Questionable advice from Pulmomologist

wading thru the muck! · Post by **wading thru the muck!** » Sat Mar 19, 2005 7:26 am

Mikesus,

I am in agreement with Ted's description. I think Ted was confirming the point of view I was expressing. It shocks me that the medical community seems to be disjointed in their understanding of this. It is a dangerous thing when the person carrying out a prescription is not on the same page as the prescribing Doc.

BTW, how's that extended data analysis spreadsheet for the Encore Pro software comming along?

FL andy · Post by **FL andy** » Sat Mar 19, 2005 7:35 am

[quote="wading thru the muck"
In FL andy's specific case it is unclear what pressure he really needs because when he refers to clearing apnea events we don't know if he was told using derek's doc's, we call 'em all apneas, definition or if they were just full apneas, cleared at 13cm. My point is that whether this and other cases mentioned on the forum, have occured from lack of correct information or a misunderstanding of the correct proceedure, it is SCARY that this is occuring. To me, it is just another indication of the sad state the sleep disorder treatment industry is in.

Titrator and Wader,

Perhaps both of you are correct in what you present. My orignial titration was for a cpap not a bipap. The next sleep study will be to titrate specifically for a bipap setting.

my original cpap titration is summarized as follows:

EP IP MIN CA OA MA HYP AHI
5 4 5 0 3 0 1 46.2

6 6 6 0 0 0 0 0

7 7 49 0 4 0 1 10.4

8 7 12 0 1 0 4 27.3

9 9 11 0 2 0 2 21.8

10 10 15 0 0 0 5 20.8

11 11 10 0 0 0 0 0

12 12 82 0 0 0 1 1.0

13 13 23 0 0 0 0 0

17 14 57 1 1 0 1 3.2

I first tried a cpap for a few days and found my mouth soon filled with air and I was forced to open my mouth to expel the air pressure that had built up. My Internist said I cannot tolerate cpap and should go on bipap. He had the settings made to 13/9. I used this settin for only a few days and was done without a smart card.

Thinking that I should see someone more knowledgeable in sleep disorders I went to a Pulmomologist. He reviewed the complete sleeep study and changed the settings to 13/6.

I had the following "averages" from the smart card in a Respironics BiPap Pro 2, averaged over three weeks at a 13/6 setting.

OA 9.5
H 4.3
S 112.1

The reason I went to the Pulmonologist yesterday was to try to get the OA score under 5.

In any event, I think a *bipap* titration is in order. I am leaning towards waiting another month with the current settings and then getting a bipap titration study done. The destat SaO2 reading of 69 concerns me a little.

Derek's experimentation tells me not to worry too much about a score of 112 snores per hour - I have a 50 lb dog who is a mouth breather that sleeps on my bed and on the floor directly adjcent to the bipap and I know he many times interfers with the hose. I still don't know where the "sensor" or "sound detector" for snores is stored, but someday you guys will tell me.

I want you to know that I appreciate your advice to these specific statistics.

Andy

FL andy · Post by **FL andy** » Sat Mar 19, 2005 7:38 am

Too bad I cant get the spacing right in the above post.

Andy

derek · Post by **derek** » Sat Mar 19, 2005 10:01 am

Ozij aka Fascinated asked me to post FLandy's data in tabular form:

derek

FL andy · Post by **FL andy** » Sat Mar 19, 2005 10:29 am

Derek,

How ya do dat?

derek · Post by **derek** » Sat Mar 19, 2005 11:20 am

You don't want to know:

1) Cut the data from your post, saved it as a .txt file.
2) Imported into Excel, put borders around it.
3) Saved to a pdf file
4) Took screen-shot of pdf (Alt-PrintScrn)
5) Pasted into PaintShop Pro
6) Cropped the image
7) Saved as a jpeg image
6) Uploaded to my web server machine
7) Included in post using [img]...[/img]

I told you you didn't want to know....

FL andy · Post by **FL andy** » Sat Mar 19, 2005 11:32 am

Derek,

You're right. I shouldn't have asked.

I doubt I could do that when I used Windows XP. Now that I switched to a Linux OS, it's probably father along the learning curve than I am now..

Thanks for all your hard work on this list. We all appreciate you, I know I do.

Andy

Guest · Post by **Guest** » Sat Mar 19, 2005 11:39 am

derek wrote:You don't want to know:

1) Cut the data from your post, saved it as a .txt file.
2) Imported into Excel, put borders around it.
3) Saved to a pdf file
4) Took screen-shot of pdf (Alt-PrintScrn)
5) Pasted into PaintShop Pro
6) Cropped the image
7) Saved as a jpeg image
6) Uploaded to my web server machine
7) Included in post using [img]...[/img]

I told you you didn't want to know....

Why do I get the feeling that derek was doing all this while ALSO doing his taxes, reading a book, and talking on the telephone?! .....and having lunch.

Do you teach this stuff?
I can't even figure out how to do #6 and #7 and post pictures here to the message part. (and I'm a member but didn't log in)

-SWS · Post by **-SWS** » Sat Mar 19, 2005 12:54 pm

Ted, that great explanation helps me to understand too. This topic got me to researching a bit. Ted, Wader, EPAP pressure seldom if ever turns out to be the equivalent of what that patient's fixed CPAP pressure would have been if I understand correctly. Wader, I know this whole EPAP/IPAP titration method veers off the point that you were trying to get at, but I want to make sure I correctly understand the IPAP/EPAP titration method myself. I'm sure others would like to understand as well. To that end, Ted, do I now understand this correctly: EPAP always ends up being less than what fixed CPAP pressure would have been. EPAP is never "sometimes equal to" CPAP pressures (for some patients) as I had previously thought, right?

Also, if only hypopnea or flow limitation occur during expiration, then EPAP is not increased at that point in titration. Rather, EPAP will only be incresased to address full apnea closures that occur during expiration, right? If lesser hypopneas and flow limitations are detected during expiration then they are allowed to stand during titration without increasing EPAP. By the time EPAP gets high enough to address full apneas during expiration, then the (even higher) IPAP pressure only has partial airway closures to deal with on a residual basis. Right?

Also, if hypopneas and flow limitations are allowed to occur during expiration, are some patients at higher risk of CO2 retention---or is it that hypopneas and flow limitations never occur during expiration because the patient can make the respiratory effort to clear them once full-blown apneas are adequately addressed?

Ted, your clear explanations are MUCH appreciated by yours truly!

gailzee · Post by **gailzee** » Sat Mar 19, 2005 1:51 pm

wouldn't an apap be a better choice for this fellow?

Specifically one with software? he can show written "proof" to the naysayer no nothing, docs' who want a pc of sleep study action dollars and RT's wo are paid by same? Call me cynical, but I think an apap may work for him? Pressures sound high to me?

Just a thought or suggestion? Dr. probably won't like apap either.......

ooyy

wading thru the muck! wrote:I'm refering ONLY to conditions where Bipap is prescribed as an alternative to cpap for patients who have trouble tolerating a high pressure requirement. In that case it is COMPLETELY illogical to use the titrated pressure as the EPAP pressure setting unless the titration was wrong. So far nobody has said anyhting to convice me otherwise. Feel free to try though.

Mikesus · Post by **Mikesus** » Sat Mar 19, 2005 1:54 pm

He has an APAP, I think... He is just testing different pressures... Guess he is our resident Lab Rat

rested gal · Post by **rested gal** » Sat Mar 19, 2005 2:27 pm

This is the way I understand it, too:
SWS wrote:

EPAP pressure seldom if ever turns out to be the equivalent of what that patient's fixed CPAP pressure would have been if I understand correctly.

and this:

EPAP always ends up being less than what fixed CPAP pressure would have been.

For a long time I had thought that it took more pressure to deal with apneas than with hypopneas. But when you really think about the simplest definitions:

apnea = full closure of the throat
hypopnea = partial closure of the throat

...then one can see where it wouldn't take as much pressure to open the throat a little bit. Voila' - it's no longer an apnea! The throat is partially open now, so it now meets the definition of an hypopnea. But to get the throat FULLY open so that it no longer can be considered a hypopnea or a limited air flow - it takes even more pressure to push those tissues back completely out of the way.

I know there's more to the definition of apnea/hypopneas than that, but in simplest terms, the hypopneas are harder to prevent because it's harder to keep the throat fully open than it is to let it be partially open. Stopping the hypopneas and limited flow situations is the ultimate goal of a straight cpap titration.

The same principle would apply then to a bi-level titration. Stop the apneas down at the lower pressure (EPAP) while you're on the way to the real goal...that of stopping those pesky hypopneas in order to keep the throat fully open with a higher pressure (IPAP).

Titrator · Post by **Titrator** » Sat Mar 19, 2005 2:35 pm

Hi Gail,

Bilevel machines use software just like auto machines. The data is comprehensive, you get tidal volume and minute ventilation, respiratory rate. These are parameters you do not get with 99% of all autopaps.

SWS, I am trying to follow your line of thought, but there isn't hypopnea on exhalation if the apnea is completly cleared. The exhalation pressure is only used to clear apnea, this will allow a patient to blow off Co2.

A bilevel is used with many copd patients, or anyone who is known as a "retainer". Bilevel devices are also used with timed mode. The timed mode is used to control respiratory rate. For some patients, if you don't use a timed bilevel, they can possibly hypoventilate which will cause one to retain C02.

At the other end of the spectrum, a patient can experience hypercapnia, which is the same as hyperventilating. In other words, the CO2 drops out of range.

Bilevel machines are extremely interesting to me. It is concidered non-invasive mechanical ventilation.

Regards,

Ted

Guest · Post by **Guest** » Sat Mar 19, 2005 2:40 pm

Ted,

So is your description an explanation of why bipaps are for people with hypoventilation (which my doctor says I have)?

Titrator · Post by **Titrator** » Sat Mar 19, 2005 2:54 pm

Hi there,

hypoventilation can come from a number of sources. For me, hypoventilation comes from having weight around my middle. It makes it harder to get a full breath, and can disrupt your respiratory rate.

Some bipap machines use a backup rate. The machine will initiate a breath if you do not, or cannot. For people who normally breath spontaniously in the range of normal respiration, 12bpm to 20bpm, a garden variety spontaneos bilevel can be used.

People with central apnea from say a brain injury, will also use a backup rate to initiate a breath.

There are many, many instances that one would use a machine like this.

That's why the board certified sleep physicians make the big bucks.

Regards,

Ted

Questionable advice from Pulmomologist

I am afraid to ask.but...........