Auto Data Interpetation

[brasshopper]

Pretty much all masks have engineered holes that are designed to give exhalations a place to go.

These engineered holes should always pass a certain amount of air at a certain pressure - that is, if you are getting pressure X, these holes should pass Y amount of air (probably measured in liters per minute) and if you track the pressure, you should see the leak go up and down with it - if the "leak" goes up when the pressure does not, it is a real leak and not just metered exhalation air exchange.

I searched but was unable to find a formula - and even if there was a formula, it would be dependent on the coefficient of the release nozzles. Probably best to just plot it for a time when you do not feel you had any bad leaks and then use that as a base to decide when your leak is worse.

[SnATLGa]

Thanks everyone. My leak number bugs me. I have the Comfortgel Petite pretty snug and can't believe it leaks much at all, yet I have a leak number you see above. I am nearly always sleeping on my back, SO, any ideas what is causing my leak level? I never hear any leakage before I go to sleep. Think the leak is due to the CO2 vents. If so, how are some people getting near zero leak levels? There must be some other issue. Any ideas what it could be?

[Handgunner45]

SnATLGa,

Some machines allow you to input the mask that you are using. It will then adjust your leak rate down by the manufactured exhaust rate of that particular mask. Your Remstar does not have that option. You would have to look at the paperwork that came with your mask and find out the exhaust rate for the pressure you are using. You could then subtract that from the leak rate shown on your data to determine actual leakage. Of course the exhaust rate will vary with the pressure that your auto supplies so this would be hard to nail down exact, but it should be able to get you close.

[SnATLGa]

Thanks for the input. I went to the Respironicswebsite and pulled up the brochure for the mask I have and it has a leak vs. pressure graph which shows the leak rate for my mask at 8-10 pressure is approx. 25, so I now feel like I have the mask adjusted properly and have done all I can do.Mu AHI went back to about 5 when I raised the top end pressure last night. It would be nice to see the AHI go down to less than 5, but I'm happy with the results I am getting regardless of the data.

[Guest]

I'm newbie here and have to introduce myself. My name is Alex, 28 y.o. from Hungary. I have been looking for such kind of forum for a long time and at least I'm here. Hope that I'll become a member of this community and finally get the answers on all my questions, and may be my experience will be useful for all the ppl around. My Geek code QA7fMi9imv2udB.

[rested gal]

While we're at it, I'm curious how to get the readings from my S8 Autoset Vantage. I thought the info popped up in the window in the morning but apparently you need to access the menu a little further. I was able to scroll through the basic menu but nothing was there about last night's data, and I assume that data will be erased at noon today. I do not have the smart card in yet. Perhaps that's the problem?

Any help is much appreciated.

Hi Rastaman,

GoofyUT gave you good instructions how "not to" access the clinical menu.

With most ResMed machines, if you want to quickly check your nightly results in the little window the next morning through the User menu (not the clinical menu) here's how:

1. Hold down the right arrow button.
2. While holding it down, press the left arrow button and hold it down, too...you're now holding both buttons down together.
3. After a few seconds, the words "Efficacy Data" "day"will appear in the window. Release the two buttons.
4. Press the Left button for "Enter".

You'll see "Press" (pressure) - I think that's the 95th percentile pressure. If so, that pressure AND pressures UNDER it were effective at preventing apneas and hypopneas 95% of the time during the night. It doesn't mean you spent 95% of the time AT that pressure.

Press the button under the down-arrow to go through the next items.

Leak
AHI (below 5.0 is doing very well)
AI
HI

To get out of the menu, press the righthand button under the word "Exit" a couple of times until you see the word "Settling" in the menu. You're out of the Efficacy data and the machine is ready to use again.

Important: If you want to see the data that way, without going into the clinical menu, you have to look at it before noon. At twelve noon that data from the night before disappears, cleared out so that the machine is ready to show new data the next day.

The data is not erased...it stays in the machine for downloading with a ResLink card. Just can't be seen in the display window via the User menu after midday. Can continue to be seen via the Clinical menu.

I can't remember if there's a setting that has to be turned on in the Clinical menu to let a person use the Efficacy data menu, or if that's already available to the User by default.

Getting to see quite a bit of data without having to use software is a cool feature on the ResMed machines...the Vantage and the Elite. The Spirit, too.

[Rastaman]

RG, Thanks for the details. I really do appreciate it. This is a new world and slowly I'm learning

Perhaps you or someone here can shed some light on these readings. I don't expect much because this is only 2 days worth of readings but if there is anything to gleen from them, I'd like to know about it.

Date: 6/8/2006

15.8
Leak: 0.70 L/S
AHI: 8.4
AI: 1.1
HI: 7.3

Date: 6/9/2006

15.4
Leak: 0.22 L/S
AHI: 7.9
AI: 0.6
HI: 7.3

*6/9 Went to a concert this night and had a few adult beverages.


Let me add that I've been having good luck with the Swift Mirage these last two days. So good in fact with medium pillows that I'm starting to wonder if I should cancel my mask switch-out for this Wednesday. I'm intrigued by the Mirage Activa. I just don't know how it might compare to my current mask. This Swift mask is VERY easy to clean and take apart and put back together again. I'm able to put the chinstrap on myself easily now and the mask.

Side question about the S8 Autoset Vantage, When I get up to get a drink of water I'm not sure if I should just disconnect the mask at the hose or actually hit the on/off button. With the Remstar Plus it auto-sensed me connecting the mask and would kick on in a few seconds. I liked that feature. I think this machine has the same feature but it must be turned off. I'm guessing because If I just connect like I did before it doesn't come on.


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CPAPopedia Keywords Contained In This Post (Click For Definition): AHI

[Rastaman]

How do I know what each number means?

[GoofyUT]

I'm having a similar experience with my S8 AutoSet Vantage. My numbers in terms of AHI are coming out consistently at 7-10. But they are almost hypops! I typically get AIs of 1.0 or less and HIs of 7.5 or more. As I've posted before, if I lie there awake after an arousal with it on, and check my numbers an hour later, my AHI will have increased by 1-2, and they will all be hypops.

Now, I understand that ResMed detects hypops different than most others (U shaped versus square-wave shaped hypops), but does this mean that my AHIs are artificially high, becaus emy HIs are artificially high?

RG-Thanks so much for the detailed instructions on getting efficacy data the easy way! Until Sergeant Bob posted them yesterday, I had no idea that you could access the data outside the Clinical Menu. Now, I know an easy way to do so. Best as I can tell, there is no way of making this available to users in the User's menus. You can enable SmartData which gives users access to Leak, Pressure and Usage in the users results menu, but that's it. BTW, ResMed reports pressures as 95% pressure as opposed to Respironics' 90% pressures.

Rastaman- The S8 does have a SmartStart feature which you can enable in the Clinical Menu settings menu. It works GREAT with a Swift. It'll turn the blower on within a second of your first exhalation into the Swift, and will stop the blower about 2 seconds after you take the Swift off. It doesn't work at ALL with an F&P HC431A, and I don't believe that it will work with any other mask with an entrainment valve.

Cheers!

Chuck

[GoofyUT]

BTW RM-

The first number is your 95% pressure. In your case, it means that 15.8 or less cmH20 is resolving 95% of your events.

The leak is your mask leak rate, beyond the bias rate of the Swift if you entered Swift as the Mask you're using on the mask menu in the settings menu. Both of the rates you list are decent (the 0.22L/s is better). I have many nights when my leak rate comes out at 0.00L/s, or 0.004L/s. Some come out at 0.16. I read a post from someone who says that, acording to what they ehard from ResMed, any leak rate below 4.0L/s allows the algorithm to operate OK, and above 4.0 the algorithm begins to degrade. That sounds awful high to me.

AHI= your apnea-hypopnea index. (Total Apneas + Total Hypopneas/Total time in minutes/60= Events per hour) Less than 5 is considerd to be normal. (Less than 5 events per hour)
AI=Apnea Index (same formula counting just apneas)
HI=hypopnea index (same formula counting just hypopneas)

Hope this helps.

Chuck[/i]

[rested gal]

I think the leak rate ResMed advises should not be exceeded is 0.4, not 4.0. But I've been known to plunk down decimal points in the wrong place many a time! Not on a check, yet, thank goodness.

You're right, GoofyUT, about ResMed reporting a 95th percentile pressure, and the other two major mfgrs reporting a 90th percentile pressure.

Leak rate is another difference in reporting. ResMed and Puritan Bennett report leaks in liters per second; Respironics in liters per minute.

[Rastaman]

So ideally I should want to see AHI of 5 or less then? Is that possible? And if I don't reach it, what does that mean?

I'm going to try and get the smarton feature to turn on. And I'm going to continue to monitor these results in a log book nightly.

Does anyone suggest me putting the datacard in? The DME didn't request that I do that but I do have a card and a bubble mailer, I assume in case they do ask me to do that.

[GoofyUT]

Thank you RG!!!

I was awful worried that ResMed was supposedly able to have its algorithm operate with a leak rate of 4.0L/s, which is torrential. The 0.4L/s makes much more sense.

Rastaman-
You can download data at any time by simple inserting the SmartCard into the slot in the back. I also got a blank bubble mailer and a protective folio for the SmartCard with my S8 Vantage. I learned yesterday that my pulmonologist (sleepdoc) only has Encore for Respironics, so my ResLink data won't do me any good with him. (Which raises the question as to why he ordered me a ResMed in the first place. Or maybe the DME pulled something funny. I'll find out Monday when I go for my FIRST check-up in the 10 FREAKIN' WEEKS since my sleep study, without so much as a "Hi! Howya doin'??" call from my sleep doc.) I'm gonna be true to my word here, and I AIN'T GONNA SETTLE FOR THIS CRAP!!!!!

So yes, you can download data to your Smartcard, and then mail it to your congressman or Santa Claus or Osama Bin Laden or someone like that in the nifty bubble mailer they give you, cause apparently no sleep professional bothers with ResMed AutoScan.

Frustrated Chuck

[DME_Guy]

I would raise your max pressure. I'm still not sure why anyone would limit the max pressure but I hear that a lot on this forum. If you need your pressure at 15 or 16 to prevent an event, why wouldn't you want that?

You did have a large leak for 3 minutes. That's not too bad. It's easy for the full face masks to become dislodged when you roll on your side. The average leak is due to the ehaust port on the mask.

The Respironics algorithm will raise pressure when it detects 3 or more snores in a minute. It looks like it did it's job there.

Overall, it looks good. Just raise the max pressure so you don't limit the machine and you should be doing even better.

Here is what I have:

Set on Auto w/ Cflex at 7-14.
90% Pressure=10.1 Avg 8.1.
AHI=5.4 with highest at 14 and lowest (2/3 of night) at 7.
Avg Nonresponsive index=.2.
Avg obstructive Apnea-1.9 with highest at 14 cm.
Flow Limitation=1.0.
Snore Index=23.4. Highest at 7cm and drops to <10 at 8+ cm.
Avg leak=37.3 Avg 90% leak=44.7. Avg large leak=3 min.
Avg Apnea 12 sec. Avg daily apnea=251 sec.
Avg daily flow limitation=.5/hr.
Avg daily variable breathing=33%.

[Rastaman]

[quote="GoofyUT"]Thank you RG!!!

I was awful worried that ResMed was supposedly able to have its algorithm operate with a leak rate of 4.0L/s, which is torrential. The 0.4L/s makes much more sense.

Rastaman-
You can download data at any time by simple inserting the SmartCard into the slot in the back. I also got a blank bubble mailer and a protective folio for the SmartCard with my S8 Vantage. I learned yesterday that my pulmonologist (sleepdoc) only has Encore for Respironics, so my ResLink data won't do me any good with him. (Which raises the question as to why he ordered me a ResMed in the first place. Or maybe the DME pulled something funny. I'll find out Monday when I go for my FIRST check-up in the 10 FREAKIN' WEEKS since my sleep study, without so much as a "Hi! Howya doin'??" call from my sleep doc.) I'm gonna be true to my word here, and I AIN'T GONNA SETTLE FOR THIS CRAP!!!!!

So yes, you can download data to your Smartcard, and then mail it to your congressman or Santa Claus or Osama Bin Laden or someone like that in the nifty bubble mailer they give you, cause apparently no sleep professional bothers with ResMed AutoScan.

Frustrated Chuck