Question about chart (shown inside)… is this caused by leak?

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MikeSleeper
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Question about chart (shown inside)… is this caused by leak?

Post by MikeSleeper » Tue Apr 08, 2008 4:19 pm

Thanks in advance to some experienced chart readers out there. I am so early on my learning curve (4-days on CPAP; APAP really) and trying to fine tune to get AHI down, so really appreciate your time looking at this chart.

Below is my encore viewer chart from last night. I’ve finally raised my max APAP pressure (w A-Flex) high enough to have some headroom above the reported 90% (P=16). So my range is now 12 low and 17 high. But there was still a 3/4 hour where the pressure maxed out (see the yellow box starting at 5 hours). Whole bunch of OA’s in there, the bulk for the evening and the major contributor to my AHI of 6.7

My question is this: There was some mask leakage during that period… not a huge amount… at P=15=current max, my mask is rated 43 L/min and this leak during this period looks like about ave 55 total, so about 12 L/min excess. From what I read here that is not enough to blow the max pressure off the top, but there are some larger spikes in there, can those do it? And are those OA readings caused by that? Or is this likely just a normal APAP algorithm doing its job; i.e. I hit some authentic OAs, pressure keeps going up to adjust… can’t go up enough, OAs continue for a while and settle down finally, pressure comes down. And the little extra leakage is just result of the higher pressure (and not enough leakage to be the cause of all that behavior). If latter, if this is just the result of not having the max set high enough, well then I’ll raise my max some more… but I am getting up there in pressure so want to make sure I am not raising max too high against an incorrect interpretation of the chart. By the way, no central apnea reported in my sleep study.

Thanks for your master minds on this! I owe you.

Michael

Image [/img]

Machine: Respironics Auto/A-Flex -
SW: EncoreViewer
Humidifier: Respironics M-series heated
Mask: F&P FlexiFit HC431

mindy
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Post by mindy » Tue Apr 08, 2008 8:49 pm

Michael,

I'm certainly not an expert at this but will give you my opinion for whatever that is or isn't worth. There definitely is one segment where your top pressure isn't high enough. IMHO, the leak numbers don't go high enough to cause concern, even in that small segment. Others may disagree. Remember that the machines are designed to compensate for a leakage but they can't handle large leaks (of which you have none).

You could increase the top pressure or alternatively try a single pressure (CPAP mode). I'd be tempted to try 14 for that.

Mindy

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jules
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Post by jules » Tue Apr 08, 2008 9:12 pm

With the sequence of apneas and the spikes in the leak graph, the data for that time period is "fishy" imho - you might have had a ton more apneas that weren't recorded due to "big" leaks that didn't register as a LL on the report.

Remember that the encore reports have a whole hour's worth of data in a small width on the screen and lots of things could have happened that aren't being shown the the screen.

The software gives you a better picture of what is going on than just LED output averages, but it still isn't everything.

MikeSleeper
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Post by MikeSleeper » Tue Apr 08, 2008 9:22 pm

thanks Mindy and Jules.

Mindy: good comments, thanks!

Jules: Thanks; are you saying you recommend improving the leak situation before going further with interpreting the chart? Or just write off that segment as a weird one and only base judgments on the rest of the chart?
Thanks, Michael.
Machine: Respironics Auto/A-Flex -
SW: EncoreViewer
Humidifier: Respironics M-series heated
Mask: F&P FlexiFit HC431

mindy
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Post by mindy » Wed Apr 09, 2008 5:09 am

Michael,

If you have any "large leaks", then you'll see a solid bar at the top of the graph for however long it lasts. They are quite obvious as I've seen on at least 5 occasions!

Mindy

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Mask: Swift™ FX Bella Nasal Pillow CPAP Mask with Headgears
Humidifier: S9™ Series H5i™ Heated Humidifier with Climate Control
Additional Comments: Pressure 7-11. Padacheek
"Life isn't about waiting for the storm to pass, it's about learning how to dance in the rain."
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Wulfman
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Post by Wulfman » Wed Apr 09, 2008 5:38 am

My recommendation would be to set your machine in CPAP mode at a pressure of 12 and C-Flex setting of 2 for a week and see what it looks like. I'd be willing to bet that you'll sleep a lot better, too.

Den

(5) REMstar Autos w/C-Flex & (6) REMstar Pro 2 CPAPs w/C-Flex - Pressure Setting = 14 cm.
"Passover" Humidification - ResMed Ultra Mirage FF - Encore Pro w/Card Reader & MyEncore software - Chiroflow pillow
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NightHawkeye
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Re: Question about chart (shown inside)… is this caused by l

Post by NightHawkeye » Wed Apr 09, 2008 6:23 am

MikeSleeper wrote:Thanks in advance to some experienced chart readers out there. I am so early on my learning curve (4-days on CPAP; APAP really) and trying to fine tune to get AHI down, so really appreciate your time looking at this chart.
Congratulations on having the good sense to monitor your therapy from the beginning, Michael. You've probably figured out already that "tweaking" this therapy is a trial-and-error proposition, too. Even the "professionals" don't have a better approach than trial-and-error.

You've got some obvious rough spots in the data due to clustered apneas. So what caused those? Might it have been because you were sleeping on your back? Might it have been because the machine induced central apnea? Could it have been because you were mouth-breathing at the time?

You asked if it could be due to leaks. My opinion is no. I think problem leaks would show up as much higher spikes. It also doesn't look like mouth-breathing to me. Of course, your data while mouth-breathing could look somewhat different from mine.

It also doesn't really look like central apneas to me, but since they occurred at the machine's highest pressure, you wouldn't necessarily get an NR indication from the machine to alert you of it.

If the apneas were cause by you sleeping on your back, then raising the top pressure might help that. Of course, if you have access to your sleep lab data that might tell you something about your pressure needs while on your back. Unless your sleep lab titrated you near the low-end of your APAP range, you might consider raising the top pressure and see if you get any improvement.

On the other hand, if your titration value was on the low side of your APAP range, then follow Den's advice and see if you get an improvement.

Continue to monitor results after tweaking, and in a few days make additional adjustments as needed.

Just my $0.02.

Regards,
Bill


MikeSleeper
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Post by MikeSleeper » Wed Apr 09, 2008 9:40 am

Thanks all for your great advice. The predominance seems to be "not a leak issue" and that is my gut as well.

I am intrigued by the two comments saying to try switching from apap to cpap using a pressure at the lower end of my current apap range. I'd love to hear more explanation on that. Clearly I am having many OA events above that lower level... and apparently not leak-driven spurious data. Is there something about the apap process that can drive worse OA experiences as it cycles to higher pressures (again ruling out leaks)? Are we proposing centrals? Curious on your thoughts behind that, those who wrote it.

Thanks again all, excellent help.
Michael

Machine: Respironics Auto/A-Flex -
SW: EncoreViewer
Humidifier: Respironics M-series heated
Mask: F&P FlexiFit HC431

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Wulfman
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Post by Wulfman » Wed Apr 09, 2008 9:50 am

MikeSleeper wrote:Thanks all for your great advice. The predominance seems to be "not a leak issue" and that is my gut as well.

I am intrigued by the two comments saying to try switching from apap to cpap using a pressure at the lower end of my current apap range. I'd love to hear more explanation on that. Clearly I am having many OA events above that lower level... and apparently not leak-driven spurious data. Is there something about the apap process that can drive worse OA experiences as it cycles to higher pressures (again ruling out leaks)? Are we proposing centrals? Curious on your thoughts behind that, those who wrote it.

Thanks again all, excellent help.
Michael
Besides Apneas and Hypopneas, snores and leaks will drive up pressures and at some point, they can feed on each other.
You need to determine what's going on.
From what I see on that one chart, you have fewer events at the lower pressure. As it goes up, they become clusters. You need a process of elimination to rule out some things that are going on.
One of the reasons I don't do well on an Auto is my snores. If they get enough freedom to start, my pressures will rise.....and disturb my sleep.

Den

(5) REMstar Autos w/C-Flex & (6) REMstar Pro 2 CPAPs w/C-Flex - Pressure Setting = 14 cm.
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MikeSleeper
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Post by MikeSleeper » Wed Apr 09, 2008 11:42 am

Den, very good explanation, thanks for that. I was wondering about those clusters. I've seen them every evening, and, interestingly almost always around the same time of night, same pattern: they get started, the pressure goes up, and then they really get going in a cluster. I'll experiment also with cpap a bit, as you suggest, and see how that goes; use a process of elimination.

Michael

Machine: Respironics Auto/A-Flex -
SW: EncoreViewer
Humidifier: Respironics M-series heated
Mask: F&P FlexiFit HC431

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Wulfman
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Post by Wulfman » Wed Apr 09, 2008 12:37 pm

MikeSleeper wrote:Den, very good explanation, thanks for that. I was wondering about those clusters. I've seen them every evening, and, interestingly almost always around the same time of night, same pattern: they get started, the pressure goes up, and then they really get going in a cluster. I'll experiment also with cpap a bit, as you suggest, and see how that goes; use a process of elimination.

Michael
Do you have a copy of your sleep study (PSG)?

Are you familiar with the term "pressure-induced Centrals"? If you DO have your sleep study (or when you get it), be sure to check for "Central Apneas" on it. It's also possible that they didn't take you up to a pressure where they might have occurred, too. But, anyway, SOME people are susceptible to them and they're prevalent above certain pressures. A person with an Auto who has that susceptibility needs to limit their upper pressure.
In many cases, I believe a person can find the right single pressure with a data-capable CPAP......you don't absolutely have to have an Auto to do it.

Den

(5) REMstar Autos w/C-Flex & (6) REMstar Pro 2 CPAPs w/C-Flex - Pressure Setting = 14 cm.
"Passover" Humidification - ResMed Ultra Mirage FF - Encore Pro w/Card Reader & MyEncore software - Chiroflow pillow
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MikeSleeper
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Post by MikeSleeper » Wed Apr 09, 2008 1:21 pm

Thanks Den

Yes, I am familiar with central apneas. There were none observed on my initial sleep study but they did not titrate (long story) and I am scheduled to go back again to do that (long wait), which of course means they did not have chance to uncover any pressure induced apneas (yet).

I will definitely play with some cpap sessions at diff single pressures to see what happens. I would like that to be true (for example cpap at 12 work to for me), esp since I am now getting up there on the max pressures, which I would like to avoid if possible; high P's complicates many things for me like leakage, sinus and ear pressure, etc. So eager to stay low if possible, motivates me to test this.

I have to admit though, I have tried the cpap single setting with C-flex (during the day for a short awake session when adjusting my mask), and I find I like the A-flex cycle much better, it seems much smoother. Too bad A-flex is not available in the cpap mode of the M-series.

Machine: Respironics Auto/A-Flex -
SW: EncoreViewer
Humidifier: Respironics M-series heated
Mask: F&P FlexiFit HC431

MikeSleeper
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Post by MikeSleeper » Thu Apr 10, 2008 9:59 am

Well, per above recommendations I tested switching to CPAP. Set P at 13 (C-flex 2). Results? A nearly identical chart as above (SEE BELOW) in terms of number of OA's and the clustering of them. AHI same (6.5). Leaks all within range. So what does that tell me. It does not seem in my case that the clusters of OAs are a side affect of the APAP cycles, which is what I wanted to test for (thanks for that suggestion, I had to try it). On the other hand the upward APAP cycles, up to P=17 so far, are not helping to knock those remaining OA's out. Could be that I still need to reach higher pressures to do that. Or maybe I need to give this a full week to see if it settles out?

No complaints, I feel much better, and an AHI of 6.5 sure beats 25 as in sleep test (and my previous life) (and RDI=31). I'll keep experimenting with different settings to continue to fine tune.

Thanks all for your help in examining the chart!

Michael

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Machine: Respironics Auto/A-Flex -
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Humidifier: Respironics M-series heated
Mask: F&P FlexiFit HC431

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Wulfman
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Post by Wulfman » Thu Apr 10, 2008 11:50 am

Hi Mike.

Thanks for trying the straight pressure test.
Interesting though......your snoring and apnea "ticks" are lining up. It's kinda hard to tell about the leakage......some of it does and some of it doesn't line up.

Two thoughts/questions come to my mind about your "clusters". One is to ask whether you have had any history of GERD (there's also a "silent" version, too, which may not be apparent). And, the other is to wonder whether those "events" (snoring and apneas) are happening during a certain sleep stage (which would be difficult to determine from the Encore reports).

See what happens over the next few nights. I'm not sure whether more or less pressure would be the way to go. After a few more nights, I'm thinking that I would drop the pressure.....maybe even down to 10 to see what that would look like.
Do you have a copy of your sleep study and were there any mention of Central apneas?


Den

EDIT: Just re-read one of your previous posts about Centrals......but keep that possibility on the back burner.
(5) REMstar Autos w/C-Flex & (6) REMstar Pro 2 CPAPs w/C-Flex - Pressure Setting = 14 cm.
"Passover" Humidification - ResMed Ultra Mirage FF - Encore Pro w/Card Reader & MyEncore software - Chiroflow pillow
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NightHawkeye
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A Different Opinion

Post by NightHawkeye » Thu Apr 10, 2008 12:07 pm

Mike,

Your pattern of apneas looks identical with the earlier data. Your OA index climbed up higher with the lower pressure as well. Sure looks like ordinary OA. Put the machine back in APAP mode and raise the top pressure up to 17 or 18. At least that's what I'd try tonight.

If that doesn't yield any convincing results then go ahead and torture yourself by slowly collecting data more thoroughly while you continue to experience a large AHI.

Just my $0.02.

Regards,
Bill