Switched from PR System1 to ResMed AirSense 11 Autoset

ChrisD wrote: ↑

Mon May 02, 2022 1:30 pm

chunkyfrog wrote: ↑

Mon May 02, 2022 1:15 pm

I would FIRE any doctor insisting my cpap be left at factory defaults.
His JOB is helping me find an effective range for TREATMENT;

Factory defaults exist for some reason or other,
but I doubt they are appropriate for ANYONE but a very few.

I'll find out more tomorrow afternoon at a follow-up appt.

Thanks,
Chris

Met with the Nurse Practitioner of the Neurologist. She agreed that the pressure of 4-20 was "for newbs" and that I did the right thing in setting it to close to my original prescription of 11-14. She even suggested that I should set the ceiling higher, like 17 and monitor my numbers.

Also, suggested trying another new mask, the AirFit P30i. Should be an experience as I've never tried the nasal pillows before.

ChrisD wrote: ↑

Tue May 03, 2022 3:37 pm

Met with the Nurse Practitioner of the Neurologist. She agreed that the pressure of 4-20 was "for newbs" and that I did the right thing in setting it to close to my original prescription of 11-14. She even suggested that I should set the ceiling higher, like 17 and monitor my numbers.

Really. Why one could almost say that the doctors recommendation of arbitrarily switching your established (and successful) pressure of 11-14 to 4-20 was a stupid recommendation.

dataq1 and IAF should be along soon for more of their virtue-signaling.

I'm guessing IAF might have to go for another walk to cool off.

Dog Slobber wrote: ↑

Tue May 03, 2022 4:16 pm

Just trying to follow up with an honest question. Given that ChrisD is changing machines, is there harm in beginning his settings at 4-20 versus 11-14 ?
Previous reply suggested that a delay involved with increasing the pressure based on need (i.e. automatic increases) was problematic.
My question related to the length of that delay.

Mine is not just a idle curiosity. I have my settings set to 4-20, even though I tend to top out at approximately 14 -15. I obviously let the automatic pressure increase algorithm do it's job - raising when FL increases, decreasing when not needed.

Is that harmful or stupid?
I AM JUST TRYING TO LEARN.

BTW, good on you Chris D - wishes for continued success.

Tec5 wrote: ↑

Tue May 03, 2022 8:11 pm

Dog Slobber wrote: ↑

Tue May 03, 2022 4:16 pm

Just trying to follow up with an honest question. Given that ChrisD is changing machines, is there harm in beginning his settings at 4-20 versus 11-14 ?
Previous reply suggested that a delay involved with increasing the pressure based on need (i.e. automatic increases) was problematic.
My question related to the length of that delay.

Mine is not just a idle curiosity. I have my settings set to 4-20, even though I tend to top out at approximately 14 -15. I obviously let the automatic pressure increase algorithm do it's job - raising when FL increases, decreasing when not needed.

Is that harmful or stupid?
I AM JUST TRYING TO LEARN.

BTW, good on you Chris D - wishes for continued success.

Tec5,

It's my opinion that the "wide open" setting of 4-20 can be 1) a diagnostic tool to see where your apneas are so the settings can be fine tuned later with continual monitoring. 2) a setting by sleep docs to set it and forget it, trusting the machine to find and fix the apneas as long as you are using the machine the minimum number of hours per night for insurance compliance.

During my initial overnight sleep study they slowly increased the starting pressure until the occurrence of apneas subsided. With my starting pressure set at 11, the machine is preventing the apneas from even starting. If I do have an apnea, the machine is already at a pressure that increasing it will not take too long or be that noticeable to me while I am asleep.

My rational in setting the new machine to near the old prescription was that with those settings my AHI was consistently below 1.0 To me, that says it is working very well and I didn't want to mess with that.

Curious as to what your #'s are with the 4-20? Have you ever tried bumping up the starting pressure to see if your AHI comes down?

Thanks. Same back at you.

Chris

Tec5 wrote: ↑

Tue May 03, 2022 8:11 pm

Dog Slobber wrote: ↑

Tue May 03, 2022 4:16 pm

Just trying to follow up with an honest question. Given that ChrisD is changing machines, is there harm in beginning his settings at 4-20 versus 11-14 ?
Previous reply suggested that a delay involved with increasing the pressure based on need (i.e. automatic increases) was problematic.
My question related to the length of that delay.

Mine is not just a idle curiosity. I have my settings set to 4-20, even though I tend to top out at approximately 14 -15. I obviously let the automatic pressure increase algorithm do it's job - raising when FL increases, decreasing when not needed.

Is that harmful or stupid?
I AM JUST TRYING TO LEARN.

BTW, good on you Chris D - wishes for continued success.

Automatic machines do not try to "blow through" an apnea. As you noted, they try to preempt it by raising pressure when they identify flow limitations, and they respond by raising the pressure after an apnea had resolved and breathing resumes.

You can learn more here, for example:
https://www.resmed.com.au/healthcare-pr ... technology
Or by diligent searching for "algorithms" and Automatic titration, or words to that effect.

Also worth mentioning, from the above site, my emphasis:
In addition, the algorithm provides more subtle changes in therapy pressure to minimise sleep disturbance. The AutoSet for Her algorithm also automatically adjusts the minimum AutoSet pressure if multiple apneas are occurring below a certain threshold.

Tec5 wrote: ↑

Tue May 03, 2022 8:11 pm

Mine is not just a idle curiosity. I have my settings set to 4-20, even though I tend to top out at approximately 14 -15. I obviously let the automatic pressure increase algorithm do it's job

You don't understand how APAPs work, it have to be tuned properly to "do it's job"

Tec5 wrote: ↑

Tue May 03, 2022 8:11 pm

Is that harmful or stupid?

It's harmful to you, to your health,and to your sleep. therefore it's stupid.

Tec5 wrote: ↑

Tue May 03, 2022 8:11 pm

I AM JUST TRYING TO LEARN.

Are you? are are you just an argumentative troll.

Time will tell.

ozij wrote: ↑

Wed May 04, 2022 7:50 am

Also worth mentioning, from the above site, my emphasis:
In addition, the algorithm provides more subtle changes in therapy pressure to minimise sleep disturbance. The AutoSet for Her algorithm also automatically adjusts the minimum AutoSet pressure if multiple apneas are occurring below a certain threshold.

While that's a great first step in an actual 'auto' machine that one can just set and forget and get good treatment from, even the For Her resets to whatever the program defaults are every time you start a session with hit. it's always a brand new night as far as the machine is concerned, it has no parameter memory from previous sessions to guide it's behavior.

Unfortunately.

If the machines had a mode where they remembered that the average needed min pressure from the last week was 12.5 (for instance) and started with a min pressure of 12.5 automatically, then they really would be 'auto, self titrating' machines, but there are no known machines on the market that do that.

Probably because sleep doctors don't want machines that smart.

Can't we have a discussion that doesn't devolve into personal insults and invective - thereby derailing the topic ?????

I thought I asked why using 4-20 (min-max) considered harmful (or stupid)? Pugsey (if I can paraphrase) said that may take too long to react to an obstructive event. The obvious question then is how long does it take? Certainly if it takes 20 minutes, as Pugsey suggests a truckload of events could occur in the interim. On the otherhand, if a rise to effective pressure occurs in 1 minute, it's unlikely that a "truckload of events" would be seen. I say that not to repudiate Pugsey's position but to underscore that TIME is an essential factor, so my followup question is how much of a delay (lag in time) is involved.

Those of us who already know that they need a minimum pressure of 10, and that can tolerate an entire sleep session at 10... it is perfectly reasonable to set their minimum at 10.
But there are those of us (I am one) that get terrible aerophagia at a constant minimum of when in fact 85% of the sleep session is effectively treated with pressures ranging from 4-7 cm

So, is it harmful (or stupid) for my doctor and I to agree on a 4-20 setting?
And if it is harmful, I'd like to be able to coherently explain to my medical professional why it's harmful.

ChrisD wrote: ↑

Wed May 04, 2022 7:17 am

Curious as to what your #'s are with the 4-20? Have you ever tried bumping up the starting pressure to see if your AHI comes down?
Chris

Hi Chris,
Thanks for your reply.
I'll send you a private message tomorrow ( I should be sleeping now), explaining more fully where
I'm "coming from". For some reason, this thread has become a superheated personal platform, so maybe it's best we share privately.
Wishing you continued success with your transition.

Tec5 wrote: ↑

Wed May 04, 2022 9:56 pm

Can't we have a discussion that doesn't devolve into personal insults and invective - thereby derailing the topic ?????

I thought I asked why using 4-20 (min-max) considered harmful (or stupid)?

Asked and answered.

Why did you decided to derail the topic?

Tec5 wrote: ↑

Wed May 04, 2022 9:56 pm

On the otherhand, if a rise to effective pressure occurs in 1 minute, it's unlikely that a "truckload of events" would be seen.

It doesn't.

Tec5 wrote: ↑

Wed May 04, 2022 9:56 pm

So, is it harmful (or stupid) for my doctor and I to agree on a 4-20 setting?
And if it is harmful, I'd like to be able to coherently explain to my medical professional why it's harmful.

So, troll. Got it.

palerider wrote: ↑

Wed May 04, 2022 10:15 pm

Tec5 wrote: ↑

Wed May 04, 2022 9:56 pm

I thought I asked why using 4-20 (min-max) considered harmful (or stupid)?

Asked and answered.

Not really, see below

palerider wrote: ↑

Wed May 04, 2022 10:15 pm

Why did you decided to derail the topic?

It was you that introduced the notion that a 4-20 setting was stupid , and later that it was harmful.

NOW, Trying to get on track (and ignoring the flame throwing invectives), Perhaps my question is better understood by way of a graphic of an actual OSCAR report. For context in this snapshot:
Last prior event was CA at 1:17
Succeeding event was H at 4:40
no snores, no leaks, the only activity was low level FL

at 2:51:15 FL was 0.11, pressure was 5.09
at 2;51:30 FL now advanced to 0.20 and pressure increased 5.6 cm
at 2:52:00 Fl now ""steady" at 0.19 and pressured increased to 6.4 cm
at 2:52:15 Fl now "steady" at 0.20 and pressure increased to 7.07

It's pretty clear that in the face of a FL that increased by 0.09 units the machine responded in 60 seconds to increase the pressure by 2.0 cm (a 40% increase). In actuality, the machine responded within 15 seconds.

The settings on this machine are 4-20. Inspite of that, the response time is pretty darn fast.

And that is why I'm questioning the statement that a 4-20 is stupid or harmful, because it doesn't appear to be response time. So what is it?

You know, I knew this guy that lived half way up a hill that had an outhouse at the top of that hill. Every time he needed to relive himself, he would walk to the bottom of the hill and run to the outhouse at the top. When asked why he did that, he said that was how all his family members did it (about five) so he did it that way too.

Not many people around here thought that was a very good reason, but left him to his folly.

JPB

Tec5 wrote: ↑

Fri May 06, 2022 9:08 am

And that is why I'm questioning the statement that a 4-20 is stupid or harmful, because it doesn't appear to be response time. So what is it?

You are a troll who refuses to accept information.

I'm done wasting time with you.

You just keep your settings wide open and delude yourself into thinking you're getting good treatment.

For the rest of you, who aren't trolling and are open to new information, adjust your min pressure settings intellectually.

Another perspective on the 4-20 setting:

Sometimes that setting is used for home titrations. Once there is a week or so of data, the settings can be adjusted based on the data.

I think a low setting of 4 is little risky for the reasons already pointed out--many people feel like they are suffocating at only 4 cm/H2O, they can't get any pressure relief, and that discomfort can cause people to simply give up before they've even had a real chance. It would make more sense to start somewhere between 6 and 8, and that way new users can also experience some exhalation pressure relief which might be more comfortable, too. Open to 20 is OK for most, but, as some have pointed out, there are reasons for limiting the maximum pressure like aerophagia and sleep disruption. If there is a knowledgeable professional or user who can adjust accordingly, then an upper limit of 20 can be reasonable just as an empirical assessment, and let the data dictate if it should remain there or not.

I have seen some posts here about how the machine algorithms respond to apneas. I think Pugsy has posted about this before. The algorithms, from what I understand, do not respond quickly. They may send out a test puff of air to see if it's truly an obstruction, and raise the pressure only gradually to avoid overcorrecting or causing leaks. The adjustment to manage apneas can take several minutes, it's not instantaneous. There have been discussions about "chasing apneas" suggesting that when the lower number is set too low, it takes longer for the machine to respond to an apnea and therefore it may have to respond with a higher pressure than is actually needed because it takes a while to get on top of an apnea already in progress rather than preventing it in the first place. I seem to remember charts posted illustrating this. Therefore, the data can guide the setting of the lower number, at least. And some people do better at a fixed rather than an auto-adjusting setting--not everyone--but that's what the data can help determine.

A doctor who prescribes a setting of 4-20 to begin the titration process makes some sense, but a doctor who believes that a setting of 4-20 will "catch all the apneas" so that his or her job is done demonstrates ignorance about how the machines work. I don't think we have the answer about which category the OP's doctor falls into, because it sounds like the OP has a follow-up appointment with that doctor and perhaps the doctor will pay attention to more than just compliance data. I think the fact that the OP was already titrated and using CPAP for many years suggests that the doctor may be of the second category, but perhaps the doctor deserves the benefit of the doubt. More evidence is needed before concluding the doctor is "stupid" for suggesting the 4-20 setting, but I would think the doctor would at least look at the OP's previous levels and suggest a more refined setting even to titrate on the new machine.

They may send out a test puff of air to see if it's truly an obstruction, and raise the pressure only gradually to avoid overcorrecting or causing leaks.

That's what the Respironics machines do...that little test puff.
ResMed's do something a little differently called FOT. Explained (sort of) in the manual.
Both are for distinguishing centrals from obstructive in nature events.

Neither machine will increase the pressure if it thinks the event is central in nature.
Neither machine will increase the pressure DURING the apnea event even if obstructive in nature. It can't blow the airway open and it won't even try.
What it will do is evaluate things (OAs, hyponeas, FLs and snores) after the obstructive event has passed and make a decision based on what has been going on and then decide if it wants to increase the pressure or not and if it wants to increase the pressure how much and how much time to do it in. If someone has a lone OA or hyponea and doesn't have FLs or snores as well then there is a good chance the machine won't do anything for just one lone event.

I do think that the presence of FLs is likely going to be the primary driving force for a more rapid increase in pressure. We see that pressure response even without any flagged events showing up. Those graphs where people ask "why is my pressure increasing all the time and I don't have any events"....and then we look at the FL graph and there activity everywhere. It's very obvious that the machine is responding to the FLs.

As to one person's question about the time frame...the manufacturers never tell us exactly what the auto adjusting algorithm really uses to make its determination. They don't tell us how big the FL has to be to get a more aggressive response. They don't tell us how many OAs or hyponeas need to have happened within some sort of time frame to earn a pressure increase or how much FL needs to be going on with those OAs or hyponeas to earn a response.
There's a lot we just aren't ever told. It's probably somewhere in the patent but I have never bothered to look because I just trust the machine to do what it is supposed to do...I don't need to know the exact parameters. Doesn't matter what it is because I have zero control over the auto adjusting algorithm.
If someone just HAS to know what the time frame is...go dig up the patent and start reading.

Some people will do just fine with a minimum of 4....for various reasons it will work just fine for them.
Usually those people are the lucky ones whose OSA is very well treated and rather low pressures. Like maybe they only need 7 or 8 cm pressure to keep the airway open and the machine can go from 4 to 7 or 8 in a relatively short period of time. Now if someone happens to need 14 cm to hold the airway open then that 4 cm starting point might be a problem especially if someone doesn't have a lot of FLs to kick the machine in the butt and make it respond faster.