Why would an APAP prescription be lower than a CPAP?

[5thumbs]

My doctor prescribed 17 cm H20 CPAP. 17 was uncomfortable so I switched over to APAP with 9 as the lower setting and 17 as the high hoping to spend more time at lower pressures. My AHI went from 20-24 (untreated) to a 30 day average of 1.3 with APAP. My 30 day average 95% pressure is around 13 cm H20. I told my doctor this in preparation for my next appointment in a month and asked if I should set it to CPAP 17 cm H2O. Interestingly, this was his response...


"I reviewed your CPAP titration sleep study report. If you are going to use the Auto feature I would recommend a lower setting of 11 cm of water. But if the pressure is causing problems you can leave it how you have it set for now and we can discuss it further at your visit."

Why would you use a lower pressure on APAP as opposed to CPAP?

Also, I'm happy that he did not chew me out for messing with his prescription.

Thanks
5thumbs

[DoriC]

Good for you! That's why it's so important to be able to track your data. Don't forget, a sleep study is only one anxious night in a strange environment hooked up to wires and the tech may or may not be the most qualified. I'm hoping one of the pros will come by and answer your Subject question, it's a good one. Keep us posted.

[archangle]

"I reviewed your CPAP titration sleep study report. If you are going to use the Auto feature I would recommend a lower setting of 11 cm of water. But if the pressure is causing problems you can leave it how you have it set for now and we can discuss it further at your visit."

That sounds to me like he's recommending auto 11-17, which makes sense to me. He may be worried that 9 is too low.

What range do you think he's recommending?

[5thumbs]

DUUUGH! OK, I think you solved it! Makes sense as it is quite clear that he says lower setting AND he brings up that the added pressure is 11 (which is still under my 95% pressure of 13). This may be able to stop the AHI's before they start. I do notice that on some nights they clump together.

Thanks again, you are pretty smart (or I am pretty slow!).

5thumbs

[archangle]

Thanks again, you are pretty smart (or I am pretty slow!).

You're welcome. And don't worry, we all take turns exposing our moments of stupidity to the general public.

[avi123]

Why would you not leave it on APAP? Even if you set the max pressure on 17 cm in the APAP then the 95% pressure would be lower regardless of the min pressure setting.

See it in my case.

Notice in the ReScan Stats that I set the APAP on 13cm max, but the actual 95% pressure is 11.2 cm:



Once I get my optimal pressure graph I like to confine it between the max and the min:



Many Docs are not familiar with APAPs b/c usually there is no sleep study dedicated to APAP.

[archangle]

Why would you not leave it on APAP? Even if you set the max pressure on 17 cm in the APAP then the 95% pressure would be lower regardless of the min pressure setting.

I think it was just miscommunication and the doctor wanted APAP 11-17.