Aerophagia w/ BiPAP

I've used a CPAP for 2.5 years and have had aerophagia. My doctor prescribed me a BiPAP (Resmed S9 Auto BiPAP). My aerophagia has not improved. Does anyone have any idea what settings are availabe to tweak that could possibly help with the issue? The doctor prescribed a min EPAP of 6, Max PS 6cm. Max pressure of 13 cm. This was based on a BiPAP titration sleep study. I don't want to deviate from the doctor's prescription, but if there are other settings the respitory therapist could modify (user type preferences), I would want to investigate that. Any thoughts?

Mr Sleepy wrote:My doctor prescribed me a BiPAP (Resmed S9 Auto BiPAP). ... The doctor prescribed a min EPAP of 6, Max PS 6cm. Max pressure of 13 cm. This was based on a BiPAP titration sleep study. I don't want to deviate from the doctor's prescription (emphasis added)

Asking for clarification here. There is no such machine as a Resmed S9 Auto BiPAP. The current auto bi-level from Resmed is called the S9 VPAP Auto. And then there is the PR System One REMStar BiPAP Auto that is made by a different company. To help you figure out which machine you actually have, here are pictures of both auto bi-levels.

The Resmed S9 VPAP Auto looks like this:


The PR System One BiPAP Auto looks like this:

It's important to know which machine was actually prescribed and which company's bi-level titration machine was used for your titration study because the Auto algorithms for the S9 VPAP and the System One BiPAP work quite differently from each other with the prescribed settings of min EPAP = 6, max IPAP = 13, PS = 6. On the S9 VPAP, that PS setting is the constant difference between IPAP and EPAP: In other words, IPAP - EPAP = PS all night long. On the System One BiPAP, that PS setting is indeed the max PS. In other words, 2 <=IPAP - EPAP <= PS all night long.

An example using your prescribed settings illustrates the differences in the two machine's algorithms and how they affect the pressure settings.

If you are using a Resmed S9 VPAP with the settings:

• min EPAP = 6
  PS = 6
  max IPAP = 13,

then your pressures actually are doing the following: At the start of the night, EPAP = 6 and IPAP = 12. Notably the EPAP and IPAP will increase and decrease together so that IPAP-EPAP = 6 all night long. Hence we get these ranges for the pressures:

• 6 <= EPAP <= 7
  12<= IPAP <= 13
  IPAP-EPAP = 6

And note that this is a pretty tight Auto range.


If you are using a PR System One BiPAP Auto with the settings:

• min EPAP = 6
  PS = 6
  max IPAP = 13,

then your pressures actually are doing the following: At the start of the night, EPAP = 6 and IPAP = 8. Note that on the PR BiPAPs, the EPAP and IPAP are increased for different reasons. On the PR BiPAP Auto, the IPAP is increased for flow limitations, RERAs, and hypopneas, and the EPAP is increased for snoring and OAs. And this means that during the night the difference between IPAP and EPAP is also allowed to vary. The PS setting controls how far apart the IPAP and EPAP pressures are allowed to get. With a PS = 6, that means that all night long the machine must maintain 2<= IPAP - EPAP <= 6. And so here's the basic strategy for increasing pressures on the PR BiPAP:

• If IPAP-EPAP=2 and the EPAP needs to be increased, both IPAP and EPAP will be increased. (If the IPAP needs to be increased, only IPAP will be increased.)
• If 2 < IPAP - EPAP < 6, then IPAP and EPAP will be increased independently of each other. If snoring is detected, only the EPAP will increase. If a couple of hypopneas are detected in a short period of time, only the IPAP will be increased.
• If IPAP-EPAP = 6 and IPAP needs to be increased, then both EPAP and IPAP will be increased. (If the EPAP needs to be increased, only the EPAP will be increased.

The upshot of this much more complex algorithm for increasing pressures is that pressure settings will stay in the following ranges during the night:

• 6 <= EPAP <= 11
  8 <= IPAP <= 13
  2 <= IPAP - EPAP <= 6

which is a rather different set of pressure ranges than the S9 VPAP Auto with the same settings.


Please keep in mind that many sleep docs don't really understand the differences in the Auto algorithms for the S9 VPAP and the PR System One BiPAP. They often think both machines work the same way when it comes to how they adjust the pressures during the night. And since you do NOT want to "deviate from the doctor's prescription", the first thing you should do is to call the doc's office and try to verify exactly what the doc had in mind when s/he wrote the prescription for min EPAP = 6, max IPAP, max PS = 6. You also should find out whether the bi-level titration was done using a Respironics BiPAP titration machine or a Resmed VPAP titration machine.

If the doc wants you to have a wider EPAP range than 6--7cm, then it could be that the only way you'll be able to get the intended prescribed pressure range is for the DME to swap the S9 VPAP out for a PR System One BiPAP Auto.

Good luck in determining exactly what it is your doc intended to prescribe for you AND in getting your machine set up so that it works the way the doc wants it to work.

Robysue,

Thank you so very much for all of the information. I believe you solved my problem. I was actually prescribed a PR System One BiPAP Auto. When talking to my DME provider, I told them I was very interested in a the Climateline hose as I had humidity issues and excessive rainout (even with a hose cover). The DME ended up selling me the Resmed S9 VPAP Auto with the Climateline. I suspect they programmed the Resmed with the PR System One prescription settings. As you pointed out, that could have very different outcomes. I will go back to my doctor and see if he is comfrtable with me having the Resmed unit, and if so, see if the settings prescribed need to be modified.

I really can't thank you enough. That was a lot of information you were kind enough to share.