Medical mediator needed

[Papit]

Are there any docs or techs on board here who could call the ResMed Patient and Clinician Support in San Diego, 800-424-0737 to get some info in my behalf, and for anyone else here who’s interested in knowing why a patient’s flow limitation graphs are showing many maximum high spikes every single night while his average AHI is about 1.0 consistently for three months after being switched from the S9 AutoSet to the S9 VPAP Adapt. During the patient’s use of the AutoSet for over a year, AHI averaged 17 while flow limitations were consistently very low. What explains these anomalies? The relevant Lab and Titration tests can be faxed for review if needed.

I called the Patient and Clinician Support groups on the above number several weeks ago and was informed that there is an adjustment to my treatment that may be needed, but that they would give that information only to a doctor who called in with the above questions. (My doc hasn't called them and actually sent me a letter telling me in writing that attending to patients’ “curiosity” is not a necessary thing for him to do. I suppose he likes my AHI so much that he presumes the machine need not be checked nor is anything else needed, much less answering questions to deal with patient “curiosity”. I wonder if the AMA and medical schools take the same view?

If anyone like a Sleep Doctor or a Sleep Tech can call them to ask about the above anomaly and fill us in, that would be greatly appreciated.

Thanks.

[jnk]

It is not ResMed's job to teach us what the graphs mean. Although they don't stop us from looking at the graphs, they don't make the graphs for us. They make them for the clinicians.

The pros, perhaps rightly so, might view your question as much the same thing as their getting a call asking, "Can someone please explain to me why my thermometer doesn't report exactly 98.6 degrees every single time I take my temperature?" The answer is, it generally doesn't matter unless it reports that you have a fever.

Similarly, if your AHI is fine, docs consider the condition treated. If we as patients choose to use the numbers some other way, we do that on our own without them.

When we as patients with good machine-reported AHI tweak our pressures up or down, we do it to improve how we feel, not to fix how the graphs look.

When I used to go to my mom and say, "It hurts when I do this," Mom used to say, "Then don't do that." Similarly, if we have a good machine-reported AHI but find that the other numbers and charts are disturing our peace of mind, it might be best not to look at them. Those charts and numbers MAY help us find the right pressure for feeling our best. But may not. So our using them that way is not something done so much by the docs and manufacturers, since they don't care about how we feel as much as we do.

[chunkyfrog]

I have to agree with jnk. Averages and trends are the important data.
Fine detail may or may not be significant, especially if it is recorded by a "home" machine.
As long as the net result is positive, there is probably nothing to be concerned about.

[hueyville]

This qualifies as an odd post. If you have bothered your doctor to the point where he has sent a written cease and desist letter then my vuess is a mountain is being made of a mole hill. My sleep doctor has a full time tech that will check my machine anytime I want to drag it in. My new DME which is 4 miles from home has a resperatory tech also that will check my equipment. What neither will do is look at any info from sleepyhead or any software other than their own. If I have a question all I do is make an appointment, take my machine for themto download info from and the doctor answers questions based on his software and during a paid appointment. If mg AHI was one I would just leave it all alone and be happy. I have had nights over 90. After 2.5 years and some recent studies by my new neurologist past 10 days have averaged 10.7. Seeing as previous doc said if we ever got me xown to 15 he would be pleased, I am happy as a clam and we go back to the lab next week.

[kteague]

Papit, I'm guessing someone on here will have seen that before and/or have a plausible explanation. I think your question here is as reasonable as any other question about data and graphs and hope someone knowledgeable can address your concerns. Even if it is to say it's no big deal, it merits explanation. Do you have something going on making you question your treatment or was this an incidental finding? If I were intricately involved with my data and something was very different, I'd want to understand what I was seeing too. Good luck finding answers.

[robysue]

anyone else here who’s interested in knowing why a patient’s flow limitation graphs are showing many maximum high spikes every single night while his average AHI is about 1.0 consistently for three months after being switched from the S9 AutoSet to the S9 VPAP Adapt. During the patient’s use of the AutoSet for over a year, AHI averaged 17 while flow limitations were consistently very low. What explains these anomalies?

Papit,

I'm not a doc or a tech. So I can't help you wrangle any information out of Resmed.

But I have reviewed your comments in this thread: Re: definition of flow limitation as well as your comments on this thread. You've been asking essentially the same question on both threads:

• "Why are my FL so much higher on the VPAP Adapt even though my AHI is so much lower than it was on the AutoSet?

After looking at the data you posted in this response viewtopic.php?f=1&t=91643&st=0&sk=t&sd= ... 45#p845983 very closely, plus what you've said here and elsewhere, I'm beginning to think that the real answer to your question is:

• You are comparing apples to oranges

The two machines have different settings and different algorithms and they work in slightly different ways. But the slight differences in the way the two machine work may fully explain why you are getting different results from the two machines.

But in order to really figure out what's going on, there are three pieces of information that I need but cannot find in your posts:

1) What were the pressure settings on the S9 AutoSet when you were using it? Were you using EPR? If so, at what setting. And what are your current settings on the S9 VPAP Adapt?

2) Are you using the S9 VPAP Adapt in full Auto mode (where EPAP can change) or are you using it in plain Adapt mode (where EPAP is fixed)?

3) On the S9 AutoSet you've stated your AHI averaged 17. What was the break down of the events scored by the S9 AutoSet? Mostly centrals? Mostly OAs? Mostly Hs? (In other words, were you switched to the VPAP Adapt because of CompSA or CSA? Or was there another justification for moving you from the AutoSet to the VPAP Adapt?)

These three pieces of information are relevant to figuring out why the VPAP Adapt is scoring many more FLs and many less AHI events than the S9 AutoSet did because the answers to these questions control how each machine responds to your breathing pattern during the night; and that response controls how your body reacts to the algorithm, which in turn determines the data you are looking at.

If you were moved to the VPAP Adapt because of clinically significant residual problems with CAs, then the settings on the two machines and the differences between the AutoSet's Auto algorithm and the VPAP Adapt's Auto and Adapt algorithms may be the ultimate explanation for why you are seeing more FL on the VPAP Adapt and less AHI events on the VPAP Adapt.

On the AutoSet, in Auto mode the min pressure setting, the max pressure setting and the EPR setting control the range of possible pressures for each exhalation and each inhalation. As I understand it, on the VPAP Adapt, in Auto mode the min EPAP setting, the max EPAP, the min PS setting and the max PS setting control the range of possible pressures for each exhalation and each inhalation. (The "max IPAP" is equal to Max EPAP + Max PS.) If the VPAP Adapt is set to fixed EPAP mode, then the EPAP setting, the min PS, and the max PS control the range of possible pressures for each exhalation and inhalation. (The "max IPAP" is equal to EPAP + Max PS.)

And even if the settings on your VPAP Adapt seem to be direct translations of the settings on the AutoSet, the differences between the AutoSet's Auto algorithm and both the VPAP Adapt's fixed EPAP Adapt algorithm and the VPAP Adapt's variable EPAP Adapt algorithm can lead to very different (effective) ranges of possible pressures for each inhalation and each exhalation. And this could very well lead to a different physical reaction to PAP pressure in your upper airway. And that's why I think you may be comparing apples to oranges when you try to compare the data from the two different machines: Saying "the AutoSet gave me a higher AHI than the VPAP Adjust" is saying the apple is tarter than the orange and saying "the AutoSet gave me a lower FL than the VPAP Adjust" is saying the the apple less juicy than the orange.

A long and detailed EXAMPLE
What follows is an analysis of how seemingly similar settings on the AutoSet and the VPAP Adapt can lead to different overall pressure levels when the machines are actually used.

Let's suppose your AutoSet settings were something like these totally made up numbers:

• min pressure = 7 cm
  max pressure = 15 cm
  EPR = 3 cm

On any given exhalation, the pressure would be between 4 and 12 cm. On any given inhalation, the pressure would be between 7 and 15 cm. But on EVERY breath, the difference in pressure would be 3 cm. And any time the machine detected a flow limitation, snoring, or a group of two or more closely grouped Hs and OAs, the machine would raise BOTH the "EPAP" and the "IPAP" by exactly the same amount so that "IPAP - EPAP" remains at 3 cm. The AutoSet does not increase EITHER the "EPAP" or the "IPAP" when it scores CAs---even nasty clusters of CAs. And if the machine is reporting a median pressure setting of 12 cm, that would mean that for at least 50% of the night EPAP >= 9 cm and IPAP >= 12 cm.

Now let's suppose are using your VPAP Adapt in auto-EPAP adjusting mode. And let's assume your VPAP Adapt's basic settings are start out (superfically) looking as close to the AutoSet's as possible:

• min EPAP = 4 cm
  max EPAP = 10 cm
  min PS = 3 cm
  max PS = 5 cm
  (note this gives us a comparable max IPAP = 15 to the max pressure of the AutoSet's setting).

On any given inhalation, the pressure would be between 7 and 15 cm. But on any given exhalation, the pressure would be between 4 and 10 cm. So there's LESS room for EPAP to increase if the max IPAP is set to the same setting as it was on the AutoSet. And that means that over the course of the night, the average and median values of EPAP pressure are likely to be lower than they were on the AutoSet. And that means there's a better chance that flow limitations can get through since the VPAP Adapt uses increased EPAP pressure to address flow limitations.

Of course, we could just allow the max IPAP to go up to 17 and set the VPAP Adapt to something like:

• min EPAP = 4 cm
  max EPAP = 12 cm
  min PS = 3 cm
  max PS = 5 cm
  (note this gives us a comparable EPAP range to the AutoSet's EPAP range if EPR = 3).

With these settings, on any given inhalation, the pressure would be between 7 and 17 cm. On any given exhalation, the exhale pressure would be between 4 and 12 cm. BUT the difference between the IPAP and EPAP pressures now is allowed to range anywhere from 3 cm to 8 cm. In other words, it is possible that for some periods during the night that the IPAP may be much, much higher than the EPAP. And so the time spent at or near max IPAP may well be significantly greater than the time spent at or near max EPAP. In other words, it's possible that the median IPAP pressure could be 12 cm and the median EPAP pressure could be 7 cm. Now recall that with the AutoSet, if the median IPAP = 12, that meant the median EPAP = 9. And it could be that the difference in median (and 95%) EPAP pressures are allowing more FL to get through.

To make what I'm saying a bit clearer: The Adapt's auto-EPAP algorithm increases the EPAP for flow limitations, snoring, and groups of two or more closely grouped Hs and OAs. But (and this is an important but) the Adapt algorithm also sets a target minute ventilation value based on the patient's (normal) breathing patterns, and whenever the target minute ventilation falls below 90% of the target value, the IPAP is increased, but EPAP remains fixed. This is how the VPAP Adapt treats central apneas.

Now recall that I'm assuming that you were put on the VPAP Adapt because of some kind of problem with central apneas and I'm also assuming that when you were using the AutoSet, much of that average AHI = 17 was made up of central apneas. If those are correct assumptions, the fact that VPAP Adapt is successfully treating your central apneas may mean that you are spending more time with the EPAP at or near it's minimum setting while the IPAP is ranging much higher in an effort to keep the minute ventilation volume at the target level. And because EPAP is not running as high as it did (on average) on the AutoSet, you see more flow limitations on the VPAP Adapt.

[old dude]

It is not ResMed's job to teach us what the graphs mean. Although they don't stop us from looking at the graphs, they don't make the graphs for us. They make them for the clinicians.

The pros, perhaps rightly so, might view your question as much the same thing as their getting a call asking, "Can someone please explain to me why my thermometer doesn't report exactly 98.6 degrees every single time I take my temperature?" The answer is, it generally doesn't matter unless it reports that you have a fever.

Similarly, if your AHI is fine, docs consider the condition treated. If we as patients choose to use the numbers some other way, we do that on our own without them.

When we as patients with good machine-reported AHI tweak our pressures up or down, we do it to improve how we feel, not to fix how the graphs look.

When I used to go to my mom and say, "It hurts when I do this," Mom used to say, "Then don't do that." Similarly, if we have a good machine-reported AHI but find that the other numbers and charts are disturing our peace of mind, it might be best not to look at them. Those charts and numbers MAY help us find the right pressure for feeling our best. But may not. So our using them that way is not something done so much by the docs and manufacturers, since they don't care about how we feel as much as we do.

Sage advice indeed.

I wish I were better capable of following it

[Mr Concerned]

Are there any docs or techs on board here who could call the ResMed Patient and Clinician Support in San Diego, 800-424-0737 to get some info in my behalf, and for anyone else here who’s interested in knowing why a patient’s flow limitation graphs are showing many maximum high spikes every single night while his average AHI is about 1.0 consistently for three months after being switched from the S9 AutoSet to the S9 VPAP Adapt. During the patient’s use of the AutoSet for over a year, AHI averaged 17 while flow limitations were consistently very low. What explains these anomalies? The relevant Lab and Titration tests can be faxed for review if needed.

I called the Patient and Clinician Support groups on the above number several weeks ago and was informed that there is an adjustment to my treatment that may be needed, but that they would give that information only to a doctor who called in with the above questions. (My doc hasn't called them and actually sent me a letter telling me in writing that attending to patients’ “curiosity” is not a necessary thing for him to do. I suppose he likes my AHI so much that he presumes the machine need not be checked nor is anything else needed, much less answering questions to deal with patient “curiosity”. I wonder if the AMA and medical schools take the same view?

If anyone like a Sleep Doctor or a Sleep Tech can call them to ask about the above anomaly and fill us in, that would be greatly appreciated.

Thanks.

Sleep Doctors and Sleep Techs are not going to get involved with a patient's attempts at self treatment. Sorry man.

[Julie]

You haven't been around here long enough or you wouldn't have said that ... it happens all the time (we do get lucky now and again!). Of course there are things techs can't tell you right away and only your MD will do it, and some doctors don't depending on how big their egos are, how ignorant they actually are about sleep medicine and how rushed they are, but there are decent ones out there who do appreciate when pts take control and understand their own conditions and therapy (just like diabetics have done for decades) and some techs who are on this forum and work with us, not cop attitudes about who has the diploma and who doesn't. Sheesh.

[Dr Philip]

Are there any docs or techs on board here who could call the ResMed Patient and Clinician Support in San Diego, 800-424-0737 to get some info in my behalf, and for anyone else here who’s interested in knowing why a patient’s flow limitation graphs are showing many maximum high spikes every single night while his average AHI is about 1.0 consistently for three months after being switched from the S9 AutoSet to the S9 VPAP Adapt. During the patient’s use of the AutoSet for over a year, AHI averaged 17 while flow limitations were consistently very low. What explains these anomalies? The relevant Lab and Titration tests can be faxed for review if needed.

I called the Patient and Clinician Support groups on the above number several weeks ago and was informed that there is an adjustment to my treatment that may be needed, but that they would give that information only to a doctor who called in with the above questions. (My doc hasn't called them and actually sent me a letter telling me in writing that attending to patients’ “curiosity” is not a necessary thing for him to do. I suppose he likes my AHI so much that he presumes the machine need not be checked nor is anything else needed, much less answering questions to deal with patient “curiosity”. I wonder if the AMA and medical schools take the same view?

If anyone like a Sleep Doctor or a Sleep Tech can call them to ask about the above anomaly and fill us in, that would be greatly appreciated.

Thanks.

Doctors and sleep techs can not request a patient's medical records or anything that might include a patient's name or social security number with out first obtaining a patient's permission in writing. It is all part of Hippa and it protects a patient's privacy. So in order for some one to call and get your records they would need to have you fill out a medical request form. Get a form from the provider and fill it out. Sign it and then give it to whoever you want to have request your information.

[chunkyfrog]

I think our troll is back.

[Mr Concerned]

I think our troll is back.

Who is our troll? Can we make him do tricks?

[jnk]

I think it depends on the meaning of the phrase "get involved."

A number of docs and techs and even RTs may approve of it, support it to the extent they can, and even offer helpful hints to patients about it when they can.

However, I also believe that few of them have the time to train patients to do it, educate the patient about it, let alone walk all their patients through it.

If no one minds my saying so, I believe that it can be easy for some of us to get caught in the loop of thinking of the CPAP machine's reports as being merely reports of the activity of the machine. That can cause someone with a background in monitoring machines to think in terms of adjusting the machine until its reports are acceptable to the user. But in fact, the CPAP is mostly reporting on the breathing of an imperfect living organism that can't be, um, re-engineered, or adjusted, beyond certain reasonable ranges of response to airway pressure.

All humans breathe imperfectly while asleep, and that isn't considered part of the syndrome until it meets other criteria. In the meantime, clinicians and manufacturers have no reason to spend time assisting with experimental approaches to the treatment, such as changing titrated pressures for fine-tuning our comfort and personal responses to therapy, unless they happen to want to and happen to have the time for it.

In my opinion.

[Mr Concerned]

I think it depends on the meaning of the phrase "get involved."

A number of docs and techs and even RTs may approve of it, support it to the extent they can, and even offer helpful hints to patients about it when they can.

However, I also believe that few of them have the time to train patients to do it, educate the patient about it, let alone walk all their patients through it.

If no one minds my saying so, I believe that it can be easy for some of us to get caught in the loop of thinking of the CPAP machine's reports to being merely reports of the activity of the machine. That can cause someone with a background in monitoring machines to think in terms of adjusting the machine until its reports are acceptable to the user. But in fact, the CPAP is mostly reporting on the breathing of an imperfect living organism that can't be, um, re-engineered, or adjusted, beyond certain reasonable ranges of response to airway pressure.

All humans breath imperfectly while asleep, and that isn't considered part of the syndrome until it meets other criteria. In the meantime, clinicians and manufacturers have no reason to spend time assisting with experimental approaches to the treatment, such as changing titrated pressures for fine-tuning our comfort and personal responses to therapy, unless they happen to want to and happen to have the time for it.

In my opinion.

Your opinion is very much appreciated. It is also very much in line with my experience. All patients, all Humans in general, have an average AHI of 10.

I realize that this may be difficult to believe when most readers live on a forum dedicated to bringing the AHI down to zero... but it is true. AHI is the apnea hypopnea index and it is widely used by accreditted labs. Interestingly, that is not what APAP and XPAP machines use for their own internal statistics. They use RDI. Respirator Disturbance Index. In order to get a handle on this you need to know the difference between the two. AHI can only be calculated by adding up all of the 'Events' which meet the AASM criteria as an apnea... or as a hypopnea. Typically, even healthy individuals will have an average of 10 per hour. This is because our respiratory system is a lot more complicated then we would like it to be. The body regularly displays transitional centrals in between each sleep stage and after every arousal regardless of what caused it. In cases of microsezuires- a patient can theoretically have a transitional central apnea after each disturbance and display an AHI of 60/hour. All of which would dissipate if the microsezuires were properly treated.

But no... the resmed auto S9 does not use AHI. It does not apply the AASM criteria to the events it records. It does not even have the ability to determine whether or not you are asleep. Most APAP and XPAP devices use RDI. RDI is a 'quelque chose se passe' version of AHI that does not recognize the need to qualify any of the events it records.

So if the device tells you that your RDI is 10 or even 20.... or even 30....

Then you have to understand that your actual AHI is probably some where between 5 and 15 which is perfectly normal.

[robysue]

[
So if the device tells you that your RDI is 10 or even 20.... or even 30....

Then you have to understand that your actual AHI is probably some where between 5 and 15 which is perfectly normal.

Last time I checked with my sleep doc, an AHI between 5 and 15 on a PSG is NOT "perfectly normal". An AHI between 5 and 15 on a PSG is "mild apnea" and CPAP therapy is usually offered to the patient if s/he is symptomatic. If the AHI on a PSG is close to 15, the patient will usually be told their apnea is mild-to-moderate and a CPAP trial will be pushed pretty heavy regardless of whether the person has daytime symptoms.