Diana Guth, RRT

PAP and bilevel PAP are the gold standards for the treatment of obstructive sleep apnea (OSA), while noninvasive positive pressure ventilation (NPPV) is used to treat people who have respiratory insufficiency. The primary key to successful treatment of these serious disorders is the comfort of the patient with the interface. With excellent communication and interface fitting skills, providers and respiratory therapists can help the patient achieve this goal.

Assess and Communicate
The fitting process begins with a thorough assessment. Familiarize yourself with the patient’s medical condition and review her polysomnographic test (PSGT) focusing on the apnea-hypopnea index (AHI), oxygen desaturation, length of apneas, type of apneas, and apnea-triggered arrhythmias. For NPPV, look at the pulmonary function test(s) that may include FVC percent of predicted maximal inspiratory pressure (MIP) and/or arterial blood gases.

Determine the patient’s physical and psychological limitation(s) through examination and an interview with the patient, spouse/significant other, or family. Be aware of the patient’s manual dexterity, ability to raise arms to the head, and issues of claustrophobia.

Key Questions
The successful fitting starts with an interview. This not only gives you valuable information but it also begins to establish an important, trusting relationship. Some key questions to ask:

1) Why did you seek this treatment? The response can help you determine motivation.

2) Did you feel more refreshed the morning after they titrated the PAP device? Ask this if the patient had a PSGT. If the response is positive, chances are that they will adapt quickly, and you should tell them so. This encouragement can be a motivating factor to use the device.

3) Do you have any allergies or sinus problems? A “yes” answer will signal a need for a heated humidifier.

4) Do you get up to go to the bathroom frequently at night? If the answer is “yes,” you can say that successful PAP treatment will decrease or eliminate their nocturia.

5) Do you breathe through your nose or mouth?

6) Do you open your mouth while you sleep? The answers to 5 and 6 will help determine which masks to try.

7) What position do you sleep in? The answer will also help guide the interface selection.

8) Are you able to sleep/breathe lying flat on your back? This is primarily for NPPV patients. This answer will help you determine the progression of their respiratory disorder.

The answers to these questions will help you better understand the severity of the patient’s disorder and give an informed choice of interfaces. Always respond with enthusiasm, assurance, and information. Be excited that the patient’s quality of life is going to greatly improve with treatment. Review and explain the PSGT or the medical tests with the patient and perhaps spouse/partner/relative. Answer questions and address their anxieties with positive responses. This process builds trust, puts the patient at ease, and establishes a good rapport. You can even make it fun.

Interface Fitting Process
First assess the mode of breathing and analyze the nose. To determine the best mask/interface choices and sizes, you need to determine what type of breather the patient is, the type of nose bridge, and the nose length and width.

• Is your patient a nose breather, a nose breather and mouth/lip leaker, or a mouth breather?

• Nose bridge analysis is very important. The goal is a leak-free seal without undue nose bridge pressure. Historically, this small area has been the greatest cause of interface fitting failure leading to CPAP/bilevel PAP failure.

You need an effective seal to prevent leakage into the eyes (which can cause eye irritation or damage) without being so tight that it causes serious nose bridge ulcers. Nasal bridge shapes vary from flat to prominent. Flat bridges are common among Asians and African-Americans. Probably the biggest challenge is the patient with a prominent high bridge.

• To determine nose length and thus the right mask size, measure from the top of the nose bridge to under the nose. Nose width is mostly done by visual inspection. There are mask gauges available to determine mask size, but experience is the best aid.

Interfaces and Mask Categories
Nostril-type interfaces fit into the nostrils. They are held in place with straps, rigid head pieces, or dental retainers. Sizes include small, medium, large, extra large, small, medium, and large dilator depending on the model—and they are minimally invasive. Some are easy to take on and off while some have a clear line of vision allowing the user to wear glasses—and some comfortably lack straps on the side of the face. The nostril-type interface can cause the nostrils to widen. This style is best suited to: nose breathers or nose breathers/mouth leakers if used with a chin strap; those with prominent nose bridges; patients who require lower pressures, unless a heated humidifier is used; those who are claustrophobic; and those who are dexterously challenged.

Nasal masks fit around the nose and are held in place with straps or rigid head pieces. The largest selection of interfaces are from this category. The nasal mask sizes include petite, small, medium, standard, medium wide, shallow, large shallow, large, and large narrow depending on model.

Most have double cushions where 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. Some have adjustable forehead mechanisms for proper fitting.

Nasal masks are best suited to nose breathers or nose breathers/mouth leakers if used with a chin strap. Nasal masks are also good for those who are not comfortable with the nostril-style interface or want to avoid nostril stretching.

Full-face masks fit around the nose and mouth. The sizes include standard and shallow small, medium, and large. Some fit from the nose bridge to under the lower lip. Others fit from the nose bridge to below the chin. One model fits over the entire face.

They all have ingenious fail-safe valves that allow the patient to breathe room air if there is a power failure. They are all held in place with straps of varied stretchiness. Most have headgears that can quickly disengage should the patient need to suddenly remove the mask because of nausea.

While the full-face masks look cumbersome, they have become quite comfortable. These masks have been lifesavers for those people who are mouth breathers or severe mouth leakers. For the most part, patients prefer the full-face mask to the oral interface.

Full-face masks are best suited to: nose breathers or nose breathers/mouth leakers; people who are unable to keep their mouth closed; and people who are uncomfortable with the nasal interface/chin strap combination.

Oral interfaces fit into the mouth with a seal over the mouth. A small number of mouth breathers can use this interface. It is secured with a single strap that goes behind the neck. In one model the strap is optional. Some neuromuscular patients on volume-cycled NPPV use small angled mouthpieces (without mouth seals) or straw-type mouthpieces in the daytime using the sip and puff method of breathing. The mouthpiece is mounted right next to their mouth; they take a breath and are able to speak after each breath. This is referred to as the sip and puff method.

Headgear Types and Features
Headgears are designed to secure each interface model. Strap-style headgears range 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. They are attached to the mask by different types of clips or slits in the mask. Most are made of stretchy and/or breathable material. The stretchier models allow the patient to pull the mask on and off without having to manipulate clips—and this is important for patients who have dexterity problems.

In the category of rigid headgears, one can best be described as a rotated headphone style. It is secured like headphones but extends from the nose to the back of the head with sliding adjustments and straps for stability. Another model fits around and over the crown of the head. The advantages are there are no straps to touch the patient’s face and they are easy to take on and off.

Interchangeable or proprietary headgears are interchangeable with various masks. Many headgears are designed to function with a specific interface, and this is a problem with Medicare accessory coverage when a mask is not sold separately from the headgear—because the headgear and mask replacement rates do not coincide. Medicare allows a mask to be replaced every 3 months, but the headgear replacement is every 6 months. Some patients may need a new type of mask/headgear system to be able to comply with their treatment. In addition, the headgear frequently wears out before the mask.

Chin straps are used to encourage patients to keep their mouth/lips closed. They are effective with people who leak slightly out of their 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. The goal is a “stiff lower lip” to eliminate lip leaking. They come in various styles. Some are merely small patches of fabric or donut holes that cup the chin. They are secured with stretchy, Velcroed fabric on top of the head. There are other chin strap/head attachment configurations that offer more stability. There is another wide “post-face-lift” style band that can be used as an effective chin strap.

Other Comfort Considerations
A few interface systems allow patients a clear line of vision, which makes it possible to wear glasses. For the continuous NPPV user, the mask should not obstruct the line of vision. It also must to be easy for users to take the mask on and off. Some patients are dexterously challenged or by arthritis or neuropathy in their hands.

Some interfaces have quick disconnects from the tubing so that the patient can quickly go to the bathroom without having to take the interface off. This is also an important consideration for patients who have dexterity or hand strength issues.

Matching the interface to the patient involves a comprehensive selection of interfaces, in a variety of sizes, from various manufacturers. The fitting should be done at the DME office in a private room that is designated for that purpose. The room should have a bed and pillows for the patient to lie down on to properly test the interfaces.

Follow-up
Even the most skilled practitioners can not predict the success of the fitting and treatment without speaking to patients after they have used the mask for a few nights. If the treatment is going well, instruct the patient to call again in a week. Call again in a month, just to make sure that all is well, then periodically after that.

If there is a problem with the interface, the patient needs to come back for some “fine tuning,” which may be only a slight readjustment, a review of how the mask (and the other equipment) works, or fitting a different interface.

This process will not only result in a high level of patient compliance, but the patients will also be grateful for the personal service and the improvement of their quality of life. Gratifying professional, long-term friendships are established along with a reputation in the community for providing excellent patient care.

Diana Guth, RRT, is the owner of Home Respiratory Care, Los Angeles. She has worked in the HME industry for 20 years and can be reached via e-mail: diana@hrcsleep.com.