Full-Face mask

The issue of mouth leak and Full-Face masks

“I need a Full-Face Mask…”

We hear this every day, or the statement that “I am a mouth-breather”, and yet the reasoning behind these statements is quite mysterious.

Some facts:

• About 50% of the calls we receive from CPAP users who struggle with their masks come from people using full-face masks.

• About 30% of CPAP users in Australia use full-face masks.

• Anatomically, only 5-10% of CPAP users need a full-face mask.

Confused?  It’s no wonder.  Let’s explore this concept and see if we can dispel some of the myths and misinformation along the way.

Firstly, a few definitions.

A “full-face mask” is a mask that covers the nose and mouth (also sometimes referred to as an oro-nasal mask).  These differ from other masks types which only cover the nose, referred to variously as nasal masks, nasal pillows or direct nasal masks.

In one sense, having a CPAP mask that covers only the nose may seem illogical.  The idea behind CPAP is to keep pressurised air in the airway to hold the walls of the airway open when muscle tone is lost during sleep and the airway wants to collapse.  Surely, pressurised air could escape from the mouth unless it was part of the pressurised “system”, right?

Well, it’s not that simple.

 

Nasal CPAP and Airway Patency

You see, when pressurised air is put into the nose during sleep, the soft palate is pushed downwards towards the tongue at the back of the mouth and it tends to seal off the mouth from the airway.  Having pressurised air in the mouth and nose (delivered through a full-face mask) circumvents this mechanism and actually holds opens the oral airway.  Maybe if we look at some slides it will help explain this…

These slides show a schematic side view of the face and upper airway and are included here with the kind permission of Associate Professor David Rapoport MD, Director of the Sleep Medicine Program at the New York University School of Medicine.

Slide 3

The third slide (above) shows what happens when pressurised air is delivered through nasal CPAP.  The part of the tongue which falls into the airway is forced up and out of the airway and the soft palate is also pushed upwards and into the tongue.  This action effectively closes off the mouth and prevents the pressurised air escaping through the mouth.

When a full-face mask is used, as represented by the last slide (below), pressurised CPAP air is directed into the mouth and the

Slide 4

nose, lifting the and supporting the tongue out of the airway.  But because there is equal pressure on either side of the soft palate, it remains unmoved by the CPAP.  In this scenario, the sleeping patient really is a mouth breather because that is the situation that the full-face mask creates.

This means that everyone who uses a full-face mask is a mouth breather, but it may be that the full-face mask is responsible for this and not the anatomy of the patient.

Note:  We need to be careful here about being absolute when making statements about the airway. There are obviously differences in the structure of airways between individual patients and no two are exactly the same.  Some people have shorter soft palates and there are many factors contributing to the degree of relaxation which occurs in combinations of the 26 or so muscles which make up the upper airway.  Some people have also had surgery which alters the shape of the airway.

That said, Professor Rapoport contends that about 90% of the population he sees can be treated with nasal CPAP alone.

So why then are so many people using full-face masks?

Well, this probably has something to do with the process of getting started on CPAP.

Most newly diagnosed sleep apnea patients are fitted with a mask by a qualified and experienced CPAP consultant – either attached to a sleep clinic, part of a specialist doctor’s treatment team or at a CPAP equipment retailer.  These people have a difficult job.

CPAP is a confronting treatment.  Unlike a tablet which can be taken once a day, CPAP needs to be worn every night, and preferably all night.  It intrudes into the bedroom, which is a very intimate part of our lives.  It can be perceived as “being hooked up to life support”.  It can have an impact on the patient’s self esteem and view of themselves, it is not attractive and it will also inevitably impact on the bed partner.  A number of people refuse CPAP treatment as soon as it is discussed with them and up to 50% of newly diagnosed sleep apnea patients abandon treatment in the first year.

CPAP Consultants know from research that the likelihood of remaining on CPAP is improved if the patient can use a nasal CPAP mask.  So, that’s where they start.  A nasal mask of some description is normally selected from several that are tried out with the patient and therapy commences.  Sometimes this works well, and the patient gets on with settling into the CPAP routine.  But not always.

Teething Problems – Getting Used to CPAP

CPAP masks are uncomfortable.  We are used to sleeping without our face covered and having something strapped to the face during sleep takes some getting used to.  And the bed partner also needs to adjust to new noises, new contraptions in the bed and a new look on the face of their partner.

The face is also soft and can easily be marked by a poorly fitted mask.  And this is not like something worn on the body which can be covered up with clothing during the day.  Any sores or marks left on the face by overnight CPAP will be on view to the whole world the next day, causing concerned questions from family, friends, co-workers, people on the bus, etc.  “What are those marks on your face?” is not a question a newly diagnosed CPAP patient wants to answer and this adds to the problem of therapy compliance.

New CPAP users often return to the CPAP Consultant several times, looking for a mask that is more comfortable and doesn’t leave marks on the face and doesn’t disturb their partner.  They might even look for a second opinion; anyone who can offer some help to solve this problem.

Once standard nasal masks have been tried, the CPAP Consultant may offer the patient a direct nasal mask (one with the small prongs or “pillows” which push into the nostrils).  Often, but not always, these are also problematic.

So, what’s left to try?  You guessed it: the only other option in the CPAP Consultant’s arsenal, a full-face mask.

So, often it is people who struggle with CPAP in general and those who cannot find comfort with the various nasal mask options available who end up in a full-face mask.  Not because they really do need a full-face mask (anatomically speaking), but simply because the other options didn’t work satisfactorily.  Not always, obviously.  But this treatment pathway is not uncommon.

Real Mouth Leak

One problem which does sometimes arise with nasal masks is mouth leak.  This is where pressurised air from a nasal CPAP mask gets past the junction of the soft-palate and the tongue and into the mouth, where it pushes open the lips and creates a leak.

Remember that CPAP works by holding pressurised air in the airway, so a leak ultimately compromises therapy.  Now, there are three basic solutions to this issue: a chin-strap (worn over the head and under the chin to support the jaw and the lips during sleep, helping to keep the mouth closed); a small piece of tape (vertically across the centre of the lips to provide them with support, NOT EVER laterally across the whole mouth – this can be quite dangerous); or a full-face mask.

Again, the normal treatment pathway is to try a chin strap first, then tape, then possibly both a chin strap and tape at the same time.  If this doesn’t work, then we have a CPAP patient who is genuinely a mouth breather, who cannot resolve their mouth leak using other methods.  They are the 5-10% of the population who really do need a full-face mask.

OK, so what’s the problem with a full-face mask?

All standard masks work by sealing a box of pressurised air over the airway.  They achieve this by squashing the edges of the mask into the face using straps around the head.  A nasal mask seals over the bridge of the nose between the eyes, down the cheeks on either side of the nose and across the top lip beneath the nose.

A full-face mask seals over the bridge of the nose, down along the cheeks beside either side of the nose and the mouth and across beneath the mouth.  The path of this seal takes the edge of the mask out onto the fleshiest, jowls of the cheek, and that’s where the problem starts.

When we sleep, the soft tissues of the face change shape.  Muscle tone is lost and the fluids in the soft tissues of the face drain away – if you look in the mirror when you first wake up, you may look a little “drawn” or “gaunt” until the fluids refill the tissues in the cheeks.

So, the full-face mask user sits on the edge of the bed each night and straps on their mask, ensuring that the seal is secure, then they go to sleep.  Within half an hour, the relaxation of the face has changed the shape and tension of the soft tissues under the seal and the mask starts to leak.

But the full-face mask user figures this out and straps the mask a little tighter to the face to get around the problem.  And then a little tighter. And then tighter still.  And finally, the mask is tight enough to hold the seal through the night.  But all that additional head strap pressure can cause discomfort – from marks on the face which clear soon after waking to ulcerating sores, headaches, pain in the jaw and teeth, etc, etc.

The same process is also common with nasal masks, although they do not typically extend as far onto the soft tissues of the cheeks as do full-face masks.  But they also often need to be so tight over the bridge of the nose or across the top lip that the same type of problem occur.

Imagine now the level of frustration that builds in the patient as this treatment pathway is followed.

It’s no wonder that so many decide to live with the consequences of the disorder rather than face the nightly ordeal of CPAP.

CPAP can be a salvation and it can work out okay for many who need it.  But it can also be a source of frustration and conflict with and within individuals and families.

The TrueFIT^™ Custom Mask Solution

We believe that the only way to short-circuit this problem is to re-think the design of CPAP masks and deliver a truly comfortable and effective solution to sleep apnea patients who desperately need it.  And that’s what Acurest’s TrueFIT^™ Custom Mask does.

We would love to help you solve your CPAP issues and give you back sleep.energy.life.