Bizarre AI / AHI graph

[sparkinson]

Julie, its possible- Are you referring to the graphs or just in general? I don't think there are any giant leaks on the graphs- on the really bad night they didn't spike over 0.35 L/s. It looks like my graphs are just missing Events, which is pretty annoying when you are trying to figure out why your AHI is so high

Simon

[Slinky]

Ask Slinky if you can export the Thursday file to her so she can look at it on her software. There are about 110 events noted on your graph, but there should be (AHI 53.1)(8.3 hours) = 440.

If she can't read it either, tell your Sleep Lab about the discrepancy and ask them to fix it.

What time of day are you taking the Levothyroxine?

SAG

Unfortunately, SAG, one of the shortcomings of ResScan 3.4 and 3.5 is that we can NOT export files. Why on earth Resmed came up w/the stupid idea to eliminate that action is aggravating more than one of us!!!

I don't have any experience w/ResTraxx, just know that it exists so was going to ask if you also had a data card and wanted to send me the data card to try but I see you tried that already on your Dell PC so so much for that idea. SAG is right, take it in to your provider and tell THEM to FIX IT!

When they get a load of THAT data via ResTraxx it ought to blow their mind!!! You would think the minute they say that they'd be on the phone to you - or - they are aware that maybe ResTraxx has a problem and sometimes does that? You think?

AND if your provider can provide no answers I'd send that printout to Resmed and ask THEM to explain it!!!

[StillAnotherGuest]

Just copy the patient folder from ResMed > ResScan 3.0 > Patients > Sparky

SAG

[Slinky]

SAG, I just looked in MyComputer. I get two files actually: Notes.db (6.93 KB) and PatientDetails.db (846 bytes)

Trying to open the Notes.db by double clicking on it still in MyComputer produces a message:

You are attempting to open a file of type 'Database File' (.db)

These files are used by the operating system and by various programs. Editing or modifying them could damage your system.

If you still want to open this file, click Open With, otherwise click Cancel.

Now it is interesting that there are two folders: CDI and RDI and I haven't the slightest idea what they are - EXCEPT in the dim recesses of my beady little brain I remember Velbor saying something about them and I vaguely have this thought that he may have been referring to them as the ResScan data files .... but ....

[StillAnotherGuest]

The actual data file has a *.rlk suffix. All the patient folders should be in the folder called "Patients", or if not, you can find them in the "Patient Manager" under "Patient Group Location".

SAG

[sparkinson]

I emailed Slinky my data- thanks for taking a look at it. It zipped to about 24K, so its really small.

Simon

[Julie]

Hi, I was just making a wild guess, trying to find some answer to your strange events, but I know nothing about Bipaps or your 'paperwork' (plus I should have read more about your leak rate to begin with!). Hope you figure it all out.

[sparkinson]

Thanks Julie- at the moment I am taking all the help I can trying to figure this out!

Simon.

[sparkinson]

Slinky took a look at my data (thanks Slinky!), and it looked incorrect for her as well.

My DME and Clinic came through for me again though.

I took my data to the DME last Tuesday, and they passed it on to the Sleep Clinic. The doctor called me back for a second titration, this time for BiPAP and Adapt SV if needed (I think that was the term, but the treatment that is like a ventilator and CPAP in one). The clinic called me back the same day the doctor recommended a second titration (Thursday) with a cancellation that same night! Never one to look a gift horse in the mouth, I went in for third sleep study in as many weeks.

The tech was great and had been doing this for 8 years, and this titration I slept for almost 7 hours. They got some great data and didn't need to put me on the ASV mode. The tech did try me on Spontaneous timed where the machine start an inhale itself if you haven't tried to for a period of time, but in the report the doc didn't think that that had helped enough to recommend it. (What is the difference between Spontaneous timed and ASV- they sound like the same thing?). Also, I don't think my Resmed VPAP Auto 25 does timed mode- it seems like it would be really helpful for the odd central.

Interestingly for this titration, I was having an AHI of 33 on the originally titrated pressure of 14 / 8 with more centrals than OSAs (they didn't get much time with me on that pressure because I slept so badly at the first titration), and they got me up to 15/10 where the AHI was really low for several hours (I don't have the results with me, but I recall it was about 3).

Last night was the first night at home on the new pressure settings, and I had an AHI of 1.2 and AI of 0.2! Hopefully I have turned a corner with the treatment now and found the correct pressure, but I was amazed at how much difference 1cm inhale and 2 cm exhale made to my AHI. Having seen first hand how much difference a small change in pressure makes I can't help but wonder how often a titration should ideally happen, especially if weight changes or you have alcohol on a given night.

Thanks for the help in getting this figured out- now I just have to get used to sleeping with the mask on a bit more- it still wakes up several times, but its already getting better.


Simon

[Velbor]

Late coming into this discussion; have been away; thanks Slinky for pointing this out to me.
No full explanations, but several comments.

ResMed machines record detail data for only the first ten hours per night. ResMed tech services has assured me that the statistics for the entire night continue to be correctly computed after the ten hours, but forgive me, I have my doubts.

While in general detail data is captured on a minute-by-minute basis (pressure, leak), the timing of apnea events is recorded (based on looking at AutoScan exports) to the second. I have often seen two apneas, and rarely three apneas, during the same "minute". (In theory, there could be as many as 5 distinct ten-second apneas in one minute.) Since graphing is done minute-by-minute, ResScan graphs can show more than one apnea each minute, with a slightly thicker line, and multiple "seconds duration" boxes, though such situations can easily be hidden. It looks as though there is evidence of this in the "zoomed-in" graph. Still, while this may account for some of the "missing" apneas, it doesn't look like this explains all of the missing events.

Edit: I count about 22 doubles, and at least one clear triple, in your zoomed graph.

Another possible confusion contributor -- I'm not certain of this -- is how ResMed machines handle apneas which start during one "data minute" and extend into the next "data minute". As long as each apnea segment is at least ten seconds long, it has seemed possible to me that the AI calculation will break the single continuous apnea into two "pieces" for purposes of statistical handling and graphical data display. Again, I have never looked into this in detail, but if accurate, it could artificially inflate the AI count given by the machine.

The pattern of multiple "runs" of apnea early in the night is very familiar to me, though I don't anywhere nearly approach the numbers you are experiencing. I have no explanation for the underlying physiology. I have been working on and off in Excel (again with AutoScan export data) to create procedures for analyzing such "runs" (which I've arbitrarily chosen to define as beginning with at least 5 apnea events in a 10 minute period, and ending with 10 apnea-free minutes) but my programming skills have not yet mastered the task.

Please share with us anything you may find out about your "very interesting" pattern! Regards, Velbor