(05-23-2015 09:12 PM)DeepBreathing Wrote:
(05-22-2015 01:53 PM)ebitansky Wrote: First, a question I did not get answer for from anybody.
in the first CPAP study they didn't provide following statement:
At a pressure of 9cmH2O the AHI was 46.6 central events were at sleep onset, hypoxemia was resolved with positive airway pressure.
The positive airway pressure titration was not successfully completed due to residual obstructive events.
given these results recommended autoCPAP at a pressure of 5-18 cmH2o
The ASV study a year after doesn't say anything about central events.
Yeah, the wording on these things is often unclear. Central apneas at sleep onset and awakening are (I think) not uncommon and generally no cause for concern provided there is a limited number and a limited period. And I'm not really sure where you'd draw the line, but remember that your machine doesn't know if you're asleep or awake so most of these centrals could be false positives.
Sounds to me like the centrals were occurring only at sleep onset and were not significant in the overall AHI.
US federal law (HIPPA) gives you the right to a copy of your personal health records, and this includes the "full" sleep study reports, including data. Doctors or companies which ignore requests for copies of your own records can be subject to large fines
I suggest you should obtain copies of the full reports from the diagnostic study and also for each titration. From the table or plots of when events happened in time you/we would be able to see what was actually happening.
(05-22-2015 01:53 PM)ebitansky Wrote: Second Question is a series of few questions with your permission
My device is: S9 VPAP ADAPT 36027
Auto ASV mode:
available options on my machine are:
Min EPAP and Max EPAP as well as Min PS and MAX PS.
I think 36027 must be a typo. REF# 36037 was the earliest ResMed blower unit offering ASVAuto therapy mode.
Unfortunately, as on all ResMed ASV machines, in ASV modes the Max PS setting must be at least 5 higher than the Min PS setting.
(05-22-2015 01:53 PM)ebitansky Wrote: My prescription for the ASV says EPAP 6, Min PS 6 Max PS 15
Could it be that the technician was not aware of ASV Auto Mode?
Are there cases where ASV AutoMode is not advised?
What is the right way to translate this prescription to ASV Auto?
The tech and/or doctor may not have been familiar with ASVAuto mode. But the main question or issue seems to be why was Adaptive Servo Ventilator therapy prescribed instead of standard APAP or standard bi-level PAP therapy?
I suspect a standard bi-level Auto machine (I think the PRS1 BiPAP Auto with Heated Tube is the best in this category of machine) would likely have been the optimal choice in your case.
If someone is having painful problems from swallowing too much air (or from any of the other problems which very high IPAP can cause or make worse), "ASV" therapy mode might be preferable to "ASVAuto" therapy mode for an individual which needs ASV therapy (which I suspect you do not need).
Normally, an ASV machine is not authorized by insurance companies unless central apneas are predominate over obstructive apneas (while being treated by standard CPAP, APAP or bi-level therapy). I suspect this normal requirement was overlooked or ignored in your case. I suspect this because it seems from the your sleep reports that centrals were not a significant contributor to your overall AHI or RDI.
Since your main problem seems to have been obstructive events, ASVAuto may be a better therapy type to use than straight ASV, but as DB has pointed out, the max IPAP pressure can get quite high when both EPAP and PS can auto-adjust.
(05-23-2015 09:12 PM)DeepBreathing Wrote: I don't really know why you'd want a straight ASV mode though I guess there could be clinical reasons. I think the older models only had ASV and not ASVAuto, so it's possibly a hangover from that time (which might also explain why you were prescribed a constant EPAP). The ASV Auto allows the machine to vary EPAP as required to suppress obstructive apneas and keeps the pressure low until an event or precursor is detected.
Given that the central apnea result looks like an anomaly, I was going to suggest you discuss this with your Dr, but I see from your first post s/he thinks you're just non-compliant. So I think you should treat your machine like an APAP and see how it goes. As a start, try Min EPAP = 8, Max EPAP = 10, Min PS = 3, Max PS = 4. You'll need to monitor your results using SleepyHead or ResScan software and see what happens. Once you have a week's data, post it back here and let us give you some further advice.
Unfortunately, because the Pressure Support (which is a form of exhalation pressure relief) cannot be set to a fixed number, a ResMed ASV machine cannot be adjusted to behave like an APAP or an Auto bi-level machine, because in ResMed ASV or ASVAuto therapy modes the Max PS must be at least 5 higher than the Min PS.
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ebitansky, in order to set your machine to work kinda sorta like an Auto bi-level machine with a crazy aggressive attitude (which I think is the best you can do with the machine you have), I would suggest the following settings:
Therapy Mode: ASVAuto (so that the machine will be free to adjust EPAP in order to treat/prevent obstructive events, allowing you to see what EPAP the machine is deciding is needed). In brief, on standard APAP and Auto BiPAP machines it is mainly EPAP which is adjusted to minimize obstructive apneas and hypopneas.
EPAP Min: I would suggest at least 8 cmH2O (because your obstructive events will need at least this much, and because it is not good to have the Min EPAP way too low, because ResMed machines use the Min EPAP as a target EPAP level which they are always slowly trying to get back to).
EPAP Max: At least 10 cmH2O. (The maximum allowed by ResMed ASV machines is only 15.)
Min PS: At least 0.2 cmH2O (so in the machine's data you will be able to easily see the time periods which the machine considers to be inhalation versus exhalation). But actually, in your case I suggest at least 1 or 2 or 3, not only because having some reduction in pressure during exhalation is usually more comfortable but also because I think a higher Min PS would tend help keep your Respiration Rate from falling too low.
Max PS: Use the minimum allowable amount (to minimize the ASV aspect of the machine's behavior, so that IPAP is not raised unnecessarily high). The minimum will be 5 higher than whatever the Min PS is set to.
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But here's something important, here's what may even be the most important thing for success in treatment of your Obstructive Sleep Apnea: OSA is usually highly positional.
If (as I suspect may be the case) the machine will be unable by itself to lower your AHI adequately when you have rolled onto your back and are dreaming, you can help it tremendously by taking precautions that will ensure you will not ever be sleeping flat on your back, which is usually the worst position for OSA.
Try using the machine while sleeping in a LaZBoy type of comfortable lounge chair which leans back and can be used for sleeping. Or use bricks or boards to raise the head of your bed a foot or so, or wear a teeshirt with a tennis ball in a pocket or two sewn on the shirt along the spine between the shoulder blades, or wear a light knapsack with something light but bulky in it, or a combination of these different approaches, to make sure you will not ever be sleeping flat on your back.