Old CPAPer New Member hello & questions

Flow limitation (FL), or more specifically, inspiratory flow limitation (IFL).

Some people (usually those with so-called subclinical sleep-disordered breathing or those with mild-to-moderate-OSA ) are bothered when they happen. Others (usually the moderate-to-severe) ain't, since they have apparently adapted to sleep right through them. ResMed machines are designed to react to them in order to head off hypopneas and apneas, but their modern home-treatment machines do not report them to patients as part of the AHI-trending numbers. OSCAR flags them, since it is helpful info for some.

Titrating CPAP to eliminate flow limitation may be associated with improved clinical outcomes compared to treating apneas and hypopneas. . . . The current system using apneas and hypopneas does not capture all individuals who may be suffering from clinically significant respiratory disturbances during sleep. Often the most challenging cases faced by sleep medicine clinicians are patients with “normal” PSG findings despite presenting with symptoms consistent with OSA. With improved diagnostic measures and understanding of IFL, opportunities for successful treatment may follow.--2015, "The role of flow limitation as an important diagnostic tool and clinical finding in mild sleep-disordered breathing," Nevin Arora, Gerard Meskill, and Christian Guilleminault. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4688581/

Hmmmmm. Thank you for that. Not sure I understood all of it, but I was most definitely severe, when I had my sleep study. IIRC my AHI was pretty high. I'm going to ask what it was at my appointment this coming Monday.

JOinPA wrote: ↑

Wed Mar 29, 2023 2:08 pm

Hmmmmm. Thank you for that. Not sure I understood all of it, but I was most definitely severe, when I had my sleep study. IIRC my AHI was pretty high. I'm going to ask what it was at my appointment this coming Monday.

Sorry for throwing you into the deep end without warning, but each term or concept that sparks interest can be a source for further research for you, little by little over time. Since the built-in search at this forum isn't always useful, internet-searching a term then adding "site:cpaptalk.com" (without the quotation marks and with no space after the colon) in the internet-search field can get you some good info.

Many of us consider our having a full copy of our sleep-study report in our personal files to be something valuable for us to have. That, too, can inspire further online research.

JOinPA wrote: ↑

Wed Mar 29, 2023 12:50 pm

Miss Ermita, what are FLs? I'm like a complete noob, don't know the acronym. Thanks!

Ah, I should have spelled it out in my second post, as I did in my first. It’s flow limitations.

I will try to get a copy of my sleep test report on Monday. I do want to learn this stuff, I've just paid no attention to the technicalities of this before now. Loving looking stuff up, though, this is a rabbit hole I think I'll enjoy diving into!

The FLs for me last couple nights may have been some nasal congestion due to allergies. Will see if they dissipate a bit tonight.

Feeling kinda dumb, reread Miss Emerita's first post, starting to sink in. Changes so far

1. Went from 10-14 to 10-20, then to 10-15, which I had set for last night
2. EPR set to 1
3. Used tape for the first time

Tape works beautifully, but I have to remember to roll over an edge to make it easier to remove in the morning. Like I've said, I went home with my machine 6 years ago and never thought about it, never changed anything. I think I may try a ResMed F30 mask, though. The taping is going to get annoying, I can tell already. I know that one can still have mouth leaks with a FF mask, but I think it's worth the money to try an F30 and see if I like it better than the P10 and tape. No particular hurry, though.

I'll leave it alone for a week or so now, probably nothing else needs addressing at this point. Last night's graph below, with the FL popout from the last two nights. EPR def has an effect on them. Don't know what is causing them, no nasal congestion at all last night.






P.S. Gonna skip the mask experiment. Read some more and found many still need tape or cervical collar to stop mouth leaks even with the FF mask. Since I don't have big leakage problems with the P10 and I love it, I'll leave that alone. Will continue to move up the learning curve, this place is great. Thanks, all.

For people who use FF masks, it's not that they have mouth leaks, exactly. They will breathe through their mouths inside the mask for at least part of the time, and for some the resulting dryness is uncomfortable enough that they also use tape inside the FF mask. (At that point, I'm thinking why not use a pillow mask, but when it comes to comfort, individual preferences trump other people's opinions.)

Be aware that there are two difference Y-axes for the three FL graphs in your most recent post. You can customize your Y-axes if you want to; right-click on the graph label to see your options.

Yes, that tab on the tape is crucial, isn't it!

Yeah I figured out the Y-axis changes day to day, and the one in the daily details is on auto. The two I copied below I made sure to set from 0-1 and the EPR did seem to make a difference. Thanks for explaining that to me.

I'm going to sit with 10-15 and EPR 1 for a week and then see how things are. I may go back to the original 10-14 range or move it to 11-15 depending on how I'm doing.

I feel very lucky to have hit the sweet spot right out of the gate, seeing the difficulties some folks have getting acclimated to therapy. I'm very blessed, that's for sure.

So, no complaints whatsoever, but continuing my learning journey. Trying to learn more about OSCAR. So, last night the CA line showed up in the events graph, it had not been there prior. My understanding it only populates once you have an event of that type. Watching LankyLefty on YooToobz about interpreting the CA events trying to learn. Was 10-15, EPR =1, with tape, and got a ClimateLine heated tube yesterday. Full graph:



Now on to my two CA-flagged events. If I understand LankyLefty correctly, the first one probably is not because it is preceded by a big spike? The second one probably is legit? And why was the one to the left of the second one not flagged? I know the machines don't classify everything correctly. What does this mean for me, anything? Sleep is still fine, I'm just trying to understand the difference between apneas and hypopneas and what it all means to me. Thanks!



Finally, it looks like my original 10-14 pressure prescription was correct, but I'm not changing any settings for a week.

JOinPA wrote: ↑

Fri Mar 31, 2023 7:30 am

the first one probably is not because it is preceded by a big spike?

I would agree, fairly obvious.

JOinPA wrote: ↑

Fri Mar 31, 2023 7:30 am

The second one probably is legit?

Maybe. Can't really see enough of the flow rate prior to the flagged event to be certain but even if it was a real asleep central that in itself doesn't mean much. Remember it's normal to have a few centrals here and there.
Number one would be the sleep onset centrals that it is common and normal to have during sleep stage transition.
And sometimes we see flagged stuff that we just can't tell for sure what it really is.

JOinPA wrote: ↑

Fri Mar 31, 2023 7:30 am

why was the one to the left of the second one not flagged?

Most likely the criteria to earn a flag wasn't met.
Maybe not quite the 10 second duration would be my best guess.
Remember all the different flagged events need to be at least 10 seconds in duration.
9.5 second duration doesn't meet criteria and won't get a flag.

Very helpful, thanks! I did not know about the 10 second criteria. The more one knows about Oscar, the more useful it is. I appreciate the response!

There are other criteria besides the "at least 10 second" rule but it is probably the most common.

example..
Hyponeas have the 10 second thing but also the amount of air flow reduction can vary (depends on brand definition to some extent) between 40 % and 79% reduction. I will be honest I have seen some hyponea flags that I wonder how in the heck that breath met any criteria for anything.

OAs...air flow reduction of 80% to 100% along with the at least 10 second rule.

Centrals..no air flow and no effort to breath for at least 10 seconds but the airway isn't blocked with saggy airway tissue..with centrals there is simply no effort to breath. Hold your breath for 15 seconds...that's essentially a 15 second central apnea. Now since you are awake when you do it it is a choice you make to not breath and doesn't really mean anything.
When asleep is a different story but it isn't always a bad story because it's normal to have a few real asleep centrals anyway. Centrals aren't a problem unless present in large numbers or causing desats and sometimes having a lot of centrals is just a symptom of poor sleep quality caused by something not related to airway issues. So sometimes centrals seen are a symptom of a sleep problem and not necessarily the cause of the sleep problem.

Finally we need to remember that the machine can and will flag arousal/awake events in the hyponea and OA categories along with centrals but it seems false positive centrals are the most common. I personally have seen arousal related hyponeas and OAs myself and so blatantly awake/arousal related that it isn't even questionable....so I know it happens.
The machine will think they are real though and respond accordingly.

Well, at the suggestion of Lazarus, I got a copy of my sleep reports, both the original and the titration study. Can't interpret much of it, except the summary notes, of course. But my AHI was 41.8 and sleep apnea listed as severe. MUCH loud snoring, and lousy sleep. It's amazing to think back on that time because I pretty much slept like a baby as soon as I got on CPAP therapy. Never looked back.

They noted a lot of leg movement, and suggested I watch that, and maybe revisit it, but it's never been an issue. I sometimes wake up in the same position I fell asleep in on those rare nights I don't get up for a bathroom break. I don't move much. Maybe that was related to the poor sleep I was getting at the time.

lazarus wrote: ↑

Tue Mar 28, 2023 4:56 pm

I was gonna say "me and palerider," but frankly I'm a little scared of him.

Ehhh. The worst he can do is block you which really does suck as he is one of the most knowledgable on settings ‍♀️ but whatever.

JOinPA wrote: ↑

Fri Mar 31, 2023 12:24 pm

. . . slept like a baby as soon as I got on CPAP therapy. . . . sometimes wake up in the same position I fell asleep in . . . I don't move much. . . .

We don't always do well at judging our sleep movements, since by definition we are unconscious. Only objective continuous overnight video can establish that. Patients are often amazed to see themselves sleep-dancing on tape when they would swear they never moved a muscle all night. But if you feel fine and never get sleepy during the day with treatment, that level of investigation isn't generally necessary for any medical/safety reasons.

The main reason to have copies of your sleep tests in your personal file is that it establishes your degree of medical need for, and response to, PAP, which proofs you should have. It will also be useful if you ever need it for comparison purposes should you ever again need a sleep study for some reason. Furthermore, it points you in a direction for researching your SDB, not just SDB in general. But then I feel much the same way about all important medical-testing records. I have had docs make a big deal about thanking me for copies of tests from my files, since the state of medical-file sharing in the medical industry in general in the U.S. is spotty at best.

Some forum members have removed personal identifying info (all self-identifying [for security] and all or most lab/doc-identifying [for courtesy]) and then posted sleep study details using imgur, if interested in getting forum feedback. You may or may not want to bother with that, since you seem to be doing very well with your therapy and with your personal research into SDB.

babydinosnoreless wrote: ↑

Fri Mar 31, 2023 1:01 pm

he is one of the most knowledgable

Yeah. Which scares me.