How to determine my current no-CPAP AHI

[BigWing]

Is it possible to set the min and max pressure on a CPAP machine to zero for one night, in order to simulate the original no-CPAP sleep test?

The reason I ask is that my first week of CPAP (using an Airsense 10 Auto with P10 nose pillow mask) has dropped my AHI from the 20 measured in my hospital sleep test to around 2.

However, the leak readings were a little high so I have just tried a chin strap last night for the first time, and it has improved my leak readings considerably AND dropped the AHI to 0.4. So I just wondered if the chin strap on its own would be sufficient for me.

Just a thought.

[PeaceLoveAndPizza]

In short. No. You cannot simulate the sleep test with a CPAP machine as the equipment used for both are vastly different.

Would a chin strap stop your apnoea’s? Likely not. The reason your AHI dropped from 20’s to 2ish is the CPAP therapy. The chinstrap only helped you get from 2 to 0.4.

[Gideon]

The closest you can do is set min and max to the machines min (4 cmw). You can tell if you still have apnea getting through at that level or that you are well tra=eated at that pressure.

The next step would be to get an inlab diagnostic sleep test to prove you are, for now, apnea free.

[SarcasticDave94]

Good pointers by the others. I just want to add that CPAP is a therapy not a cure. While you use it, you get the benefits. When you stop using it, the benefits also stop.

[PeaceLoveAndPizza]

The closest you can do is set min and max to the machines min (4 cmw).  You can tell if you still have apnea getting through at that level or that you are well tra=eated at that pressure.  

The next step would be to get an inlab diagnostic sleep test to prove you are, for now, apnea free.

G, would you please explain that further? I am not understanding how setting pressure to 4 would show anything other than how you would react to a pressure of 4. I get the in-lab diagnostic testing, but that is not at pressure. Once you add pressure it seems that you no longer can test for apnoea as you have added an external variable into the mix. Schrödinger’s CPAP?

It is an interesting thought though on how one can test oneself for apnoea’s using a CPAP machine…

[dataq1]

The most direct and short answer to the OP is, you have to subject yourself to a several* day sleep study to establish your typical AHI, then decide what level of "normal" you are willing to accept.

A less expensive, but fuzzy, approach is to configure your machine to constant continuous positive pressure of 4 cm for several days (preferably a week or more)  and then assess the difference between minimal treatment and one's normal treatment . 

I did this withOUT my wife's knowledge (as she insisted that APAP was doing nothing to improve her sleep after a year at APAP 6-20 and a 95% pressure of 10.5. Her AHI averaged 2 to 3. 

So I (having had her prior consent several months earlier) conducted a "minimal treatment test". 

She never recognized that I had changed her settings, and her subjective assessment of her sleep quality remained stable ...and her AHI increased about 1.5 point 

What we concluded after the test was that she was, in fact, getting some benefit from the additional (pressure) treatment. 

BUT beyond that, we felt that you just can't extrapolate the AHI to a zero pressure.
  
* I'm am of the conviction that a one-night sleep study, even under the most ideal conditions (at home, own bed, etc) is likely to NOT represent the typical or normal respiratory/sleep behavior, rather the one-night sleep study should be viewed as a snapshot in time, which might be typical but can just as easily be the occasional bad night - due to any number of conditions.

Just my opinion....

[BoxcarPete]

The minimal pressure test is certainly a good checkpoint for determining whether or not PAP can possibly be removed, but I wonder if there's any way to get some at-home sleep study hardware and keep it for oneself at any price, or if it's actually impossible to monitor your own off-PAP symptoms with real data in today's medical system.

[Gideon]

Gideon Wrote:[url=https://www.apneaboard.com/forums/Thread-How-to-determine-my-current-no-CPAP-AHI?pid=495685#pid495685][/url]The closest you can do is set min and max to the machines min (4 cmw).  You can tell if you still have apnea getting through at that level or that you are well tra=eated at that pressure.  

The next step would be to get an inlab diagnostic sleep test to prove you are, for now, apnea free.

1. Min Pressure test (The closest you can do is set min and max to the machines min (4 cmw)),  This IS STILL providing treatment, but on a PAP machine the min pressure is as close to zero you can get!  you can get one of two results

A. You show no apnea, thus you can conclude that you are well treated at that pressure, NOT that you are cured!
B. Sufficient apnea shows thus indicating that you are NOT apne free without CPAP

Given result A, The next step would be to get an inlab diagnostic sleep test to prove you are, for now, apnea free.

[DancesWithCats]

You could presumably run an oxygen monitor without cpap/apap and get some insight. Set a computer to record audio and/or video and gain some more. Not to a "clinical" standard unless you're going to go well beyond affordable equipment, but informative.

Buying a recording O2 monitor would have cost less and told me most of the important bits from my overpriced at home sleep study, and I'd still have it. So far I haven't bought one, but I probably should pry my wallet open one of these days.

[BigWing]

Buying a recording O2 monitor would have cost less and told me most of the important bits from my overpriced at home sleep study

That's an interesting thought. There is one at Amazon by ViATOM for just £19.99 which says it will do that [sorry - the forum would not let me include a link to it].

Would that data effectively highlight apnea events?