Use cpap machine for sleep study?

Is it possible to use the recording function of your cpap to determine your AHI number with no machine correction?

I messaged my sleep professional asking if a new sleep study might be called for and ,of course, got no reply.

As an asside, I got under the magic number [5] last night for the first time in my cpap career with almost no leaks. I feel really good.

GeneMpls wrote: ↑

Wed May 31, 2023 9:53 am

Is it possible to use the recording function of your cpap to determine your AHI number with no machine correction?

No.
Not possible because the machine has to be on to record and the lowest pressure available is 4 cm and that's still considered to be a therapeutic pressure.

No.

Your CPAP will always be creating positive pressure and treating you, although minimally. Therefore it will always being measuring treated therapy.

GeneMpls wrote: ↑

Wed May 31, 2023 9:53 am

I messaged my sleep professional asking if a new sleep study might be called for

Why would you want another sleep study? For most people, OSA is lifetime.

So I could dial in 4cm and get an approximation?

I had open heart surgery [unconnected] and my wife now sez that I do not have the noticeable apneas that she listened to for years before I resumed cpap and, aside from today, I have not noticed any of the positive physical markers that I enjoyed early in my cpap ride. I am just searching for info, I believe that sleep apnea is a forever thing [well, I am 77 so maybe not forever? ]

GeneMpls wrote: ↑

Wed May 31, 2023 10:48 am

So I could dial in 4cm and get an approximation?

No.

GeneMpls wrote: ↑

Wed May 31, 2023 10:48 am

So I could dial in 4cm and get an approximation?

1. Are you using OSCAR?

2. What are your current pressure settings?

Dog Slobber wrote: ↑

Wed May 31, 2023 10:51 am

GeneMpls wrote: ↑

Wed May 31, 2023 10:48 am

So I could dial in 4cm and get an approximation?

No.

you're so negative!

I have used Oscar from the start- I am now at 14cm which my sleep pro picked out last year. Everyone told me to bring my cpap to the hospital but no-one really wanted any part of using it. And I had other things on my mind after surgery. After rehab I have returned to cpap therapy but had a harder time the second time around- it is finally getting better/easier. Before surgery I would wake up and feel great, eyes wide. Now I don't get those feelings anymore. I am not trying to obtain permission to quit, more like looking for info about why it is so different [and why my sleep is now not the chaos it was before].

So you are using straight CPAP at 14.0 cm pressure. Yo

Here is how to find out some things and maybe optimize your machine settings. Change the mode to APAP with min pressure 12.0/max 20.0. Check the pressure line in OSCAR the next day. You are looking to see if the machine increased the pressure above 12.0. Let us know the results in this thread.

You are going to keep lowering the pressure until the machine makes significant increases in the pressure or events start to increase.

Taking any meds now?

Julie- I am taking a bunch of medications prescribed by my cardiologist [almost all different from the drugs I was taking for high blood pressure for most of my adult life [prescribed by my GP] My BP was often under 100 during cardiac rehab [they would check 3 to 6 times during/before/after the session].

CGranny- I am still trying to stabilize on the cpap, it has taken some perseverance as I had a lot of leak problems with F30i mask and taped mouth to prevent jaw drop. Finally getting good night sessions with mostly AHIs of 10 and a bit under. Surgery [ aortic valve and double bypass] was the end of January, so I am feeling mostly healed. It was not as bad as I expected [the recovery].

GeneMpls wrote: ↑

Wed May 31, 2023 9:53 am

Is it possible to use the recording function of your cpap to determine your AHI number with no machine correction?

4cm constant pressure is therapy (or your term “machine correction”, so strictly speaking the answer is no.

But comparing event indices between constant 4 and auto adjusting may be educational, if you are willing to look at a week (or more) at each condition for comparison purposes.

Consider what the sleep lab is doing when you are being “titrated”. They compare your body’s breathing response to various levels of applied pressure, to come up with an optimum suggested pressure.

I am going to post a couple charts for comparison- one before surgery [end of Jan, 23] and one now [jun 2,23] as the apneas seem like they would mean something.
Before surgery I could feel a real difference from a night of cpap treatment

https://www.dropbox.com/scl/fi/tk8so52w ... nv2372hnhx

And this one is from night before last I believe

https://www.dropbox.com/scl/fi/rlsy8a05 ... nlww0mpi9d

The apnea flags are really different now... and I do not feel the 'supercharge' like I did. I feel good [my heart function is way better] just different. For instance my hips felt fatigued this morning which they would sometimes before surgery, and feel good the next day. Thanks Gene

Based on your Jan chart, your Apnea's were grossly undertreated.
You had an AHI of 14!!!!!

Based on your recent chart, your Apnea is still undertreated.
AHI is till 5.53.

Some explanation for the difference:

• Variance, but a difference of 9.5 in AHI is unlikely to be explained by variance.
• The high AHI night you posted, you could have spent alot of time on back or with your neck kinked. There is a lot of clustering
• You did turn off EPR (2). This can explain a reduced AHI, as that effectively increases pressure by 2 cm, half the time.
• A combination of the above.

With a 14cm treated AHI of 5.53, you clearly still need CPAP therapy.

Having said that I would consider increasing your pressure, and switch to APAP mode.

But no, you're still in the CPAP therapy club.