C-Flex and the I:E ratio

[ShinRyoku]

It's my opinion that your actual I:E is not inverse when using Cflex. I think it's only the graphical representation coupled with false measurements by either SleepyHead or the machine which makes it appear so when cardiographic artifacts are present.

Could be. I can't think of any reason that cardiographic artifacts would show up superimposed on inspiratory flow only when C-Flex is on.

[Jay Aitchsee]

Could be. I can't think of any reason that cardiographic artifacts would show up superimposed on inspiratory flow only when C-Flex is on.

I can't answer that, but maybe the rendering only makes it appear that these artifacts are occurring during inspiration. There is quite a bit of difference in the pressure profiles between Cflex and Cflex off and Cflex and EPPR on/off. A major difference is that Cflex pressure relief diminishes with a reduction in Flow, so it doesn't stay constant through the expiratory phase and would typically be very little at the end of the period. EPR, on the other hand, is a fixed reduction for the entire expiration period. See pages 24 and 25 of http://c.ymcdn.com/sites/www.gameshme.o ... s_2016.pdf

In reviewing my own results, I see these artifacts throughout the cycle, but not on the leading and trailing edges of inspiration wave and not on the expiration wave until after max exhale has passed. In other words, they are not apparent during periods of maximum change in Flow Rate. There's probably a clue in there somewhere, but I don't know what it is.

[ShinRyoku]

This is what I'm thinking and I've alluded to it before: The manufactures, ResMed and Phillips, have not made any ventilator type data, such as Inspiration/expiration time, I:E ratio, Respiration Rate, Tidal Volume, etc. available to users of their non ventilation capable machines through their associated software. I believe this is because this type of information really doesn't apply to ordinary cpap application.

Fwiw, my AirCurve 10 Vauto is not ventilation capable but does report those data:

[Jay Aitchsee]

This is what I'm thinking and I've alluded to it before: The manufactures, ResMed and Phillips, have not made any ventilator type data, such as Inspiration/expiration time, I:E ratio, Respiration Rate, Tidal Volume, etc. available to users of their non ventilation capable machines through their associated software. I believe this is because this type of information really doesn't apply to ordinary cpap application.

Fwiw, my AirCurve 10 Vauto is not ventilation capable but does report those data:

Products in the ResMed AirCurve line have Non Invasive Ventilator features. Some more, some less. Therefore, the data is included for the line.

A couple of other statements I made earlier in this thread:

SleepyHead does provide the I:E ratio since the measurement is available from some machines. Generally those machines, advanced models of which, are ones which may provide some ventilation. This includes many Bi Level lines of machines. The I:E ratio is generally not available from machines which have no ventilator capabilities, i.e., autopap and cpap.

But here's the thing, we are talking about a parameter (I:E) that has no valid application in basic cpap. SleepyHead is able to derive Inspiration and Expiration time from the flow rate data, but that does not mean it is correct. It might be, it might not be, depending on the circumstances. Interestingly, SleepyHead presents Inspiration and Expiration times for my S9 autoset, but ResScan (ResMed Software) does not. I believe this is because the variables are not appropriate to autoset application. ResScan does provide Inspiration Time, Expiration Time, and I:E for machines that have ventilator capabilities.

(emphasis added}

[ShinRyoku]

ResScan does provide Inspiration Time, Expiration Time, and I:E for machines that have ventilator capabilities.

(emphasis added}[/quote]

The AirCurve 10 Vauto is considered ventilator capable? What does ventilator capable mean?

[Matt00926]

Most people in the field, even though it's trademarked by Philips Respironics, just call any bi-level device a BiPAP. I've heard "BiPAP" used by respiratory therapists, EMTs, by physicians in hospitals, etc,.

In my personal opinion, it's all about the mode of therapy one is using, and the reason for that mode. If you own a Respironics Trilogy 100 and are using it in CPAP mode, you would not be using the machine to aid in augmenting ventilation. If you use the same device in spontaneous bi-level mode, because you have OSA and are intolerant to higher CPAP pressures, you also may not be using the machine to augment ventilation.

Further, bi-level machine is not a ventilator unless it has a backup rate and alarms. Perhaps even add a backup battery/portability into the mix as well.

Also, the bi-level machines for home use that are geared towards respiratory patients, and not just OSA, are often capable of inspiratory pressures up to 30cm H2O (and higher) and sometimes have a lower minimum EPAP setting possible of 3cm H2O instead of 4. With the Trilogy, using an active circuit with an exhaust valve, you can even turn the EPAP off.

[Jay Aitchsee]

The AirCurve 10 Vauto is considered ventilator capable? What does ventilator capable mean?

A machine that has Pressure Support (bilevel) could be considered as having ventilator properties. The Vauto has Pressure Support, Trigger and Cycle settings, and Inspiratory Time Control. It is in a line of machines that is considered to have NIV features. ResMed makes I:E, the original topic of this thread, along with other such data, available for machines in this line. It does not make these data available for its cpap and autopap machines. My point was that I:E did not apply to cpap and autopap. What is yours?


https://emedicine.medscape.com/article/ ... verview#a2

Ventilatory support can be achieved through a variety of interfaces (mouth piece or nasal, face, or helmet mask), using a variety of ventilatory modes (eg, volume ventilation, pressure support, bilevel positive airway pressure [BiPAP; see the image below], proportional-assist ventilation [PAV], continuous positive airway pressure [CPAP]) with either ventilators dedicated to noninvasive ventilation (NIV) or those capable of providing support through an endotracheal tube or mask. Older models of noninvasive ventilators required oxygen to be bled into the system, but current models incorporate oxygen blenders for precise delivery of the fraction of inspired oxygen (FIO2).

https://www.resmed.com/us/en/healthcare ... entilation
See the word "Ventilator" mentioned in the decriptions of some in the AirCurve Line

[ShinRyoku]

My point was that I:E did not apply to cpap and autopap. What is yours?

Seems that every time I am curious to learn about something, it somehow offends you . In this case, I was wondering what ventilator capable meant, so I asked. You had referred to ventilator capability several times. At first I thought I knew what it meant, but my machine didn't meet the definition I had in mind, so I asked.

[Jay Aitchsee]

My point was that I:E did not apply to cpap and autopap. What is yours?

Seems that every time I am curious to learn about something, it somehow offends you . In this case, I was wondering what ventilator capable meant, so I asked. You had referred to ventilator capability several times. At first I thought I knew what it meant, but my machine didn't meet the definition I had in mind, so I asked.

No, no, I'm not offended and I haven't been before. I just wasn't sure what you were asking, or why. Anyway, my point was/is that information such as I:E derived from machines not designed to provide it may not be accurate. This seems to be especially true when dealing with Phillips Respironics equipment. And I was speaking more about a line or class of machines rather than a specific model, something I didn't make explicitly clear.

Now, this last bit about PR is purely my perception. It's just that when questions involving inverse I:E come up they seem to be most often from users of PR equipment. I don't spend much time over there, but I seem to recall reading something similar posted on apneaboard by one of their moderators, Sleeprider, or Sleepwrangler maybe, something like that. I'll have a look and see if I can find it and provide a link if I do.

In the meantime, was your question answered?

Edit to add Links:
So it was Sleeprider. He has a lot of posts on apneaboard regarding false I:E readings. You can search using the keyword "inverse".
Here is one:

I saw the inverse I:E ratio, but with Philips machines, it is totally unreliable without a closeup of the flow rate chart. Usually, it is the result of a hitch in the expiratory flow pattern.
http://www.apneaboard.com/forums/Thread ... #pid212535
06-29-2017, 06:24 PM

By hitch, I assume he is talking about cardiographic artifacts.

My theory is that most of these individuals that record inverse I:E actually have normal I:E
http://www.apneaboard.com/forums/Thread ... #pid202578

Sounds like he and I are on the same page.

[ShinRyoku]

I just wasn't sure what you were asking, or why. Anyway, my point was/is that information such as I:E derived from machines not designed to provide it may not be accurate. This seems to be especially true when dealing with Phillips Respironics equipment. And I was speaking more about a line or class of machines rather than a specific model, something I didn't make explicitly clear.

In the meantime, was your question answered?

Yes, thank you; and thanks for the links!

[ajack]

Your i:e is fine either way, but the flex can increase the ratio, as it acts like a small bpap. the machines can miscount the respiration rate and mess up the stats. If you are concerned you can do what you are doing and zoom in.

If it were my chart, I wouldn't think about i:e, I would raise your min to around the median pressure of 14, it should help with some of the obstructive events and that may also fix some funny breathing patterns the machine can miscount? From what you have shown, the machine is counting fine.

[Jay Aitchsee]

Continuing this conversation, below are SleepyHead results from a Phillips Respironics DreamStation. All comparisons of the Statistical Inspiration to Expiration times as well as spot comparisons indicate an "inverse" I:E. However, I believe this is not the case. In the example, the reported I:E at the cursor is 2.69:0.95, which would be inverse. However, I believe the true I:E is approximately 2:3, which is not inverse. I believe the machine or SleepyHead is confused by the ballistocardiographic artifacts (heartbeats) resulting in an erroneous expiration time and therefore an erroneous I:E. I believe the fault probably lies with SleepyHead since the DreamStation does not have ventilator capabilities and ordinarily this class of machine would not report Inspiration Time, Expiration Time, or I:E ratios.