PR System One Titration Question

I am titrating my minimum EPAP value on my PR System One machine.
I don't understand the relationship between the min EPAP, Max IPAP and PS values.
It's the PS part that has me confused.

My current min EPAP is 9 cm H2o, max IPAP is 20 cm H2O, and PS is 3.5.
The data reports the 90% avg EPAP is 10 and the 90% avg IPAP is 12.5.
The graphs show only about a 2 cm H2O difference between the EPAP line and the IPAP line.

My goal is to get my OSA index as low as possible without blowing out the CSA index.
Currently the OSA index is between 0 and 1.9, the CSA index is between 2.5 and 15.

Best overall was OSA 1.4 and CSA 2.5.

Comments, suggestions?????

JDS74 wrote:I am titrating my minimum EPAP value on my PR System One machine.
I don't understand the relationship between the min EPAP, Max IPAP and PS values.
It's the PS part that has me confused.

The PS number is the maximum difference allowed between EPAP and IPAP. So if IPAP - EPAP = PS and IPAP needs to be increased, the machine will increase both IPAP and EPAP at the same time. And when IPAP - EPAP < PS, and IPAP needs to be increased, only the IPAP will be increased and the EPAP will be left alone.

The minimum difference between IPAP and EPAP seems to be 2 on the PR S1 BiPAP Auto---at least as near as I can tell based on my own BiPAP Auto numbers. So if IPAP - EPAP = 2 and the EPAP needs to be increased, the machine will increase both IPAP and EPAP. But if IPAP - EPAP > 2 and the EPAP needs to be increased, the machine will only increase the EPAP and the IPAP will be left alone. And in my experience, the starting values for IPAP and EPAP are: EPAP = min EPAP value and IPAP = EPAP + 2.
(At least that's what happens in my (very low) pressure range of Min EPAP = 4 and Max IPAP = 8: the machine starts with IPAP = 6 and EPAP = 4.)

My current min EPAP is 9 cm H2o, max IPAP is 20 cm H2O, and PS is 3.5.
The data reports the 90% avg EPAP is 10 and the 90% avg IPAP is 12.5.
The graphs show only about a 2 cm H2O difference between the EPAP line and the IPAP line.

If your PS = 3.5, then the EPAP and IPAP will always be within 3.5 cm of each other.

The minimum difference between EPAP and IPAP is 2 cm. So if your EPAP and IPAP lines are always about 2cm apart, most of the time the pressure increases in both EPAP and IPAP are being driven by the need to increase EPAP when IPAP - EPAP = 2.

My goal is to get my OSA index as low as possible without blowing out the CSA index.
Currently the OSA index is between 0 and 1.9, the CSA index is between 2.5 and 15.

Best overall was OSA 1.4 and CSA 2.5.

Comments, suggestions?????

No real ideas on what you can or should be doing to bring that CAI down: But a CAI = 15 is way too high in my humble opinion as a patient, not a medical doctor. Is there a correlation between higher CAI's and higher EPAP or IPAP levels? What's the max EPAP and IPAP you've reached on nights with bad CAI's?

Hi . usually bipaps are meant for hypoventilation or shallow breathing at night. The difference in epap to ipap augments your volumes when you take a breath. But you have to have your own consistant respiratory effort. They don't always correct central sleep apnea or cheynne stokes respiration which is another central apnea. Were you diagnosed with central sleep apnea or cheynne stokes? It is very important to know that. There are different machines for central apnea.. they havea back up rate to breath for you... find out for sure what you have.. steve rrt

Thanks for the clear explanation of the PS part of my question. Changing the PS value would seem to not provide any difference.

I've only had a couple of nights with the CSA index as high as 15, most are down below 6.
The higher nights seem to be correlated with personal stress.

My diagnosis is OSA, CSA, Cheyne-Stokes, RLS, and PLMS with the initial AHI of 28.

So I gather that as I have moved from min EPAP of 5 to 9, I may be a little too high. The numbers were slightly better at 8 to 8.5.

I've had a few nights with the AHI below 5 in the process but the results vary.

Next step is to back off to 8.5 and see what happens for a couple of days.

It is my understanding that my insurance will be totally uninterested in paying for an ASV machine when I'm getting numbers near to or below 5 even though the Cheyne-Stokes continues.

Thanks again

Since you are thinking of lowering that EPAP a bit, you might also want to increase that PS a bit to allow the IPAP to increase without making the EPAP increase.

The PR S1 Auto seems to use data concerning Flow Limitations, RERAs, and Hypopneas to adjust the IPAP, and data concerning OAs and vibratory snores to increase EPAPs. I believe that it's not supposed to increase the pressure when it detects a CA.

I can't find anything in the literature that indicates the System One does anything but detect and report CA's. My data certainly doesn't show anything. Thanks for the hint of increasing the PS just a little. I'm going to move to a 8.5 cm H2O for the min EPAP and will change the PS to 4 from 3.5.

It's not supposed to do anything for a CA since the airway is already open. It is supposed to increase the EPAP if it detects two OA's (I think) close enough together. Or an OA with snoring. Or enough snoring.