Ventilator-Assisted Living©

Fall 2005, Vol. 19, No. 3

(continued)

Masks, Part II: Noninvasive Interfaces
(Updated October 2009)

*Diana Guth, RRT, Owner, Home Respiratory Care, Los Angeles, California (Diana@hrcsleep.com)

“When choosing an interface, go to a home health care company that employs experienced respiratory therapists and offers a variety of interfaces to try. You want a comfortable, well-fitting, easy-to-use interface that provides effective assisted ventilation. Remember to lie down to test the interface in the body position in which you sleep!”

Just what is an interface?

It’s a term that is often interchangeable with “masks,” but an interface is what enables the delivery of air to a person by connecting to one end of the tubing that is connected at the other end to a ventilator or CPAP unit. Invasively, it’s a tracheostomy or endotracheal tube. Noninvasively, it’s a range of masks and other appliances that are discussed in the following text.

My “Top Picks” are strictly subjective. They are based on more than 20 years of experience in home respiratory care. For a complete listing of noninvasive interfaces, check IVUN’s Resource Directory for Ventilator-Assisted Living.

Nostril-type interfaces. Often known as nasal pillows or cushions, these interfaces fit into the nostrils. They are held in place with straps, rigid headpieces or dental retainers, and are available in a wide range of sizes. Some are easy to put on and take off, some provide a clear line of vision allowing the user to wear glasses, and some are more comfortable due to a lack of straps on the side of the face.

Nostril-type interfaces can cause the nostrils to widen, which may be cosmetically undesirable. This style is best suited to nose breathers or nose breathers/mouth leakers if used with a chinstrap; those with prominent nose bridges; individuals who require lower pressures, unless a heated humidifier is used; individuals who are claustrophobic; and those who have limited use of their hands.

Top Picks: Mirage® Swift II™, Swift LT™ and Swift LT™ for Her (ResMed); Opus™360 (Fisher & Paykel Healthcare); OptiLife™ and ComfortLite™ 2 with Pillow Cushion (Philips Respironics) and Breeze® SleepGear™ with Nasal Pillows Assembly (Covidien).

Nasal masks. These interfaces fit around the nose and are held in place with straps or rigid headpieces. The largest selection of interfaces is in this category. In addition to the usual range of sizes, nasal masks are also available in shallow and narrow depending on the model. Some nasal masks have adjustable forehead mechanisms for proper fitting.

Most nasal masks have double cushions – air is trapped between the two cushions to seal the mask without putting undue pressure on the bridge of the nose. The inner cushion is more rigid, made of silicone, rubber or gel. The outer cushion is thin and contoured to the inner cushion. Some cushions are removable for cleaning and mask size interchange. The SleepWeaver™ (Circadiance) is made of cloth.

Nasal masks are best suited to nose breathers or nose breathers/mouth leakers if used with a chinstrap.

Top Picks: Mirage Micro™ and Activa LT™ (ResMed); ComfortGel™ and ComfortLite™ 2 with Simple Cushion (Philips Respironics); Zest (Fisher & Paykel Healthcare).

Full face masks. These blow air to the nose and mouth. Some fit from the nose bridge to under the lower lip. Others fit from the nose bridge to below the chin. The FitLife™ total face mask (Philips Respironics) fits above the eyes and below the lower lip like a triangular snorkel mask. There are a couple of masks that are mouthseals with nasal pillow protruding up to the nostrils. They avoid the nosebridge, give a clear line of vision but are a bit tricky to fit; the Liberty™ (ResMed) is a Top Pick in that category. Face masks look cumbersome, but they are quite comfortable. In my experience, individuals prefer the face mask to a nasal interface with chinstrap or oral interface.

Full face masks all have fail-safe valves that allow the user to breathe room air if there is a power failure. They are all held in place with straps of varied elasticity or have headgear that can quickly disengage if the mask needs to be suddenly removed and the individual has adequate hand and arm dexterity.

Face masks are best suited to nose breathers or nose breathers/mouth leakers; people who are unable to keep the mouth closed; and people who are uncomfortable with the nasal interface/chinstrap combination.

Top Picks: Mirage Quattro® full face (ResMed); ComfortFull™ full face (Philips Respironics) and the Forma ™ full face mask (Fisher & Paykel Healthcare).

Oral interfaces. Usually referred to as mouthpieces, these come with and without outer mouthseals. Some mouth breathers can use this interface.

Two models with mouthseals are the Oracle™ 452 (Fisher & Paykel Healthcare) and the Bennett Seal Mouthpiece Assembly (Covidien). The Oracle fits into the mouth with a flange that fits in front of the teeth: an outer seal covers the mouth. The Bennett is a standard mouthpiece with an outer seal. Both are secured with a single strap over or under the ears, although the Oracle’s strap is optional.

Mouthpieces without an outer seal are generally used for mouth intermittent positive pressure ventilation (MIPPV), also known as “sip and puff.” Some individuals with neuromuscular disorders use MIPPV with volume-cycled ventilators during the daytime with small angled mouthpieces or straw-type mouthpieces. (Some individuals have even learned to sleep with these.) The mouthpiece can be mounted close to their head so that they can take a breath and speak after each breath. Individuals with use of their hands can hold the mouthpiece to take a breath when they need one.

Custom masks. With the increased use of CPAP units to treat obstructive sleep apnea and bilevel ventilators to treat hypoventilation in people with neuromuscular diseases, the commercial mask market has exploded and broadened the range of available masks so that well-fitting masks are easier to find. Some ventilator users have had their dentist configure an appliance that fits in the mouth and extends upward over the nose. Custom masks are available in the USA and Europe – see IVUN's Resource Directory for Ventilator-Assisted Living.

Pediatric masks. Commercial masks for children, particularly infants, are limited. In the USA, respiratory health professionals adapt adult commercial masks. ResMed's Kidsta™ is designed specifically for children. Soft Series™ (Philips Respironics) masks in pediatric and small sizes frequently fit. Adult nasal masks used as full face masks, such as the ComfortGel™ (Philips Respironics) have also been successful. In Europe, some hospital pediatric departments make custom masks for their patients.

Vented and nonvented interfaces. A vented interface is designed with exhalation ports built into the mask so that it functions with a controlled leak to allow exhaled air to escape. Because of the continuous flow of air from either a CPAP unit or bilevel ventilator, the interface must have exhalation ports.

A non-vented interface has exhalation valves built in and is designed to work without a leak because the valve closes during inhalation and opens during exhalation. These interfaces are most often used with a volume-cycled or pressure support ventilator.

Top Picks: ResMed Ultra Mirage™ NV Nasal, Mirage™ NV Full Face and Ultra Mirage™ NV Full Face and the Respironics Image3 SE (this may only be available to hospitals).

Headgear. Headgear, made of stretchy and/or breathable material, secures most interfaces. Strap-style headgear can provide from two to five point connections. Some straps are attached to nylon caps, satin bases or webbing. They feature sizing and securing adjustments using Velcro and/or buckle or clip mechanisms and attach to the mask by different types of clips or slits in the mask.

The more elastic models allow the individual to pull the mask on and off without having to manipulate clips – important for individuals with limited hand dexterity.

Breeze®SleepGear™ is rigid plastic head-gear that is secured like headphones but extends from the nose to the back of the head with sliding adjustments and straps for stability.

Interchangeable or proprietary headgears can work with various masks. Many headgears are designed to function with a specific interface. This is a problem in the USA for Medicare reimbursement for accessories when a mask is not sold separately from the headgear because the headgear and mask replacement schedules do not coincide. Medicare allows a mask replacement every three months, but headgear replacement is every six months. Unfortunately, the headgear frequently wears out before the mask.

Chinstraps. These are effective with people who leak slightly out of the mouth or lips, but they will not really keep someone’s jaw closed because the jaw is strong. They should be adjusted to fit snugly under the lower lip for a “stiff lower lip” to eliminate air leaks. Some are merely small patches of fabric or donut holes that cup the chin. They are secured with stretchy Velcro fabric on top of the head. Other chinstrap/head attachment configurations offer more stability. A wide post-facelift style band (Design Veronique, also distributed by Philips Respironics) is also an effective chinstrap.

Other considerations. A few interface systems provide a clear line of vision, making it possible to wear glasses. Some interfaces have quick disconnects from the tubing so that the individual can use the bathroom quickly without having also to remove the interface – an important consideration for people with limited dexterity or hand strength. Alternating interfaces to relieve pressure points is advisable, using one during the day and another type while sleeping. Alternating is also beneficial during respiratory tract infections.

*Disclosure: Author participates occasionally in focus groups and beta-testing for ResMed.

Links to main page of websites of companies mentioned in the above article:
Covidien
Fisher & Paykel Healthcare
Philips Respironics
ResMed

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