...

It would kind of make sense that if you raise your lower limit closer to your 90% figure, the number of increments to get to your 90% figure is fewer. So instead of taking 6 attempts at raising the pressure, maybe it only has to take 2 or 3. In those extra 3 attempts maybe an event slipped by...

While I'm a big fan of having the software with an autopap to see my overnight data, I think getting the AHI "down" is important only if a person is not feeling good on treatment. For someone not getting relief from their sleepy symptoms it can be helpful to know, "Were there prolonged periods of leaks?" "Was the pressure bumping the ceiling often and possibly need to be given more headroom?"

I believe (am not a doctor, though !) that it really doesn't matter much if the AHI on autopap is 2 or 3 or 5 or even 7 (the supposed ideal being 5 or below). What really matters is how we feel in the morning and throughout the day.

We can tweak and adjust pressure settings this way and that trying to achieve a consistently low AHI, which, when you come right down to it is only a number. And...is a number dependent upon so many variables during the night. Variables such as the position one was sleeping in...how a particular machine reads a particular person's breathing. Environmental sounds that might have been keeping one from spending much time in certain stages of sleep where more events can show up. Aches or pains from other conditions causing micro-arousals. Colds, allergy or sinus problems causing more tissue congestion on one night than another. What a person ate or drank - or how late in the evening they had a drink. On and on and on. So many variables that could change the pressures used and "AHI" from night to night.

cpaper, you mentioned that when you set your lower pressure at 6, your AHI was in the 4-5 range. Did you note how you felt the next day? And when you set the lower pressure up at 10, your AHI dropped to 1.4. Did you note how you felt then? And what about lower pressures between 6 and 10? What I'm getting at is...looking just at the AHI number and trying to get that AHI number down, down, down from "5" might not really yield much difference in how we feel.

That "90%" number is misunderstood, imho. I *think* (but you know me and math! lol) it means that particular pressure or lower pressures were taking care of things fine. I think it's important to look at the Encore table chart to see just how much of your night was spent at pressures much, much lower than the highlighted "90%" number. And then consider the tradeoffs. Upping the lower pressure to essentially what you'd be on if you had a straight cpap loses a lot of the benefits of spending a good part of the night at lower pressures with an autopap. However that could be a good tradeoff for some people. I think each individual would have to decide that based on how he/she feels.

Of course, even if you raise the lower pressure to very close to your titrated pressure, you'd still have the other good benefit of an autopap going for you - having some margin up at the top in case more pressure were needed than the sleep study titrated pressure.

It really is fascinating to look at the data, tweak the pressures and see what happens. But bottom line, again and again and again, imho, is how one feels in the morning.

The higher the pressure, the more apt some masks are to spring leaks (not usually a problem with the Breeze pillows or Activa I use, but a consideration with many other masks). Higher pressure can dry the nasal and throat tissues more ...not as much problem if a heated hose is helping the humidified air actually get to you...but still, the faster the air flow, the more drying.

Before I worried too much about trying to drop an AHI that was registering only 4 or so, I'd consider, "How do I feel?" I'd think long and hard about what more pressure might do to increasing mask leaks, possibly increasing mouth air leaks, etc. If I felt the same in the morning whether the AHI was 0.n or 4.n, I don't think I'd give up the possible benefits of spending much of my night at lower pressures. In other words, if raising the lower pressure produced only a lower AHI number - and no significant difference in how I felt - what would be the point?

If raising the lower pressure setting makes one feel better; than definitely, go for it. The low pressure is there for comfort, so playing around with the lower pressure setting on an autopap can do no harm, imho. Bottom line is "how you feel" - regardless of the AHI - or the "90%" number.

Rested Gal, I kinda came to that same conclusion when someone had asked what the best software / hardware for monitoring OSA. I thought about it and answered our bodies... I personally have to balance higher pressure against mask leak (Ultra Mirage FF). Also, some folks seem to like 4 or 5 on the low end, to me that is too low, so I have it set higher. But, that in itself is the beauty of an APAP, add CFLEX and that is just icing on the cake.

rested gal wrote:
If raising the lower pressure setting makes one feel better; than definitely, go for it. The low pressure is there for comfort, so playing around with the lower pressure setting on an autopap can do no harm, imho. Bottom line is "how you feel" - regardless of the AHI - or the "90%" number.

Sorry, the sleep docs disagree with you in changing ANY of your CPAP settings. Comfort is key but so is treating the apnea. Having a too low pressure will not necessarily treat the apnea events. In my case, my lower pressure had to be risen to the maximum titrated pressure. In fact, I had to turn off Auto Pap and use straight CPAP. Unfortunately, with auto and without, I never felt any better only worse while using CPAP, and that was using CPAP for a year. I only felt better after I stopped using CPAP. That's how bad CPAP made me feel. Of course, everyone's different.

rested gal wrote:

This is exactly why many sleep doctors don't recommend auto paps.

I could very well be wrong, but my understanding is that it's "normal" for non-OSA people to have occasional apneas/hypopneas and perhaps even a few centrals during sleep. That's why an AHI under 5 from a sleep study is considered "normal" and not needing cpap treatment, isn't it?

I guess I'm missing your point, Guest, as to "exactly" why doctors single out autopaps to bash?

What values may seem normal today, surely will likely not be normal tomorrow. It probably wouldn't be a bad idea to take these numbers with a grain of salt since sleep apnea is still a very new disorder/disease. I would want to get the numbers as low as possible because who knows what these events, even less than 5 are actually doing to your body in the longterm.

Sleep doctors don't usually approve APAPS because they are simply not smart enough or fast enough to respond to events. I have heard this many, many, many times. However, just because this is the case, it doesn't mean that one should NOT try an autopap because everyone is different and the key is to find what is best for you.

Sleep doctors don't usually approve APAPS because they are simply not smart enough or fast enough to respond to events.

My take is that sleep doctors don't usually approve AutoPAPs because they simply don't understand AutoPAPs. Here's an example:

Anonymous wrote:

wading thru the muck! wrote:These are events that the machine did not resolve... Left-overs! If you have an unresolved AHI of 5 or less that is supposed to be good. I shoot for 1 +/-, but 5 should be just fine. The key is whether or not you feel better.

This is exactly why many sleep doctors don't recommend auto paps.

Some sleep doctors claim that AutoPAPs require at least some apneas occur to prevent yet other apneas. This is a myth. AutoPAPs will discern obstructive precursor events such as snore and flow limitation to prevent apneas. Despite this proactive leveraging of treatment, some apneas and hypopneas will go untreated. However, patients on fixed pressure CPAP machines rarely achieve an AHI of 0.0 as well.

Aside from the AHI issue itself, cortical arousals are a health and quality-of-life issue as Rested Gal's post implies. The essence of her post is to allow an Autotitrating machine to titrate to it's fullest "minimum pressure value" or allow it to titrate with a higher set "minimum pressure value"----whichever yields better health. Excessive cortical arousals yield poor health, poor cognitive functioning, and therefore greater actuarial risk. For better or worse our own subjective assessment of how well we sleep is at least as important as our nightly AHI measurements (which don't measure excessive sleep disturbances that can be machine related).

Miko wrote:Sleep doctors don't usually approve APAPS because they are simply not smart enough or fast enough to respond to events. I have heard this many, many, many times. However, just because this is the case, it doesn't mean that one should NOT try an autopap because everyone is different and the key is to find what is best for you.

How about "just because this ONCE WAS the case"... Pay attention, it's been said several times that the autopaps of the past were far inferior to those of today.

There are a lot of people on here who do really well with AutoPAP. Your assertion that they don't respond fast enough is ludicrous, when lots of people have posted their numbers indicating that they are getting sufficient treatment.

I'm sorry, I may be coming down a little bit hard, but it feels like in the last couple of days, there are several people who seem to have decided to make this board a much more contentious place, and your assertion in contradiction to most of what's been said falls right into that line.

Liam, no more humor today.

Liam1965 wrote:

Miko wrote:Sleep doctors don't usually approve APAPS because they are simply not smart enough or fast enough to respond to events. I have heard this many, many, many times. However, just because this is the case, it doesn't mean that one should NOT try an autopap because everyone is different and the key is to find what is best for you.

How about "just because this ONCE WAS the case"... Pay attention, it's been said several times that the autopaps of the past were far inferior to those of today..

Go back and read my post, the last sentence. BTW, I reckon you don't subscribe to the "don't shoot the messenger theory". 'nuff said.

I'm a bit confused . What message ? Which messenger ?

Did this get carried over from another thread ?

Chris

-SWS wrote:

.
Some sleep doctors claim that AutoPAPs require at least some apneas occur to prevent yet other apneas. This is a myth. AutoPAPs will discern obstructive precursor events such as snore and flow limitation to prevent apneas. Despite this proactive leveraging of treatment, some apneas and hypopneas will go untreated. However, patients on fixed pressure CPAP machines rarely achieve an AHI of 0.0 as well.

Amazingly, this is not so. I now know personally several people using CPAP and they told me that their AHI is zero or close to zero. Of course, I doubted them. But, when I went into their menu of their cpap, I seen this was indeed the case. The same goes with my DME who also uses CPAP and my GP.

Miko wrote:

-SWS wrote: Some sleep doctors claim that AutoPAPs require at least some apneas occur to prevent yet other apneas. This is a myth. AutoPAPs will discern obstructive precursor events such as snore and flow limitation to prevent apneas. Despite this proactive leveraging of treatment, some apneas and hypopneas will go untreated. However, patients on fixed pressure CPAP machines rarely achieve an AHI of 0.0 as well.

Amazingly, this is not so. I now know personally several people using CPAP and they told me that their AHI is zero or close to zero. Of course, I doubted them. But, when I went into their menu of their cpap, I seen this was indeed the case. The same goes with my DME who also uses CPAP and my GP.

Yes, Miko. Some CPAP users achieve 0.0 AHI measurements, and some AutoPAP users achieve 0.0 AHI measurements. Most patients do not achieve a perfect AHI of 0.0, however. As Wader said, an AHI of less than 5 is the goal of even PSG titrations. AutoPAPs achieve that goal more often than not. Most doctors that blast AutoPAPs are still blasting the sensor and algorithmic shortcomings of the "old technology" AutoPAPs versus the modern AutoPAPs, which many/most patients here seem to fare quite well with. I also think there are some sleep professionals that secretly despise the AutoPAP's ability to deny them recurring PSG revenue....

I agree SWS. That old saying "Follow The Money" Seems to work well in this industry.

Cheers,

Chris

rested gal wrote:... I'm tellin' ya, I wish SWS were back!!!

Rested Gal, you said it better than I ever could have! The RemStar/Encore NR apnea category will log primarily central apneas, but any apnea that did not respond to those three pressure increments will be logged as NR---exactly as you described.

The 420e strives to avoid pressure-inducing central apneas with these two techniques: 1) cardiac-oscillation detection algorithmically equates to either maintaining pressure or backing down, and 2) the adjustable "command on apnea" setting imposes an upper pressure limit with which any apnea may be treated.