AirSense AutoSet - different approach to titration?

Hey,

I've been titrating my CPAP for a few weeks now trying to find the sweet spot. There's a few things I don't understand when it comes to self-titration. A lot of resources claim that you should ideally keep your minimum pressure 1-2 cm below your median. This doesn't really make much sense to me. AirSense AutoSet works by increasing minimum pressure AFTER it detects an OA to prevent further events... then it steadily drops the pressure all the way back to the set minimum. And another OA occurs. Shouldn't the ultimate goal be to ideally prevent ALL OAs?

Even if your AHI is 1, of which it's an OA every hour of your sleep then your sleep still gets disrupted quite a lot... I find myself definitely less rested if my OAs are distributed throughout the night than if they're clustered together in a single event.

Shouldn't we be aiming to have our minimum pressure very close to 95%? That way we'd theoretically prevent any OA from occurring. This is of course if you can tolerate the pressures in your 95% and don't develop a lot of centrals due to the higher pressure...

What do you think?

SleepyTony wrote: ↑

Tue Feb 06, 2024 6:38 am

Shouldn't the ultimate goal be to ideally prevent ALL OAs?

IMHO that's an unrealistic goal and if that's the only goal it will probably drive a person nuts.

My own personal goal.....sleep good and feel good no matter what the "numbers" say.

AHI of 0.0 doesn't necessarily mean a person has slept great and will feel great the next day as evidence by all the people who come here with sub 1.0 AHI numbers yet they complain of crappy sleep and feeling crappy when they thought they should feel like superman/superwoman.

SleepyTony wrote: ↑

Tue Feb 06, 2024 6:38 am

Shouldn't we be aiming to have our minimum pressure very close to 95%? That way we'd theoretically prevent any OA from occurring.

Not necessarily the holy grail of "numbers" that 95% number. It's too easily skewed to the high side by relatively short periods of time at a higher number. There are situations (like REM stage sleep pressure needs) where the 95% number isn't necessarily where the minimum pressure needs to be.

You want to use a minimum pressure of 16 ALL NIGHT LONG just to take care of REM related pressure needs and REM compromises of maybe 20 % (if we are lucky and normal) when the other 80% of the night a minimum of 9 cm does a great job holding the airway open???? That's what I would have to do if I followed your reasoning and while I could maybe do it....I sure don't want to. My own OSA is 5 times worse in REM stage sleep (this is a common known fact) and sometimes I need a LOT more pressure during REM.

People need to be able to look at and evaluate the big picture and not just a single "number" because "numbers" alone don't tell the whole story.

I prefer a case by case evaluation of pressure needs myself instead of blanket statements that don't take into account the big picture.

OAs are not the only metric that the ResMed algorithm responds to.

When the algorithm detects snore, flow limitations and hypopneas it also increases pressure. Responding to these, prevents all or most OAs.

Setting your minim pressure against your median (median what???) or 95% (95% of what???) is nonsense. There's no magic measurement that one sets the pressures to and that's the sweet spot.

To find ones optimal, minimum pressure, set the minimum pressure to a value close. This can be arbitrary if absolutely new or your median pressure if you have some history. your then use your machine, gather statistics. You then adjust, typically upwards, you're looking to flatten the pressure trace, reduce abrupt swings, reduce flow limitations and events.

When on a pressure, stay there a while, don't let a single night influence. as you get closer, the increments should get smaller and smaller.

A goal of 0 OAs is unreasonable, I get them all the time, but not getting them is no big deal.

SleepyTony wrote: ↑

Tue Feb 06, 2024 6:38 am

Shouldn't the ultimate goal be to ideally prevent ALL OAs?

No, the end goal is to feel energetic and without excess sleepiness the next day.

If you want to pour over statistics, start clicking on the Events tab in the OSCAR Daily View. See how long your OAs are. In my case, the short apneas are inconsequential to how I feel the next day.

Dog Slobber wrote: ↑

Tue Feb 06, 2024 7:04 am

OAs are not the only metric that the ResMed algorithm responds to.

When the algorithm detects snore, flow limitations and hypopneas it also increases pressure. Responding to these, prevents all or most OAs.

Setting your minim pressure against your median (median what???) or 95% (95% of what???) is nonsense. There's no magic measurement that one sets the pressures to and that's the sweet spot.

To find ones optimal, minimum pressure, set the minimum pressure to a value close. This can be arbitrary if absolutely new or your median pressure if you have some history. your then use your machine, gather statistics. You then adjust, typically upwards, you're looking to flatten the pressure trace, reduce abrupt swings, reduce flow limitations and events.

When on a pressure, stay there a while, don't let a single night influence. as you get closer, the increments should get smaller and smaller.

A goal of 0 OAs is unreasonable, I get them all the time, but not getting them is no big deal.

I think I just learned something VERY valuable, thanks! I've been at this for close to a year and things still mostly suck.

"You then adjust, typically upwards, you're looking to flatten the pressure trace"

Do you have a visual example of what this should look like? I'd greatly appreciate that! Cheers.

Lucky7 wrote: ↑

Sat Aug 17, 2024 12:30 am

Dog Slobber wrote: ↑

Tue Feb 06, 2024 7:04 am

OAs are not the only metric that the ResMed algorithm responds to.

When the algorithm detects snore, flow limitations and hypopneas it also increases pressure. Responding to these, prevents all or most OAs.

Setting your minim pressure against your median (median what???) or 95% (95% of what???) is nonsense. There's no magic measurement that one sets the pressures to and that's the sweet spot.

To find ones optimal, minimum pressure, set the minimum pressure to a value close. This can be arbitrary if absolutely new or your median pressure if you have some history. your then use your machine, gather statistics. You then adjust, typically upwards, you're looking to flatten the pressure trace, reduce abrupt swings, reduce flow limitations and events.

When on a pressure, stay there a while, don't let a single night influence. as you get closer, the increments should get smaller and smaller.

A goal of 0 OAs is unreasonable, I get them all the time, but not getting them is no big deal.

I think I just learned something VERY valuable, thanks! I've been at this for close to a year and things still mostly suck.

"You then adjust, typically upwards, you're looking to flatten the pressure trace"

Do you have a visual example of what this should look like? I'd greatly appreciate that! Cheers.

This is me optimizing my ranges:

• I was slow and deliberate when I made changes, ensuring that changes were statistically significant.
• I changed one thing at a time.
• Not presented in Device Settings changes is also experimentation with Soft Response, (which is garbage BTW)
• I was somewhat new to CPAP and over-cautious about the maximum pressure.

An interesting phenomenon, that wasn't intuitive to me at the time, and also represented on the history graph is:
Increasing my minimum pressure lowered the machines need to increase pressure. This is clearly visible as the maximum pressure achieved in the night is lower on the increased pressures. This actually makes sense, as higher minimum pressures take care of flow limitations and hypopneas preventing the more serious OAs.

This can be beneficial to those who experience mask leakage or aerophagia because of high pressure. But, try telling them to increase their minimum pressure to decrease the machines overall pressure.

Oh wow, THANK YOU!

"But, try telling them to increase their minimum pressure to decrease the machines overall pressure."

I've actually seen this (I think?) in a family members data. To me it DOES make sense, things are more controlled at baseline so the algo doesn't go all hamfisted.

Also, if I might ask: it looks like when you switched to bi-level you basically used your APAP min pressure on the VAuto as your baseline min?

Lucky7 wrote: ↑

Sat Aug 17, 2024 10:37 am

Also, if I might ask: it looks like when you switched to bi-level you basically used your APAP min pressure on the VAuto as your baseline min?

Yes.

I found an amazing deal on an unused AirCurve 10 VAuto on an online marketplace. I picked it up and set it up the same, or at least as much as possible.

But the terminology is kind of opposite:

• On an AirSense you set the minimum pressure value for inhalation(IPAP), then the EPR will then lower it for expiration (EPAP).
• On an AirCurve, you set the minimum pressure for expiration (EPAP), then the PS will increase it for inhalation (IPAP).

But, I dropped my EPAP by 1 CM and added an extra CM of PS because Pugsy suggested suggest the extra CM of differential is more comfortable and she preferred. That was good enough for me.

Dog Slobber, very interesting data! Congrats on your great deal on the VPAPauto! Very helpful that you shared your results with us! Interesting that your AHI's during your last APAP settings were very similar to your results with VPAPauto. I have some questions for you:

1. Did you notice any differences in how well you slept and how refreshed you were throughout the day between the two systems or while doing the titration?

2. Is there enough difference to justify the higher cost of a VPAPauto over APAP (assuming typical pricing)?

3. What criteria is used by sleep doctors to assess whether a patient should be prescribed VPAPauto over APAP? (I simply don't know, not challenging you at all).

4. My APAP settings are higher than yours (Min 15 Max 17, EPR 2). At times I've played with 15/18 but pressure getting high and not as comfortable. My AHI's are 99% below 2 and probably 90% below 1. I sleep well. Do you think I would potentially benefit from a VPAPauto?

Thank you again for sharing your data and responding to my questions!

MyIdaho wrote: ↑

Sat Aug 17, 2024 5:40 pm

1. Did you notice any differences in how well you slept and how refreshed you were throughout the day between the two systems or while doing the titration?

No. The only real difference I felt was the better comfort level of the AirCurve over the Air Sense while using it.

MyIdaho wrote: ↑

Sat Aug 17, 2024 5:40 pm

2. Is there enough difference to justify the higher cost of a VPAPauto over APAP (assuming typical pricing)?

For me, no. In Ontario, Canada to buy an AirCureve VAuto, it's about $2500CAD, and AirSense AutoSet about $1000. Not worth the 2.5 times difference.

But, I now have a lifetime supply of AirCurve 10 VAutos from the Online MarketPlaces

MyIdaho wrote: ↑

Sat Aug 17, 2024 5:40 pm

3. What criteria is used by sleep doctors to assess whether a patient should be prescribed VPAPauto over APAP? (I simply don't know, not challenging you at all).

I have no clue. But I also know that in Ontario, I would not have qualified for a BiLevel. I didn't even qualify for an APAP. Because in Ontario, CPAPs are subsidised by the government, they have strickt guidelines about qualifications. I didn't even qualify for an AutoSet, but because the "For Her" model was an exception.

MyIdaho wrote: ↑

Sat Aug 17, 2024 5:40 pm

4. My APAP settings are higher than yours (Min 15 Max 17, EPR 2). At times I've played with 15/18 but pressure getting high and not as comfortable. My AHI's are 99% below 2 and probably 90% below 1. I sleep well. Do you think I would potentially benefit from a VPAPauto?

If you take a look at my AHI when I switched from the AirSense to the AirCurve It dropped from 0.36 to 0.17, this was with similar settings, Now, my IPAP was 1cm higher. But, I was at the point of diminishing concerns, the difference while technically twice as good, was still only 0.19. Meaningless.

I have heard that the breathing algorithm and BiLevel algorithm to transition from IPAP to EPAP is more comfortable and beneficial. One significant and measurable difference between the two was the reduction of Flow Limitation. But some of that can be explained by the extra 1cm of pressure support.

I just wanted to mention that I got my VAuto at an excellent price from forum member LSAT. It was lightly used and everything was in great shape. The arrangements all went smoothly. The OP might want to send a private message to LSAT about possibly getting a VAuto.

I got the VAuto because I had heavy flow limitations even with EPR of 3. With PS of 5, my flow limitations are very well controlled. I sleep somewhat better with the VAuto than I did with the ResMed Airsense 10 Autoset.

I explained my situation to my primary care physician in the Kaiser medical system, saying that I knew Kaiser wouldn't pay for a bi-level machine but that I wanted to have a prescription handy in case I needed to buy my next machine new. He did that willingly.

EPR of 3 doesn't seem to be cutting it for me either. My main problem is RERA'S/UARS from what I can tell. I should look for a VAuto.

But, I now have a lifetime supply of AirCurve 10 VAutos from the Online MarketPlaces

Like, you have a stash of VAuto machines?