Question about BiPAP settings

Well, after another sleep test, my Dr. says that BiPAP may be better for me as I am having difficulty with CPAP. My current CPAP setting is 14. The setting my Dr. wants for BiPAP is 19 and 13. Mr. Dr. says that the measurements are totally different than the CPAP ones. Is this true? I find it difficult to believe that my intake setting has risen that much in 2 months (give or take). Thanks

EPAP or the exhale pressure addresses apnea and is similar to CPAP. IPAP or inhale pressure addresses Hypopnea both can address snore.

EPAP is generally set to where it eliminates all frank apnea no higher. IPAP is increased higher to eliminate Hypopnea, the spread between the two (i.e. between your 19/13 setting) is called pressure support. They have you set with a 6 cm pressure support, did they give you a reason why like UARS?

Did they titrate you in the lab with that 19/13 setting? and how did you feel afterward? Or did they titrate you at 14 cm and your doctor decided you needed 19/13?

I was titrated at 18 and 13. The study recommended my pressure to be set at 19 and 15 (my error on previous post). I felt terrible after the test. Bad headache and exhausted!

I would try what they recommended, but if you don't feel better at home start bringing the IPAP down so it is only 3-4 cm higher than EPAP. If you lower EPAP, bring IPAP down with it.

If they gave you a copy of your study, look for a titration table, it should show the Apnea, Hypopnea and snore numbers seen at each pressure increase they tried.

But your EPAP only needs to be high enough to eliminate the apnea. I would drop the IPAP down to a 4 cm pressure support spread and see how you feel (i.e. use 17/13).

Feeling bad (not rested) and headache can be from too much pressure. If they where chasing that hocus pocus UARS then that would account for the 19/13 setting or 19/15 setting. But if they were chasing UARS, you should see a reduction of spontaneous arousals on your report, if there was no change there then no reason to tolerate the higher pressure. Obviously you are not feeling much better.

When you adjust pressure, adjust the EPAP to eliminate just the Apnea, then keep IPAP no higher than 4 cm above that unless you simply feel better with more pressure support.

Thanks for the help. I'll dive a little closer into the sleep study. I know that the second one was BiPAP all night, so maybe there is something there...

Unfortunately my sleep study results do not indicate any apnea or snores at any pressure. It's just a summary report. My big question though, is my CPAP setting of 14 different than the BiPAP setting of 19 and 15? I told me Dr. that the whole reason for me looking into BiPAP was because I had difficulty exhaling on the CPAP at 14. It appears that now it's even more pressure. Isn't that counterproductive?

DepDave wrote:My big question though, is my CPAP setting of 14 different than the BiPAP setting of 19 and 15? I told me Dr. that the whole reason for me looking into BiPAP was because I had difficulty exhaling on the CPAP at 14. It appears that now it's even more pressure. Isn't that counterproductive?

I think you'll be very pleasantly surprised at how easy it will feel to breathe out at 15 on a bipap machine set 19/15, than it did to try to breathe out against a straight 14 on CPAP.

I know it sounds weird, but most people (including me) find that it's just something about there being a difference in a higher inhale pressure and lower exhale pressure that makes exhaling feel VERY easy, almost regardless of how high that inhale pressure is.

I hope it's a Respironics bipap they give you. Respironics' bilevel machines have a feature that can be turned on called "Bi-Flex" which gives even more drop to the beginning of the already lower EPAP pressure. Makes getting the exhalation started that much easier. In the Respironics line, insist on the BiPAP Auto...don't accept the BiPAP "Plus" if you have any say-so in the matter at all. The Plus will give only "hours of use" info (compliance.) The BiPAP Auto, which can be set to operate in just bipap mode, so the DME should be willing to fill the prescription with that machine, records much more data...full data about your AHI, leak rate, etc. while sleeping. Encore Viewer software works with the BiPAP Auto.

If for any reason you don't like any of the Bi-Flex settings (similar to what C-flex does, Bi-Flex "1" gives the least extra drop, 2 gives a little more drop, and 3 gives the most drop...to the start of the EPAP) there is another "comfort" setting on the Respironics bilevel, called "Rise Comfort". That governs how fast the machine switches to the full IPAP pressure when you start to inhale. Can't use both those "comfort" features (Bi-flex and Rise Comfort) at the same time, but you can experiment with both to see which gives you the smoothest, easiest breathing. I prefer Bi-flex at 3, myself, but everyone's different.

When you get your bilevel machine, PM me your email address. If I have the Provider manual for the particular brand you're given, I'll be glad to email it to you.

I really think you're going to like "breathing" with a bilevel machine. Extremely comfortable.

Thanks rested Gal. I really appreciate your feedback. I hope I can tolerate it and start to feel better. Now the waiting game for the machine.

Mr. Dr. says that the measurements are totally different than the CPAP ones.

I was told by my doctor's office that the pressure numbers used are not equal for CPAP and BiPAP. I went from 17 on CPAP to 14/10 and then 16/11 on BiPAP. I was confused that my exhale pressure was lower and asked about it. I was told the same thing as you.

Well, I'm glad to know I'm not the only one that info was told to! I have been in contact with the DME company and voiced my concerns. Unfortunately I wasn't talk to a RT at the time. Gotta wait for their call...

I believe the Dr is telling the truth that Bilevels will produce different results for different folks.

For a very normal OSA person, the epap only needs to be set high enough to eliminate the obstructive apneas and keep the airway open enough that air can flow (and bare minimum snoring). The ipap pressure needs to be higher than epap and enough to reduce hypopneas and flow limitations to an acceptably low number.

The CPAP pressure is set to do both the above with one pressure. Thus, there isn't a good correlation between CPAP titration and Bilevel titration but some rules of thumb do seem to work - the RoT I rely on to convert a CPAP titration into a Bilevel titration is, if CPAP titration is over 10 CMs then set epap to that -2 and ipap to that +1. Min gap of 3 CMs.

For some people a 2 CMs gap will work well - thus CPAP titration -1 & +1 another option and one I would apply for when the CPAP titration is 10 or below.

Auto Bilevels are an interesting alternative - the one I have tried (and I know Rested Gal likes as well) is the Respironics tank Bipap Auto. While I haven't tried the M series version I am told is is equally as good. The other Bilevel Auto is the Resmed Vpap Auto & Slinky swears by it.

The difference between them has a lot to do with how the epap and ipap are adjusted. The Resp models monitor each (epap & ipap) separately & adjusts them independently within a set of rules to maintain a min epap-ipap gap. It doesn't allow a fixed gap to be set & starts the night with a default gap of 2 CMs. The Resmed Vpap Auto maintains the epap-ipap gap that gets set in it & will adjust both epap and ipap together. I couldn't say if one technique is better than the other having only ever tried the Resp Bipap Auto (with BiFlex) model & it is a good machine.

When ever I hear of someone having a prescription for an epap-ipap gap greather than 5 I wonder what other complication the titration showed up. If the epap to ipap gap gets set too far apart (& without good reason) there is the likelihood of triggering hyper ventilation in some people.

But as well all usually realize, everyone is different & what works best for one may not be at all good for another.

Good luck

DSM

izzyb wrote:

Mr. Dr. says that the measurements are totally different than the CPAP ones.

I was told by my doctor's office that the pressure numbers used are not equal for CPAP and BiPAP. I went from 17 on CPAP to 14/10 and then 16/11 on BiPAP. I was confused that my exhale pressure was lower and asked about it. I was told the same thing as you.

It all depends on the type of event was being taken care of with the pressure. On CPAP, the single pressure has to eliminate both the apnea and hypopnea and snore.

On Bilevel it can be different, for example: if you require say 14 CPAP to eliminate they apnea and get AHI down to 5 or less, it may only require 9 cm to eliminate the apnea, the rest of the pressure up to 14 may be to eliminate Hypopnea and/or snore.

So on a Bilevel, the two different pressures address SDB differently. EPAP or exhale pressure mainly addresses the obstructive apnea and vibratory snore. The IPAP or inhale pressure mainly addresses the hypopnea and flow limitation. If you have the Encore software with a Remstar Bilevel, it will even report these separate events under IPAP or EPAP at the bottom of the Daily Detailed report.

So once you know what each pressure does you can better fine tune the pressure on Bilevel which can result in a slightly lower pressure. And as RG mentioned you can better tolerate that higher pressure on a bilevel as opposed to CPAP. The higher IPAP pressure seems to mask the exhale effort even if it was the same as CPAP pressure was.

On a Adapt SV, you first titrate the patient on CPAP and find the pressure that eliminates the obstructive apnea (depicted in Respironics Titration Guide), then you input that setting into the EPAP pressure setting. The rest is pretty much automatic, it will adjust the IPAP pressure to control the breathing. The result is many times a lower pressure to eliminate apnea and settings to stabilize breathing through tidal volume manipulation.

But the basic rules apply, EPAP is adjusted to eliminate the frank obstructive apnea, then IPAP is adjusted up higher to eliminate the residual events it addresses and offer pressure support. When you titrate this, you start with IPAP the same as EPAP (i.e. CPAP) and/or with the smallest delta or pressure support. Some machines like the Auto won't allow you to set the pressures the same, they maintain a 2 cm delta.

So your doctor left off the "depends" part, as we didn't make this stuff up. Many times the EPAP pressure is the same as CPAP, it just depends on the events which make up your particular SDB events.

rested gal wrote:

DepDave wrote:My big question though, is my CPAP setting of 14 different than the BiPAP setting of 19 and 15? I told me Dr. that the whole reason for me looking into BiPAP was because I had difficulty exhaling on the CPAP at 14. It appears that now it's even more pressure. Isn't that counterproductive?

I think you'll be very pleasantly surprised at how easy it will feel to breathe out at 15 on a bipap machine set 19/15, than it did to try to breathe out against a straight 14 on CPAP.

I know it sounds weird, but most people (including me) find that it's just something about there being a difference in a higher inhale pressure and lower exhale pressure that makes exhaling feel VERY easy, almost regardless of how high that inhale pressure is.

I hope it's a Respironics bipap they give you. Respironics' bilevel machines have a feature that can be turned on called "Bi-Flex" which gives even more drop to the beginning of the already lower EPAP pressure. Makes getting the exhalation started that much easier. In the Respironics line, insist on the BiPAP Auto...don't accept the BiPAP "Plus" if you have any say-so in the matter at all. The Plus will give only "hours of use" info (compliance.) The BiPAP Auto, which can be set to operate in just bipap mode, so the DME should be willing to fill the prescription with that machine, records much more data...full data about your AHI, leak rate, etc. while sleeping. Encore Viewer software works with the BiPAP Auto.

If for any reason you don't like any of the Bi-Flex settings (similar to what C-flex does, Bi-Flex "1" gives the least extra drop, 2 gives a little more drop, and 3 gives the most drop...to the start of the EPAP) there is another "comfort" setting on the Respironics bilevel, called "Rise Comfort". That governs how fast the machine switches to the full IPAP pressure when you start to inhale. Can't use both those "comfort" features (Bi-flex and Rise Comfort) at the same time, but you can experiment with both to see which gives you the smoothest, easiest breathing. I prefer Bi-flex at 3, myself, but everyone's different.

When you get your bilevel machine, PM me your email address. If I have the Provider manual for the particular brand you're given, I'll be glad to email it to you.

I really think you're going to like "breathing" with a bilevel machine. Extremely comfortable.

Hi restedgal! Can you clarify how those "Rise Comfort" settings work? Do they increase the speed of the switch to full IPAP from 1 to 3, or do they decrease the speed from 1 to 3? Thanks.

I understood my doc to mean that a, for example, 17 on a CPAP is not the same pressure as a 17 on a BiPAP.