Does a Resmed Airsence 10 detect mouth breathing?

[monkeychow]

Hi All,

I'm new at CPAP.

Discovered I have sleep apnea - due to extreme exhaustion, osteoporosis and some other health issues I've had going on. Basically I've felt like hell for a long time - I'm sure folks here can relate.

When I did a sleep test my AHI was over 100.

This is my 8th day of CPAP - and I have a rental Resmed Airsence 10 Auto - the tech seems to have set it between 8-14. Using a nasal pillows mask as I have a giant neck beard like something out of Lord of the Rings.

Something seems to work as according to the machines report when I turn it off my AHI's have gone down to around 0.5 - some nights even lower like 0.2 or 0.1.

So all has been going well - however the least 2 mornings I have woken up with my mouth a little open and drool/spit on the pillow (suggesting to me it was open for a while).

However the machine still shows the leak rate as having a smily face icon.

So my question is - does this matter? Am I likely to mouth breathing to an extent that's ruining the therapy? Can the resmed actually tell if I'm mouth breathing? That is - does the happy face mean the leak was at acceptable levels - or am I tricking it into thinking it's working when it's not.

Thanks for any help

[justMongo]

welcome to Apneaboard.

The criteria for the smiley face is less than optimal.
The Resmed Airsence 10 Auto does not detect that your mouth is open.
However, by looking at ones leak graph for the night, one can usually infer if leaks are from the mask or the mouth.

Mask leaks are generally sporadic and spikey; mouth leaks generally flat-top.

[monkeychow]

Thanks so much. Can I just ask a quick follow up as I phrased my initial question badly...

I didn't mean to ask if the Resmed can detect that someone's mouth being open is the cause of a leak compared to other potential causes such as the mask not fitting.

I mean more broadly, if my mouth were open to an extent that would disrupt therapy would the Resmed show this as a leek? (Even if it doesn't specify the cause of the leak) Or is it possible the Resmed thinks everything is working but it really isn't?

Sorry if this is a stupid question. I'm sort of new to all this!

[mchlwise]

The Resmed has a certain threshold where it's programmed to decide if it's a "bad" leak, or one that isn't bad enough to go to a frowny face over.

I *KNOW* that I've had problems with mouth leak. Waking up with a dry mouth. Using lots of water in the humidifier. etc. etc. But it has never gotten to the point that Resmed thinks it's bad enough for a frowny face.

Is it affecting therapy? Almost certainly. The machine will bump up pressure to try to keep it where it should be compensating for the leak. But your therapy will not be as good as it could be if your mouth was shut.

Personally, I use a chin strap.

[justMongo]

The point of therapy is to maintain a positive pressure. When the leak rate is high enough, the blower cannot keep up the flow volume and pressure falls.
Then, therapy is essentially lost.

Controlling leaks can be an issue. My mask covers both nose and mouth. I cannot tolerate leaks because it wakes me. So, I have been able to find the right FFM and adjustment. If leaks don't bother your sleep, the machine can provide therapy even with a leak; as long as the leak does not compromise the delivered pressure to you.

[trish6hundred]

Hi monkeychow,
WELCOME! to the forum.!
Much success to you with your CPAP therapy.

[PaulaO2]

It also depends on how wide you are opening your mouth during your sleep. Wide open with air rushing out vs simple lip leaks. Both will cause dry mouth to almost the same degree. The machine cannot possibly keep up with the wide open leaking but it might be able to with the lip leaks.

The problem with any kind of mouth leaking is you are waking up from them. You may not remember but you are. So you aren't getting the rest you need.

[zonk]

Leak is a leak, whether from mask or/and mouth
Prolong high leak reduce the effectiveness of the therapy and mouth leak dry the mouth

[OpalRose]

So someone correct me if I'm wrong, but if you experience enough high leaks during the night, your therapy is compromised.

The air flow actually does not increase, but decreases, and therefore the machine cannot maintain proper pressure and may miss apnea events.

Therefore that low AHI with high leaks is not accurate. This is why it's important to address your leak problems.

[DeepBreathing]

A prolonged high leak will compromise the therapy. All masks leak to a certain extent in order to vent your exhaled breath - this is intentional leak. Resmed machines report the excess or unintentional leak which is additional to the intentional venting. An unintentional leak greater than 24 L/min is regarded as a large leak. On the S9 machines (and I think it's the same on the AirSense) you will get a smiley face if you have large leaks less than 30% of the time. As Mongo said this is less than optimal - they are setting the bar too low. You need to have a really protracted large leak to get a frowney face, and by that time your therapy is well and truly compromised (in my view).

Apart from the fact the machine can't maintain therapy pressure at large leaks, they can be very disruptive to your sleep, preventing you from sleeping soundly even if you're recording a low AHI.

A relevant point is that you need to set the mask type (ie pillows, nasal or full face) on the machine so that it can estimate the intentional leak rate. If you have this setting wrong then the machine won't know what the leak really is.