What am I doing wrong?

[Ht538]

I've been doing CPAP for about two months and my AHI is always super low and primarily centrals. I had mild apnea to begin with and even at a setting between 4-6 my AHI has been typically less than 1.

Still I see my machine ramp up every night but dont understand what it is responding to. So since I dont snore and have only logged a handful of apneas, maybe a dozen hypopneas the whole time ive been on CPAP, I am starting to wonder if flow limitation is what drives the machine pressure up. I have used my machine, Resmed AutoSet for her with a window of up to 10 for the pressure, but as I go higher in pressure the only thing that happens is the CA numbers increase. So while I am not generally concerned about CA number since its still super low and I think some are just restless sleeping junk... Is there a benefit to using higher pressure to see if the flow limit numbers go down even further. They are usually really low anyways. Secondly, I thought that flow limitations were what led to hypopnea/apnea, but most of my non CA events theres no flow limitation, so I am really confused and thinking I am not understanding this. download/file.php?mode=view&id=10747

BTW my mask pressure is pegged at 6 for all of the pics except the last one.

download/file.php?mode=view&id=10748

The only reason I am even pursuing a higher pressure, is that I still dont feel rested even with 8+hours of sleep. I fall asleep easily and dont usually get up more than once to use the bathroom in the muddle of the night. So I am really trying to see if there are improvements to be made in my therapy even though my AHI itself is really low since I understand that AHI isnt always the whole picture.

This last pic is what my ramp usually looks like.download/file.php?mode=view&id=10750

[LSAT]

Your machine can't "ramp up" higher than 6 since that is what your max pressure is set at. Oscar indicates that the highest pressure has been 6. It's very normal for CAs to increase for some people as pressure rises higher than what is needed. Ignore the CAs. I don't understand what you are concerned about..
You could turn off the ramp..with your pressure settings it is useless.

[Julie]

Agree - 45 mins to ramp to min. pressure of 6 is the biggest waste of therapy time going... plus don't understand why max pressure's set so low - it's keeping the min. pressure from rising if and when needed.

[DreamDiver]

At such a low pressure, I wonder if ramp is even necessary. Have you considered trying starting without any ramp?
Might be nice to see the graphs for the whole night as well as closeups.

[Ht538]

My problem/question LSAT is that I am doing this whole thing and not getting any symptom improvement. Its a bit of a hassle and I am not feeling any benefit so I am trying to see if theres something I should change to optimize therapy here to get some benefit or CPAP just isnt worth the effort. I dont have any weight issues, dont snore and dont have any cardiovascular issues so better sleep is the whole reason I am doing this at all. My pressures are so low and lack of other issues than the sleep makes me wonder if somehow I was misdiagnosed, or have such mild OSA issue that CPAP isnt the answer for me. I still find myself having to adjust or becoming aware of it at night, whereas I never used to wake as much before.

And before anyone suggests other issues, I have been tested for everything under the sun, dont have insomnia and am really grasping for something to help here. I dont have any mental health issues at the moment that are impacting sleep as far as I know (I have ADD but i am not taking any stimulants). I am otherwise healthy.

So I adjusted my max pressure to 8 and had a zero AHI with a handful of centrals (which I think is no big deal). Pressure never really maxed out, but it appears that the machine was responding to flow limitations.

Screenshot (14).png (121.6 KiB) Viewed 18550 times

I really dont understand how much flow limitation is an issue...I am assuming all sorts of folks with allergies or stuffy noses have that at some point? Should I be pursuing eval by an ENT more aggressively based on this (mildly deviated septum from a broken nose)? I also usually dont have as many leaks...Usually means I need to change out the cushion so I will do that today. I'll also take the suggestion of turning off the ramp....I thought the dr office said it was supposed to be in auto and would go off as soon and the machine thought I was sleeping so I dont know why its taking the full 45 min. I usually fall asleep quickly.
This screenshot is from the night in the last post.

Screenshot (15).png (119.34 KiB) Viewed 18550 times

[Pugsy]

I'll also take the suggestion of turning off the ramp....I thought the dr office said it was supposed to be in auto and would go off as soon and the machine thought I was sleeping so I dont know why its taking the full 45 min

There are 2 choices in the setup menu for ramp....
page 16
https://www.respshop.com/manuals/ResMed ... %20her.pdf

Auto ramp is where it is supposed to turn itself off when it thinks you are asleep or after 30 minutes whichever comes first.

If it is taking 45 minutes it is set to regular ramp being on...you have to change it to auto if you want the other ramp that senses sleep.

[Miss Emerita]

Your flow limitations aren't horrible, but the FL chart is fairly busy. FLs may be present because of a stuffy nose due to allergies or other problems in the nose (e.g., deviated septum or enlarged turbinates). If that's what is going on with you, higher pressure is quite unlikely to help.

But another cause for FLs is the relaxation of tissues lower in the airway -- not enough to cause even a hypopnea, but enough to restrict flow partially. This can often be addressed by your settings. The reason to address these FLs is that they are causing you to work harder to get breathe in, and over the course of a night, the effort can add up. In addition, those extra efforts may be preventing you from getting as much deep and REM sleep as you need.

A higher minimum might help, but an additional way to try addressing FLs is to add some EPR (expiratory pressure relief) to your settings. EPR can be set to 1, 2, or 3. So, for example, with a pressure of 8 and EPR of 3, 8 is what you get when you inhale, but your pressure when you exhale is 5.

You have so few obstructive events that I think you can safely experiment. I would like you to have expert advice about what exactly to try. For what it's worth, my own experiment in similar circumstances was to use an EPR of 3 with a range of min 7 to max 8.

That was of some help, though to tell you the truth, I didn't really whip the FLs until I got my current machine, which can offer more EPR (though with my machine this is called pressure support). I am glad I pursued that course, because even when I have a lousy night with many wake-ups due to pain, I feel more rested with the much-reduced FLs.

[Ht538]

Pugsy, my machine screen says auto, but I thought it worked like you indicate and the 45 min as indicated on Oscar doesn’t make sense...so I dont understand what’s going on. I just set it to 15 to avoid the whole question.

Miss Emerita, the EPR is on and set to 3 so I think that’s what you were suggesting. At least that’s what the menu on my machine says, that’s the highest I can go and with my starting pressure at 4 I would think that’s almost like no CPAP at all :0

I am really curious to see how the next few nights go. Thanks to all for the tweaks!

[Ht538]

As far as expert advice, my follow up with the sleep doc was underwhelming. He basically said my AHIs are low so it *must be working* and said I could take it or leave it. I guess if AHI is the measure of success, he nailed it. Too bad Symptom relief doesn’t count in his metric for success. I suppose if I started with moderate or severe apnea I would probably notice some difference by now. It’s really frustrating that those of us in the mild category are told to do this, but there’s not much support in terms of patient relief or giving us any help to make a risk based decision on wether or not to proceed if things don’t seem to be helping. It’s also been impossible to find much info on the benefits of cpap for mild cases. The studies are primarily focused on AHI in moderate to severe cases.

Miss Emerita, it’s heartening to hear that flow limitation reduction held some measure of success for you! I’ll keep chasing...constant fatigue and brain fog are debilitating

[Pugsy]

Oh...the settings in OSCAR show ramp for 45 minutes but it says Auto in the ramp menu?

That could be a known bug in OSCAR...it often doesn't report the settings accurately. If often tells me that I have no humidifier attached and I for sure do. When in doubt...look on the machine and not in the settings area that OSCAR/SleepyHead reports.

Instead look at the pressure line itself and see how long the ramp takes before you go up to the minimum pressure.

[Ht538]

Ah...it’s only taking like 10 minutes to ramp. Makes sense, I’m usually so tired I think I’m asleep before I hit the pillow.

[Ht538]

But sometimes I go quite a while for a pressure increase. I think I am asleep but there isn’t anything to prompt a pressure increase so it goes a while at the lower pressure.

[Pugsy]

But sometimes I go quite a while for a pressure increase. I think I am asleep but there isn’t anything to prompt a pressure increase so it goes a while at the lower pressure.

How the auto adjusting algorithm works explained by me below. If your machine takes a while to increase the pressure then it obviously isn't sensing the warning signs that are needed for the auto adjusting algorithm to feel the need to do anything. We can have periods of sleep where nothing bad happens and the machine just doesn't need to do anything. My OSA is worse in REM...it doesn't normally do much except when I am in REM which accounts for only 20 % of the night.

It's a common thought that the machine senses an apnea event of some sort and immediately thinks "OMG I need to increase the pressure" and it does it and blows the airway open.
Nothing is further from the truth in terms of what actually happens.
While any apnea event is happening...obstructive or hyponea....the machine sits by and twiddles its little thumbs until the airway opens up naturally. Then the auto adjusting algorithm kicks in and does some evaluation of the current and past status of the airway....and then decides what to do. All this takes time and if you have a cluster of events happen then there's an inherent amount of time spent twiddling the thumbs that slows down the response as well.

Central/clear airway apneas....the machine simply won't respond to at all because the airway is already open and more pressure won't help. Unless someone has a machine designed with a special algorithm to deal with central apneas....centrals get ignored by regular cpap/apap/bilevel machines.

It's a common thought that the machine can respond and go to much higher pressures that might be needed (once the machine goes through its evaluation process and decides more pressure is needed) in the blink of an eye. That it can go from 5 to 10 cm or higher in the blink of an eye. It simply doesn't respond that fast...it can't. It increases a little bit at a time and evaluates as it increases. All this "thinking" can take several minutes to get done and all the while the machine is gradually increasing the pressure the airway can continue to collapse and have apnea events happen.

The whole key to using auto adjusting pressures and having it work optimally is to use it with a minimum pressure that does the bulk of the work preventing the collapse from happening in the first place and then do some increases as needed for special needs...like supine sleeping or REM related worsening of OSA.

They work best when preventing the collapse in the first place and not trying to fix something that gets broken after the break has already happened.
So we need to use a minimum pressure that means the machine can get to what might be needed for those special circumstance in a timely fashion...not take 20 minutes but instead take maybe 5 minutes. We have to give the machine a better head start when using auto adjusting pressure mode.

I have REM dependent OSA meaning my OSA is much worse in REM than in the other stages of sleep. Supine sleeping has never been a big factor for me but REM sure is. It's documented that my OSA is 5 times worse in REM than in non REM and I learned that during REM I might need 6 to 8 cm more pressure than I need in those other sleep stages.
Now I could use a fix pressure that would cover the REM pressure needs but that would mean using around 15 cm all night long just to cover the 20% of the time I am in REM. I could do it but it's not much fun. Instead I prefer to use a lower pressure for 80% of the night and have that lower pressure still be close enough to get to where I need the pressure to be in a timely fashion to deal with REM related pressure needs.

Sometimes all we need to do to give the machine a better head start is a relatively small increase in that minimum pressure.
So I use a little more minimum all night so that I don't have to use a lot more all night. Make sense???

You really only had the one time frame where the machine couldn't do a good enough job....I suspect supine sleeping but it could have been REM or it might have been a combination...on your back and in REM. Doesn't really matter...I think people should sleep in whatever position promotes good sleep if at all possible and since we have no control over REM...just be pre-emptive and cover both with a little more minimum.

I suspect that all you need to clean up your report a little better is a minimum somewhere around 6 to 7 cm...might need a little more but I would start with small increase because often once a better minimum is in place the machine won't have to go as high.
I have seen people see a reduction in the max that is much more significant than the minimum increase.
One case comes to mind where the person was seeing pressures reach 18 cm quite often but with a little 2 cm increase in the minimum the max pressure reached never went above 12 cm.

Prevention is the key....not trying to fix it after it happened. All machines work this way...use a minimum pressure to hold the airway open for most of the time and then increase for the special circumstances that might cause a higher pressure.

[Ht538]

Pugsy, following up after visit with sleep doc. I’m still tired but he says my numbers are great...AHI usually less than 1 avg pressure is 5.9
So mystery persists. Still tired but therapy is supposedly working. Sleep doc also mentioned that the musty is still out on long term risks of mild-OSA. So I am starting to feel that CPAP may not be for me.
I feel like I still fiddle with it at night and the machine hose/noise is disruptive to me and my bf. I am just not finding any sleep improvement, in fact feeling I don’t sleep as deeply. I’ve agreed to give it at least another month.
Thanks for the consistent response/advice...it’s one of the few reasons I’ve even gotten this far!

[Miss Emerita]

Ht538, you won't get the full benefit of an EPR of 3 when your pressure is under 7, because 4 is as low as the machine goes. I don't know whether there would be any dramatic change if you set your minimum to 7 (or more), but it's a thought.