ResScan Graph and info question

I have a new Autoset 2 with ResScan software. I have downloaded the last 5 days of data and I have SOME idea of what I'm looking at, but would really like a few pointers on what I SHOULD be looking for, and just have a couple questions.

1: I have some apnea events, they have numbers shown above them, such as 10, 12, 13, 15. What do those mean?

2: I have an AHI graph, it looks like a constant upslope from the beginning of the hour to the end of the hour, and then it drops back to the bottom and starts over at the beginning of the next hour. What is this and what does this form tell you?

3: With the AHI graph, there are numbers up the left side. 0, 15, 30, etc. The upslope is going from 0-10 per hour in some, in a stead slope, on other days it's over 15 at the highers part of the upslope. What is this and what does it mean?

4: When I have an apnea event, the machine does NOT always raise the pressure before, during or after. Why is this? Why does it adjust pressure if not for that reason?

That's all for now, thanks in advance.
JC

1] The numbers above the Apneas are the length in seconds of that apnea.

2] The Resmed starts recounting the hypopneas each hour.

3] I "think" the top at the end of the hour is the number of hypopneas that hour. But I'm not gonna swear on that and I'm too lazy to go digging thru the manual to be sure.

4[ This question has to do w/the Resmed algorhythm and I can't begin to explain it. You would need SAG, SWS, RestedGal, jnk - someone one heck of a whole lot smarter than me to explain it.

Ok, that makes sense, and I appreciate your reply. Can you give me an example of a hypoapnea? Would it just be hard snoring, or quick "hiccup" in my breathing? Some of the actual apnea events have numbers as high as 15 on them. That is 15 full seconds that I went without breathing, and then the machine appears to do very little to "fix" it. That seems sort of disconcerting.

JC

The answer to number 4 is contoversial, and depends somewhat on a person's point of view. -SWS would be the one to explain it in the best neutral and insightful terms. But I can try to give you my personal take based on what little I think I know from reading his posts on the matter and how I have come to view it for it to make sense in my little brain:

Autos these days seem to be more about trying to prevent events than they are about reacting to them, especially when it comes to apneas. The machines have to draw some lines in the sand somewhere in order to keep from reacting to every little change in breathing and raising pressures through the roof. For example, ResMed has chosen not to react to apneas that seem to come out of the blue (no snores or flow limitations leading up to it) when the machine is already putting out 10 cm or so--it assumes that is most likely a central apnea and may be a normal thing, not the sort of obstructive event that should change how much pressure is put out. (Centrals can occur naturally when changing sleep states, for example.)

Now, it may be right in one instance and wrong in another on that, but every machine has its own way of playing the odds when it comes to such matters. That is why some people do better on one brand of auto than another. But, generally speaking, most machines do well enough with reacting to the way someone breathes, as long as they have the usual flow limitations and snores that lead up to events, as long as leak is fairly low, and as long as the minimum pressure is set within a few cm of what is needed all night to prevent apneas.

All machines monitor some precursors to apneas and hypopneas. Some react directly and decisively to the events themselves to see if they respond to that. Others are more cautious and gradual in pressure changes. But they all seem to do fairly OK for the most part at what they do most of the time. Autos are a new enough technology that they are far from perfect. Indeed, many of the long-timers here prefer to use straight CPAP pressure for the best sleep most nights and only use an auto once in a while if they want to see where it lands, since that can be useful information in finding what straight CPAP pressure might work best for them all night.

Others can correct the above if I've shaded it too much with my personal biases.

jeff

Maybe what I need to do is adjust the min. pressure up from 4.5 to closer to where it averages the whole night, instead of letting it drop back down so far. That might be part of what I'm missing, BUT, with this machine I've feeling better than with my trial repsironics M that I used for a month, and definately better than my FP604 that had a set pressure of 8.

That is sort of the idea, isn't it, when you are self-medicating as many of us do....to adjust the min. and max closer to where they need to be so as to "fine tune" it as much as possible while still allowing some auto adjustment for "issues"?

JC

jrcmlc wrote:Maybe what I need to do is adjust the min. pressure up from 4.5 to closer to where it averages the whole night, instead of letting it drop back down so far. That might be part of what I'm missing, BUT, with this machine I've feeling better than with my trial repsironics M that I used for a month, and definately better than my FP604 that had a set pressure of 8.

That is sort of the idea, isn't it, when you are self-medicating as many of us do....to adjust the min. and max closer to where they need to be so as to "fine tune" it as much as possible while still allowing some auto adjustment for "issues"?

JC

Maybe 2 cm or so below what you need is low enough for the minimum, as a general rule, unless you have a real reason to go lower. That is not the stance of the docs or the manufacturers, but it seems to be what many users have decided on their own works best for them. There is no need to limit the max unless someone is having trouble with runaway pressures shooting up.

Self-medicating must always be done very carefully, especially if it is a single malt and aged longer than 10 years. Oh, wait, I think I got off on a different subject there, didn't I? Wrong board. Sorry.

jeff

LOL. I'll adjust the pressure tonight and let er' eat for a few days and see how it goes. Just as a point of info, same everything, different machines, one was a Respironics M auto, and the new one is a Resmed auto. The M auto showed AHI of 4.5ish, the resmed shows around 3ish. Is that just the nature of the different machines, or ? I thought I had read that the resmeds usually read HIGHER?

JC

The Resmeds tend to score the hypopneas more aggressively than some of the other brands. Therefore your HI is often higher w/a Resmed. But your AI shouldn't be that far off from the other brands.

With that in mind, and the fact that I feel so much better, although that could be skewed, I'd say the ResMed is doing a good job so far. I'll adjust it tonight and see what happens for a few days.

Thanks for the info guys.

JC

Oh, I searched and couldn't find too much positive info, is there a preferred, cheap pulseox to help with this "self-medicating" or are they all high, unless you want something that doesn't work?

JC

I have to post this: some of us set a higher max in our APAP range than we ever expect to need just so the machine can so there if it needs to. While I was titrated to 10 in Aug '07, my CPAP machine was set to 11 (common practice to bump 1 cmH2O). Then, I lost 53#s and was backsliding into untreated apnea (losing therapy air, I was so clueless then I didn't know what was happening and had a dumb CPAP so doubly clueless ). Doc loaned me an APAP to get data and my pressure needs had indeed dropped. On my current APAP, we've set 6-15 (currently using 6.4 as min to see what numbers I get). 15 is high as I only maxed out at 12 but if the machine needs to go there, I haven't prevented it by setting the max too low; plus, that pressure will likely wake me up and that would start normal breathing anyway. I had no centrals in my PSG, so doc is not concerned with inducing them via pressure.

JNK did a good job of explaining why a machine would not respond to an event. For ResMed xPAPs, if the pressure is already 10 or higher when an apnea occurs without the defined precursors, the pressure is not increased as it might be a central. If preceded by the defined precursors, the pressure is increased up to the defined max to stent open the perceived airway narrowing (hypop) or collapse (apnea) regardless of the pressure when the flow limitation occurred. All APAPs will decrease the pressure when breathing is stabilized. Some are sensitive to these changes in pressure and prefer to run their APAPs in CPAP mode as they have better numbers and/or better sleep (less sleep stage shifting). There is no predicting who will be sensitive to pressure changes. I have fragmented sleep with multiple wakeups throughout the night with straight pressure and much better sleep using APAP mode.

I also seem to have better sleep with the APAP, but last night I bumped the min. pressure closer to the the low-end of the adjustments it's been making, which was 6, and I still had an AHI of 4, and still had several events. The 1st part of the night was perfect, no hypo, no real apnea, and then after 2 hours there were a few issues.

The pressure rarely gets above 10 on my unit, but I did have a few centrals on my sleep study, so I wonder if I'm going about this the right way.

On the bright side, my leak for the last 2 days has been zero.

JC

An AHI of 4 on a ResMed? I would gladly give my eyeteeth for that.

My averages across the last week are:

Avg daily use: 7:18
apnea index: .4
% time in apnea: .1
Hypopnea index: 3.6
AHI: 4.0
Leak Median: 0
Pressue median: 6.8
Pressure 95th%: 10.8
Pressure max: 12.0

I assume from the last comment that these are pretty good, but I'm kind of picky, I still have events every night (except one so far) and I'd like to have none, or even less, and would like to know how to get AHI down some more...

JC

jrcmlc wrote: . . . I'd like to have none, or even less . . .

I pulled that quote out of context to make the point that there is a profound truth in those phrases that we have all had to come to grips with one way or another with home-machine data. Perfectly healthy people have occasional apneas and hypopneas, so there is no need to shoot for 'better than healthy.'

The numbers our home machines give us are estimates meant primarily for the purpose of trending data. The idea is to get a baseline when you are feeling good, and occasionally to make a small change, either up or down if we're talking pressure, and see what that does to your numbers for a few weeks to see if you went the right direction or if nothing much changed. Your numbers will also let you know if things start to slowly deteriorate for some reason so you know to investigate or review your lifestyle and sleep-hygiene habits.

But an occasional "apnea" as reported by a home machine may actually be a central event that would not even be scored in a PSG study, and ResMeds are quick to score changes in breathing as "hypopneas" that, similarly, might not be scored as such in a sleep study.

So, don't waste your time chasing ghosts, if you are feeling better. We all enjoy geeking out with our numbers and charts and stuff, and the data is a very useful tool. But part of the scientific approach with it is to recognize its limitations.

Don't shoot for an exactitude beyond what your capabilities for measurement are.

I would say pat yourself on the back for how great you are doing--it feels good, and it makes the people around you laugh when they see you do it. At least my wife laughs at me when I do it because I have to push really hard on my elbow to reach back there.

jeff