Varying AHI Readings on BiPap Auto SV Advanced

I am using a Respironics Bi-pap Auto SV Advanced. I am using an EPAP minimum and maximum of 8. Using the EncoreReader software, I am observing that my AHI readings vary quite a bit from day to day. I've had readings as low a 5 and as high as 16, with no particular pattern. Is this a normal range? During my sleep study my AHI was 30 (untreated) . Central apnea was observed, which is why I am on this particular machine, but the software is showing only about 1 per night now.

AHI readings of 5-16 aren't very good. Have you called your Dr. and let him know? On treatment, your AHI should be below 5. Can you post a shot of your nightly repoart?

Thanks for your reply. How can I post a screen shot? I did one and saved it as a .bmp file but I have no idea how to post it. Copy & paste doesn't work.

Do another screen shot but save it as a jpg file. BMP will be huge...

Once the image is cropped and saved to your liking you will need to upload that image to some photo hosting site. I use Photobucket. There are others.

Once you have it uploaded to hosting site, copy the IMG address of the image and paste it here in a post.
Must have the brackets on both ends or it won't show up.

Preview your post to see if the image shows up, if not try again.
Once you do it once, you will see it is very easy.

Most people here use Photobucket.com to keep copies of scanned reports in jpg form.. When you type in a reply here, use the [img] numbers from your image downloaded to that site to add here. The scanned report should show up. I hope i explained myself correctly. Good luck!

Ok- let's see if it worked ! I didn't quite understand the directions, so I've done it 2 ways.



http://s1235.photobucket.com/albums/ff4 ... =CPAP1.jpg

I copied the whole address from the img code box, it copied the IMG Brackets too
pasted here
should be able to see the image without having to go through the link. I am lazy And sometimes these links take a long time to load.

Hope you don't mind my doing this.

Could you take the time to add your equipment to your profile? It will help those that come here to see what your equipment is at a glance in a single post instead of having to search the thread.
Don't know how? Go to the upper left corner under the banner and click on User Control Panel. From your profile tab go to the Equipment tab and add what you use in Text please. Images of machines all look alike and again involves someone clicking on a link to see what you use.

You might also add Bipap Auto SV to your subject title. This will likely catch the attention of those members who can offer ideas based on their experience with your type of machine. I can help with the images but I can't help with your machine question.

Most of that AHI is hypopneas. If it were me, and I saw a report like that, I would raise my EPAP by 1 cm and see if that eliminated some, if not all of the hypopneas. When you raise the EPAP it will automatically raise your IPAP Min.

If you try it tonight, let us know how it goes.

Thanks. I updated the subject heading and also my equipment in my profile.

I have tried all different EPAP settings (ranging from 6 to 11) and none of them seemed to help. The AHI numbers are just all over the place. Here's a list of the EPAP's I tried and the resulting AHI's:

EPAP 6 - AHI 13 (and I felt just awful the next day)
EPAP 7 - AHI's 14, 4, 7, 13, 10, 9, 15, 9
EPAP 8 - AHI's 5, 4, 11, 13, 9, 8, 11, 6, 8, 11, 16, 7, 9, 12, 5, 16
EPAP 9 - AHI's 10, 14
EPAP 10- AHI's 6, 10, 12, 8, 7, 11, 14, 11, 13, 10, 10, 11
EPAP 11 - AHI's 10, 12, 9

So I actually get most of the lower AHI's at an EEAP of 8. But those AHI's are still way beyond what should be expected. I have had really no excessive leaks. The "expected" leak rate for my mask at an EPAP is 8 is 28 LPM. I average 29 to 32, which seems within an expected range.

I see my doctor next week. I guess he could order another sleep study, but that would seem a waste as a sleep study is just a snapshot of one night. I could have an AHI of 4 at a EPAP of 8 on the night of the study, only to have a 16 the next night.

Examining this purely for shape because IANAD. Why does your EPAP not bounce a little bit above the min EPAP setting? Does the BiPap Auto SV Advanced have both hard and soft limits for min EPAP? On mine, min EPAP bounces just a tiny bit. Secondly, does the IPAP tend not to ever approach the max pressure limit? When my IPAP spikes up its more spiky. Your IPAP seems to reach an even limit. Could that mean you need to increase the max pressure limit?

I have no access to my machines settings, curious how you are changing them?

By having your EPAP min and EPAP max set the same on this machine, you are eliminating of of this machine's significant advantages-- the ablity of supply therapy like that of an autoadjusting CPAP. The ASV part takes care of your central apnea issues, but does little to help more 'plain vanilla OSA' problems.

Here is what I would try (The usual IANAD disclaimers apply): Set your EPAP max 2 cm higher than your EPAP min, for starters. If this makes an improvement, try 3 cm. Stop if this aggravates your central apnea issues. You might also increase your max pressure slightly, if you find you are improving, but coming close to your max pressure.

As an example, on my ASV advanced, my EPAP min is 8 cm and EPAP max is 15 cm. This accommodates the significant changes I see in my therapy from day to day. This was the original prescription setting (the rest is in my signature), and I have not had to touch the settings in 9 months.

Good luck. You have a great machine, so you should be able to get great therapy.

Mr Bill wrote:I have no access to my machines settings, curious how you are changing them?

Take a peek here and see if this might shed some light on your question. Supposedly it should work with all the machines listed.

http://www.apneaboard.com/PR-System-One ... -Setup.htm

Thanks. I will increase my EPAP max by 2 tonight and see what happens. I learned how to change the settings myself.

Last night was the worst reading I have ever gotten: AHI was 21. At that level, I might as well not even be using the machine.

Will let you know tomorrow what I get with the increase EPAP max.

timbalionguy wrote:By having your EPAP min and EPAP max set the same on this machine, you are eliminating of of this machine's significant advantages-- the ablity of supply therapy like that of an autoadjusting CPAP. The ASV part takes care of your central apnea issues, but does little to help more 'plain vanilla OSA' problems.

Here is what I would try (The usual IANAD disclaimers apply): Set your EPAP max 2 cm higher than your EPAP min, for starters. If this makes an improvement, try 3 cm. Stop if this aggravates your central apnea issues. You might also increase your max pressure slightly, if you find you are improving, but coming close to your max pressure.

As an example, on my ASV advanced, my EPAP min is 8 cm and EPAP max is 15 cm. This accommodates the significant changes I see in my therapy from day to day. This was the original prescription setting (the rest is in my signature), and I have not had to touch the settings in 9 months.

Good luck. You have a great machine, so you should be able to get great therapy.

Timbalionguy,

Is this where the advanced machines are different from the older SVs? I don't believe I have a min EPAP and a max EPAP. I just have an EPAP and a Min and Max IPAP. My EPAP and MIN IPAP are the same with my max IPAP set 10 higher.

Bev