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PR, are you suggesting a try at auto BiPAP and let the machine seek its settings? That was kind of where I was at in post #1. I can change it to a CPAP if I want to. My purpose in doing this is to see if I can drive off the centrals that came when pressures got higher in APAP. FWIW, the auto CPAP never seemed to go higher than 14 cm for me and my 95% pressure is closer to 12.

This was written by jnk awhile back and explans the difference between ResMed and Respironics on how the PS works, it starts here- I think you may misunderstand the differences between the two machines and how each machine must be set. They are both good autobilevels, but you can't set either of them up correctly by attempting to use the numbers that were used on the other brand of machine. You have to think about the numbers and translate them for how you want the other brand of machine to run.

As an illustration, think of inhale and exhale as being two dancers. On the Respironics dance floor in the Respironics world, the two dancers dance two different dances without caring what the other dancer is doing. You simply set the size of the dance floor and you tell the dancers the maximum distance they are allowed to get from each other during their separate dances (there is an automatic minimum to keep them from bumping into each other), and they each do their own thing. Sometimes they dance close to each other, and sometimes they dance far apart. That distance varies. On the other hand, on a ResMed dance floor in the ResMed world, the two dancers do the same dance and are always the exact same distance from each other, but they can still roam the full dance floor, as long as they do it together. So if you mistakenly set the fixed distance of the dancers to be the same size as the dance floor, you keep the dancers from moving at all.

In other words, for the Respironics machine, you set the maximum IPAP and minimum EPAP (the size of the dance floor), then you set the MAXIMUM pressure support, or maximum distance allowed between the two separate pressures (dancers). For the ResMed, you similarly set a maximum and minimum (the dance floor), but then you set the ACTUAL pressure support, the fixed distance (or, difference) between inhale pressure and exhale pressure for the night. On that machine, those two pressures increase and decrease TOGETHER, NOT SEPARATELY, moment to moment, during the night (since the two do the same dance together).

squid13 wrote: In other words, for the Respironics machine, you set the maximum IPAP and minimum EPAP (the size of the dance floor), then you set the MAXIMUM pressure support, or maximum distance allowed between the two separate pressures (dancers).

you also set the minimum pressure support (at least on the 60 series) somewhere between 0 and maxPS

maxPS can be up to the difference between minEPAP and maxIPAP, or 8, whichever is smaller.

Sleeprider wrote:PR, are you suggesting a try at auto BiPAP and let the machine seek its settings? That was kind of where I was at in post #1. I can change it to a CPAP if I want to. My purpose in doing this is to see if I can drive off the centrals that came when pressures got higher in APAP. FWIW, the auto CPAP never seemed to go higher than 14 cm for me and my 95% pressure is closer to 12.

if you're going to use an auto bipap, you might as well experiment with it

what pressures seem to cause centrals?

if you know you need at least 11, then set the minEPAP to 11, then take a guess on maxIPAP, maybe 15?

for an exploratory session, I'd set minPS to zero and maxPS to 3 and see where it takes you, though you could go with four, and just let the pressures wander.

I've heard tales of people that get MORE centrals with the greater ventilation that a bipap (or twiddling with EPR on resmeds) give. that's why i think that den's suggestion of epap 11 ipap 14 or 15 (giving you a pressure support of 3-4 more than you're used to) could be bad. (aflex 1 gives up to a half a cm drop, if you're breathing very deeply, less for smaller breaths.)

if you liked the xflex of 1, then stick with that for comforts sake.

basically, I'm suggesting, a little experimentation, and see how it responds to you, and you respond to it

squid13 wrote:This was written by jnk awhile back and explans the difference between ResMed and Respironics on how the PS works, it starts here- I think you may misunderstand the differences between the two machines and how each machine must be set. They are both good autobilevels, but you can't set either of them up correctly by attempting to use the numbers that were used on the other brand of machine. You have to think about the numbers and translate them for how you want the other brand of machine to run.

As an illustration, think of inhale and exhale as being two dancers. On the Respironics dance floor in the Respironics world, the two dancers dance two different dances without caring what the other dancer is doing. You simply set the size of the dance floor and you tell the dancers the maximum distance they are allowed to get from each other during their separate dances (there is an automatic minimum to keep them from bumping into each other), and they each do their own thing. Sometimes they dance close to each other, and sometimes they dance far apart. That distance varies. On the other hand, on a ResMed dance floor in the ResMed world, the two dancers do the same dance and are always the exact same distance from each other, but they can still roam the full dance floor, as long as they do it together. So if you mistakenly set the fixed distance of the dancers to be the same size as the dance floor, you keep the dancers from moving at all.

In other words, for the Respironics machine, you set the maximum IPAP and minimum EPAP (the size of the dance floor), then you set the MAXIMUM pressure support, or maximum distance allowed between the two separate pressures (dancers). For the ResMed, you similarly set a maximum and minimum (the dance floor), but then you set the ACTUAL pressure support, the fixed distance (or, difference) between inhale pressure and exhale pressure for the night. On that machine, those two pressures increase and decrease TOGETHER, NOT SEPARATELY, moment to moment, during the night (since the two do the same dance together).

This is a very cool analogy, and one I can relate to. Thanks!

palerider wrote:

Sleeprider wrote:PR, are you suggesting a try at auto BiPAP and let the machine seek its settings? That was kind of where I was at in post #1. I can change it to a CPAP if I want to. My purpose in doing this is to see if I can drive off the centrals that came when pressures got higher in APAP. FWIW, the auto CPAP never seemed to go higher than 14 cm for me and my 95% pressure is closer to 12.

if you're going to use an auto bipap, you might as well experiment with it

what pressures seem to cause centrals?

if you know you need at least 11, then set the minEPAP to 11, then take a guess on maxIPAP, maybe 15?

for an exploratory session, I'd set minPS to zero and maxPS to 3 and see where it takes you, though you could go with four, and just let the pressures wander.

I've heard tales of people that get MORE centrals with the greater ventilation that a bipap (or twiddling with EPR on resmeds) give. that's why i think that den's suggestion of epap 11 ipap 14 or 15 (giving you a pressure support of 3-4 more than you're used to) could be bad. (aflex 1 gives up to a half a cm drop, if you're breathing very deeply, less for smaller breaths.)

if you liked the xflex of 1, then stick with that for comforts sake.

basically, I'm suggesting, a little experimentation, and see how it responds to you, and you respond to it

A sense of adventure!

I kind of agree, and it works with the Dance posted by Squid13. I sat down a few minutes with the fixed bilevel, and it feels pretty good. My centrals are not so much from over-pressure, but getting stuck at the bottom of the exhalation and just not inhaling. I sometimes get a pressure pulse from the APAP that kick starts things. So it's not an inability to exhale against pressure, it is just stopping. The bilevel seems to send a strong rush of pressure at that point and it feels pretty good, yet exhalation is relaxing. We'll see to night. I have no idea whether auto bilevel is better for me than fixed, but I'm not afraid to experiment a bit.

Thanks.

Sleeprider wrote:A sense of adventure!

I kind of agree, and it works with the Dance posted by Squid13. I sat down a few minutes with the fixed bilevel, and it feels pretty good. My centrals are not so much from over-pressure, but getting stuck at the bottom of the exhalation and just not inhaling. I sometimes get a pressure pulse from the APAP that kick starts things. So it's not an inability to exhale against pressure, it is just stopping. The bilevel seems to send a strong rush of pressure at that point and it feels pretty good, yet exhalation is relaxing. We'll see to night. I have no idea whether auto bilevel is better for me than fixed, but I'm not afraid to experiment a bit.

Thanks.

Try them both. You won't know till you try. I was just suggesting a starting point.


Den

.

I'll be starting there...Kind of like having a new toy, but geeky.

I'm not riding the motorcycle this time of year, or I'd be trying out the TPMS sensors for may Garmin Zumo 590.

See what I did there? More air pressure geekyness.

Too bad Pugsy is not online these days. She really has great insights on this kind of stuff, and I read her thread on trying out different bilevel machines. I would be lying if I didn't acknowledge some of the veteran members...including the Palerider who went to bilevel, event though their problems did not originally use that solution.

Interesting night. I didn't sleep well, but scored a 0.67 AHI, mostly on events while I was awake. The RERA was ridiculous at 2.39. I started the night in auto biPap and was awake at 3:30 and not falling back to sleep. I just felt over ventilated, and the differential pressure (pressure support 3.5) was too disruptive. So I switched to fixed BiPAP. Again, I had set it up with more differential than I needed.

So, while AHI results are good, I need to go back in with lower pressure support or pressure differential to not be awakened. Too early to conclude BiPAP is better or worse for me, although AHI was very good, it was not as restful as APAP I am more accustomed to after 7 years.

Do I understand correctly that if PS min = 0 and PS max = 0 then the unit will act as an APAP with equal IPAP and EPAP within the set range? Similarly if PS max is set to 3, then the IPAP EPAP pressures can vary by up to 3 cm, but may be anywhere from 0 to 3 at any point in time?

Sleeprider wrote:Do I understand correctly that if PS min = 0 and PS max = 0 then the unit will act as an APAP with equal IPAP and EPAP within the set range?

yes

Sleeprider wrote:Similarly if PS max is set to 3, then the IPAP EPAP pressures can vary by up to 3 cm, but may be anywhere from 0 to 3 at any point in time?

huh?

if psmax is 3, then ipap can get up to 3cm higher than epap, though no higher than maxipap.

Thanks. Sorry for being so confusing, I was probably thinking of Squid's dance moves.

Sleeprider wrote:Thanks. Sorry for being so confusing, I was probably thinking of Squid's dance moves.

the way you phrased it "if PS max is set to 3, then the IPAP EPAP pressures can vary by up to 3 cm" made it seem that you thought that the ps setting had some effect on epap. and while it indirectly can, it has more effect on ipap, since ipap=epap+ps.

though, if you set minepap 10, maxipap13, minps=0 maxps=3, then your pressures could range from

10/10 (epap is always second) to
13/10 to
13/13 and anywhere in between.

with the machine (and I'm guessing here) bumping epap for ah events, and ipap for snores and FL events.

That is very close to how it moved last night. I had minPAP 11 maxPAP 18 and PS Max 3.5. Mostly IPAP and EPAP stayed at 11, but 40% of the time IPAP moved higher, but no more than 2.5 above EPAP. The part of the night on auto biPAP was actually better for me than when I switched to fixed BiPAP.

Last night was a good night of sleep but AHI up to 1.3 and some pretty long FL OA events (up to 50 seconds combined). Used auto bi-level PS min 0, PA max 2, range 10.5 to 18

Will change to PS min 1, PS max 3 range 11 to 18, and see what that does. Pressure support in bilevel feels pretty good, but too much is disruptive.

I've been following this thread trying to learn about bilevel. I was wondering if you guys might have a link to the clinical manual for the machine Sleeprider is using. It might help me to read it so that I can follow this thread without asking off topic things. I'm asking those in another thread geared towards my newbie knowledge base, and I didn't want to pollute matters here. However, Sleeprider I am learning a lot reading about you working with the bilevel and the thoughts others are posting. Thanks for sharing, and I appreciate the point in the right direction.

Best,

Mike