Is there a minimum difference between IPAP and EPAP pressure

[old dude]

I know that this might be ordinarily called "pressure support" but since I use my Auto BiPAP machine in the fixed Bilevel mode I wasn't certain that PS would be the correct term. Anyway, I've been using pressures of 11/7 with good results, AHI normally ~ 1.0 or less. But my snoring seems to be creeping up a bit so I thought I'd try bumping my EPAP pressure up to 7.5 to see if that might help.

Is 3.5 cm enough of a spread between IPAP and EPAP, or does it even matter?

Thanks all.

[Pugsy]

The spread is mainly a comfort thing. You probably won't be able to "feel" much difference between 4 PS and 3.5 or heck, I couldn't tell a big difference when I tried 3 PS. When I got down to 2 PS then I could tell more of a difference in terms of how easy it was to inhale and exhale when compared to 3 and 4 (which probably is the most comfortable for me but I am okay with 5 also).
Hurts nothing to try it that I know of. People use less of a spread depending on needs and comfort.

[jnk]

If a bilevel is prescribed for comfort, making comfort adjustments may not matter. If bilevel is prescribed for some other reason, less delta (PS) may matter. Generally for sleep, the minimum delta considered actual bilevel therapy is 4.

As a general rule, IPAP is what addresses snores; EPAP is mostly about apneas, as I understand it. IPAP is for most everything else. But there are exceptions to every such rule of thumb, of course.

[old dude]

If a bilevel is prescribed for comfort, making comfort adjustments may not matter. If bilevel is prescribed for some other reason, less delta (PS) may matter. Generally for sleep, the minimum delta considered actual bilevel therapy is 4.

As a general rule, IPAP is what addresses snores; EPAP is mostly about apneas, as I understand it. IPAP is for most everything else. But there are exceptions to every such rule of thumb, of course.

Ahh jnk, I guess I was laboring under the false assumption that EPAP was what addresses snores, not the other way around. I got that impression from reading search results here, so perhaps I need to go back and search more.

I am guessing that the BiPAP was originally prescribed for comfort, but my original doctor didn't say for sure and at the time I didn't know enough to ask. My original Rx was pressures of 17/13 after an AHI of 131 at my sleep study. I've never had any indication that my case was complex.

Any way, I bumped my EPAP up to 7.5 last night but haven't yet downloaded the data to see if there was any improvement so I'll see I suppose.

Edited to add: With few exceptions, the majority of my AHI number is composed of Hypopneas. I very rarely have any OA events.

[jnk]

4.3.1.6

The recommended minimum IPAP-EPAP differential is 4 cm H2O . . .

4.3.2.5

IPAP may be increased . . . if at least 3 min of loud or unambiguous snoring are observed . . .

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2335396/

[The Latinist]

Generally for sleep, the minimum delta considered actual bilevel therapy is 4.

Indeed, the EPR on the S9 Elite and S9 Autoset provides a delta of 3.

[bavinck]

Generally for sleep, the minimum delta considered actual bilevel therapy is 4.

Indeed, the EPR on the S9 Elite and S9 Autoset provides a delta of 3.

So what does this imply for us that want to use EPR of 3 on our autoset?

[The Latinist]

Generally for sleep, the minimum delta considered actual bilevel therapy is 4.

Indeed, the EPR on the S9 Elite and S9 Autoset provides a delta of 3.

So what does this imply for us that want to use EPR of 3 on our autoset?

I don't know that it implies anything, necessarily. The only thing I think it suggests is that someone whose pressure relief needs are 3 cmH20 or less need not invest in a bilevel machine.

[jnk]

So what does this imply for us that want to use EPR of 3 on our autoset?

IMO, means you better watch data to make sure you don't need to raise your starting pressure in auto mode.

ResMed pulled a fast one by providing, virtually, bilevel comfort in a CPAP blower. Sneaky little devils.

The good thing about that is that it is super comfy for many. Bad thing is that it seems to lower pressure during exhale to the point that in the opinion of some, theoretically, that comfort feature can actually have an impact on therapy in straight CPAP by lowering prescribed pressure during exhale to the extent that apneas may be more likely to happen for some patients. Naturally, an Autoset will sense if that starts to happen and will compensate.

No biggie for most, even in straight CPAP, since many docs tend to tack on a few extra cm in the Rx, just in case.

But some of us who tweak and dial-wing to find our own optimal pressure in straight (as in non-auto) CPAP mode will raise our pressure on an S9 CPAP by the same number of cm that we use in EPR, just to make sure we have enough "EPAP" to prevent apneas. No reason to do that in auto mode other than to make sure starting pressure is within a cm or two of what we need to prevent apneas from the get-go. Data will show if EPR starts to have any impact.

Hope that helps. If not, ask away.

[bavinck]

So what does this imply for us that want to use EPR of 3 on our autoset?

IMO, means you better watch data to make sure you don't need to raise your starting pressure in auto mode.

ResMed pulled a fast one by providing, virtually, bilevel comfort in a CPAP blower. Sneaky little devils.

The good thing about that is that it is super comfy for many. Bad thing is that it seems to lower pressure during exhale to the point that in the opinion of some, theoretically, that comfort feature can actually have an impact on therapy in straight CPAP by lowering prescribed pressure during exhale to the extent that apneas may be more likely to happen for some patients. Naturally, an Autoset will sense if that starts to happen and will compensate.

No biggie for most, even in straight CPAP, since many docs tend to tack on a few extra cm in the Rx, just in case.

But some of us who tweak and dial-wing to find our own optimal pressure in straight (as in non-auto) CPAP mode will raise our pressure on an S9 CPAP by the same number of cm that we use in EPR, just to make sure we have enough "EPAP" to prevent apneas. No reason to do that in auto mode other than to make sure starting pressure is within a cm or two of what we need to prevent apneas from the get-go.

Hope that helps. If not, ask away.

Thanks for the response, very helpful. I am running 8-14 right now, with a very comfortable EPR of 3. I am finding the low end when starting I do not think 5 on exhale is providing the right support. My 90% pressure looks to be about 11-11.5. The autoset does not seem to want to go any higher than about 12-13. Was thinking of asking my doc is 10-15 with epr 3 might work better. I can live with less epr if I have to, but the epr 3 setting is really nice - and totally prevents mouth leaking.

[jnk]

My opinion (and I'm nothing medical) is that I wouldn't bother raising my pressure unless data showed that some apneas were happening. But that's just me. Autoset is pretty aggressive at getting the pressure up where it needs to be when it senses indications of obstruction. And home machines are very good at scoring apneas.

On the other hand, if you are someone with a brain that is super-sensitive to pressure changes during the night (and a number of us are), raising pressure to what you need most of the night may make for a more restful night.

In my opinion.

[The Latinist]

ResMed pulled a fast one by providing, virtually, bilevel comfort in a CPAP blower. Sneaky little devils.

The good thing about that is that it is super comfy for many. Bad thing is that it seems to lower pressure during exhale to the point that in the opinion of some, theoretically, that comfort feature can actually have an impact on therapy in straight CPAP by lowering prescribed pressure during exhale to the extent that apneas may be more likely to happen for some patients. Naturally, an Autoset will sense if that starts to happen and will compensate.

I'm not sure why you think that's sneaky. Perhaps it is inadvisable to have EPR on a machine that can't respond to changing pressure needs, but that doesn't really make it a sneaky move. As long as the patient is titrated with pressure relief, it shouldn't be an issue; and the S9 Elite does provide full user data including flow rate, so it should be possible for the patient and his doctor to adjust pressures higher or reduce EPR if necessary.

[jnk]

The sneaky thing is that a lot of docs don't understand the treatment machines. But if they did, some docs might not like the concept that a comfort feature available to patients can actually lower the pressure enough during exhale to impact the effectiveness of therapy, if that is actually so. (The docs are mostly there to diagnose and prescribe. After that, they mostly turn treatment over to the DME.) I hear that some machine people believe the competition delivers its comfort feature(s) in a way that is less likely to have a negative impact on therapy. I'm not smart enough to know for sure, myself.

But if it is actual bilevel in the sense of delivering two different pressures, it can be sneaky, in practice, to call it a CPAP. We now have a situation in which patients are being titrated in labs with CPAP but are getting treatment machines that are virtual BPAP. SUPER-sneaky!

And the feature has to be considered in the context of the average patient and the patient in the less-than-ideal circumstance, in my opinion. Many docs (the vast majority perhaps?) don't bother to look at treatment data. Many DME employees (the vast majority, perhaps?) don't look at efficacy data (and probably would have no idea what it means). Many patients (the vast majority, perhaps?) do not look at data. Thus the potential, at least, for some patients to be affected negatively by a full drop in the delivery of the prescribed pressure during exhale in a nonautotitrating machine.

In theory.

Love ResMed machines. Wouldn't turn my back on the company for a second, though. I'm no fan of any company with a minimum-allowed-price policy for Internet sales. Means to me they are working for the brick-and-mortar DME cartel instead of working for patients. Just my opinion.

[The Latinist]

That seems to me to be an issue of doctor incompetence and poor communications, not of sneakiness on the part of the manufacturer.

[jnk]

Doctors generally have no control over what brand of CPAP a patient gets, so it is insidious any time one brand acts very differently from another brand. Some docs don't prescribe autos for much that reason--the manufacturers are too secretive about their algorithms, so docs can't be sure how their patients will react and then can't be sure if it is the fact that it is an auto or the fact that a particular manufacturer's algorithm is not well-suited to that patient. Putting out a virtual bilevel that is marked as a CPAP could be considered by some much the same sort of shenanigans. It is the manufacturer's job to educate, clarify, and label--not to hide the differences in cloaking language that buries the difference in fine print. In my opinion.

In my case, I was prescribed bilevel but have switched over to the ResMed APAP, just to save my payers the unneeded expense of the increased cost of the bilevel. Wouldn't it be cool if that caught on and ResMed lost a bundle on fewer docs prescribing bilevels? I think that is part of the reason ResMed is less than clear, less than forthcoming, on it all.

But I tend to be a bit of a conspiracy theorist.

Maybe Snowden could get a job at ResMed and let us know what is really going on. He may find (to paraphrase Mother from "Sneakers") that their machines are made out of the same parts that NASA used when they faked the Apollo moon landings.