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Georgio wrote:Just now I changed them to 5, 6, 30, & 6, which I assume will make the machine more sensitive to my events. You can see some of both my M-Series and Intellipap nightly data charts in the discussion thread on cpap.com, to help you judge my setting assumptions.

Giorgio,

I'm almost certain your new flow settings will make the machine LESS sensitive, not more sensitive. Out of the box, a hypopnea is recognized when flow drops to 50% of recent average. With your new settings, flow would need to drop much further, to 30% of the recent average, to be recognized. Same with apnea, out of the box it will recognize an apnea below 10%, with your new setting it would have to drop much further, all the way to 5%. To make the machine more sensitive, you want to make the numbers higher, not lower.

For those interested, this is my correspondence with DevilBiss:

Georgio,

Glad you are getting some direction. You may use my comments as you wish on cpap.com. Also be aware of the 30% for 6 seconds is very sensitive. One of the things that may happen is the pressure “spiraling up” quicker than you wish. I like 40% for 10 as an option to default settings but you can adjust to the best for you.

Hope that helps

DAVE

From: Georgio
Sent: Thursday, April 02, 2009 10:46 AM
To: Henry, Dave
Subject: Re: cpap.com Intellipap/M-Series Challenge

Dave,

Thanks very much for your response and interest in helping with my therapy. I was pleased to learn that the Intellipap does in fact have the capability to adjust it's therapy detection settings. While that seems logical, it's not really clear that the advanced submenu won't only change reporting. I checked my Intellipap and the four available settings in the Advanced Submenu were all at the default settings. Just now I changed them to 5, 6, 30, & 6, which I assume will make the machine more sensitive to my events. You can see some of both my M-Series and Intellipap nightly data charts in the discussion thread on cpap.com, to help you judge my setting assumptions.

Please let my know what you think about my adjustments.

Also, I request your permission to copy our discussion to the cpap.com thread, as the folks there are hungry for information on your product to determine if it may provide superior therapy and be a future purchase.

Georgio

From: DeVilbissHC.com>
Subject: cpap.com Intellipap/M-Series Challenge

Date: Tuesday, March 31, 2009, 4:37 PM

Georgio,

I am the Respiratory Clinical Specialist for DeVilbiss Healthcare and a Registered Respiratory Therapist and would be glad to help with your questions. Let me give a couple responses to your questions and we can have a dialogue with other issues you may have.

1. Changing the Apnea % and Apnea duration or Hypopnea% and Hypopnea duration in the “AutoAdjust mode” allows for changing the algorithm’s sensitivity which changes response of the AutoAdjust.

2. There is a “CPAP mode” in the Autoadjust that will only change these definitions and the reported information which makes it a little confusing comparing the 2 modes.

3. The AutoAdjust algorithm is based on presence and density of the abnormal events, so if both these criteria are not met, pressure will not be changed. Were there any changes made to your Intellipap apnea and hypopnea settings?

I look forward to emailing with you.

Thanks

DAVE

Here is my analysis and numbers I plan on trying with the Intellipap:

(I'm not absolutely certain that I am comparing apples to apples regarding the 2 manufacturers settings.....it appears so......however if anyone has comments to the contrary, please let me know.)

I like the apnea settings for your second trial, but I still think you are adjusting hypopnea in the wrong direction. I think you'd want to set that to 60% for 10 seconds.

El "The" Pap, you had me going for a minute, however, I believe the flow numbers represent the percentage of flow "reduction", i.e. 40% flow reduction is less and more sensitive than 80% flow reduction to be recognized as an apnea.

Georgio, how is the Intellipap working for you at the new settings? Inquiring minds want to know!

What is the clinical menu code for the DeVilbiss IntelliPAP AutoAdjust? I just finished no less than 30 phone calls last week with my DME, Doctor, Doctor's Referral Person and the Sleep Therapist to get my machine changed to the IntelliPAP Auto because of this thread. I find the direct involvement with the company and outstanding reviews a great testiment to this product. I'm looking forward to receiving it sometime this week and will be happy to report my experience with it.

If posting the information is an issue, please PM me.

God Bless,
Diehart

As far as I know it is permissable to post whatever information or comments you have on the Intellipap at this time. In fact DevilBiss is soliciting comments. I am holding off before trying new settings on the Intellipap. I want to get over a cold or virus or something first. I hope to try a night within the next few days. Then I may try one or two nights at a time. I will be sure to post my experience. I have to add that it is impressive that the machine's therapy can be adjusted in a way I don't think any others can.

Georgio

I must have been feeling adventurous last night because I hooked up the Intellipap with the new settings when I went to bed.

Checked data first thing this morning. Disappointment. With the new therapy settings the Intellipap reported an AHI 4 times higher than with the previous settings.

Makes me wonder about El Pap's comment that maybe we are adjusting the machine to be less sensitive? However the data did show that the pressure did vary more during the night than ever before with the previous settings.

So the AHI is way up, even though the machine appears to have been more responsive?

I feel markedly worse this morning than when I use the M-Series.



I will advise DevilBiss of my poor results and see if they have any other suggestions. Machine still does not work for me.

Georgio

Georgio,

If I'm reading the chart correctly (it's a little small), it looks like for the large part of the night you had 0 apneas and the events were all hypopneas. That doesn't sound too bad to me.

How you feel may or may not be a good measure for adequacy of therapy .... imho, one night isn't enough time to tell.

Mindy

Georgio,I was wondering if your specific machine was faulty - and therefore so badly non-responsive. Have you had a chace to try another one?

O.

An AHI of 4.2 is extremely high for me and consistant with the way I feel. My AHI is always under 1, even on the Intellipap with the previously default settings.

DevilBiss has not yet commented on this latest data, however the machine appeared to respond more often during the night at these new therapy settings, however AHI went up and feeling is worsened.

We will see what DevilBiss says, however I don't see anything that would indicate a problem with the machine.

Georgio wrote:Makes me wonder about El Pap's comment that maybe we are adjusting the machine to be less sensitive? However the data did show that the pressure did vary more during the night than ever before with the previous settings.

So the AHI is way up, even though the machine appears to have been more responsive?

Your machine is now more responsive to those detected hypopneas. Here is why you now see increased pressure-response activity to those hypopneas:

Dave at DeVilbiss wrote:Also be aware of the 30% for 6 seconds is very sensitive. One of the things that may happen is the pressure “spiraling up” quicker than you wish.

Rhetorical question- Why do some patients fare better with no pressure increase immediately after detected hypopneas? In some cases the hypopneas are not only central in nature, but the aggressive pressure increases can actually cause yet more central hypopneas.

So Georgio, the next logical experiment would be to make the machine's hypopnea response even less sensitive than you originally had it.

ozij wrote:Georgio,I was wondering if your specific machine was faulty - and therefore so badly non-responsive. Have you had a chace to try another one?

O.

I've wondered the same regarding my IntelliPap.

Your data looks almost exactly like mine. Last night I had ZERO apneas recorded and I think that's a first for me. However I had a LOT of hypopnea events and they wake me up so I need to track them down. I also think it's important to know what a particular setting MEANS if we're going to make changes. The way I'm reading the Advanced Menu options seems to be indicating that the percentage setting is is a figure representing how far below normal flow we must fall before registering as an event.

For example (just tossing out easy numbers, not meant to be representative of actual):

Let's say our normal flow is 100

Default Hypopnea% is 50%
I read this as: Respiratory flow must drop to 50% of normal and stay at or below 50% of normal for the time specified in Hypopnea Duration. Default for that is 10 seconds.
So respiratory flow of 50 for 10 seconds registers as a Hypopnea event.

If we change Hypopnea% to 40% and change nothing else.
Respiratory flow must fall 40% from normal for 10 seconds. This means you still HAVE 60% respiratory flow. You've made the machine more sensitive because now your respiratory flow only needs to drop 40% from normal instead of having to drop to 50% below normal.

If we change Hypopnea% to 60% and change nothing else.
Respiratory flow must fall 60% from normal for 10 seconds. This means you still HAVE 40% respiratory flow. You've made the machine less sensitive because now your respiratory flow needs to drop 60% from normal before registering an event.

So the apnea% or the hypopnea% are not percentages of what you HAVE, but rather percentages of how far you have fallen off of the normal.

A hypopnea% setting of 40% would be telling the machine that if I reach a respiratory flow that is down 40% from my normal (not 40% OF my normal), start working on this as a hypopnea event. A hypopnea setting of 50% would ignore that same scenario and wait until I've reached a 50% reduction from normal before reacting.

So LOWERING that percentage number makes the machine more sensitive, and RAISING it makes the machine less sensitive to these events.

Now here's a bigger question...
If the machine pressure is set, such that I have ZERO apnea events recorded, but lots of hypopnea events. Do I want to CHASE the hypopnea events by making these small and granular adjustments or do I do something much simpler and INCREASE my low pressure setting in an effort to keep the airway splinted open and PREVENT the hypopnea events?

yardbird wrote:Now here's a bigger question...
If the machine pressure is set, such that I have ZERO apnea events recorded, but lots of hypopnea events. Do I want to CHASE the hypopnea events by making these small and granular adjustments or do I do something much simpler and INCREASE my low pressure setting in an effort to keep the airway splinted open and PREVENT the hypopnea events?

Let's revisit the fundamentals of hypopneas:

1) APAP machines cannot reliably differentiate obstructive hypopneas from central hypopneas
2) Obstructive hypopneas tend to fare better with a pressure increase
3) Central hypopneas can actually increase in numbers after a pressure increase

So yardbird, the answer to your question about whether to treat your hypopneas with more pressure (preemptive or responsive) is really a matter of methodical trial and error. For some patients, preemptively addressing hypopneas is the best thing to do. For other patients responsively addressing hypopneas with more pressure is the best bet. And for yet other patients, laying off any kind of pressure increase (preemptive or responsive) is the best bet for hypopneas.

The four experimental junctures of hyponea treatment:

Category A:
1) more preemptive fixed pressure
2) less preemptive fixed pressure
--------------------------------------------------
Cattegory B:
3) more APAP-responsive pressure directly after hypopneas
4) less APAP-responsive pressure directly after hypopneas

While using an APAP, one of those two pressure strategies from category A is typically combined with one of the pressure strategies in category B above. Most APAPs allow user adjustment of category A by the way of a minimum APAP pressure, but limit category B execution to the algorithm. The AutoAdjust allows the user to adjust category A with a minimum APAP pressure. However, the AutoAdjust also allows the user to influence category B with changes to the hypopnea sensitivity adjustment. That is potentially an effective feature in my own way of analyzing. But it requires an understanding of two very different hypopnea etiologies with two potentially very different human responses to pressure increases.

The outcomes will theoretically be influenced by a somewhat unique patient-combination of: 1) obstructive hypopneic closure, and/or 2) dysregulated central hypopneic response. Those two hypopneic etiologies can occur separately or in combination in human physiology. They are not mutually exclusive etiologies.