Chin strap, leaks and AHI

General Discussion on any topic relating to CPAP and/or Sleep Apnea.
SarahB
Posts: 67
Joined: Thu Jan 18, 2018 1:09 pm
Location: Scotland

Chin strap, leaks and AHI

Post by SarahB » Sat Apr 14, 2018 3:37 pm

A few nights ago I abandoned my chin strap as the combination of chin strap and nasal mask was very uncomfortable and made it impossible to sleep on my side. I had also been using a bit of tape to keep my lips closed and I thought that would be sufficient to stop me mouth breathing as it's strong stuff and doesn't come off in the night.

The difference in comfort is fantastic! :D However .... the time over the leak redline has increased significantly and has been between 10% and 23% of the time. It used to be less than 10%, usually below 5%. My lips are still taped together all night, at least in the centre. I leave the sides untaped as I can have difficulty breathing through my nose. I assume the leaking is through my mouth but it could be the mask, now that I'm sleeping on my side, even though it seals well when I test it.

All of this doesn't seem to have affected the AHI which is still below 1.0 each night, so should I give up my comfort to deal with the leaks or have a good night's leaky sleep? I hadn't been feeling well rested before and was hoping that being more comfortable would help.
Resmed AirSense 10 Autoset. Mask: Resmed Airfit N20 nasal mask

User avatar
Pugsy
Posts: 43989
Joined: Thu May 14, 2009 9:31 am
Location: Missouri, USA

Re: Chin strap, leaks and AHI

Post by Pugsy » Sat Apr 14, 2018 5:32 pm

Not all leaks are mouth leaks.
Mask movement leaks can happen too.
Try taping the lips totally instead of partially just one night and see if the leaks are still big...and if they are then you know mask movement leaks.

Then evaluate just how far you are going into large leak territory to earn that flag...is it 28 L/min or 38 L/min or 48 L/min where you are going up to.
The machine is going to be fairly accurate up to maybe 35 L/min excess leak. Above that and the machine might start missing events..might not. Usually first sign that the machine is having a problem knowing what is going on is you will see Unknown Apnea flags...the machine knows something is going on but can't quite put a name to it.

Then evaluate how long you were deep in large leak territory. I don't even blink an eye about it until I hit 35 L/min as long as they don't wake me up and I am sleeping good and feeling good.

ResMed will still give you Mr Smiley face until you have 30% or more of the night over 24 L/min.
I like to keep it under 10% myself but sometimes I don't make it.
At the same time I look at how far above 24....like if I have 30 minutes at 26 L/min...who cares if I slept through it.
Doesn't matter if it is mask leak or mouth opening leak...a leak is a leak but ruling out mouth opening helps you look at ways to reduce it if it's really big or really prolonged or disturbs sleep if it's mask movement.

Up to you where you decide to make your line in the sand...ResMed is okay with 30%...that's a lot of big leak depending on how deep into large leak territory you go. So I opt for a smaller % of time but I don't use 24 L/min as my red line threshold to start me worrying.
I may have to RISE but I refuse to SHINE.

SarahB
Posts: 67
Joined: Thu Jan 18, 2018 1:09 pm
Location: Scotland

Re: Chin strap, leaks and AHI

Post by SarahB » Sun Apr 15, 2018 2:32 am

Thank you Pugsy. That's very helpful and encouraging. :D

My husband has told me this morning that I was breathing out of the corners of my mouth during the night so I'm pretty sure that's where the leaks are coming from. Obviously they have got worse since I took off the chinstrap.

Here are last night's results compared to a typical night with the chinstrap. AHI has gone up higher than usual. There are periods of quite large leak when there are also clusters of hypopnea events. The long period of leaking might have gone on even longer but around 5am my husband told me I was being noisy and I obviously heard him and closed my mouth. :lol: The average level of leak is quite high but possibly not unacceptable?

I think I need to try to improve these results a bit but don't want to tape my mouth entirely. I have trouble with my nose shutting down on me at a moment's notice so need a small gap if I have to get air in through my mouth. (I'm going to speak to the doctor about nasal obstruction as it's a problem.)

However, I can't describe what a fantastic sleep I had last night! I am feeling so rested and refreshed now that I can sleep comfortably. :D I'm reluctant to give that up if I don't have to.
screenshot-20180415-084434.png
screenshot-20180415-084434.png (74.32 KiB) Viewed 188 times
Attachments
3.4.18 N 0.14.png
3.4.18 N 0.14.png (69.39 KiB) Viewed 188 times
Resmed AirSense 10 Autoset. Mask: Resmed Airfit N20 nasal mask

SarahB
Posts: 67
Joined: Thu Jan 18, 2018 1:09 pm
Location: Scotland

Re: Chin strap, leaks and AHI

Post by SarahB » Sun Apr 15, 2018 2:33 am

Sorry, don't know why that first graph has appeared twice!
Resmed AirSense 10 Autoset. Mask: Resmed Airfit N20 nasal mask

User avatar
Pugsy
Posts: 43989
Joined: Thu May 14, 2009 9:31 am
Location: Missouri, USA

Re: Chin strap, leaks and AHI

Post by Pugsy » Sun Apr 15, 2018 7:34 am

I fixed the duplicate image for you. For some reason it got attached twice.

Now about the night that might not be so pretty number wise but you report
SarahB wrote:
Sun Apr 15, 2018 2:32 am
However, I can't describe what a fantastic sleep I had last night! I am feeling so rested and refreshed now that I can sleep comfortably. :D I'm reluctant to give that up if I don't have to.
Which is quite telling and I personally think very important.

12.86 % of the night you were over 24 L/min...hours of use not quite 8 hours...to simplify the math...12% of 8 hours is a little less than 1 hour total and when you had the leaks they mainly were in the 4 to 5 AM time frame.

Here's how I would look at this report if it were my report,

Number one...I look at just how deep into large leak territory you went...and looks like 32.5 L/min was the bulk of the worst part of it with just very briefly a little higher. That's not horribly horrible. Your machine is still going to be able to do it's job decently up around that 32 L/min mark. It's not going to miss flagging apnea events and it can still respond decently and I doubt seriously that it missed flagging anything and if it allowed an OA or hyponea to slip past the defenses...it didn't let a truck load of them slip by.

Yeah the 95% number itself looks a bit ugly but you have to remember the definition of a 95% number....at OR BELOW that number for 95% of the time. It is NOT an overall average like a lot of people tend to think.
The number that is closer to an overall average is that median number which is 7.90 and obviously not that bad at all. There's a small difference between median average and the usually overall average that we think about but it's not a big enough difference to worry about. There is a way to change SleepyHead so it reports the usually thought of average instead of the median average but I have played with it doing just that to see how much that statistic changes....it rarely changes much at all and for that reason I just go with the median average. It might change the 7 to an 8 or something like that but it's not a huge difference.

The "or below" part of that 95% definition is real important in this situation....because only a little over 10% of the night was spent above 24 L/min in large leak territory. So the bulk of the night (and a pretty good size bulk chunk) you were below 24 L/min.
The 31.20 95% leak number...makes it appear that your leaks were horrible but they really weren't.

Once someone sits back and actually looks closely at the big picture it's easy to see that the bulk of the night the leaks were far from horrible and the relatively short period of time where there were some large leaks... they weren't horribly horrible and still within the machine's ability to decently deal with. It's not like the machine just can't do a thing if it barely gets into large leak territory...it's a thing where the deeper you go the more trouble the machine might run into. Now if you had been at 55.5 L/min instead of 35/L/min for a lot of the time...we might have a different discussion but again we would look at the overall big picture more than just one single 95% statistic.

Me personally...I am good with 10% to 15% of the night being over the red line threshold as long as the leaks don't wake me up until I start seeing 40 L/min or more getting hit for very long.
And I don't panic if I have one night here or there that is just god awful ugly in terms of leak line as long as I have slept decently and feel good. If I start seeing a lot of nights like that then I do something and for me the something is usually shrink my head gear as it's usually got stretched out and not fitting so snug.

So your report of sleeping and feeling better is hugely important to me because without sleeping and feeling better any nice low leak numbers really don't mean squat do they. What's the goal here? Good solid sleep and keep the OSA events under control in the process.. You met those goals. A handful of events like you had...not a big deal since you report feeling and sleeping great and I don't blame you for not wanting to give that up. I wouldn't give it up if it were me.

Yes...using a chin strap added to the tape improves the numbers...but it worsens the sleep quality because it's just more crap on the face and your face doesn't like more crap on it. Mine wouldn't either and that's why I opted to not use a chin strap for 2 reasons...one there wasn't an urgent huge need to use a chin strap and two..I simply didn't want to because for me it disturbed my sleep more to have it on my face.
You can't ever have much chance of feeling those good numbers if your sleep quality suffers for any reason.
This is why I say that any leak no matter how big or little that disturbs sleep needs to be fixed...but fixed because it is messing with sleep quality and not necessarily therapy quality.

You are new to this therapy and you are still in the learning curve...don't expect perfection in anything in terms of numbers...heck I am nearly 9 years into this and I still don't always get perfect anything. One night I might not go above 5 L/min in leak the entire night and the next night it might not go below 20 L/min...it happens. Long term I have more good nights than not so good nights though and more importantly leaks themselves don't usually disturb my sleep. About the only time they ever disturb my sleep is when I am trying a new mask and still in the learning how to fit/seal it optimally.

Now there are some forum members who just have to have more perfect leak numbers because the numbers are hugely important to them..hey, that's fine...everyone gets to determine their own personal lines in the sand.
Yeah...I let a little bit of large leak slide but for me I learned a long time ago that for me to get a 100% perfect leak line all the time I would have to use something (like a chin strap) that actually hurt my sleep quality significantly. My face just didn't like it and for me it really was more trouble than it was worth.
There are some people who are okay with a chin strap..that's fine...more power to them...
For me I ended up feeling worse and sleeping worse using it despite some really good "numbers" and how sleep and feel is HUGELY important to me.

So my advice...do whatever let's you feel the best....learn to evaluate the big picture in terms of leak and not just the 95% statistic because it is so easily misleading. Ignore SleepyHead's any little message about "you are leaking way to much" because SH makes mountains out of molehills sometimes.

Remember number one goal...good quality sleep because without it...good numbers don't mean squat.
We got a lot of people here who are getting perfect numbers...really low AHI and really low leak numbers and they are still feeling like crap for some reason or other.
If you need a little crack in the sides of the tape as a back up for when congestion happens...use them. Subsequent little leaks out those sides isn't a huge major problem as long as you don't do it all night or half the night.

You are new to this therapy...give yourself a little extra leeway in your expectations and don't be too hard on yourself if you have a night where things just go to hell. It happens..and it happens to us long term veterans too.

Below is an example of what I saw one morning when I looked at my report....this is pretty bad for me...but it is a rarity that I see something this bad....and it was mask movement because I taped my mouth to make sure. This was trying a new nasal pillow mask and I was having lots of leaks and wanted to make sure it wasn't mouth breathing.
Eventually I had to change size of the headgear in this situation...go smaller so that the mask didn't move around so much.
This was the DreamWear gel pillows...I ended up needing the small frame to get rid of the mask movement stuff.
And yeah...these leaks did wake me up some...that's why I was trying to figure out exact cause and how to fix.

Image
I may have to RISE but I refuse to SHINE.

SarahB
Posts: 67
Joined: Thu Jan 18, 2018 1:09 pm
Location: Scotland

Re: Chin strap, leaks and AHI

Post by SarahB » Sun Apr 15, 2018 8:02 am

Pugsy wrote:
Sun Apr 15, 2018 7:34 am

So your report of sleeping and feeling better is hugely important to me because without sleeping and feeling better any nice low leak numbers really don't mean squat do they.
My thoughts exactly! :D There's more to a good night's sleep than just breathing. And some of my low numbers disguised the fact that I was wriggling around uncomfortably for the first hour or two, wide awake.

Thank you once again for your advice, insight and common sense! That's put my mind at rest as I was just concerned that I might be compromising the therapy. As you say, it's still early days and all a bit experimental still.
Resmed AirSense 10 Autoset. Mask: Resmed Airfit N20 nasal mask

User avatar
Pugsy
Posts: 43989
Joined: Thu May 14, 2009 9:31 am
Location: Missouri, USA

Re: Chin strap, leaks and AHI

Post by Pugsy » Sun Apr 15, 2018 8:37 am

I actually don't think you are even compromising the therapy and if you are it's for such a short period of time that it's not the end of the world.

From my own personal experience...the machine seems to do a decent up job until maybe 40 L/min in excess leak and maybe better than I think. Obviously the problem we have when in really big leaks and we don't see events....did they not happen or did the machine miss them...we just don't know for sure.
I developed the attitude that IF they did happen during the 10 minutes I might be in really big leak...like over 40...I don't care..it's not the end of the world for a few apnea events to slip past the defenses during those 10 minutes.

I used to try for perfect everything but learned rather quickly that perfect comes at a price and the price for me was sleep quality and for me that's too high of a price.
I may have to RISE but I refuse to SHINE.

SarahB
Posts: 67
Joined: Thu Jan 18, 2018 1:09 pm
Location: Scotland

Re: Chin strap, leaks and AHI

Post by SarahB » Sun Apr 22, 2018 1:47 am

One week on and I just have to report back. Everything is still a bit leaky but no worse than before. However, at last I am definitely beginning to feel the benefit of being on CPAP. The difference over the last few days is amazing! I've been rushing around actively from morning till night and still feeling energetic when it's time to go to bed! This set up is definitely working for me. :D
Resmed AirSense 10 Autoset. Mask: Resmed Airfit N20 nasal mask