Complex Sleep Apnea

[Sauron]

It may do that, too, but you had mentioned aerophagia was excessive when Pressure was 16 and EPR was 0.

When gradually increasing the Pressure up to 16, having EPR set to 1 would likely be reducing aerophagia, at least a bit.

I didn't explain that very well. I should have mentioned when I tried a pressure of 16 was several weeks ago before I had started reducing EPR. So when I tried 16 previously the EPR was set to 3.

[vsheline]

... when I tried a pressure of 16 was several weeks ago before I had started reducing EPR. So when I tried 16 previously the EPR was set to 3.

Nonetheless, when gradually increasing the Pressure up to 16, having EPR set to 1 would likely be reducing aerophagia, at least a bit.

After gradually increasing the Pressure to 16, you could turn off EPR to see whether it is better with it or without it.

[Sauron]

Nonetheless, when gradually increasing the Pressure up to 16, having EPR set to 1 would likely be reducing aerophagia, at least a bit.

After gradually increasing the Pressure to 16, you could turn off EPR to see whether it is better with it or without it.

Why would aerophagia reduce with higher EPR?

I had assumed (very probably incorrectly) that perhaps EPR would make aerophagia worse by the increase in pressure after exhaling "catching you by surprise"?

I'd like to understand the mechanics of it better.

[vsheline]

Nonetheless, when gradually increasing the Pressure up to 16, having EPR set to 1 would likely be reducing aerophagia, at least a bit.

After gradually increasing the Pressure to 16, you could turn off EPR to see whether it is better with it or without it.

Why would aerophagia reduce with higher EPR?

… perhaps EPR would make aerophagia worse by the increase in pressure after exhaling "catching you by surprise"?

Well, whether EPR increases or decreases aerophagia may depend partly on your individual breathing characteristics - like for example how quickly or slowly your breathing transitions between exhalation and inhalation. What I have said is what I have found to be true for me.

Without EPR, when we start to exhale the pressure will go up a bit before the machine recognizes it should reduce the airflow, to lower the pressure back to its target. The faster or harder we exhale, the larger the pressure increase before the machine reduces the airflow and lowers the pressure back to its target. Without EPR, during this time of momentary higher pressure is when I think aerophagia is most likely to start, with air getting pushed into the esophagus during exhalation and later swallowed into the stomach.

When EPR is on, the momentary higher pressure at start of exhalation is followed by a lower pressure for the remainder of the exhalation period (because EPAP = Pressure setting - EPR), which tends to lessen the likelihood of air getting pushed into the esophagus during exhalation and later swallowed into the stomach.

At the start of inhalation there is a slight suction into our lungs, which tends to decrease the pressure at the start of inhalation. Although EPR, if turned on, increases the pressure during inhalation, the small amount of suction created by our lungs inhaling may tend to lessen the likelihood of air getting pushed into the esophagus during inhalation and later swallowed into the stomach.

Also, since exhalation typically lasts up to twice as long as inhalation, the lower pressure caused by EPR during exhalation typically lasts most of the time, overall. (Unlike EPR, though, Respironics Flex lasts for less than half of the exhalation period, but Flex still covers the time of largest rate of exhalation.)

[Sauron]

Well, whether EPR increases or decreases aerophagia may depend partly on your individual breathing characteristics - like for example how quickly or slowly your breathing transitions between exhalation and inhalation. What I have said is what I have found to be true for me.

Without EPR, when we start to exhale the pressure will go up a bit before the machine recognizes it should reduce the airflow, to lower the pressure back to its target. The faster or harder we exhale, the larger the pressure increase before the machine reduces the airflow and lowers the pressure back to its target. Without EPR, during this time of momentary higher pressure is when I think aerophagia is most likely to start, with air getting pushed into the esophagus during exhalation and later swallowed into the stomach.

When EPR is on, the momentary higher pressure at start of exhalation is followed by a lower pressure for the remainder of the exhalation period (because EPAP = Pressure setting - EPR), which tends to lessen the likelihood of air getting pushed into the esophagus during exhalation and later swallowed into the stomach.

At the start of inhalation there is a slight suction into our lungs, which tends to decrease the pressure at the start of inhalation. Although EPR, if turned on, increases the pressure during inhalation, the small amount of suction created by our lungs inhaling may tend to lessen the likelihood of air getting pushed into the esophagus during inhalation and later swallowed into the stomach.

Also, since exhalation typically lasts up to twice as long as inhalation, the lower pressure caused by EPR during exhalation typically lasts most of the time, overall. (Unlike EPR, though, Respironics Flex lasts for less than half of the exhalation period, but Flex still covers the time of largest rate of exhalation.)

That all makes sense, thanks for the thorough reply. It didn't even occur to me that the aerophagia could occur while exhaling.

So far I haven't consciously noted any increase or decrease in aerophagia by lowering the EPR, and for whatever reason I seem to be getting better results without. So I think I'll leave it off while I gradually increase the pressure a little. If I have trouble with aerophagia again (or find exhaling too uncomfortable) I can always turn it back on.

I'm also trying to make only single (and small) changes now and leaving them for a week to get a bit of a trend before drawing any conclusions.

Slow and steady wins the race.

[vsheline]

So far I haven't consciously noted any increase or decrease in aerophagia by lowering the EPR, and for whatever reason I seem to be getting better results without. So I think I'll leave it off while I gradually increase the pressure a little. If I have trouble with aerophagia again (or find exhaling too uncomfortable) I can always turn it back on.

After you get up to 16 and have left it there for at least a week or two, I suggest changing EPR to 1 to see whether it improves or worsens hypopneas and aerophagia.

Again, on a ResMed Elite, having Pressure=16 and EPR=1 is the pretty much the same as having a bilevel ResMed VPAP S set to EPAP=15 and PS=1, which may decrease the number of hypopneas when compared to Pressure=15 and EPR=off.

Likewise, having Pressure=17 and EPR=2 is the pretty much the same as having a bilevel VPAP S set to EPAP=15 and PS=2, which may decrease the number of hypopneas when compared to Pressure=15 and EPR=off.

And so on and so forth. So in this way you can test whether a bilevel machine is likely to be of any benefit to you in controlling hypopneas or reducing daytime sleepiness

By the way, for many people having a few centrals while we are transitioning into sleep is normal and these centrals should be subtracted out before calculating the central hypopnea index and AHI. (Of course, the machine does not do that, so we will need to manually correct the AHI reported by the machine.)

Take care,
--- Vaughn

[Sauron]

After you get up to 16 and have left it there for at least a week or two, I suggest changing EPR to 1 to see whether it improves or worsens hypopneas and aerophagia.

I'll definitely do that, thanks.