How to make ranges in IPAP/EPAP settings?

I'm arising from my long-time lurker depths to ask for help on this one. New sleep doctor, who seems pretty good, gave me a new Rx, but I'm a bit stumped on how to input it. I have a Respironics Remstar Bipap Auto M Series. The new Rx is IPAP 8 to 20, EPAP 4 to 15. I've never been given a range before on each setting, just things like IPAP/EPAP 14 and 8. I've been fiddling with my settings for years and know how to change them, only there's no range setting like that which I can see. There's a Max IPAP and a Min EPAP setting in the display, with a support number that only allows the maximum of the difference between the two. (Do I sound like a math teacher?) So, for example, I can set EPAP/IPAP to 6 and 12, and the support number allows me to input a minimum of 3.0 and a max of 6.0. If I change EPAP/IPAP to 7 and 12, then the support number range is 3.0 to 5.0. So, any clues on how I do these ranges of IPAP/EPAP 8-20 and 4-15?

I'm forever fiddling with this machine, going auto vs non-auto and adjusting my pressures up and down. I don't make radical changes and adjust by .5 or 1.0 each time I make a change, and then I give it 3-4 weeks to try it, unless it seems a really bad change. I was on higher numbers (I/E of 16/12) which seemed to work well for about a year, but lately they haven't so I found a new doctor (last doctor visit was 3 years ago). They're horrified that I can change my own settings; they don't seem to realize how many of us are left high & dry with "Here's your magic machine. My doctor job is done." And they're silly in other ways, saying that if I don't want my mask to leak at night, then I shouldn't move while I sleep. Isn't that funny?!! Okay, so I'll wear a strait-jacket to bed or glue myself to the wall.

Anyway, my solution last night was to go with I/E of 9/6 with supp of 3. Actually a lousy night's sleep, but I think that's due to my body adjusting to the sudden drop from 12/8. (The doctor saw no need to phase in changes; thought I'd try her advice.) Spent 90% of my time at 8/6, so I figure I need to go lower on the EPAP setting. But still confused on how I input a range, or if I even need to since the point of an auto machine is that it should adjust the range as needed. Any advice appreciated! Thanks as always for everyone's contributions to this forum, which has been a lifesaver for me.

sonogo wrote:I'm arising from my long-time lurker depths to ask for help on this one. New sleep doctor, who seems pretty good, gave me a new Rx, but I'm a bit stumped on how to input it. I have a Respironics Remstar Bipap Auto M Series. The new Rx is IPAP 8 to 20, EPAP 4 to 15. I've never been given a range before on each setting, just things like IPAP/EPAP 14 and 8. I've been fiddling with my settings for years and know how to change them, only there's no range setting like that which I can see. There's a Max IPAP and a Min EPAP setting in the display, with a support number that only allows the maximum of the difference between the two. (Do I sound like a math teacher?) So, for example, I can set EPAP/IPAP to 6 and 12, and the support number allows me to input a minimum of 3.0 and a max of 6.0. If I change EPAP/IPAP to 7 and 12, then the support number range is 3.0 to 5.0. So, any clues on how I do these ranges of IPAP/EPAP 8-20 and 4-15?

If you look at the differences between the EPAP values and the IPAP values for those ranges, it looks like the doc is trying to say a PS of 4 or 5 with your particular machine with IPAP at 20 and EPAP at 4. That's pretty much wide open and let the machine decide. The overall range given is 12 cm H2O which seems to me a little large.

Didn't work for me as the machine doesn't react fast enough to correct an OSA without it disturbing my sleep. I started out with 20/5 and PS 3 and the best result I got with those settings was AHI of 10 or so. I'm now at a much narrow range and getting AHI's that vary from 2 - 5 mostly because of CSA's.


You don't say how the new Dx was developed. Did you have a new sleep study? Did your reports show excessive CSA's and the doc wants to lower the max pressure to see if these go down? Any discussion about the settings?

Yes, the Rx came from a new sleep study, the 3rd titration I've had in about 7 years. This last one wasn't very productive. For whatever reason, the lab environment was stressful and I only slept 4 hours, and not very deeply or normally, so they didn't have much data to work with.

They suspect I have centrals, and I do too, given what I read about others' experiences. The hope was that the lower settings would stop the centrals over time.

I don't quite understand the PS concept though. If you had a 20/5 setting, wouldn't you want your PS to be much higher so that the machine could react more quickly? Or maybe I should ask: just what is PS supposed to do? I thought it was about how fast and high the machine would react, but I must have it wrong.

jnk and Rested Gal have given good descriptions on how the Pressure Support works for both the Respironics and the Resmed bi-levels. Rested Gal just repeated them or a link to them w/in the last month, two months at most. The PS of the two manufacturers work considerably differently.

Basically, as I understand it, Resmed's Pressure Support locks IPAP and EPAP to w/in the Pressure Support range, i.e. if PS is set at 4, then IPAP and EPAP can wander anywhere w/in the range set BUT can never be further apart from one another than the PS setting. Resmed also does not recommend a PS greater than 10. Whereas PR's Pressure Support can range anywhere w/in the IPAP and EPAP pressure range as long as they get no closer together than the PS setting. But I am NOT the brightest candle on the cake so be sure to check out jnk's and Rested Gal's explanations.

The most common Pressure Support setting seems to be 4-5 cms. The 4 cms is understandable since Resmed's EPR maximum ability is 3 cms. PR never does tell us the maximum ability of their C-Flex and A-Flex but then there are some definite differences in just how the EPR and the Flex's work.

sonogo wrote:I don't quite understand the PS concept though. If you had a 20/5 setting, wouldn't you want your PS to be much higher so that the machine could react more quickly? Or maybe I should ask: just what is PS supposed to do? I thought it was about how fast and high the machine would react, but I must have it wrong.

The reaction time is part of the algorithm that lets the machine decide what is going on. It takes several seconds for the auto BiPap machine to separate a OSA from a CSA and then it either increases the pressure (OSA) or just records the event (CSA). ASV machines work differently and do react to CSA's as well as to other sleep anomilies. For me, this time allows me to struggle to breath and interrupts my sleep architecture making me sleepy the next day. Titrating the EPAP up to 11.5 got me to the place where mostly my obstructives are suppressed ( if EPAP is enough to keep the airway open, then there will be no chance that the airway will be closed during the inhale cycle. ) For me, and EPAP of 11.5 isn't enough the keep the airway open always so even with and IPAP of 14.5, there are occasional obstructives. This is a tradeoff with CSA activity and unless I switch to an ASV type machine, I'm just living with it.

It is my understanding that for Respioronics machines, the PS value controls the distance between IPAP and EPAP at any particular time. It is the maximum distance ( pressure difference ) allowed with a minimum being 3 cm H2O. So for a 20/5 setting and PS = 3 as my machine was delivered, the pressure starts at 8/5 and then starts adjusting depending on conditions from there. IPAP could increase to 9, 10, 11 etc. while EPAP could remain at 5. But if EPAP increased from 5 to 7 , for example, then IPAP would be forced ( by the minimum 3 cm H2O separation rule ) to move from 8 to 11.

On a little more shaky ground here but ResMed machines use the PS value as a fixed pressure difference so for a 20/5 setting, the pressures would start at 8/5 but any algorithmic change would affect both. So if the EPAP changed to 6, for example, then simultaneously the IPAP would increase to 9 and so forth.