DeVilbiss IntelliPAP titrating me too low (lg graphic)

[cosmo]

DeVilbiss SmartLink Desktop Software


Why does the IntelliPAP like to keep me so low?

[Slartybartfast]

Looks like you have tried three different machines and they all show very different event profiles throughout the night, yet the AHIs are comparable. But the Intellipap seems to be running at a lower pressure most of the time relative to the other two machines. Don't know why that would be other than the obvious, that the machines use different triggers and algorithms to determine responses to breathing irregularities. I have both the S9 Autoset and Intellipap and I've noticed when I check data in the morning that the Intellipap seems to run around 8-9" pressure while the S9 will show 10-11". Yet the reported AHI is about the same and I feel the same when I wake up regardless of which machine I use.

So long as your AHI isn't significantly different, I wouldn't worry about the lower pressure. But I agree that it's an interesting puzzle.

[DreamStalker]

Each machine has different algorithms for responding to events.

As I recall, ResMed algos were more aggressive than Respironics. So ResMed machines ramp up faster after first sensing an event whereas Repironics takes its time ramping up pressure in response to events. I'm not familiar with the Intellipap algos but I'm sure the difference is in the algos. Plus your min/max settings are different for the intellipap compared to the ResMed and Repironics.

There is just too much variability from one night to the next even when using the same machine. You are comparing single individual nights for different machines. For a more meaningful comparison of the algos you need to use each machine with the same min/max settings, the same mask interface, each for a couple of weeks and then compare the 2-week average efficacies and resulting pressure stats between the 3 APAPs. A 6-week project/experiment and then the results would only apply to you and not necessarily everyone else.

[cosmo]

Higher pressure needs is more accurate for me. I just started to bump it up.

[Slartybartfast]

You're leaving the machines set essentially wide open. It's a lot to expect any of them to give you good therapy that way. You need to set the low pressure setting at a realistic level. Your 95% number appears to be somewhere around 11-12, so I'd set it around 8-9 and see how it does. The Resmed uses flow limitation to trigger pressure increase, while the Intellipap uses snores. It might be that you don't snore very much. Don't know what the PR uses.** But for heck sakes, dial a realistic low pressure setting into your machines and don't make them work so hard trying to figure out what you're doing.

**[Edit: Someone just PMed me that the PR uses both flow limitation and snore to trigger pressure increases, like the Resmed does, and the PR also blips the pressure every so often to see what happens. The Intellipap's algorithm is very sensitive to snores; I think the reasoning is that snores are caused by flow limitation, so rather than straining its electronics trying to discern something from flow limitation, the Intellipap simply waits for a snore to develop, which is probably the reason it didn't increase the pressure while the other two machines did. But my point still remains: don't expect any automatic machine to work optimally by running it without a realistic lower pressure limit.]

[archangle]

Small AHI measurement differences between different machines are not that meaningful even if you set them at the same manual pressure.

Your OA and CA indices are very low. Hypopnea detection is much more iffy than apnea detection. Even that is pretty small.

[cosmo]

My prescription was for a range of 5-15cm. I was leaving it wide open to titrate and see what each machine would have me at.

Luckily, I had data from other machines. I would have been kept at a low pressure and ineffective treatment otherise. My AHI ceiling is only at 5-6AHI so an AHI of .8 vs 1.8 AHI is a lot to me. That is 2x-3x the amount of events.

[DreamStalker]

I think he needs to decide what it is he is trying to do with all three of those APAPs.

Is he looking for the best APAP algorithm?
Is he looking for the lowest AHI? Lowest AI? Lowest CA? Lowest HI?

Either way, comparing individual nights with different machines is pointless and meaningless.

[cosmo]

How is it pointless again? I know my neck didn't grow or shrink overnight

If you can't follow, stop trolling my post as you have done in other threads and GTFO

[Slartybartfast]

My prescription was for a range of 5-15cm. I was leaving it wide open to titrate and see what each machine would have me at. [snip]

5 - 15 cm encompasses most of the working range of your machine, so that really doesn't help much. Any DME can take a machine off the shelf and say "5-15" with no need for a doctor. A titration study should result in the recommendation of a single pressure which is required to stave off most apneic events. Since your lab didn't do so, you need to zero in on that figure, or at least a narrow range of pressures.

[cosmo]

My titration study was the sleep dept handing me an Respironics APAP with 5-20cm for a week They sent me a new machine and filled the prescription with 5-15cm. Pretty generic so I guess they figured the APAP would take care of business. It worked out ok. Now I've set my own pressure and optimized the treatment.

It doesn't really matter anymore, I'm not using the IntelliPAP on a daily basis.

[Slartybartfast]

Ok I understand now. That's too bad they are so cavalier about your therapy. All I can recommend is for you to use your 95% pressure number as your guide. The more sophisticated PR and Resmed machines will give you a 95% level that is close to what you would have received following a titration study. And if the Intellipap is set with a reasonable minimum pressure level, it will work fine, too.

A good way to proceed would be to assume that is your needed pressure level, and set the lower pressure appx 2 cm below that level. So if you had a 95% of 12, set the low level at 10 and let the upper level stay at 20, or 15, if you like (it doesn't really matter what the upper level is; you shoudn't ever reach it.)

Watch your AHI with that setting for a couple of weeks and note any trend.

[hyperlexis]

Amazing differences between the brands -- it just goes to show the fact that APAP is still an evolving technology and the machines are not 'perfect' -- nor are APAPs a proper substitute for quality sleep physicians or titration studies. And, also, perhaps the DeVilbiss is more accurate and the S9 is the inaccurate one? Hmmm? Perhaps you really do need a lower number? Higher does not equal better after all. DeVilbiss has a very detailed study posted on its site explaining the technology used in its machines, and its algorithms. They seem to know what they are doing -- however if something seems broken, why not call the DME or the manufacturer itself? Perhaps they can help troubleshoot it to see if something is just plain broken.

My PR60 has similar issues sometimes. When I switch masks around (it's nighttime fun!....) my auto pressures definitely change. FF masks kick the pressures way up over 11ish, and nasal masks drop my pressure needs way down, to the 4's and around. Even with no significant leakage, the pressures change that much. No clue why.

But regardless, if you are concerned, call your DME or the manufacturer and have them help troubleshoot the machine. Good luck!

[cosmo]

Perhaps you really do need a lower number? Higher does not equal better after all.

But regardless, if you are concerned, call your DME or the manufacturer and have them help troubleshoot the machine. Good luck!

Yeah, the whole point of leaving it wide open was to see what my lowest point was. Only the IntelliPAP kept me so low. I have more days with the IntelliPAP and it was similar in pressure. I didn't want to upload all days since what I already posted was graphically heavy. Some might have broadband caps or even dialup.

Not many people are posting their IntelliPAP data. One other user does, his name is Growing. His machine also sets him at similar low pressure as mine. He doesn't have other data apap machines to compare to so he's always questioning his treatment. He was never titrated and is using the IntelliPAP for this purpose. viewtopic.php?f=1&t=85772&st=0&sk=t&sd=a

I probably wont pursue this any further since my experiments are pointless and meaningless

[growing]

No, cosmo. Your experiments have not been meaningless. With many others, I am also studying your observations, keenly and getting a lot from your experiences on Intellipap's behavior particularly its function along side other popular machines. I have also taken note of Slarty's suggestion.
Thanks for starting this thread that has given us useful info.