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Re: Can cpap detect diff between central/obstruction? - one can!

Posted: Sun Mar 15, 2009 7:43 pm
by Slinky
Ha, ha, Doug!! Gotchya beat by a year and a half. My first great grandchild (a boy) was born a year ago August!!! Enjoy the little one when he/she gets here!

Re: Can cpap detect diff between central/obstruction? - one can!

Posted: Sun Mar 15, 2009 7:47 pm
by dsm
Slinky wrote:Ha, ha, Doug!! Gotchya beat by a year and a half. My first great grandchild (a boy) was born a year ago August!!! Enjoy the little one when he/she gets here!
It is to be a boy - wonders of modern ultrasound picked up the difference some months back

We bought the new mum a digital camera so she can start taking pics right away. They are in NZ & I am in Aust so
the photos will be my 1st view before I fly over in a couple of months after grand daughter has got over it all.

Cheers

DSM

#2 am parking this link here so I can find it gain easily - talks about a new Respironics SV style machine plus
has the links to the patents for the Vpap Adpat SV.

viewtopic/t40082/Resmed-AutoSet-CS-2.html

Re: Can cpap detect diff between central/obstruction? - one can!

Posted: Mon Mar 16, 2009 8:35 am
by Slinky
Yeah, my greatgrandson is in South Carolina and I'm in Michigan. *sigh* Doesn't seem fair, the father is my first grandchild and he was born in Missouri w/us in Michigan. Then my granddaughter was born in Kansas w/us in Michigan. FINALLY, my daughter had my two youngest granddaughters and THEY are just 10 minutes away! We missed out on so much w/the distances ... having these two close by has been so great ... those 16+ hour drives one way can be a drag ... especially when you have to leave to come home and leave them behind. And then when they come here - there's that other set of grandparents and family we have to share them with, plus their friends ...

Re: Can cpap detect diff between central/obstruction? - one can!

Posted: Mon Mar 16, 2009 8:37 am
by OutaSync
In chapter four of the book, "Deadly Sleep", by Dr. Mack Jones, he says,

Upper Airway Resistance Syndrome (UARS)
I had been to a sleep seminar in St. Petersburg, FL where Dr. Christian Guilleminault, a highly respected sleep disorders expert from Stanford University, discussed his concept of a narrowed airway in which one inhales with extra effort (like trying to inhale through a straw) creating a much greater negative pressure in the chest than usual, (like minus ten to minus thirty cm H2O pressure or greater, when normal is minus five cm H2O pressure).

This, in turn results in a dramatic change in the flow of blood into and out of the heart, so much so, that in some cases the walls of the heart actually collapse. This can potentially cause sudden cardiac death. Dr. Guilleminault showed examples of this with echocardiograms in sleeping patients with UARS. The point was made that the "gold standard" for detecting UARS is an esophageal pressure monitor (Pes monitor). The pressure monitor is attached to the end of a small catheter, passed through the back of the nose and swallowed, positioned about half-way down the esophagus. It lies in the mid-esophagus during the PSG and measures the negative pressures in the chest as one inhales during the night.

Most sleep techs are not trained to insert these. Patients protest because it is uncomfortable and techs don't like to get their patients upset with them even before test begins. Therefore most sleep labs don't use them. Instead, they were using the unreliable nasal thermistors (heat detectors) for changes in air flow from the nose (more recently, nasal pressure transducers have proven more reliable for this purpose and most labs are using them).


If UARS is so deadly, why aren't more sleep centers testing for it?

Re: Can cpap detect diff between central/obstruction? - one can!

Posted: Mon Mar 16, 2009 11:13 am
by jnk
OutaSync wrote:In chapter four of the book, "Deadly Sleep", by Dr. Mack Jones, he says,

Upper Airway Resistance Syndrome (UARS)
I had been to a sleep seminar in St. Petersburg, FL where Dr. Christian Guilleminault, a highly respected sleep disorders expert from Stanford University, discussed his concept of a narrowed airway in which one inhales with extra effort (like trying to inhale through a straw) creating a much greater negative pressure in the chest than usual, (like minus ten to minus thirty cm H2O pressure or greater, when normal is minus five cm H2O pressure).

This, in turn results in a dramatic change in the flow of blood into and out of the heart, so much so, that in some cases the walls of the heart actually collapse. This can potentially cause sudden cardiac death. Dr. Guilleminault showed examples of this with echocardiograms in sleeping patients with UARS. The point was made that the "gold standard" for detecting UARS is an esophageal pressure monitor (Pes monitor). The pressure monitor is attached to the end of a small catheter, passed through the back of the nose and swallowed, positioned about half-way down the esophagus. It lies in the mid-esophagus during the PSG and measures the negative pressures in the chest as one inhales during the night.

Most sleep techs are not trained to insert these. Patients protest because it is uncomfortable and techs don't like to get their patients upset with them even before test begins. Therefore most sleep labs don't use them. Instead, they were using the unreliable nasal thermistors (heat detectors) for changes in air flow from the nose (more recently, nasal pressure transducers have proven more reliable for this purpose and most labs are using them).


If UARS is so deadly, why aren't more sleep centers testing for it?
Here is my oversimplified, nonprofessional take on that important question:

So, let's say that a person is sleepy and tired during the day, sees a doc, and gets a NPSG. There are basically three possible outcomes, three categories, broadly speaking. Broad outcome possibility number one (1) is that the person gets diagnosed with OSAS, gets PAP treatment, and stops being sleepy and tired during the day. Outcome possibility number two (2) is that the person gets diagnosed with OSAS (with no obvious complicating factors), gets PAP treatment, and is STILL sleepy and tired during the day. Outcome possibility number three (3) is that the person does NOT meet the diagnostic criteria for OSAS (and seems to have no obvious complicating factors), so does not get PAP therapy, BUT remains tired and sleepy during the day.

UARS, in my opinion, is a term some doctors use to explain the reason further testing and variations of PAP treatment should be tried to help people in categories two and three.

One group of researchers may especially concentrate on those who fall into category number two (using PAP but still sleepy and tired) and another group of researchers may concentrate especially on category three (don't meet insurance definition of OSAS, but tired and sleepy). Those two groups of researchers are unlikely to think in exactly the same terms, even when they agree that some people seem to benefit from further testing and treatment with individualized forms of PAP therapy.

Some researchers may argue that more channels of testing are needed on NPSGs to better define what UARS is. Others may think that a person's feeling better after having PAP therapy tweaked especially for them is proof enough that some sorts of SDB beyond OSAS are out there that can be greatly helped with PAP. Researchers retitrating OSAS patients who are still sleepy may view what they do as basically chasing minor flow limitations. Those treating tired people without the OSA diagnosis might call it doing something else. But it all boils down to trying to make people feel better by pressurizing their airway and trying to find a way to get insurance to pay for it.

Any quality-of-life treatment lacking clear diagnostic guidelines is going to look suspicious to insurance companies, so the docs sometimes have to overstate their case when discussing how life-threatening UARS may or may not be. I don't blame them.

At least, that's how it looks from the view of the simple world I live in.

Re: Can cpap detect diff between central/obstruction? - one can!

Posted: Mon Mar 16, 2009 11:39 am
by rested gal
OutaSync wrote:If UARS is so deadly, why aren't more sleep centers testing for it?
viewtopic.php?p=276621#p276621

Read dllfo's post about pulling out the PES.

And my post about what a sleep tech said a doctor did.