Why doesn't APAP respond to apneas?

OutaSync wrote:Changing my will, now.

Bev

Thank you, Bev!

Just kidding, of course! But just in case I wasn't do you have any other cool electronics? I just got a new IPOD, so I'm good there...

Just got a GPS. Sure does help. Now my sleepy brain doesn't have to figure out how to get places and it 's not so scarey having to drive in the City after dark. It will also work in Europe, so the next time I go visit my son, in Spain, I can wander around and stlll be able to find my way back to his house. You can have that too. Just change the "Take me Home" address.

Bev

Much prefer to keep you around the forum!

Besides, we just bought two new GPS units. I must admit that ours don't work in Europe...

What model?

Navigon 5100. Love it. Gives me live traffic info!

OutaSync wrote:Navigon 5100. Love it. Gives me live traffic info!

The Navigon 5100!!!!???!! Whoa!!! That's a VERY nice unit! Just a quick rundown of those features:

The Navigon 5100 Sales Brochure wrote: This take anywhere device is simple to use and offers:

* A host of premium features no other GPS offers
* Up to 12 map updates when you accessorize with FreshMaps
* Extra guidance with exclusive 3D Reality View™ and Lane Assist
* Free Lifetime Traffic that works out of the box
* Exclusive Zagat® Ratings and Reviews
* Intuitive menus and stunning 2D and 3D maps
* Easy-to-read map views that adapt to your needs

Once again, Bev, thank you very much!!! Thank you very much, indeed!!!

-SWS wrote:

OutaSync wrote:My best pressure range for AHI is what I was using 14-17.

Alright. I just looked at your Encore results on page one of this thread. With pressure endlessly sitting at 14 cm you appear to get a very acceptable AI and HI. There's a slight chance with BiPAP AutoSV that you just may be able to eventually drop below that 14 cm, however.

Only problem with that theory is if she blew right past an ideal pressure finding below 14 cm due to centrals seen. You have to consider the machine got to that pressure along the way responding to central apnea with pressure. Granted she did a manual titration with the Minimum pressure observing a false AHI. As you mentioned before if some of those apnea could be neurological based, with increased pressure support and target volume she gets from the SV she may not have had them at all.

If she needs the higher EPAP support it will indicate that on her Encore Reports. I see nothing wrong with following the lab titration guide, it teaches her on what to change to a particular condition instead of simply guessing.

Here is some more spec info from PC Direct:

Settings
– Max IPAP = Min IPAP –30 cmH2O
– Min IPAP = EPAP –30 cmH2O
– EPAP = 4 –25 cmH2O
– Rate = Auto, off, fixed (4 –30 BPM)
– Rise = 1 –6 (100 –600ms)
– Timed Insp = 0.5 –3.0 sec (0.1 increments)
– Ramp Time = 0 –45 min
– Ramp Start = 4 cmH2O –EPAP
– Humidity = off, 1 –5
– Display parameters Pressure, Volume, Leak

I would like to see us discuss Inspiration Time and how that might change ones breathing to a particular scenario. Respironics keeps resorting to 1.2 seconds when it sees a problem, I wonder why they choose that value? With the range of that setting seems it could vary quite a bit.

Snoredog.

I agree re using Respironics recomm titration - but, I would start Bev off at around 10 for epap as we already have a working baseline. Her data will quickly allow that epap to be adjusted. Thus based on the std approach nums would be from me 10,13.23 except I would drop IpapMAX to 20 - have said already until evidence shows otherwise, I can't see IpapMax above approx 20 CMs serving any purpose at the early states,

Re Insp time - that param is not required (in fact it is not available) if Bev goes to BPM=AUTO which is what most of us (incl you) have already suggested - and is IMHO the best choice.

Insp time & ratio only come into play if a Backup rate is set (e.g. BPM=10 rather than BPM=Auto). Auto sets the other values automatically.

DSM

Snoredog wrote:I would like to see us discuss Inspiration Time and how that might change ones breathing to a particular scenario.

I think that's a good idea, Snoredog.

Snoredog wrote:Respironics keeps resorting to 1.2 seconds when it sees a problem, I wonder why they choose that value?

Well, Respironics is not telling clinicians to set IT at 1.2 seconds, as if that's a magic value. Rather Respironics is saying don't set IT at anything less than 1.2 seconds if the titration-protocol decision branches happen to bring the clinician to that point. The sleep tech will set IT at the appropriate value based on measured respiratory parameters---but no less than 1.2 seconds per Respironics' recommendation.

Again, that titration protocol is based on robust real-time measurements. And it's intended to occur in a single night. Short of being able to make those measurements, and differentiate central/obstructive/mixed events, etc. the suggested PSG titration procedures represent FAR more bedroom guesswork than following Respironics' FAQ recommendation for this exact situation---at least as a starting point for Bev.

Starting with an EPAP of 14 cm, Bev should be able to replicate her current very good AI and HI. IPAP max and Auto backup rate will work on any outstanding periodic breathing or central apneas. That's her best baseline from which to observe IPAP peak, IMO. Again, there shouldn't be much A or H at those settings based on her current results. She can unilaterally tweak down, 1 cm at a time, looking for improved comfort. As she does, she may need to extend IPAP max upward if that unilateral "tweak down" causes her to hit that diminishing IPAP max ceiling.

I agree there are always multiple ways to skin any cat. The FAQ suggestions are not just my preferred method, they are also the Respironics preferred method. How is Bev going to differentiate centrals and mixed events in her bedroom using a PSG titration protocol minus all that equipment? How is she going to determine which IT value (at no lower than 1.2) needs to be set?

Following the Respironics FAQ suggestion should really be a no brainer here. Attempting to perform a full-blown titration in the bedroom---with no PSG measurement and differentiation equipment---is admittedly more impressive for our egos. Bev's best sustained results are no less than 14. That's where her first night EPAP should be set IMO. And the other numbers should all key off that value exactly according to the Respironics FAQ recommendation. Overriding the Respironics suggestion for this situation, as if we somehow know more than the manufacturer does despite our limited experience, is also great for our egos.

I really think Respironics put their FAQ recommendations in place only after giving those procedures some very serious thought.

snoredog wrote:I see nothing wrong with following the lab titration guide, it teaches her on what to change to a particular condition instead of simply guessing.

But I do agree that the titration guide can provide help regarding what changes may be necessary when certain things go wrong---such as unresolved PB being scored on the Encore Charts.

Bifurcation is still a key clue with her IMO, but I won't go off on that tangent right now. More discussion on IT soon... for sure!

dsm wrote:I agree re using Respironics recomm titration - but, I would start Bev off at around 10 for epap as we already have a working baseline.

Doug, I missed that working baseline of 10 for epap. Where is that?

SWS,

The working baseline is Bev's cpap titration - taking this approach is in the SV titration guide. It is one of the things in big bold letters

I mention 10 also as being a good starting point as knowing how SVs work I have no doubt we will know withing 1 to 2 days if it needs
moving upwards.

Just to help you with this confusion I'll repost the Q&As from Respironics re the Bipap SV what it does and and how to translate a CPAP titration to it.
I know you have read this before because we discussed it months ago ?.
Cheers

DSM

http://bipapautosv.respironics.com/faq.aspx

Look for ...

Q. Is it necessary to titrate these patients?
A. Yes. To treat the complexity of this (sic) patients as well as establish a baseline CPAP or BiPAP pressure for OSA, an in lab titration is necessary.

Q. Can an identified candidate w/ Complicated Breathing Patterns, Central, and/or Mixed Apneas or Periodic Breathing (CSR), be put on the device w/o coming into the sleep lab?
A. If the CPAP or BiPAP pressure is already determined in lab, the patient can be put directly on BiPAPautoSV. To assure that the patient is being properly treated it is a good idea to download the SmartCard data after 7-10 days.

Q. What settings should be used in this case?
A. For the set up of these patients it is advisable to use the CPAP or BiPAP pressure from the “old” unit,set the IPAPmax 10cmH2O above the CPAP or BiPAP pressure and set the back up Rate to Auto.

Not so hard to follow ? surely ?

DSM

Sorry, Doug. I didn't miss the Respironics titration procedures and FAQs.

What I did miss was that we somehow had a good working value of 10 cm. Where did that good working value of 10 cm come from? I don't see that anywhere on the CPAP titration.



It's hiding in there somewhere.... surely.

dsm wrote:I mention 10 also as being a good starting point as knowing how SVs work...

I also missed the significance of 10 cm in the BiPAP AutoSV patent descriptions and manufacturer literature. What's the significance of EPAP at 10 cm regarding SV design?

SWS,

So what epap would you start from allowing that you are not doing it in a lab - 4 CMs or 14 CMs ? if yes to either of those then why ?
If not then why not ? (no lab remember )

DSM

I simply asked Bev what her best results were:
viewtopic.php?f=1&t=35298&start=120#p304114

Bev very simply stated that 14 to 17 yielded her best AHI.

So where does your 10 cm come from? I never got the answer to that one. Just boomerang questions. I wanna know where 10 cm came from in her CPAP titration, and I wanna know how an EPAP of 10 cm relates to the design or operation of SV.

that is where my 9 cm came from, that 8/31/07 report. You can see going all the way to 17 cm didn't make much difference in her OA seen. Wonder if the Alice 5 was mis-scoring those events.

the hope is, pressure support and the SV extending that inspiration time will prevent the centrals, if it does, then she spends a lot less time in higher pressure therapy. I believe the SV will eliminate the conditions for the CA's to exist.

At only 13.5 minutes at 9 cm, they felt compelled to fly by it. Perhaps for a good reason, or perhaps for no good reason whatsoever. Regardless, 13.5 minutes at 9 cm doesn't sound as reliable to me as Bev having spent plenty of nights to find her best pressure range via Encore Pro.

Just my opinion, though. More importantly it's Bev's measured opinion.

-SWS wrote:I simply asked Bev what her best results were:
viewtopic.php?f=1&t=35298&start=120#p304114

Bev very simply stated that 14 to 17 yielded her best AHI.

So where does your 10 cm come from? I never got the answer to that one. Just boomerang questions. I wanna know where 10 cm came from in her CPAP titration, and I wanna know how an EPAP of 10 cm relates to the design or operation of SV.

SWS,
Because you can be so confusing at times I need to know just what you are thinking in order to understand in what context you want an answer. If for example you appear to be being pedantic I need to know that (& perhaps understand why ) For example you never asked SD to give any dissertation on his choice of 9 CMs for epap but seem intent on drilling me on the matter - in another thread you asked me to justify IpapMAX of 25 when it wasn't my suggestion (it was SD's) - you appear not to have read the whole post nor my ref to SD making those particular suggestions that included IpapMax of 25. Then you talked as if 25 was the absolute IpapMax when we have discussed for a year or so that it Bipap SV can go to a max of 30 CMs. You can be very confusing at times, I can never make assumptions.

BUT,
knowing how the SV works from real world use, I would be more than happy to start Bev off at 10 CMs as within one session's data I believe would know how far up I needed to move epap if at all. Again having used an SV, I am quite certain (& others have said the same thing in this thread) that the PS capability of the SV is most likely going to allow her to run epap lower than she has been up until now and I believe this is fair comment. Maybe within a session or two we would be back at 14 CMs but I would bet not. My intuition says she might need about 12. BUT, the reason I would start her lower (10 CMs) is because she has serious aerophagia & if I can get her working at a lower epap then I will be archiving two helpful objectives.

Now how about you answer my question. what epap would you start with and why ?

DSM