CPAP Mask Leaks and How to Fix Them
One of the most common barriers to success with CPAP is difficulty maintaining a good mask seal. A leaking mask can cause a number of problems, one of which is actually potentially dangerous. Read on to find out how to fix the most common causes for CPAP mask leaks and avoid potential pitfalls.
How to Stop CPAP Masks from Leaking: the Basics
A better question than, "How to stop air leaks in CPAP masks?" is, "How do I prevent air leaks in the first place?" A lot of your success with a given CPAP mask is attributable to things that happen even before you put the mask on for the first time and hit the start button on your CPAP.
First, you want to try to find a mask style (nasal pillows, under-the-nose nasal, nasal, hybrid, full face mask) and model that are likely to be a good match for your personal needs and preferences. We have created a guide for our clients that steers them in the right direction for their initial mask selection. You can access that guide here.
Second, make sure that you select the proper size. If you go to a brick-and-mortar DME, they will let you try on various masks and find the right size for you. If you are ordering over the Internet, "fit packs" or "starter packs" that provide all the available sizes of cushions are a great way to go. You literally cannot choose the wrong size with this option. If you do not choose a fit pack, make sure to print the sizing tool for the mask you're interested in at 100% scale and measure your face to find the right size. Do not assume that, for instance, just because you're a big person that you need a size large - this is often not the case.
Some general guidelines for mask seal are:
- If your machine has it, use the mask fit test option at the beginning of the night before you start therapy.
- Don't overtighten the mask straps. They should be snug but not super-tight. If you are needing to have the mask so tight to maintain a seal that the straps leave deep grooves on your face, then you probably have the wrong mask or mask size.
If this seems overwhelming, you might want to consider a "virtual CPAP setup" with our respiratory therapist to review how to get a good mask seal as well as how to use your machine properly.
What Is a Good CPAP Leak Per Minute?
For ResMed machines, the target leak rate is to have a 95%th percentile leak of <24 L/min. If you are above this rate on a given night, you will get a sad face - or "frowny face" as some of my patients describe it - on your display in the morning. For other manufacturers' machines, my typical goal is <1% of the night in a high-leak state. Really with leak, the lower the better.
High leak on a ResMed CPAP download; this patient will have seen a lot of "sad faces" on her display
Why Is it Important to Fix CPAP Mask Leaks?
In addition to being irritating and making it hard to sleep while using your CPAP, high leak levels can compromise the effectiveness of CPAP. In a nutshell, if the air is escaping "outside of the system" then it's not going down your throat where you need it and your airway will be more likely to continue to close up on you during sleep.
CPAP Mask Leaks Due to Old/Damaged Equipment
This is one of those items on the checklist for troubleshooting leak that is akin to asking a person who can't get the TV to work if the TV is plugged in. CPAP masks degrade over time and will inevitably cause leak to go up.
Problems with CPAP cushions that can cause leak include:
- stiff, noncompliant rubber due to age
- tears, cracks or rents in the cushion from use
- residue build up on the cushion from lack of regular cleaning
Issues with CPAP mask headgear that can cause leak include:
- stretching out of the headgear over time so that it no longer fits well on the head
- loss of the "stickiness" of the Velcro on the headgear or loss of the magnetism of the magnetic snaps
CPAP Mask Leaks Due to High Pressure
Is your CPAP mask popping off of your face during the night due to high pressure? This is more common with nasal pillows and, to a lesser extent, full face masks. Nasal pillows are less securely sealed to your face than nasal masks. Full face masks have a greater surface area that needs to be sealed to your face which can make them harder to manage than nasal masks.
If this is a chronic issue with you, I suggest either:
- Switching to a traditional nasal mask
- Asking your sleep doctor to reduce the pressure on a fixed pressure machine or "cap" the pressure on an auto-CPAP machine. By cap the pressure I mean, reduce the upper The tradeoff to this strategy is that you sleep apnea won't be fully treated.
CPAP Mask Leaking into the Eyes
When I counsel patients about CPAP being extraordinarily safe, I do cite two exceptions. One issue that can cause harm is chronic mask leak into the eyes. This can dry the eyes out and cause ulceration of the cornea, the outer layer of your eye that surrounds your pupil. [The other issue is not cleaning your equipment properly.] Fortunately, this is really rare because people typically can't tolerate vast quantities of air blowing into their eyes and usually wake up and adjust their mask to make the problem go away.
CPAP leak directed at the eyes can cause eye irritation or corneal ulceration
The most common reason for chronic CPAP mask leak into the eyes is REM-related leak in full face mask users. We go through periods of REM sleep every 90-120 minutes. During REM, our muscle tone drops to the lowest point during the night and this can cause the jaw to fall down. If the mask travels with the jaw, air will leak towards the eyes.
The easiest fix is a chin strap. There is only one chin strap design that I have found to be effective and this is it. Many chin straps have a vector of pull that actually moves the jaw somewhat backwards, worsening obstructive sleep apnea and ineffectively keeping the mouth closed. I like this chin strap because it pulls the jaw as straight "up" as possible and not backwards. I counsel my patients that, in this situation, the goal is not to apply the chin strap super-tight. I want them to start with just barely overlapping the Velcro at the vertex of the head. The goal is not to rigidly seal your jaws shut but rather to give some gentle support to your mandible so that it doesn't drop a lot when you enter REM. Continue to gradually increase the tension of the chin strap as needed. Note: the chin strap should be put on before you put your full face mask on.
An eye shield that hugs tightly to your eyes such as this one is another way to approach this problem.
CPAP Air Leaks Due to Facial Hair
Facial hair is often a major contributor to CPAP mask seal leaks. Moustaches can impair nasal masks' seal and beards can disrupt full face masks'. If you are a bearded gent and can keep your mouth closed while you sleep, I would suggest trying a nasal pillows mask to start. The nasal pillows design won't come into contact with your facial hair. If you are a mouth breather in your sleep, we've found that the AirTouch F20 full face mask typically provides the best seal. Note, this mask is unique in using a memory foam cushion. While the seal is typically better with facial hair than a typical silicone cushion, the AirTouch's cushion typically needs to be changed more frequently, usually every 1-2 months.
Joseph Krainin, M.D., FAASM is the founder of Singular Sleep, the world's first online sleep center. He is a Fellow of the American Academy of Sleep Medicine and board-certified in both sleep medicine and neurology. He has been practicing medicine for over 10 years.