Flow limitation question

johantv wrote:Don't know what to think of these articles. Should I try the ResMeds EPR setting for pressure relief?

@tan, did you try the EPR settings? (My specialist advised me not to use it!). What I read it's just a pressure relief of 1,2 of 3 cmh20 at exhaling but not benificial to treatment. Tried it one of two night but didn't notice much difference.

Yes, I initially had EPR==2 set for my APAP, during my first two months. Then, I set EPR==3 for I like it even better and am not in favor of EPR==0 at all. But now I come to think that I should return it back to the original 2 and see what happens for there is said to be a big difference in how one feels and breaths in sleep and while awake.

palerider wrote:

johantv wrote:Don't know what to think of these articles. Should I try the ResMeds EPR setting for pressure relief?

@tan, did you try the EPR settings? (My specialist advised me not to use it!). What I read it's just a pressure relief of 1,2 of 3 cmh20 at exhaling but not benificial to treatment. Tried it one of two night but didn't notice much difference.

it drops your base pressure, in cm, by whatever number it's set to.

if you're on the borderline with just barely enough pressure to prevent events, then turning on epr will drop you below that level and you'll have more events.

so, if for example, your pressure is 10, and you turn on 3 epr, then your pressure will actually be 7, except when you're inhaling... and that can cause people trouble.

Hmm, never thought of that. This seems counter-intuitive to me: doesn't positive pressure get in the way of normal breathing on exhale? Isn't what Bi-level machines are for with their even greater range of EPR or its equivalent?

Can anyone, who has a refreshing night sleep and with a low AHI, please post a picture of their SleepyHead charts with Flow Limitations present? I am eager to compare them with mine.

tan wrote:

palerider wrote:

johantv wrote:Don't know what to think of these articles. Should I try the ResMeds EPR setting for pressure relief?

@tan, did you try the EPR settings? (My specialist advised me not to use it!). What I read it's just a pressure relief of 1,2 of 3 cmh20 at exhaling but not benificial to treatment. Tried it one of two night but didn't notice much difference.

it drops your base pressure, in cm, by whatever number it's set to.

if you're on the borderline with just barely enough pressure to prevent events, then turning on epr will drop you below that level and you'll have more events.

so, if for example, your pressure is 10, and you turn on 3 epr, then your pressure will actually be 7, except when you're inhaling... and that can cause people trouble.

Hmm, never thought of that. This seems counter-intuitive to me: doesn't positive pressure get in the way of normal breathing on exhale? Isn't what Bi-level machines are for with their even greater range of EPR or its equivalent?

If you "need" a pressure of 10 cm. to keep your airway open and EPR drops your exhale pressure to 7 cm., you could have apneas at the point of where you finish your exhale cycle and begin your inhale cycle.
The options are to reduce the EPR setting or increase the pressure setting.

Some people are affected and some arenn't. Some experimentation is necessary.


Den

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Wulfman... wrote: If you "need" a pressure of 10 cm. to keep your airway open and EPR drops your exhale pressure to 7 cm., you could have apneas at the point of where you finish your exhale cycle and begin your inhale cycle.
.

I see, but isn't natural to have a short pause between exhale and inhale? And doesn't the machine detect when an exhale ends and attempts to resume pressure for a next inhale?

In my case, I usually have only one-three OA/HA events a night complimented with a similarly few CAs.

tan wrote:

Wulfman... wrote: If you "need" a pressure of 10 cm. to keep your airway open and EPR drops your exhale pressure to 7 cm., you could have apneas at the point of where you finish your exhale cycle and begin your inhale cycle.
.

I see, but isn't natural to have a short pause between exhale and inhale? And doesn't the machine detect when an exhale ends and attempts to resume pressure for a next inhale?

no, as I said, the machine raises pressure at the start of an inhale. unless (iirc) you don't attempt to inhale for over 15 seconds, then it will suspend epr, raising the pressure back to ipap (or, set) levels.

just like bi-level.

tan wrote:

Wulfman... wrote: If you "need" a pressure of 10 cm. to keep your airway open and EPR drops your exhale pressure to 7 cm., you could have apneas at the point of where you finish your exhale cycle and begin your inhale cycle.
.

I see, but isn't natural to have a short pause between exhale and inhale? And doesn't the machine detect when an exhale ends and attempts to resume pressure for a next inhale?

In my case, I usually have only one-three OA/HA events a night complimented with a similarly few CAs.

It waits for your "effort" (inhale or exhale). It's not a "ventilator" and doesn't try to force you to breathe. In other words, it follows your breathing effort......these XPAP devices are categorized as "flow generators".


Den

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tan wrote:Can anyone, who has a refreshing night sleep and with a low AHI, please post a picture of their SleepyHead charts with Flow Limitations present? I am eager to compare them with mine.

Ok, I think I'm the opposite of what you asked for, because I think I'm in the same boat as you. Hopefully Pugsy will come back, because she was the one who looked at my FLs -- which look a lot like your FLs -- and said no wonder my pressures stay up!

I have been raising my minimum pressure because what I have been seeing is that my A10 blows right through the minimum as soon as the machine decides that I'm asleep, and then never returns unless I stop the machine and start a new session. Last night I tried a little experiment where I reached over and stopped the machine every time I woke up, so that I have a record of when I was awake. Interestingly, the pattern is that I have lots of FLs that drive my pressure up and up, and then the FLs back off and the pressure drops, and I wake up.

Everybody else complains about the high pressures waking them up, and the machine has lots of sophisticated software to keep the pressures down, but since everyday is Backward Day for me, I'm the poor slob who wakes up when the pressure falls!

cathyf wrote:

tan wrote: soon as the machine decides that I'm asleep, and then never returns unless I stop the machine and start a new session. !

the machine doesn't know whether you're awake or not, that's a feature of the 'for her', but, if you think about it, your throat doesn't relax and start giving you flow limitations while you're awake....

so as soon as you fall asleep, you start getting FLs and then the machine reacts to them.

tan wrote:Can anyone, who has a refreshing night sleep and with a low AHI, please post a picture of their SleepyHead charts with Flow Limitations present? I am eager to compare them with mine.

like this?

Here's one of my Flow limitation graphs from a while back. They are really boring.

Thanks for the answers, I'll try the EPR.
Any suggestions where to start? Now I have APAP 6-12, no EPR.
Should I start with APAP 7-12, EPR =1 and perhaps than go to APAP 8-12, EPR=2.

@Tan, My AHI is always low, so I can show you two graphs.

Below my Flow Rate when I tried CPAP 5 cmH2O (august)
The night had an AHI of 0.63. As you see lot's of FL's. Got very tired in August, so low pressure was not for me.


Below my Flow Rate at this moment APAP 6-12 cmH2O (yesterday)
The night had an AHI of 0.71. As you see still FL's, however they are not that high anymore.

thank you, everyone, for your responses, now I have a few pieces of some objective evidence to substantiate my subjective feeling that my treatment is not optimal.

It would be great, if more people with "normal" AHI posted their Flow Limitation charts here, please, and described how refreshing their night sleep was. I hope I am not asking too much.

johantv wrote:Thanks for the answers, I'll try the EPR.
Any suggestions where to start? Now I have APAP 6-12, no EPR.
Should I start with APAP 7-12, EPR =1 and perhaps than go to APAP 8-12, EPR=2.

@Tan, My AHI is always low, so I can show you two graphs.

@johantv, did you feel considerably better after the night with AHI==0.71 than after the one with AHI=0.63

cathyf wrote:

tan wrote:Can anyone, who has a refreshing night sleep and with a low AHI, please post a picture of their SleepyHead charts with Flow Limitations present? I am eager to compare them with mine.

Last night I tried a little experiment where I reached over and stopped the machine every time I woke up, so that I have a record of when I was awake. Interestingly, the pattern is that I have lots of FLs that drive my pressure up and up, and then the FLs back off and the pressure drops, and I wake up.

Could it be that you had waken up a bit earlier -- maybe even at or after the peak -- not realizing that and only after you were fully awake, only then you stopped the machine?