SYSTEM ONE resistance... mask setting? what does this mean?

Pugsy wrote:Do you suppose the lower resistance drop with the Swift FX explains the fact that when I tried the various System Resistance settings that I really didn't notice any difference with any of the settings (how it felt while awake), nor any difference in reported leak which I saw nothing other than normal variables.?

I think in order to answer that question objectively, one would need to look at the detailed pressure waveform and see if Peak Inspiratory Pressure is a little higher; Inspiratory Time a little shorter; and the C-Flex Effect a little more apparent.

Pugsy wrote:

deltadave wrote:Swift FX:

Resistance Drop in pressure measured (nominal):

at 50 L/min: 0.4 cm H2O
at 100 L/min: 1.4 cm H2O

Lower than one would have suspected.

Do you suppose the lower resistance drop with the Swift FX explains the fact that when I tried the various System Resistance settings that I really didn't notice any difference with any of the settings (how it felt while awake), nor any difference in reported leak which I saw nothing other than normal variables.?
Tried this back when I was using APAP 10/20 and overall average was around 12. For me I saw no added benefit or drawback that I could perceive with any of the settings.

I tried playing with this setting this morning while using XS pillows and a pressure of 7, and I found it to be outright uncomfortable, especially with C-Flex+. The most uncomfortable part was how sharp the transition to inhaling was; it felt like it was trying to inflate my nose using one of those compressed air tins. I don't think I'll use this option.

I spoke with the Respironics company tech while speaking with them about an issue with my total face mask, which my DME RT could not definitively answer. Then while I had him on the phone, asked what the resistance setting for my mask should be. He said that the setting should be at its lowest for nearly everyone. The System One machine resistance setting can be set up for those who use extremely small air tubes, like for a child, or really small air tubes for a nasal mask. If the machine was set on auto, he felt it was even less important. For most of us it is not relevant, those who need the resistance setting raised up will have like a Peds RT who is knowledgeable in how to proceed.

Yes, I was also amazed that the Respironic's tech would get on the phone with me, as they usually say talk to your DME. I think it has to do with having a really good question, being able to clearly say that I had already spoken with my DME RT, and to be polite.

GumbyCT wrote:

GumbyCT wrote: Dave need I ask?

Giants or Red Sox?

Unprecedented silence?.. wait til next year?

How many days til pitchers & catchers?

deltadave wrote:On this Second Greatest Sports Day of the Year, I must admit to having been briefly perplexed as to the nature of your question.

However, upon careful reflection, I see the answer as being a resounding "Yes!!"

It might surprise you to know that for 27yrs. I was a member of the Patriot Wing.

deltadave wrote:I think in order to answer that question objectively, one would need to look at the detailed pressure waveform and see if Peak Inspiratory Pressure is a little higher; Inspiratory Time a little shorter; and the C-Flex Effect a little more apparent.

Well, that is way above my skill level and/or my desire to put all that under the microscope.
Sounds like more work than I could or would want to do when it was just a passing curiosity anyway.

What skill, there's no skill.

Run Resistance at 0, then 4, then superimpose the waveforms and analyze the aforementioned areas:



In the areas of analysis, Peak Pressure should be a little higher, waveform narrower (reflecting decreased I-Time) and the C-Flex is more pronounced (dips a little more).

deltadave wrote:Run Resistance at 0, then 4, then superimpose the waveforms and analyze the aforementioned areas:

Ahh, I see now said the blind man.
I might just do that. I have no printer though. Will have to email the waveforms to myself and go over to my Mom's and use her printer the next time I go see her which is a short drive to another town for me.
Not sure if I could just eyeball it enough to see any difference.

Since I tried all the settings and didn't feel any difference and since it isn't related to leak line numbers, I just have always left the setting at 0.

13 days til pitchers and catchers.....

Bons wrote:13 days til pitchers and catchers.....

Are the GIANTS actually larger than life or are they GI-Ants?

Pugsy wrote:Since I tried all the settings and didn't feel any difference and since it isn't related to leak line numbers, I just have always left the setting at 0.

I can't imagine how I lived so long without it? Talk about dial winging.

GumbyCT wrote:I can't imagine how I lived so long without it? Talk about dial winging.

You know me...always ready to go into the wild unknown.
To be honest...after I tried it...big let down. I suppose it might be useful somewhere sometimes for someone but for me...the resistance control thing was more like marketing hype that didn't mean much to me.
At least when I turned off AFlex there were obvious negative repercussions to that experiment.
I was rather disappointed that Resistance settings seemed to be such a "nothing" factor....at least for me.

Pugsy wrote:I was rather disappointed that Resistance settings seemed to be such a "nothing" factor....at least for me.

It would seem that Resistance Control would only have benefit (application) with a mask of High Pressure Drop.

With the test conditions CPAP 10 cmH2O C-Flex+ 3 EasyLife Medium:

Resistance = 0:



Resistance = X5:



an impressive, abrupt (uncomfortable) drop in C-Flex is seen. This also seemed to create some "autocycling" (never a good thing).

The next question to ask is:

Why do some masks have such a huge pressure drop, especially when the leak characteristics have nothing extrordinary aboout them?

deltadave wrote:Why do some masks have such a huge pressure drop, especially when the leak characteristics have nothing extrordinary aboout them?

For a nasal pillow/prong mask, the leak rate comes from the vent hole, but the resistance comes from the small opening where the air goes into the nose. The two are unrelated.

deltadave wrote:Why do some masks have such a huge pressure drop, especially when the leak characteristics have nothing extrordinary aboout them?

Did you notice my new Canadian accent?

archangle wrote:For a nasal pillow/prong mask, the leak rate comes from the vent hole, but the resistance comes from the small opening where the air goes into the nose. The two are unrelated.

From the perspective of the end user, there are a number of factors that contribute to Resistance (Pressure Drop) which must be considered in the search for "effective treatment pressure".

These may include:

• Tubing length (although
  

  Respironics wrote:The device automatically compensates for pressure drops associated with a 182.9 cm (6-foot) smooth bore tube.)

• Addition of bacteria filters and or humidifiers:
  
  
• Addition of extension tubing;
• Using a mask that has a tubing extension with a reduced (15 mm) diameter;
• Designed leak rate;
• Aperture to patient (NM, FFM, pillows, etc.); and
• Turbulence characteristics

These factors could have huge ramifications in therapy. Let's say a patient received titration with OptiLife, determined a fixed pressure and decided, for instance, to go with Generic Brand CPAP machine and put all the above noted crap on it.

And to my previous point, at first glimpse, it would seem that Swift-type interfaces would have a similar (GoLife, OptiLife) Pressure Drop issue, but according to specifications, they don't.

deltadave wrote:

deltadave wrote:Why do some masks have such a huge pressure drop, especially when the leak characteristics have nothing extrordinary aboout them?

Did you notice my new Canadian accent?

What accent?